"I had read in the literature that...cadmium and other toxic trace elements [are] increased when we have these particulate plastics in the soil. So, that was of concern to me," Kirkham, a plant physiologist and distinguished professor of agronomy at Kansas State University, told EHN.
Kirkham's expertise is in water and plant relations and heavy metal uptake, so she decided to conduct her own research in which she cultivated wheat plants exposed to microplastics, cadmium, and both microplastics and cadmium. Then she compared these plants to those grown without either additive. She chose cadmium because it's poisonous, carcinogenic, and ubiquitous in the environment due to human activity—it's shed from batteries and car tires, and is naturally found in the phosphate rock used to make agricultural fertilizers.
"Cadmium is everywhere," said Kirkham.
At the end of the experiment she sent her wheat plants off for analysis, and, validating previous reports, the plants grown with microplastics were more cadmium-contaminated. "The plastics really were acting as the vector for uptake of the cadmium," she said.
Her experiment became a chapter in the new book, Particulate Plastics in Terrestrial and Aquatic Environments.
"I think people just haven't felt that microplastic uptake by plants is an issue," said Kirkham. "It just hasn't been in the public eye."
Mary Beth Kirkham (left) in her lab at Kansas State University. (Credit: k-state.edu)
Microplastics, loosely defined as plastic pieces smaller than 5 millimeters across, or roughly the size of a small grain of rice, have made their mark on both the global ecosystem and the popular consciousness, famously killing seabirds and raining down on wilderness areas. And while the impacts of ocean microplastics have been the subject of significant media and scientific attention, researchers say that most microplastics are actually accumulating on land, including agricultural areas. One estimate suggested that 107,000 to 730,000 tons of microplastics could be dumped onto agricultural soils in the U.S. and Europe every year, compared to the 93,000 to 236,000 tons that enter the oceans.
Microplastics arrive on farms through processed sewage sludge used for fertilizer, plastic mulches, and are even intentionally added as slow-release fertilizers and protective seed coatings. In just the last few years, an uptick in research has uncovered alarming potential impacts of this contamination on all aspects of agricultural systems from soil quality to human health.
Microplastics can also enter agricultural soils through the degradation of plastic materials used by farmers, such as black plastic mulch. (Credit: Charles Dawley/flickr)
Sewage sludge, mulch, and slow-release fertilizers
Luca Nizzetto, a research scientist at the Norwegian Institute for Water Research, began studying microplastics in agricultural soils after he noticed that most research on microplastics focused on oceans.
"Most of the marine sources are actually land-based," Nizzetto told EHN. "No one was looking at what was happening close to the source." When his team began evaluating potential land sinks for microplastics they "immediately [identified] agriculture as one of the hot areas."
Microplastics can enter agricultural lands via sewage sludge, the solids that are filtered out of wastewater, which are commonly used to fertilize agricultural fields. Microplastics get into the wastewater originally through laundry, personal care products, and urban runoff.
Nizzetto said that most of the microplastics are retained in the sludge as the water is cleaned in treatment facilities and, in a 2016 paper, his team estimated that between 125 and 850 tons per million people are annually dumped on European agricultural lands via sewage sludge. Nizzetto also reported in the same paper that roughly 50 percent of sewage sludge is processed for agricultural application in both Europe and the United States.
Microplastics have been reported in U.S. sewage sludge as early as 1998, and in 2020 researchers estimated roughly 21,249 metric tons of microplastics are released to U.S. agricultural lands from sewage sludge annually. Because of their recalcitrance in soils, U.S. researchers have even investigated the possibility of using the contemporary microplastics profile of soils as an indicator of past sewage sludge application.
Microplastics can also enter agricultural soils through the degradation of plastic materials used by farmers. Kirkham said that in the 1950s, plastic covering replaced glass in greenhouses. Plastic mulches were also popularized, becoming commonplace across much of the world. These mulches, sheets of plastic laid out on the ground to suppress weeds, warm the soil, and retain moisture, are challenging to recycle and costly to dispose of.
According to Kirkham, farmers may end up piling them up on their land or burning them to avoid disposal costs. Nizzetto said that in some areas, the mulches are simply left to break down into the soil.
Intentionally manufactured microplastics are another source of microplastic emissions to agricultural soils, according to Nizzetto and other researchers that EHN spoke with. These can include plastic encapsulated slow-release fertilizers and plastic coatings intended to protect seeds from microorganisms.
A 2017 report compiled for the European Commission estimates that up to 8,000 metric tons of plastic from slow-release fertilizers are broadcast onto Western European agricultural soils annually (although they said that a percentage of this may not be microplastics). A 2019 European Chemicals Agency report listed emission amounts as 10,000 metric tons for slow-release fertilizers, and 500 metric tons for treated seeds every year. Figures for the U.S. were not available.
Microplastics can arrive on farms through processed sewage sludge used for fertilizer. (Credit: CityofGeneva/flickr)
Microplastics alter the physical and biological properties of soils
Sixteen days into Kirkham's microplastics and cadmium experiment, her plastic-treated wheat plants began to yellow and wilt. Water had been pooling on the top of the soil in the plastic treated plants, but to keep her experiment consistent, she had to give all the plants the same amount of water.
"The particulate plastic appeared to clog the soil pores, prevent aeration of the soil, and cause…the roots to die," said Kirkham. Plants without microplastics, even the cadmium-contaminated ones, were in much better shape. "It was the plastics that were controlling the growth more than the cadmium."
Another team of researchers reported similar results. They found that exposure to plastics resulted in reduced weight, height, chlorophyll content, and root growth of Arabidopsis thaliana, a relative of cabbage and broccoli. In this study, the researchers used nanoplastics, which are plastic pieces that are less than 100 nanometers in size. For scale, the novel coronavirus measures 60 to 140 nanometers.
The full impact of microplastics contamination in agricultural soils, particularly as concentrations increase with time, is unknown. However, studies have shown that microplastics possess physical and chemical characteristics that have the potential to alter soil bulk density, microbial communities, water holding capacity, and other properties that influence plant development.
Earthworm impacts
Esperanza Huerta Lwanga, a soil scientist affiliated with both Wageningen University & Research in the Netherlands and El Colegio de la Frontera Sur in Mexico, has investigated the effects of microplastics on earthworms, creatures widely considered a boon to farming because of their ability to aid decomposition, add organic nutrients to the soil through their waste castings, and increase the aeration of soil.
"When I was doing research on soil invertebrates' distribution at different home gardens in Tabasco, Mexico, I found microplastics. And in those soils with microplastics, there were not earthworms," Huerta Lwanga told EHN.
This observation motivated her to study earthworms directly. In her subsequent experiments, she found that worms attempted to avoid microplastics, but when the soil concentration reached 7 percent, they began to ingest them along with the soil, concentrating the plastics in their castings, and transporting them through different layers of soil. In their 2018 paper, Huerta Lwanga's team cautioned that rainwater flows through earthworm burrows into groundwater, creating a clear conduit for microplastics to enter groundwater systems.
Huerta Lwanga also said that microplastics caused an 8 percent to 25 percent mortality rate in earthworms depending on the dose. In their paper, she and her colleagues hypothesized that mortality may be partly caused by microplastics abrading the digestive tracts of earthworms, making it more difficult for them to absorb nutrients. Damage to the digestive tracts of earthworms that ingested microplastics has been documented by other researchers.
Once microplastics enter an ecosystem, they can proliferate through trophic levels, such as when a bird eats an earthworm.
Or when a person eats an apple.
Images microbead localization in the root, stem and leaf of a wheat plant. (Credit: Effective uptake of submicrometre plastics bycrop plants via a crack-entry mode)
Passing through plant—and human—tissue
Earlier this year, Yongming Luo, a professor at the Yantai Institute of Coastal Zone Research and the Nanjing Institute of Soil Science in China, and colleagues reported microplastics accumulation in wheat and lettuce plants exposed to microplastics in a laboratory setting. The researchers grew the plants in hydroponic and soil systems with microplastics that had been laced with fluorescent dyes. The researchers analyzed cross sections of the plants under a microscope outfitted to detect the fluorescence. The roots, stems, and leaves lit up.
"For decades scientists have believed that plastic particles are too large to pass through the physical barriers of intact plant tissue. But our new study disproves this assumption," Luo told EHN.
Luo's team reported that the microplastics seemed to be entering the plants through cracks in the roots where lateral branching occurs as well as diffusing through cells at the developing root tips.
A team of scientists also reported earlier this year that they had detected microplastics in Italian supermarket produce including carrots, lettuce, broccoli, potatoes, apples, and pears. The researchers wrote that they found the most microplastics contamination in apples and the least in lettuce, and speculated that the perennial nature of a fruit tree allowed microplastics to accumulate more than in annual crops.
"If microplastics are getting into our vegetables, they are getting into everything that eats vegetables…which means they are in our meat and dairy as well," said Luo.
Microplastics have previously been detected in honey, beer, and seafood.
With clear and uncontrolled pathways into human food systems, ingestion of microplastics by humans is practically unavoidable, but the consequences of ingestion are as of yet unknown.
Plastic microfibers have been found in malignant lung tissue biopsies of cancer patients. These plastics were probably inhaled rather than swallowed, but the concern that microplastics can become lodged in tissue and cause dangerous inflammation remains. Studies of mammals forced to ingest microplastics in laboratories have also provided evidence that microplastics can pass through cell walls, move through the body, accumulate in organs, and impact the immune system.
Microplastics are chemically active materials, capable of attracting and binding to compounds known to harm human health. In addition to cadmium, microplastics have been shown to accumulate lead, PCBs, and pesticides. Further, plastics are manufactured with their own suite of toxic compounds, which can include BPA, an endocrine disruptor. Researchers have suggested that both acquired and endogenous compounds could leach out of degrading plastics into their environment, whether that be soil or human tissue.
"Because we are concerned that microplastics may harm our health…we find it interesting that the precautionary principle is not [being] applied," Sophie Vonk, a researcher at the Plastic Soup Foundation in the Netherlands, a group dedicated to ending plastic pollution, told EHN. "So as long as there's no proof, we just find it okay that we're being exposed to these particles every single day, by our food, water, the air we breathe."
Scientists have detected microplastics in supermarket produce (Credit: loonyhiker/flickr)
What to do?
Since microplastics enter agricultural systems through a variety of means, addressing this issue would require a multi-tiered approach.
The Plastic Soup Foundation has a long standing campaign to eliminate the use of plastic microbeads in personal care products. This would likely reduce the amount of plastic that ends up in sewage sludge. The group also supports limiting single-use plastics generally, as these will ultimately break down to microplastics that end up polluting both ocean and terrestrial environments. "We're not anti-plastic," said Vonk. "We feel like plastic can be very useful for certain purposes, but the way we're using it now is just really, really not clever."
The European Chemicals Agency has proposed an EU-wide ban on intentionally introduced microplastics, including those in personal care products as well as the slow-release fertilizers and seed coatings used in agriculture. Some states in the U.S. have also moved to ban microbeads from personal care products.
To address the plastic mulch issue, Nizzetto said that one helpful step would be to make companies that manufacture plastic mulch films responsible for their recycling and disposal. This would help reduce inappropriate disposal at farms.
The use of biodegradable plastics for mulch has also been proposed, but these polymers potentially come with their own set of problems. For instance, one of Huerta Lwanga's studies found that a biodegradable plastic negatively impacted wheat growth more than a conventional plastic used in the study. Also, there has been controversy over whether some "biodegradable" plastics actually degrade into harmless compounds, or whether they just break down into microplastics faster. Such controversy surrounds oxo-biodegradable plastics, which the EU moved to ban in 2019.
Another alternative to plastic mulch, developed by researchers at the Rodale Institute in Pennsylvania, involves growing nutrient-sequestering cover crops and then rolling them down to form a thick mat. Farmers then plant into the mat, which itself persists and inhibits weeds, lets water through, and adds nutrients instead of microplastics to the soil. According to the researchers' report, the technique can replace more than 90 pounds of plastic mulch per acre.
Gladis Zinati, director of the vegetable systems trial at Rodale and co-author on the report, told EHN that the strategy is scalable to large farms and emphasized the importance of building up healthy soils on farmlands to support long term resiliency.
Much more research is needed to paint a complete picture of the scope and impacts of microplastic pollution of agricultural soils. But in the meantime, the plastics will continue to accumulate.
"This is a kind of irreversible contamination," said Nizzetto. "There's no way to remediate this kind of contamination at the scale of agricultural soils."
Banner photo credit: Shutterstock
The findings build on a body of evidence that absorbing or ingesting the ubiquitous chemical may harm people at doses 20,000 times lower than what the U.S. Food and Drug Administration (FDA) says is safe — doses comparable to levels at which most of us are exposed.
"This should change how the FDA and other people look at the safety of BPA," Jerry Heindel, former health scientist administrator at the National Institute of Environmental Health Sciences and a co-author on the new paper, told EHN.
The studies were part of an unprecedented $30 million-dollar project co-led by the FDA called the Consortium Linking Academic and Regulatory Insights on BPA Toxicity, or Clarity for short. Launched in 2012, Clarity combines a traditional regulatory guideline study from the government and investigational studies from academics with the aim of reconciling a long-standing dispute over data and conclusions on the health effects of BPA.
Academic scientists for decades have linked the chemical—found in plastic containers, food can liners, and paper receipts—to a wide array of health problems including cancer, diabetes, obesity, infertility, and behavioral problems. BPA does its damage, in large part, by mimicking and messing with hormones in the body. And it is just one of hundreds of such endocrine-disrupting chemicals we encounter every day.
Related: How willful blindness keeps BPA on shelves and contaminating our bodies
However, despite this mounting evidence of harm, the FDA has maintained BPA's safety and dismissed findings from independent scientists that BPA can harm people at very low doses—even when relatively high doses prove innocuous.
"Guideline studies have not provided much evidence of harm. But academics are finding harm all over the place," Pat Hunt, a geneticist at Washington State University in Pullman, Wash., who was not involved in Clarity, told EHN.
So far, the Clarity effort has fallen well short of its goal to bridge that gap.
Cheryl Rosenfeld, a biologist at the University of Missouri, author of the new paper, and a Clarity investigator. (Credit: University of Missouri)
In November 2019, EHN published a year-long investigation of the FDA's handling of BPA science, including Clarity. It found a "willing blindness" among U.S. regulators to modern science on endocrine-disruptors, and concluded that they may be operating on the fringes of scientific integrity, possibly with the intent to keep the current testing and regulatory regime intact.
The FDA's traditional targets for tests, such as weighing organs and looking for overt signs of toxicity, are generally insensitive to the unique and often subtle effects of BPA and other endocrine disruptors, such as behavioral changes or infertility years down the road.
"The difference in regulation that would be required to account for this low-dose effect is huge. I'm not sure the FDA has the courage to do that," Thomas Zoeller, a biologist at the University of Massachusetts Amherst, and an author on the new paper, told EHN. "BPA is big money. The FDA is sensitive to that."
The FDA released its Clarity Core study, a comprehensive report from the government's side of the project, in 2018. But no comparable publication has combined the academics' independently published findings. A government-led integrated report that pulls together findings from both the government and academic scientists was scheduled for completion by the end of 2019. It has yet to be released.
"We felt we needed to make our own report, to be sure our voices would be heard," Cheryl Rosenfeld, a biologist at the University of Missouri, Clarity investigator, and an author on the new paper, told EHN.
Eight of the 10 academics who have published studies as part of Clarity contributed to the new paper. Because all of the Clarity investigators shared tissues from the same rats and followed the same study protocols, much of the noise that typically makes comparisons between studies difficult was eliminated. The team leveraged this opportunity to apply a novel statistical approach to look for patterns across different datasets generated in the laboratories of multiple investigators using organs from the same animals.
Related: Clouded in Clarity: A comic on chemicals & controversy
"We combined everyone's data to see what the picture showed," said Rosenfeld. "It's correlation, not causation. But, ultimately, we were able to show that low doses of BPA don't just target one system, they go after multiple systems." If there was a low-dose effect on the mammary glands, for example, there was likely also a low-dose effect on the spleen in the same animals.
In all, the new paper links BPA to interrelated impacts on the brain, prostate, urethra, mammary gland, uterus, ovary, spleen, heart, and body fat.
In an emailed response, an FDA spokesperson said the agency "along with other global food safety authorities, has extensively evaluated the totality of available evidence on the safety of BPA. The weight of the evidence shows that BPA is safe for its authorized uses in food packaging."
The spokesperson said the agency has not reviewed the new study but "will continue to monitor scientific developments and take steps as appropriate to protect public health."
Hunt and others said the new study should be a red flag for the FDA.
"It's easy for a regulator to dismiss a study or handful of studies. But when you have this series of studies of the same animals and see correlations across the studies, that gives you much more confidence," said Hunt. "This strengthens the conclusion that these low dose effects are real, and can't be dismissed as spurious."
Low doses matter
Most effects across the studies appeared at the lowest dose tested in Clarity: 2.5 micrograms per kilogram of body weight per day, which falls in the upper range of what an average person is believed to be exposed to.
However, human biomonitoring studies may underestimate actual exposures. Hunt co-authored a paper published in December that found the tests used by federal agencies to estimate exposure to BPA are woefully inaccurate. "If we are being exposed to much higher levels than we think we are, and if these animal studies are finding effects at increasingly lower doses," she said, "then that suggests we have a real need to reconsider the safety issues here."
In the U.S., what the government considers a safe exposure level for BPA — 50 micrograms of BPA per day per kilogram of body weight — has remained untouched for more than 30 years. Europe dropped its safety limit to 4 micrograms of BPA per kilogram of body weight per day in 2015.
The FDA generally assumes an increasing-dose-increasing-harm relationship in its evaluation of chemicals. A dose-response curve should therefore always be monotonic, according to the agency, which means it will never change direction from positive to negative, or vice versa.
Researcher Pat Hunt with lab mice in her Washington State University lab. (Credit: Lynne Peeples)
When they deem a dose of a chemical safe, their investigation typically follows an efficient, seemingly common-sense method. They start by exposing lab animals to extremely high doses of the chemical, incrementally drop the doses until they no longer detect obvious harm, then cut that last number down by a margin of safety to create a "safe" exposure limit. As a result, they may not necessarily have tested health effects at that dose — or at any lower doses.
"How many additional studies will be required for all chemicals since we haven't been going low enough?" Bernard Robaire, a reproductive toxicologist at McGill University in Montreal, who was not involved in Clarity, told EHN. His own research dating back to the 1970s identified effects of hormones and hormone mimics that were not monotonic. "Non-monotonicity is not new," he said. Robaire suggested that the new findings do lend credence to the growing concerns about the health effects of BPA and other endocrine disruptors.
Laura Vandenberg, an environmental health researcher at the University of Massachusetts Amherst's School of Public Health, who was not involved in Clarity, also noted the agency's reluctance to accept new science and independent evidence of harm. "The FDA has suggested that all the effects that occur at lowest dose — whether in the academic studies or in their Core study — are spurious effects," she told EHN. "This analysis would suggest that they can't just hold their nose and pretend something is not real."
BPA is also just the tip of a very large iceberg. Many other endocrine-disrupting chemicals, including BPA replacements such as bisphenol-S (BPS), may raise the risk of health problems. Evidence suggests that these chemicals may even be exacerbating the effects of COVID-19. The people at most risk from the virus have underlying conditions such as obesity or diabetes.
"We can't say endocrine disruptors are why people are getting fatter or have diabetes," said Hunt. "But we can see from animal models that this is what we would predict from exposure."
It remains unclear as to how the new paper will play into the final Clarity report, or if the government will respond with any changes in how they assess the safety and regulation of endocrine-disrupting chemicals.
"We need to hear from the FDA," said Vandenberg. "If they are going to decide that the academic work was not helpful, I want them to explain why."
Banner photo: BPA testing in the lab of Cheryl Rosenfeld, a University of Missouri researcher. (Credit: Cheryl Rosenfeld)
More than 60 scientists from around the world contributed to a 2009 report, the first to offer a comprehensive review of the impact of plastics on the environment and human health, and to present possible solutions.
"One of the most ubiquitous and long-lasting recent changes to the surface of our planet is the accumulation and fragmentation of plastics," wrote David Barnes, a lead author and researcher for the British Antarctic Survey. The report was published a special issue of Philosophical Transactions of The Royal Society B, a scientific journal.
As the scrutiny of the environmental toll of plastic increases, so has its usage, the scientists reported.
Plastic manufactured in the first 10 years of this century eclipses the total produced in the entire last century
Since its mass production began in the 1940s, plastic's wide range of unique properties has propelled it to an essential status in society. Globally almost 360 million tons of plastic were produced in 2018. The amount of plastic manufactured in the first ten years of this century will approach the total produced in the entire last century, according to the report.
"Plastics are very long-lived products that could potentially have service over decades, and yet our main use of these lightweight, inexpensive materials are as single-use items that will go to the garbage dump within a year, where they'll persist for centuries," Richard Thompson, lead editor of the report, said in an interview.
Evidence is mounting that the chemical building blocks that make plastics so versatile are the same components that might harm people and the environment. And its production and disposal contribute to an array of environmental problems, too. For example:
- Chemicals added to plastics are absorbed by human bodies. Some of these compounds have been found to alter hormones or have other potential human health effects.
- Plastic debris, laced with chemicals and often ingested by marine animals, can injure or poison wildlife.
- Floating plastic waste, which can survive for thousands of years in water, serves as mini transportation devices for invasive species, disrupting habitats.
- Plastic buried deep in landfills can leach harmful chemicals that spread into groundwater.
- Around 4 percent of world oil production is used as a feedstock to make plastics, and a similar amount is consumed as energy in the process.
People are exposed to chemicals from plastic multiple times per day through the air, dust, water, food and use of consumer products.
For example, phthalates are used as plasticizers in the manufacture of vinyl flooring and wall coverings, food packaging and medical devices. Eight out of every ten babies, and nearly all adults, have measurable levels of phthalates in their bodies.
In addition, bisphenol A (BPA), found in polycarbonate bottles and the linings of food and beverage cans, can leach into food and drinks. The U.S. Centers for Disease Control and Prevention reported that 93 percent of people had detectable levels of BPA in their urine.
High BPA and phthalate exposure by premature infants in neonatal intensive care units is 'of great concern'
Flickr.com
Polybrominated diphenyl ethers or PBDEs, which are flame-retardants added to polyurethane foam furniture cushions, mattresses, carpet pads and automobile seats, also are widespread.
The plastics industry maintains that its products are safe after decades of testing.
"Every additive that we use is very carefully evaluated, not just by the industry, but also independently by government agencies to look at all the materials we use in plastics," said Mike Neal, a consumer and environmental affairs specialist at PlasticsEurope, an industry trade association, and a co-author of the report.
But some of these chemicals have been shown to affect reproduction and development in animal studies, according to the report. Some studies also have linked these chemicals with adverse effects in people, including reproductive abnormalities.
"We have animal literature, which shows direct links between exposure and adverse health outcomes, the limited human studies, and the fact that 90 to 100 percent of the population has measurable levels of these compounds in their bodies," said John Meeker, an assistant professor of environmental health sciences at the University of Michigan School of Public Health and a lead author. "You take the whole picture and it does raise concerns, but more research is needed."
Shanna Swan, director of the University of Rochester's Center for Reproductive Epidemiology, conducted studies that found an association between pregnant women's exposure to phthalates and altered genital development in their baby boys.
Also, people with the highest exposure to BPA have an increased rate of heart disease and diabetes, according to one recent study. Animal tests studies of PBDEs have revealed the potential for damaging the developing brain and the reproductive system.
Yet the effects on human health remain largely unknown. To help shed more light on the issue, the report recommends more sophisticated human studies.
"It's tough to have a smoking gun with a single animal study or observational human study," Meeker said. "We need to have different types of studies indicating a consistent pattern to more definitively determine health effects resulting from these chemicals."
But testing humans for endocrine disruptors can be tricky because phthalates and BPA pass through the body so quickly. In addition, tests for each chemical cost about $100 a pop.
Deciding which chemicals to test and at what dose is also an issue. To date, most studies have addressed single chemicals, and there are limited data on the interactions between chemicals. Compounding the problem is the discovery that endocrine disrupting chemicals may have effects at doses lower than those used in the Environmental Protection Agency's standard toxicity tests.
Current testing efforts should be thrown out. The new goal? Tests that mimic real human exposure.
Amy Soto
"It's a very complicated picture and the laboratory model of just taking one isolated chemical and giving it to a genetically pure strain of rats in clean cages, clean air and clean water and seeing what it does just doesn't come close to mimicking the human situation," Swan said.
Many researchers recommend studies that test pregnant women as well as their children. The National Children's Study will do just that by examining environmental influences on more than 100,000 children across the United States, following them from before birth until age 21.
"There are so many questions now with these chemicals in relation to cardiovascular disease, age and puberty, obesity, developmental disorders," said Swan. "We don't know what's causing it, only hints, so the beauty of the National Children's Study is that we can look at all of these endpoints and it should reveal a lot of answers."
Plastic's problems extend beyond the human body, according to the report. More than one-third of all plastic is disposable packaging like bottles and bags, many of which end up littering the environment.
Although the image of a bird tangled in a plastic necklace is by now burned into the public's eye, ingestion of plastic fragments is much more common. Once inside, plastic can pack a one-two punch by both clogging an animal's stomach and poisoning it with chemicals that have concentrated in the plastic. Some chemicals are then transferred to the food web when animals eat them.
More than 180 species of animals have been documented to ingest plastic debris, including birds, fish, turtles and marine mammals, according to the report.
Unfortunately, collecting data on plasticizers' impacts on wildlife suffers the same pitfalls as studying human health. Still, there is already evidence that chemicals associated plastics might harm wildlife.
For example, laboratory studies have shown that phthalates and BPA affect reproduction in all studied animal groups and impair development in crustaceans and amphibians.
"While there is clear evidence that these chemicals have adverse effects at environmentally relevant concentrations in laboratory studies, there is a need for further research to establish population-level effects in the natural environment," according to the report.
Charles Tyler, a professor at the University of Exeter School of Biosciences in the United Kingdom and a senior author of the report, said that scientists have shown that "some of these chemical compounds are getting into the environment and are in some environments at concentrations where they can produce biological effects in a range of wildlife species."
Traveling from coast to coast, plastic can endure for thousands of years due to the reduced UV exposure and lower temperatures of aquatic habitats.
Barnes demonstrates plastic's mobility with his account of a plastic sighting during an expedition to the Amundsen Sea where he took biological samples, the first there ever. The Amundsen, located in the Pacific Sector of Antarctica, is the only sea in Antarctica with no research station on its coast and the nearest urban center thousands of miles away.
"Even for us, getting in was a challenge because there's so much ice and it's so difficult to get there," said Barnes. "But even in that remotest of environments, there was plastic floating on the sea surface.
Plastic also serves as a floating transportation device that allows alien species to hitchhike to unfamiliar parts of the world, threatening biodiversity. Global warming further aids the process by making previously inhospitable areas like the Arctic livable for invasive species, which can be detrimental to local species.
For example, plastic items are commonly colonized by barnacles, tubeworms and algae. Along the shore of Adelaide Island, west of the Antarctic Peninsula, ten species of invertebrates were found attached to plastic strapping that was littering the ice.
"Raising the temperature just one degree can make the difference between getting to someplace and actually surviving once you get there," said Barnes.
Plastic is so resilient that even burying it deep within the earth doesn't keep it from impacting the environment. Currently it accounts for approximately 10 percent of generated waste, most of which is landfilled. But, as the report notes, placing plastics in a landfill may simply be storing a problem for the future, as plastic's chemicals often sink into nearby land, contaminating groundwater.
Plastics as a major user of fossil fuels
In addition, production of plastics is a major user of fossil fuels. Eight percent of world oil production goes to manufacturing plastics.
As plastics grow in volume at a rate of about nine percent each year, the authors emphasize that tackling its problems means addressing its sustainability.
One solution is to treat plastic as a reusable material rather than as a disposable commodity that's quickly discarded. That means making plastic more easily recyclable from the get-go by using fewer materials in the manufacturing process and increasing recycling facility availability.
"The recycling message is simple; both industry and society need to regard end-of-life items, including plastics, as raw materials rather than waste," stated the report.
Increasing the availability of biodegradable plastic, which can be made from renewable materials from plants such as corn and soy, is another option.
"Biodegradable plastics have the potential to solve a number of waste-management issues, especially for disposable packaging that cannot be easily separated from organic waste in catering or from agricultural applications," according to the report.
However, currently production capacity for biodegradable plastics worldwide is around only 350,000 tons, representing less than 0.2 percent of petrochemical-based plastic. In addition, "most of these materials are unlikely to degrade quickly in natural habitats, and there is concern that degradable, oil-based polymers could merely disintegrate into small pieces that are not in themselves any more degradable than conventional plastic," stated the report.
To help mitigate the potentially harmful chemicals in plastics, the authors recommend that more studies be conducted on the biological mechanisms that may be affected by plastic additives and in particular, low-dose chronic exposures.
In the meantime, the report recommends reducing the use of these chemicals and developing safer alternatives, a strategy known as green chemistry.
"Had this approach been in place 50 years ago it would probably have prevented the development of chemicals that are recognized as likely endocrine disruptors," the report said.
The report also suggests that plastic waste can be reduced by using labels that allow consumers to choose packaging based on a lifecycle analysis that includes all components of the manufacturing process. For example, if the product were made of mostly recycled materials, used minimal packaging and could be easily recycled, it would get a green dot. If the product were made of excessive packaging that used a lot of virgin materials, it would get a red dot.
"Personally, I feel that's the way to do it, rather than a knee jerk reaction where legislation says we can't use certain types of plastic," said Thompson. "Having that information will help drive the system because I think consumers are keen to make the right choice when provided with all the information."
Neal of PlasticsEurope said consumers, not the industry, are responsible for making sure plastics don't wind up littering the environment.
"In my view the responsibility is fairly and squarely on the consumer," he said. "People tend to pick on plastics because perhaps it's the most visible form of litter and because it's lightweight so it can move around a bit, but actually it's only a small part of the litter problem."
A responsible way to help solve environmental problems
The authors said that if plastics are made and used responsibly, they can help solve some environmental problems.
For example, one study found that packaging beverages in PET (a type of plastic) versus glass or metal reduces energy use by 52 percent and greenhouse gas emissions by 55 percent. And, solar water heaters containing plastics can provide up to two-thirds of a household's annual hot water demand, reducing energy consumption.
Plastics, if used wisely, "have the potential to reduce mankind's footprint on the Earth," Thompson said.
Editor's note: This article was first published in July 2009 by Environmental Health News and updated April 2020. It is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
In December researchers declared that the method used by federal regulators dramatically undercounted the amount of bisphenol-A (BPA) in our blood and urine. This week two dozen scientists weighed in both challenging and defending the work.
BPA is a key ingredient in polycarbonate plastic and epoxy resins. It's used to keep acidic foods like tomatoes from interacting with the metal in tin cans, is absorbed by the skin and digestive tract and rapidly transformed and passed by the body. But since the additive – along with "BPA-free" substitutions like BPZ and BPS – is ubiquitous in everyday products, traces of the chemical and its breakdown products, called metabolites, are found in almost every person on the planet.
When BPA enters the liver most of it is converted to metabolites. These metabolites are then excreted.
To accurately measure a chemical, scientists need to be able to compare what they are measuring to a known amount of the same chemical, called a standard. A 'standard' has been available for BPA for a long time.
Until recently, however, there have not been standards for the metabolites, so it was not possible to test for them directly.
To get around this the current federal test for total BPA exposes BPA metabolites from urine to a snail enzyme which in theory converts it back to the original form. They then measure the total BPA after that conversion.
The December study, published in The Lancet Diabetes & Endocrinology journal, measured the metabolites and BPA directly. The researchers discovered that the snail enzyme doesn't work how the federal scientists think it does. It does alter the metabolites chemically but not all of it to BPA. The more metabolite there is, the more it is converted to something else, not BPA.
The researchers found the average level of BPA in test subjects was 44 times higher than using the federal standard.
"This would indicate the old method is highly inaccurate," Pat Hunt, co-author of the December analysis and researcher at Washington State University, told EHN in December, referencing the U.S. Food and Drug Administration's method. "It's a case of having better tools in our hands. Tools we were using were cruder and highly inaccurate."
Pat Hunt in 2019. (Credit: Lynne Peeples)
Four letters published this week in The Lancet Diabetes & Endocrinology journal carry that debate forward.
The first, from U.S. Centers of Disease Control and Prevention scientist Antonia Calafat and 18 other researchers at university and government labs across Europe, Australia and the United States, defended the indirect, or status quo, method.
"Both human pharmacokinetic and laboratory studies have demonstrated the validity of the indirect method, the approach used by most laboratories routinely measuring BPA," they said. "Current population levels of BPA in urine are accurately and precisely measurable."
According to the response to this by Hunt and colleagues, proper vetting could not have been done without the standards needed to accurately determine the metabolites' concentration. And neither the FDA nor the CDC used those standards.
BPA interferes with our hormone system at extremely low doses. Researchers have linked it to a range of health problems, including cancer, diabetes, obesity, infertility and behavioral problems.
A year-long investigation by EHN.org found that federal agencies discount cutting-edge science that shows worrisome results at low, everyday exposures. Instead, the investigation found, regulators favor industry-backed studies and research methods that are decades old.
Two other letters counter that the new approach needs attention—and should be applied to chemical testing beyond BPA.
"We believe that measurement of 'real' BPA is the best tool to assess risks to human health," wrote Antoine Dupuis and three other biomonitoring experts at the University of Poitiers in France.
According to Hunt and colleagues, this misses the point that BPA levels in urine have been used in risk assessments, where total BPA levels of exposure are assessed by looking at BPA levels plus the levels of metabolites. Because of the enzymatic degradation of BPA in the liver and the excretion of metabolites in urine, the amount of BPA observable in blood is only one piece of the puzzle.
Incorrect exposure readings could have profound public health ramifications, cautioned Kerri Palmer and Valerie Speirs of the University of Aberdeen in a third letter. "Perceptions that BPA is present in low levels has led regulators to be dismissive about its potential adverse health effects, even though there is potential for continuous, low-level exposure throughout our lifetime."
Responding to the debate, the December study's three authors—Pat Hunt, Roy Gerona of the University of California, San Francisco; Fred vom Saal of the University of Missouri—noted in the fourth and final letter that their data are never disputed.
"Calafat and colleagues provide no criticism of our methodology, findings, or the profound implications for BPA risk assessment," they said. "To echo Palmer and Spiers: Regulators are urged to take note."
See the latest edition of the The Lancet Diabetes & Endocrinology journal for all of the letter referenced above.
The study builds on previous evidence that BPA and its common replacement BPS can pass through a mother's placenta and is the first to show the same for a range of other replacements, suggesting that fetuses are being exposed to a cocktail of chemicals linked to behavioral and reproductive disorders, among other health problems.
"We are very clearly seeing these compounds going straight to the baby at totally unacceptable concentrations," Terrence Collins, a green chemist at Carnegie Mellon University, who was not involved in the study, told EHN.
The study, published in March, looked for 15 different bisphenols—including a BPA, BPS and other popular substitutes—in 60 pairs of maternal plasma, cord plasma and placenta samples from pregnant women in South China. Four bisphenols were frequently detected in all three samples: BPA, BPS, BPAF and BPE.
BPSIP, a relatively new compound commonly used in thermal paper for store receipts, appeared at high levels in all maternal plasma samples. The researchers note that BPSIP "exhibits a similar estrogenic potency and greater reproductive toxicity than BPA."
"This is another shriek from nature, 'Stop throwing BPA, or things like it, at me,'" added Collins.
The study is concerning as BPA is a known endocrine disruptor, meaning it is capable of scrambling hormone signals, and has been linked to cancer, diabetes and infertility. In-utero BPA exposure has been shown to derail the normal growth of the brain and other organs and manifest later in life as early puberty or an increase in anxiety-related behaviors or attention deficit hyperactivity disorder (ADHD). Some replacements have been tied to similar issues including obesity and reproductive problems. The new study linked BPAF concentrations in cord plasma with both premature birth and low birth weight.
Most BPA replacements are created by tweaking the BPA molecule to form similar compounds. As a result, most pose similar health concerns. A 2017 study found that six substitutes used in products promoted as BPA-free had as much, if not more, of an estrogen-mimicking effect on human breast cancer cells as BPA.
Pat Hunt, a geneticist at Washington State University in Pullman, Wash., suggested that the latest BPSIP finding reflects an ongoing pattern of regrettable replacements.
"Oh great, another one. When is this going to end?" she told EHN. "We need to worry about all these new players that come onto the scene."
Market expands, leaving children at highest risk
BPA still made up the highest concentrations detected in the new research. Despite thousands of studies that highlight its health effects, the global BPA market continues to increase at about 3 percent per year and is projected to top seven million tons by the end of 2023.
"They are still expanding BPA into every imaginable product," said Collins. "BPA should not be produced. Period."
Meanwhile, the U.S. Food and Drug Administration maintains that the chemical poses no harm at levels to which people are exposed.
In November 2019, EHN published a year-long investigation of the FDA's handling of BPA science. It found that U.S. regulators have stacked the deck against findings from independent scientists that BPA, as well as many BPA substitutes, can harm people at very low doses.
Cheryl Rosenfeld, a biologist at the University of Missouri, published a study of mice in February that found both BPA and BPS exposure lowered serotonin production in the placenta, the primary source of the critical neurotransmitter for developing offspring. The effect could have "dramatic consequences" on brain development, Rosenfeld told EHN.
The bisphenol concentrations that the researchers found in the placenta and cord blood are both troubling, she said, as impacts may come through the placenta or by directly affecting the brain itself. "Yes, it can cross the placenta and that's important because it tells you that whatever mom is exposed to can reach the developing fetus," said Rosenfeld. "But we're even seeing effects before it gets there."
Still, not all bisphenols necessarily behave the same way. For example, BPAF crossed the placenta more readily than other bisphenols highlighted in the new study. "We can't assume that what we know about BPA will translate to the other bisphenols," said Hunt.
Searching for a safe replacement
Valspar cans. (Credit Lynne Peeples)
One newly developed bisphenol might prove a welcome change from its chemical cousins. Valspar, recently acquired by Sherwin-Williams, has created a replacement for food and beverage can linings historically made with BPA.
Rather than just slightly tweaking the chemical structure of BPA, they assessed safety alongside functionality throughout the process. They enlisted academic scientists to test the compound, tetramethyl bisphenol F (TMBPF), for a range of endocrine disruptive activities. "The evidence is very encouraging," said Collins.
"Endocrine disruptors are having a dreadful impact on civilization," he added. "We need to give Valspar its due. But we also need to know more."
But first, let's thank European supermarket chain Lidl for trying. We all must. Plastic pollution is an enormous challenge. Unfortunately they, like many, are ignoring the toxic dimension of plastic recycling. Until efforts to solve the plastic crisis fully understand plastic toxicity, they risk making today's solutions into tomorrow's problems. And not just tomorrow's minor problems—we're talking societal-disruption and extinction-scale problems.
Our research team this week found a story in The Daily Mail about Lidl's plan to wrap fish in plastic recycled from "ocean-bound plastic" collected off beaches in Southeast Asia.
Sorry. It may be well-intentioned, but for someone who understands plastic toxicity, it's a horrifying idea.
Here's why: Plastic contains many toxic substances. Scientists think about four sources:
1. The plastic itself
Some toxics come from the plastic itself: The basic building block that is the core of a plastic molecule is sometimes demonstrably toxic. Bad for babies. Bad for adults. Bad for libido. Bad for fertility, brain function and a lot of other adverse effects people care about. For example, BPA is widely used as the "monomer" that is connected in a chemical chain to make a polymer, the very definition of plastic. So are BPS and many other "BPA-free" alternatives. The monomer BPA (and BPS etc.) is a notorious endocrine disrupting chemical.
2. The additives
Some of the sources are additives (like phthalates that chemical engineers ooze into the plastic to force the plastic to attain specific characteristics, like softness or resistance to UV light or microbes). These additives aren't bound to the polymer so they ooze out of phthalate-softened PVC based Rubber Duckies. Just right for infants to suck on if your goal is to suppress sperm count once they become adults.
3. The unintended ingredients
Then there is a complicated morass called "nonintentionally added substances (NIAS)." Some of these have been identified. Others we know are there but we don't know what they are. These usually are byproducts of reactions that take place as plastic is made. One problem is that to make plastic out of a feedstock that is absolutely 100% pure would be wildly expensive. So in the real world there are impurities. And these impurities react during the making of plastic to form NIAS. But other chemical processes produce NIAS even with pure feedstock. We know some NIAS are toxic, like formaldehyde and acetaldehyde in PET plastic. But for most we are ignorant. They could be safe, or they could be toxic.
4. The environment
Lastly, plastic materials absorb toxic substances from the environment, for example from ocean water. Some of these are notorious, like PCBs, DDT (still), dioxins, and others.
Ignorance about toxicity
The result is that virtually all plastics are likely to contain toxic ingredients, especially those taken from the ocean. Some may not, but they are never fully tested. A remarkable scientific study last year made clear how ignorant we are. After the basic finding that most plastic materials tested were toxic in one way or another, the most surprising finding in their work was that a widely acclaimed bio-based plastic was among the most toxic. Oops. In that case, it was probably due to the additives.
While chemical engineers try to make food-grade plastic packaging material out of a jumble of old plastic picked off the beach, their products will unquestionably contain toxic chemicals. It's not something you want wrapped around your fish. Or finding its way into your fetus via food packaging. Very bad idea.
An epidemic of hormonally related diseases
What are some of these toxic substances? They are a litany of what doctors have identified as endocrine disrupting compounds, including bisphenols, phthalates and perfluorinated (or "forever") chemicals, PCBs, DDT (banned in the 1970s but, still, found everywhere). This nasty stuff is now associated with today's epidemic of hormonally related diseases, like type 2 diabetes, heart disease, obesity, infertility, ADHD and autism. And there are other types of toxicity imbedded in these plastics, as well: Carcinogenicity, oxidative stress, etc.
Some of those beach plastics in Lidl's recycled packaging may be safe, although literally none (really, none) have been fully tested for safety. But some of them are definitely toxic. When you mix safe plastics with toxic plastics the recycled result is always toxic. And forget hiding behind the old adage that "the dose makes the poison." Endocrine science has established that exceedingly small doses can have big effects.
Not safe for food?
That means programs like Lidl's bring you food packaging that is unavoidably toxic.
Unless they have tested each batch. In which case, Lidl, show us the data.
Many of the plans to gather plastic from the ocean and make something out of it fall victim to this basic truth. Recycling possibly safe and toxic plastics together winds up with unquestionably toxic materials. We don't want that in our food supply because stuff in packaging migrates into the food we eat. Plastic recycling solutions that don't address the toxicity of the recycled product are part of future problems. Any entrepreneur or reporter who pretends otherwise is creating a serious problem for tomorrow.
A serious problem
And this is why it's such a serious problem. The toxics in plastics are associated with declines in sperm counts so precipitous that the developed world may wind up with 4 out of 5 men infertile by 2040 or 1 out of 2 boys autistic by 2042.
This is a problem we have to take seriously, despite the feel-good sense we get from short-term solutions. Lidl investors should beware of the financial exposure this creates for the company. As we begin to understand the long-term consequences of plastic exposures, Lidl on its current path will not be on the right side of science, or history.
Pete Myers is the founder and chief scientist of Environmental Health Sciences, publisher of EHN.org and DailyClimate.org. Opinions are his own and not that of the organization's.
It was 2009, and she had recently been elected to the New York State Legislature as it considered a bill prohibiting bisphenol-A (BPA) from infant and children's products sold in the state. She voted yes on the bill, which passed in 2010.
Now she wants to see similar action on the national level.
"The FDA needs to be more transparent about what additives and chemicals are in our foods and products and how they could potentially impact us — just as we do for cigarettes," Meng told EHN.
Read the full investigation: How willful blindness keeps BPA on shelves and contaminating our bodies
Meng, who has since co-introduced federal legislation to ban BPA from food and beverage containers, is among policymakers who have reacted to a four-part series published in November 2019 by EHN. The year-long investigation found that the U.S. Food and Drug Administration has stacked the deck against findings from independent scientists that BPA, as well as many compounds used in "BPA-free" products, can harm people at very low doses.
EHN contacted 18 policymakers for comment after publication of the series. Despite numerous requests, eight did not respond at all, and seven failed to follow up or declined to comment. The three policymakers that shared their reactions expressed concern about FDA's behavior with regard to the testing and regulation of BPA, among other toxic chemicals.
We reached out due to an outcry from scientists and advocates after our investigation who say the FDA seems to be willfully ignoring science that shows BPA is harming our health and the health of our children.
The stakes are high. The chemical is used in the production of goods that pervade our lives and the manufacturing of BPA remains on the rise. The global BPA market is increasing about 3 percent per year, and is projected to reach $22.5 billion by 2022 and top 7 million tons by the end of 2023.
And, in the face of these major financial implications, the FDA keeps relying on industry studies to maintain BPA's safety — though plastic manufactures and others industries that are reliant on BPA have obvious reasons to mount a strong defense of its safety.
"We can see that there have been, to some extent, inconsistencies or lack of transparency in the information that the average American consumer is able to obtain on BPA. Obviously, that is just one chemical," said Meng, who is currently revising her BPA bill for reintroduction this year. The bill had previously stalled out in committee.
She is also pursuing federal legislation on food additives, such as Yellow 5 and Red 40, as well as potentially harmful ingredients in feminine pads and tampons.
A pattern of denial
The EHN investigation took a close look at an unprecedented $30 million-dollar project co-led by the FDA, the Consortium Linking Academic and Regulatory Insights on BPA Toxicity, or Clarity for short.
The ongoing effort aims to reconcile the long-standing dispute between government and academic scientists over the health effects of BPA, which is used in the production of goods that pervade our lives — from reusable water bottles and food containers to store receipts and dental sealants. While the FDA claims that BPA poses no risks in the amounts it is used, thousands of peer-reviewed studies from academics suggest otherwise: Absorbing or ingesting the ubiquitous chemical may harm people at doses 20,000 times lower than what the agency says is safe, comparable to levels at which most of us are exposed. An integrated report that pulls together findings from both the government and academic scientists, who based their studies on the same population of rats, is currently being prepared.
The project — originally scheduled for completion by the end of 2019 but yet to be released — has so far fallen short of its goal.
Through interviews and emails obtained via Freedom of Information Act requests, EHN uncovered various deficiencies in the FDA's science on BPA and its handling of Clarity. While each sign alone could be considered a red flag, viewed as a whole, they suggest that the FDA is missing some big warning signs about BPA and, therefore, likely misleading the public in its insistence that the common chemical poses no real health hazard.
BPA research in the lab of University of Missouri researcher and professor Cheryl Rosenfeld, who was a participating Clarity project scientist. (Credit: Cheryl Rosenfeld)
"It's disconcerting that the FDA is defending a position that doesn't reflect the newest science," David Michaels, a professor of environmental and occupational health at The George Washington University, told EHN. "At a minimum, they should be acknowledging the tremendous difference among scientists. Instead they are digging in and rejecting thousands of studies that aren't consistent with their position."
So, why the discrepancies, doubt and denial? For one thing, if the FDA were to acknowledge the low-dose health effects of BPA it could open a Pandora's box. Tens of thousands of manufactured chemicals are on the market, with hundreds such as BPA suspected to be endocrine disruptors, capable of scrambling hormone signals and, therefore, raising risks of health problems such as cancer, diabetes, obesity, infertility and behavioral problems. "It would force the agency to reevaluate its past work and would raise tremendous challenges to its work in the future," added Michaels.
The agency's behavior, he said, mirrors what he witnessed while serving as the U.S. Assistant Secretary of Labor for Occupational Safety and Health Administration between 2009 and 2017. "In general, the FDA often takes positions which are consistent with those demanded by industry," said Michaels.
Related: Clouded in Clarity—A comic on chemicals & controversy
The regulation of mercury levels in fish is one example highlighted by Michaels. While earlier consumption recommendations from the U.S. Environmental Protection Agency had reflected the newest scientific literature at the time, acknowledging that very low levels of organic mercury can affect the neurodevelopment of fetuses and young children exposed to contaminated fish, the FDA's position for many years was "much more consistent with the fossil fuel and fuel-burning industries responsible for much of the mercury that gets in the food chain," he said.
Further, while addressing issues related to cosmetics and beauty care products during his tenure with OSHA, Michaels recalled how hesitant the FDA was to "make any effort to control exposures to formaldehyde, which arises from exposure to Brazilian blowout," a hair-smoothing chemical treatment.
"We generally found FDA to be less responsive to public health concerns than we would have expected," he added.
The FDA declined to comment for this story. The agency was also reluctant to comment during "Exposed" reporting, frequently delaying responses and answering only select questions.
A good idea, in theory
BPA is used in food can linings.
Wendy Wagner, a professor of law at the University of Texas at Austin who studies the use of science by policymakers, cheered the Clarity concept, but lamented its execution. The project may just be "round one of an experiment that needs more tweaking," she told EHN.
Wagner emphasized the need to "break open the black box" and take a "hard look" at the process by which the FDA does science. On multiple occasions over the last few decades, she said, the government has manipulated the synthesis of the science.
"I've seen dozens of reported incidences of that kind of political meddling," said Wagner. "It's usually not at the bench research stage, but in the literature stage — in the synthesizing for a report." EHN's reporting, too, found hints of how the FDA may spin results across studies. Of 36 studies identified as related to neurological endpoints in a 2014 risk assessment of BPA, for example, the agency chose to only include one. That study was funded by industry.
Genna Reed, lead science and policy analyst in the Center for Science and Democracy at the Union of Concerned Scientists, echoed the same hope and concern. "It's important not just to fund these efforts but be thoughtful about the process by which these efforts are implemented and guided," she told EHN.
Reed's team conducted a survey in 2018 that found FDA employees generally felt the agency adhered to its scientific integrity policies. However, they expressed feelings that it could "better insulate scientists from undue influence from political and business interests."
The survey highlighted several issues regarding the agency's science-based decision-making processes, including evidence of the improper influence of political leadership and constraints resulting from workforce reductions.
The Union of Concerned Scientists has also looked at the agency's Good Laboratory Practice regulations. While the guidelines were designed in an effort to reduce industry misconduct, Reed argued that studies following these practices "should not be given preferential weight over studies validated by other scientific review processes." Again, in the case of BPA, the FDA has excluded from its risk assessments a large body of studies from academics, who validate their studies through different means such as peer review.
"We see so much BPA-free packaging all the time," said Reed. "The more questions that are raised by the public about these chemicals that are in our bodies and in the environment, and why they aren't being regulated by our government, the more likely it is for members of Congress in some key committees to take up this issue and figure out what the next steps are."
Seeking oversight
Sen. Tom Udall, (D-N.M.) "The FDA should be using the best available tools, including expert career staff and scientific findings, to protect public health," he told EHN. (Credit: Senate Democrats)
Some political movement is underway.
Senator Tom Udall (D-NM) stated in an email to EHN that "Congress needs to provide strong oversight to ensure that the executive branch is serving the public good – and we must assert ourselves as a co-equal branch to ensure the public interest is the first priority in every decision that is made."
"The FDA should be using the best available tools, including expert career staff and scientific findings, to protect public health. However, under this administration we've seen agencies including the FDA and EPA do the bidding of special interests – at the expense of the public interest," he said. "As a member of the appropriations committee and as the ranking member of the Senate Appropriations Subcommittee on the Interior, Environment and Related Agencies, I will continue to provide oversight to ensure that our federal agencies are serving the American people."
Udall's spokesperson added that his team "will look into this issue more to see if there are actions Congress can take to better protect public health."
Senator Patty Murray (D-WA). "I hope the FDA and all agencies involved will continue working to evaluate and take appropriate action to address any risks associated with BPA," Murray told EHN. (Credit: Peter Stevens/flickr)
Senator Patty Murray (D-WA), too, noted that she was "closely monitoring the situation regarding the regulation of chemicals like BPA."
"I encourage the FDA to follow the best available science and data to help ensure public health and safety," she told EHN in a statement. "I hope the FDA and all agencies involved will continue working to evaluate and take appropriate action to address any risks associated with BPA."
Meng's BPA bill, as previously drafted, would outlaw the use of BPA from food packaging and require BPA alternatives to undergo extensive review to avoid replacing one chemical with another that may pose similar health risks.
Meanwhile, several states are adopting bills that ban BPA, popular BPA substitutes and other endocrine-disrupting chemicals from a range of products, including receipt paper and nail polish.
While an oversight hearing might not drive change overnight, Michaels underscored its potential usefulness in "raising issues to the public and alerting the leadership of agencies that these controversies really do need to be addressed." Tobacco hearings led by Representative Henry Waxman (D-CA) in 1994 did just that, as did a series of hearings beginning in 2009 on the damage from brain injuries among NFL players.
"Up until that point, the NFL minimized the neurological effects of repeated brain hits," said Michaels. "After that hearing, the commissioner of the NFL changed his position and the league took the problem much more seriously."
He urged the same to be done for Americans exposed to toxic chemicals. "The mindless clinging to outdated science is detrimental to public health and to the development of good science and to the progress of science," said Michaels.
"Historically, many out-of-date scientific paradigms are overturned or disappear only over time, as the scientists who cling closely to them retire and new scientists take over their positions," he added. "But, given the importance of protecting the public from endocrine-disrupting chemicals, it would be a great shame if we have to wait decades for that change to occur."
We can accomplish this by acting upon today's scientific understanding that chemical exposures are contributing to those problems.
I'm going to let you in on a scientific reality that is going to transform the chemical enterprise and upend today's unscientific approach to figuring out what's safe and what is not. The safe dose of one of the biggest volume chemicals in the world— bisphenol A (BPA)—will have to be reduced by at least 20,000-fold.
This calculation is based upon data the US Food and Drug Administration (FDA) obtained in an ambitious, roughly $30 million collaborative program called CLARITY-BPA. CLARITY was designed to reconcile differences between traditional regulatory science as practiced by the FDA and results obtained by independent academic scientists funded by the National Institute of Environmental Health Sciences (NIEHS). Many significant effects were observed at the lowest dose tested, including data obtained by the FDA.
That means: Take today's FDA reference dose and divide by at least 20,000.
That's the highest exposure that would be considered safe if regulated according to existing scientific understanding. The chemical would disappear from any uses that bring it into contact with food or drinking water, human skin, or result in it evaporating into the air or melting into water.
And the same would hold for many other chemicals that disrupt hormone signaling, that is, endocrine disrupting chemicals, which have been linked to multiple health impacts including prostate cancer, breast cancer, infertility, diabetes, ADHD and autism.
Maybe not all EDCs would require a 20,000-fold reduction. Perhaps only a 1000-fold. But there are at least several hundred endocrine disrupting chemicals (EDCs) in use today that could follow this pattern. All would see greatly heightened restrictions on their uses.
And that represents an existential threat to the chemical industry.
Risky investments
3M made headlines this year for their manufacture and use of PFAS chemicals, which are contaminating water supplies across the U.S. (Credit: Holger.Ellgaard/Wikimedia Commons)
I am not anti-chemical, nor anti-chemist. We need chemicals, including plastics, to make modern civilization work. What we need, however, is to do a much better job at designing the next generation of inherently safer materials, safer than the mix we have today, which has been deployed with far too little attention to its inherent toxicity.
I've spent a significant part of my work over the last decade helping chemists design safer chemicals. I want to help them grab market share in the booming demand for safer materials. I want to help them make money.
Some people claim that chemical regulations stifle innovation. Just the opposite is true. It will require tremendous innovation to move away from hazardous chemicals and toward materials that are safer. It can be done. The scientific knowledge we possess today about what causes chemical harm is deep and wide, so much better than what we knew when hazardous materials in widespread use today were designed. Let's use that knowledge to innovate.
What's the long-term landscape? A series of events and scientific discoveries over the last two decades are revealing that not only have long-standing chemical industry practices harmed people's health, investors taking positions in chemical companies may be exposing their wealth to unexpected and large financial risks.
These risks arise from a core reality of the business of establishing what is safe and what is not: Chemicals are not thoroughly tested—if at all—for safety before being released into the market, resulting in widespread if not universal exposure, including to highly vulnerable populations like babies still in the womb. Serious harmful effects often are not detected until decades later.
Related: Deciphering the real message about BPA
All too often, as effects are discovered the responsible party—which made the initial mistake to incorporate a poorly understood chemical in products and take them to global scale—doubles down in efforts to hide or dismiss concerns about safety, using toolkits to manufacture doubt developed by the tobacco and lead industries.
Internal memos obtained through legal discovery reveal that the companies, sometimes decades earlier, had ignored or hidden scientific evidence that raised safety concerns. Three prominent examples emerged in in the past few years alone: Monsanto/Bayer with the Roundup herbicide, Johnson & Johnson with asbestos in its talc baby powder, and 3M and DuPont with their manufacture and use of perfluorinated Teflon-related "forever" chemicals, PFAS.
Thousands of lawsuits are being heard against those companies now. Shareholder values plummet as juries reach decisions. Billions of dollars are at stake. And there will be more.
Monsanto had earned a bad rap for misbehavior with its chemicals for decades. But Johnson and Johnson, 3M and DuPont didn't. They had been widely regarded as good corporate citizens. If even they have laundry this dirty in their past, how many other companies have pursued similar practices? Unquestionably many.
Weaponized data
But with the practices so widespread, perhaps the pertinent question is, can any company within this sector be presumed innocent? It's just too common a business practice. It's standard operating procedure.
Another example: Bill Moyers' 2001 documentary Trade Secrets unveiled an early 1970s conspiracy by several seemingly respected chemical companies to hide devastating scientific discoveries about the health risks of vinyl chloride, one of the most important chemicals for the plastics industry. The conspiracy involved Conoco, BF Goodrich, Dow, Shell, Ethyl and Union Carbide, some of the founding fathers of the chemical revolution.
A new weapon against these bad practices has emerged and matured since the tobacco settlements of the late 1980s: the creation of large, searchable databases of internal documents obtained through legal discovery in lawsuits, showing what the companies knew and when they knew it, and also how they conspired with federal agencies to derail needed safety regulations.
The two biggest databases are the Chemical Industry Documents Library at the University of California San Francisco, and ToxicDocs, a similar database of 20 million internal documents dating back as far as 1920, hosted by Columbia University and City University of New York. The UCSF library now includes a large set of documents released by the Attorney General of Minnesota upon settlement of an $850 million suit against 3M last February.
The lawsuits currently underway against Monsanto/Bayer, 3M and Johnson & Johnson will undoubtedly add additional documents that provide yet more evidence of cover-ups that commenced long ago. It already is a positive feedback loop, as new documents add to the body of evidence, which then stimulate more lawsuits.
Science of harm
Financial risks arise for chemical industry investments from a different direction as well: the advance of science demonstrating harm, and the evolution of science to determine what is safe.
The discovery of harm can be slow arriving—sometimes decades after a chemical is first put on the market—but impacts of harm can nonetheless be devastating.
For example, 3M's and DuPont's forever chemicals (perfluorinated compounds, or PFAS, which degrade very slowly in the environment, if at all) were first used in products in the 1940s. Scientific concerns about them started to appear in the 1990s, although internal documents indicate the companies had known decades earlier. Most of the concerns have been about cancer, low birth weights, immune system function and birth defects.
Last year, a science team in Italy unveiled results revealing a new, different set of adverse impacts, this time on male reproduction. They include decreased penis size, reduced sperm count and structural changes in the reproductive tract, classic signs of endocrine disruption. And the team's research confirmed that the contaminants interfere with testosterone action.
Even without the penis effect, 3M settled that $850M suit with the State of Minnesota. DuPont settled a case in West Virginia for $671 million in 2017 and this month the film Dark Waters starring Mark Ruffalo tells the story of the company's decades-long treachery. New Hampshire, New Jersey and New York have ongoing lawsuits.
As of the end of 2019, research by the U.S. military, the Environmental Working Group and others have documented PFAS contamination in more than 400 sites around the U.S. According to one analysis, 110 million Americans have drinking water contaminated by unsafe levels of these chemicals. This estimate is likely to grow substantially with the discovery of PFAS in artificial turf and leaching therefrom into surface water, and the haphazard disposal of untold tons of artificial turf once it wears out and must be replaced.
Many other suits will unquestionably be filed. And that's just in the U.S. These chemicals have already created furors about public health in Australia and Canada.
Upending dangerous assumptions
Lab materials from the lab of Cheryl Rosenfeld, a University of Missouri professor and researcher who studies BPA. (Credit: Cheryl Rosenfeld)
But if there is an existential threat on the horizon for the chemical enterprise, it's the compelling evidence that two of the most basic assumptions used by regulatory agencies to determine what is safe and what is not are flat out wrong. One assumption is that it's sufficient to examine chemicals one at a time. The second bedrock assumption is that high dose testing can be used to detect low dose effects. These assumptions have underpinned literally every single risk assessment (what's safe and what's not) of a chemical that has ever been done anywhere in the world.
"One at a time" fails because it doesn't acknowledge that no one is ever exposed to just one chemical at a time. We are exposed to hundreds if not thousands.
What does every physician ask a patient for whom the doc is about to prescribe a drug? What medicines are you already taking? That's because chemicals interact. One of the most ridiculous uses of this assumption is perhaps in testing pesticides. The EPA tests the "active" ingredient of a pesticide. Yet the pesticide that is available for purchase is a mixture of dozens of chemicals, many of which are added to the product sold explicitly to ENHANCE THE IMPACT OF THE ACTIVE INGREDIENT.
How can you assess pesticide safety without considering the whole product, not just the active ingredient? You can't.
"High dose testing" falls on the sword of what endocrinologists call "non-monotonicity." Many syllables, but a simple concept: Hormones, and chemicals that behave like or interfere with hormones, do different things at different doses. There are many examples of this in the scientific literature of endocrinology, the study of hormones. This is an anathema to traditional and regulatory toxicology, because that "science" maintains that "the dose makes the poison," which the regulatory agencies interpret to mean "higher doses have bigger effects."
EHN recruited a reporter, Lynne Peeples, to investigate the FDA's execution of the roughly $30 million project to reconcile their conclusions with the work of 14 independent academic labs showing harm at low levels for over a year. The investigation found that the FDA worked to ignore or discredit independent evidence of harm while favoring pro-industry science despite significant shortcomings. Key to their conclusions was rejecting statistically significant non-monotonic patterns in their own data, because, they asserted, the non-monotonic findings were not biologically meaningful. In other words, non-monotonic patterns aren't real.
Related: How willful blindness keeps BPA on shelves and contaminating our bodies
"The dose makes the poison" seems like common sense, but common sense has failed us many times in the past. Think about quantum physics or plate tectonics. Our understanding of the modern world depends upon the practical implications of those discoveries. Non-monotonicity isn't nearly as revolutionary as those scientific fields, but it is profoundly important for human health. And it is a standard, widely accepted concept in endocrinology and pharmacology. In 2012, the then-Director of NIEHS, Linda Birnbaum, editorialized that non-monotonicity should be the default assumption in the study of EDCs.
While there are multiple molecular mechanisms leading to non-monotonicity, the easiest (but incomplete) way to think about it is this: Hormones and endocrine disrupting compounds turn on one set of genes at one dose, and another at higher. Sometimes the higher dose turns on genes that shut down the genes that were stimulated by the low dose. In this case, the effect of the low dose is not visible when using high doses. It's analogous to the way a thermostat works. If the room is cold, the furnace is on. But when the temperature hits the desired temperature, the thermostat turns the furnace off.
Sometimes the high dose is so high that instead of turning on genes it becomes overtly toxic. Here's an example: doses of one part per billion of a specific endocrine disrupting chemical delivered to an infant rat causes morbid obesity as the animal matures. This is research by the U.S. National Institute of Environmental Health Sciences. In contrast, a dose of the same compound 1,000 times higher causes weight loss.
The vital piece of information needed to understand why this invalidates today's chemical safety testing requires understanding how the regulatory tests are performed. The lab doing the safety testing starts at high doses and then delivers lower and lower doses to different test groups. Once they find a dose that no longer causes a difference between the exposed and the control animals, testing stops. They use a series of safety factors, usually dividing that no effect dose by 1,000, to estimate the safe dose.
Seems logical. Seems common sense. If dose X doesn't cause an effect, dose X divided by 1,000 is surely safe. But endocrinology doesn't work that way. That might defy common sense, but it is scientific reality.
And unfortunately, because it seems so logical, the regulatory agencies in standard mode NEVER test at the estimated safe dose. 1,000-fold below? Why bother.
To save money and time, they assume that the dose 1,000-fold lower is safe.
Unfortunately, many published scientific papers now show that doses way below the "no effect" dose can cause serious adverse effects. It isn't that the high doses are safer. They, too, cause problems. It's that the effects are different. The low dose effects are serious too—like morbid obesity and reduced fertility.
Here's the one very practical implication I mentioned at the beginning: If the FDA were to acknowledge statistically significant non-monotonicity in their test of BPA—which analysis by independent scientists has confirmed—the safe dose of would be reduced by a factor of more than 20,000-fold. BPA would become virtually unusable.
For a webinar from Carnegie Mellon University featuring four of the world's leading experts on BPA explaining this calculation, go here. This webinar contains four presentations all focused on the FDA-NIEHS collaboration called CLARITY-BPA. The presentations work through why CLARITY was launched, what was found by the FDA 'guideline' study (conducted like a standard regulatory test but including low doses), what was found by 14 independent academic laboratories who also were part of CLARITY, and analysis of what it means.
Bisphenol A is one of the plastics industry's most important molecules. Incredibly cheap to make, incredibly abundant in production, incredibly important to the bottom line. Also—incredibly dangerous to human health.
Removing that one molecule alone would send tectonic signals throughout the chemical enterprise. And yet BPA is but one of at least a hundred or more molecules that have non-monotonic patterns. The replacement chemicals for BPA currently touted as 'BPA-free' are likely to be among them, although many have not been tested. 'BPA-free' does not mean 'safe.'
Non-monotonicity is truly an existential threat to today's chemical enterprise. If that enterprise is to become sustainable, it must embrace this basic endocrinological reality.
Embracing it is a path to reversing today's epidemics of chronic diseases that are driven, at least in part, by chemical hacking of the hormone messaging system by endocrine disrupting compounds.
Pete Myers, is board chair and chief scientist of Environmental Health Sciences. He is also the founder of EHN, though the publication is editorially independent.