Use of petroleum-based chemicals skyrocketed during the postwar era, most of them entering the market with little concern for safety. Now, mounting evidence links petrochemicals to the rapidly rising prevalence of a slew of chronic and deadly conditions, a review published in the New England Journal of Medicine warned earlier this month.
Petrochemical production is 15 times higher today than it was in the 1950s, with about 350,000 chemicals now approved for use globally. Yet only 5 percent of these compounds have undergone rigorous safety tests—even as the rates of numerous ailments they’re linked to continue to rise.
“You can feel the effects of climate change, and know they’re connected to fossil fuels,” said author Tracey Woodruff, a professor at the University of California, San Francisco who directs the Program on Reproductive Health and the Environment. “But the idea that fossil fuels are also connected to these chemicals we’re exposed to, and are impacting our health, I thought, wow, there’s a really important link here.”
Phasing out fossil fuels, Woodruff realized, wouldn’t just benefit the planet. It would also reduce the heavy toll hormone-scrambling petrochemicals are taking on health, particularly in low-income communities of color.
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For the new analysis, Woodruff reviewed nearly seven dozen studies linking exposure to fossil fuel-derived endocrine-disrupting chemicals, or EDCs, to an increased risk of a daunting array of health harms.
Studies have linked EDCs to increased risk of a range of health conditions, including abnormal neurodevelopment (for example, attention deficit hyperactivity disorder and lower IQ), fertility problems (poor sperm quality and impaired ovarian development), cancer (breast, prostate and kidney), early puberty and metabolic diseases (early-onset diabetes, obesity and non-alcoholic fatty liver disease), among other serious ills.
Hormones act at very low levels to control the body’s basic functions throughout life, starting with prenatal development. It doesn’t take much for chemicals that act like hormones to trip up precisely timed developmental stages, when a single cell rapidly divides into the trillions that build the body. The tiniest disruptions can derail development to cause birth defects—best exemplified by the grossly malformed limbs of babies whose mothers took the drug thalidomide for nausea—and disease.
Rates of neurodevelopmental disorders, diabetes, chronic respiratory disease and cancer have increased by up to 150 percent, Woodruff reported, as the chemical industry churned out billions of pounds a year of bisphenols, phthalates and PFAS, aka “forever chemicals,” PBDE flame retardants and other hormonally active compounds. Just last month, researchers linked prenatal exposure to pesticides and other EDCs to increased risk of congenital heart defects.
Petrochemicals have also taken an astonishing toll on lifespan.
Chemical pollution, from fossil fuel extraction and the petrochemicals added to hundreds of products—pesticides, plastics, food contact materials, cleansers, cosmetics and toys, to name a few—may kill at least 1.8 million people a year, researchers reported in The Lancet in 2022.
Experts say there is no safe level of exposure to these chemicals across the population.
The author did a “great job” making the connection between climate change and toxic chemicals and showing that the industry is increasing their petrochemical output as the energy production side of things goes down, said Julia Gohlke, an environmental health scientist at the Environmental Defense Fund who was not involved in the study.
“I think that was a really important part of this, that the petrochemical industry is booming,” Gohlke said. And that the boom, she said, will likely increase exposures to numerous harmful chemicals for workers, fenceline communities and the general population.
Roots of Lax Oversight
Nearly 50 years ago, a group of young men working in an agrochemicals unit of Occidental Chemical realized none of them had fathered a child since they’d joined that department in Lathrop, a small San Joaquin Valley town east of San Francisco.
The men ultimately agreed to do something unheard of in 1977: volunteer to submit semen samples for analysis. All seven volunteers had either “severely” low sperm counts or none at all. Donald Whorton, a leading occupational health physician who worked with their union, described the results as “grossly abnormal.”
When Whorton expanded the volunteer pool that year to 25, the results were the same for more than half of the men. These men shared something else besides their infertility: all processed the worm-killing fumigant DBCP. Whorton, who died in 2008, noted a direct correlation between their time in the unit and abnormally low sperm counts. He found seven studies showing that DBCP “has disastrous effects on testicular function.”
Scientists had already found evidence of “extremely atrophied” testes in rats exposed to DBCP in a confidential report submitted to Shell in 1958, soon after Dow and Shell started selling it. Both companies then funded a study of its toxicity, published in an obscure toxicology journal in 1961.
“The most striking observation at autopsy was severe atrophy and degeneration of the testes of all species,” the authors noted, referring to rats, guinea pigs and rabbits.
Eighteen years later, in his film Song of the Canary, documentary filmmaker Josh Hanig asked an Occidental representative, James Lindley, how he felt when he learned young men working in his plant were sterile. “I had no idea at all that we had any process here in our plant operations that could do such a thing to a human being,” Lindley said.
What about the 1961 study showing DBCP caused sterility in rats? Hanig asked.
“It did not cause sterility,” said Lindley, who went on to become Occidental’s legal counsel and president before he died in 2014. “What it showed was that with very high doses of DBCP you could get testicular atrophy. I’ve talked to two scientists who are familiar with that work and they both say, ‘Heck, we just didn’t draw the conclusion that there’d be sterility from the fact that the testicles were shriveling up.’”
In fact, one of the authors of the 1961 study knew exactly what shriveled up testicles meant. “If anyone wants to use a male birth control drug, I think we have identified one,” the late epidemiologist John Goldsmith recalled the toxicologist telling him about the results at a party in San Francisco in 1960. “But it is not very pleasant to use.”
The chemical industry has a history of hiding evidence of their products’ hazards, Woodruff and her colleagues showed in a paper published last year. The scientists compared previously secret internal documents from PFAS manufacturers, which were released following a lawsuit filed in 1999, to published studies, revealing that the companies knew their profitable chemicals were “‘highly toxic when inhaled and moderately toxic when ingested’ 40 years before the public health community did.”
Telly Lovelace, a spokesperson for the American Chemistry Council, said the trade group and its member companies are dedicated to the responsible production, use and management of chemical products in a manner that protects public health and the environment.
“While we have not had the chance to thoroughly review this new report, ACC has consistently advocated for the use of sound science and risk-based approaches to chemical regulation,” he said. Taking action when causality has not been sufficiently established, he added, “is inconsistent with risk-based U.S. chemical regulation law.”
California banned DBCP in 1977 and by 1979 the EPA suspended its use for all crops except pineapples until 1985, when it banned the potent endocrine disruptor for all uses. But it was still used abroad. And in the early 1990s, more than 16,000 banana plantation workers from Central America and the Philippines sued U.S. fruit and chemical companies seeking compensation for permanent sterility they blamed on DBCP, which is also recognized as a carcinogen.
The San Jose Mercury News, which covered the Lathrop case in the ’70s, noted in an editorial, “It’s a lot easier and quicker to send a man to San Quentin than to get a dangerous pesticide off the market.”
Entire classes of chemicals still in use have been linked to infertility, including organochlorines—the class DBCP belongs to—organophosphate pesticides like glyphosate, PFAS and the plastic additives phthalates and bisphenols.
DBCP is clearly toxic to sperm, and the industry knew about it but downplayed its effects, said Woodruff, who worked for years at the U.S. Environmental Protection Agency as a policy analyst.
“This fits a pattern that we have seen from the EPA, continuing today,” she said, “to approve the use of known toxic pesticides that go on to harm those that come into contact with them.”
Multiplying, Cascading Threats
Chemicals with similar structures often display similar toxic properties, so public health experts advocate regulating them as a class, which also helps address cumulative exposures.
In 2008, the National Research Council, a scientific advisory body, focused on phthalates to warn that cumulative exposures can have more harmful effects than single exposures. The council advised regulators to do cumulative risk assessments as a general rule, to protect health. Finally, last year, the EPA announced a plan for cumulative assessments of phthalates.
The U.S. Food and Drug Administration, meanwhile, denied a petition by public interest groups urging the agency to quickly reassess the safety of allowing phthalates in materials that contact food, Woodruff noted. But its approvals of the substances for use with food, she noted, relied on decades-old science.
The FDA is aware of updated information on phthalates that is publicly available, but industry stakeholders may have access to important information that is not public, an FDA spokesperson said. The agency has issued a request for scientific data and information on current food contact uses, use levels, dietary exposure and safety data for eight phthalates, which it will consider while assessing the compounds, the spokesperson said.
Scientists have measured roughly 150 chemicals in urine and blood through national biomonitoring projects and epidemiological studies. This represents a tiny fraction of potential EDC exposures, Woodruff noted, since standard methods can measure less than 1 percent of chemicals on the market.
Woodruff and her team have repeatedly urged the EPA in public comments to require manufacturers to submit reference chemicals for any compound it plans to register so health researchers can evaluate its safety. “They never respond,” she said.
The EPA did not respond to questions from Inside Climate News about why it does not require companies to submit such reference chemicals.
At minimum, health experts say, regulators should ban harmful chemicals for all but essential uses and require stricter safety testing before companies produce billions of pounds of substances that could cause irreversible harm.
The evidence clearly shows that ending the use of fossil fuels would reap enormous benefits for people and the planet. But it can be more lucrative to make plastics from the ethane released during natural gas fracking, Woodruff found, than selling the gas for transportation fuels, heating or generating electricity.
That explains why global chemical manufacturing is expected to double by 2030, with petrochemicals accounting for more than a third of the growth in oil demand. And by 2030, the market research firm SNS Insider projects, the $2.9 trillion chemical industry is expected to be worth $4.66 trillion.
I think most people don’t realize the chemical industry makes so much money off of all these chemicals we’re exposed to, Woodruff said.
As the fossil fuel industry focuses more on petrochemicals, she expects to see rates of disease from exposure to these toxic compounds continue to rise.
A person’s biology and age shapes their ability to withstand environmental insults. But low-income communities of color must contend with multiple factors shaped by decades of unjust economic and discriminatory policies that increase risk.
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Redlining policies have left these communities disproportionately at risk from toxic exposures—they account for the majority of those living near the thousands of U.S. facilities that make or handle dangerous chemicals—by limiting their opportunities to leave heavily polluted neighborhoods, while poverty, racism, food insecurity and lack of access to nutritious foods, medical care and economic opportunities reduce their bodies’ resilience.
Yet courses on environmental links to disease are not required in medical school, even though two National Academy of Sciences reports from the 1990s said the training was “really important,” Woodruff said.
So Woodruff devoted a special section of the review to helping health professionals recognize the tsunami of environmental risks their patients may face and identify ways to minimize them. It’s been an uphill battle.
U.S. regulators do not require monitoring for exposure or health effects for most chemicals, leaving researchers scrambling to evaluate the potential harms of the 70 percent of chemicals for which no such data are gathered.
There is no doubt in Woodruff’s mind that physicians and researchers are underestimating the influence of environmental chemicals on health.
The Environmental Defense Fund’s Gohlke appreciates Woodruff’s call to incorporate environmental health in medical training. But ultimately, both scientists said, most exposures are beyond individual control.
Both Woodruff and Gohlke believe scientists, physicians and anyone concerned about chemical exposures should push for policies that reduce fossil fuel dependence and production of harmful endocrine-disrupting chemicals.
“Reducing fossil fuel use generally is going to be a win-win,” Woodruff said. “A win for the climate and a win for our health, in multiple ways.”