Scientists now say we are just beginning to understand the damage done to the human body by the tiny pieces of plastic we drink, eat and breathe.
But newly discovered documents from chemical companies dating back decades show that industry scientists have long been aware of — and concerned about — how microplastic particles migrate beyond the guts of animals and humans, depositing in important organs. And the potential of this knowledge to affect the plastic food packaging industry.
Their concern dates back to 1974, at a scientific meeting in a New York hotel, where a German gastroenterologist presented a scientific paper showing for the first time that ingested particles like microplastics could leak into the rest of the body.
His presentation was largely ignored by the government scientists in attendance, but became a topic of anxious discussion among company scientists.
A “horror story” is how one business executive described how this research was received.
The word “microplastic” had not yet been coined, but Berlin researcher Gerhard Volkheimer showed that tiny pieces of swallowed PVC plastic could pass through the intestinal lining of animals and travel through the blood and lymph to the brain, liver and other internal parts of the body.
According to Matthew Campen, a professor of pharmaceutical research at the University of New Mexico and a leading researcher in the field of microplastics and human health, the same process applies to any small impermeable particle, including polyethylene, polypropylene and PET, the plastics that dominate today’s market and the microplastics found in the human body.
The presence of these particles in the human body has been linked to heart disease, inflammation and cancer.
Internal memos from scientists and company executives obtained by The Times reveal that for at least half a century, the plastics industry has been aware of and concerned about the potential for microplastic contamination in the human body.
The sidewalk near the iconic pink wall of the Paul Smith store on Melrose Avenue is littered with plastic cups and other single-use plastics in Los Angeles.
(Jason Armond/Los Angeles Times)
Tracey Woodruff, a professor of epidemiology and population health at Stanford University who reviewed the documents, said they indicate that scientists and executives of large chemical companies were aware and remained silent even as microplastics accumulated in tissues. She compared it to other industries that knew about the pollutants — greenhouse gases, asbestos and tobacco — but hadn’t taken steps to make them safer.
A spokesperson for the chemical industry’s largest trade group disputed that characterization.
“The scientific debate about what the evidence shows is not silence. It’s about how sound science and effective policy advance,” said Craig Davis, senior director of plastics chemistry at the American Chemistry Council. “Our industry is committed to advancing the science of microplastics by supporting independent research and policies that would contribute to it. »
He said the trade group supported a Congressional bill that would “improve scientific methods and enable gold standard science” on microplastics and highlighted its funding of the Microplastics Advanced Research and Innovation Initiative, founded in 2022 by the International Council of Chemical Associations.
The Plastics Industry Association. did not respond to requests for comment.
A significant meeting
In 1974, Irving Selikoff, a renowned toxicologist and physician at the Mount Sinai School of Medicine, hastily convened a meeting of toxicologists, union representatives, health officials, and industry executives, hosted by the New York Academy of Sciences—one of the nation’s oldest independent scientific organizations. Selikoff had denounced the dangers of asbestos a decade earlier.
This meeting was intended to address a pressing workplace issue.
Three months earlier, a doctor at BF Goodrich Co., a manufacturer of PVC plastics, identified a group of workers at a Kentucky factory with a rare and deadly form of liver cancer, angiosarcoma. Other cases quickly followed in West Virginia, New York and Pennsylvania. Federal agencies and the plastics and petrochemical industries rushed to respond.
The National Institute for Occupational Safety and Health and the Environmental Protection Agency were both new, established only in 1970. They had few scientists on staff and had no research history; they lacked the data needed to assess an unfolding disaster, much less control it.
At the time, PVC and vinyl chloride monomer – the raw ingredient of PVC – were used in a variety of household and industrial items and deemed safe by regulators and manufacturers. PVC was used to make food packaging as well as water pipes. Vinyl chloride – which usually comes in a gaseous form – was used as a propellant for lacquer, spray paint and pesticides.
“Everyone considered it safe, and it came as a shock,” said Henry Falk, a former deputy surgeon general and now an assistant professor at the Emory Rollins School of Public Health in Atlanta, who was at the meeting. The outbreak has shattered “the illusion of safety for these types of chemicals.”
At the time, Falk was a young investigator in what was then called the Center for Disease Control. It also helped identify clusters and solidify evidence linking the chemical to deadly liver cancer.
Of the 289 conference attendees, a third came from industry — Dow Chemical, Exxon Corp., Monsanto and others — and the rest came from the federal government, labor unions, academia, scientific societies, nonprofits and consulting firms.
Philip Landrigan, one of the world’s leading microplastic researchers, a pediatrician and director of the Program for Global Public Health and the Common Good at Boston College, was in attendance. He was 32 years old and also worked at the Center for Disease Control.
He doesn’t remember much about the meeting, other than that it attracted people from all over the world – Japan, Sweden and Romania – and that there was an urgency in the air.
He has no memory of Volkheimer’s presentation. Neither does Richard Lemen, also at Emory, and former deputy director of NIOSH. Neither does Falk.
For the three young scientists, it was the stars who made their mark: the renowned toxicologists and oncologists, as well as the epidemiologist who was the first to link smoking to health problems, Sir Richard Doll.
Volkheimer was the final speaker in the session “Toxicological Investigations of Vinyl Chloride-Polyvinyl Chloride; B. Experimental studies”. The researcher, who has published mainly in German, presented his work on a physiological process called persorption.
He conducted research at the Charité in Berlin – one of the oldest and most prestigious university hospitals in Europe – and showed that solid particles move through the intestinal lining when ingested, and then into the rest of the body. Since the 1950s, it has fed animals and sometimes humans small particles of potato and corn starch, iron flakes, oatmeal, pollen and PVC.
He carried out his experiments on dogs, pigs, goats, rats, guinea pigs, rabbits and chickens. For the purposes of this meeting, he highlighted studies in which he fed them microscopic PVC particles.
Within two hours of ingestion, he found that the particles had traveled to the lymphatic system, blood and organs, including the brain, liver, lungs and muscle tissue. He also found small flakes of PVC in cerebrospinal fluid – the watery fluid that circulates through and around the brain and spinal cord – as well as in breast milk.
He confirmed that the particles crossed the placenta. Caffeine and nicotine increased the speed and volume of movements in the intestine. Sleep too. They also moved faster in younger creatures.
He used potato starch as a substitute in humans, after showing in previous studies that it behaved similarly to PVC.
Volkheimer called them microparticles or simply “PVC particles”. The term “microplastics” was only coined in 2004, when a British researcher described small plastic particles he found in waters off the coast of the United Kingdom.
And even if the young government investigators present on site do not remember the speech, the leaders of several chemical and plastics companies took note.
After heavy rains in recent days, a great blue heron and other waterfowl search for food among runoff debris trapped in a trash dam in the Los Angele River in Long Beach in 2024.
(Allen J. Schaben / Los Angeles Times)
Ripples within an industry
In the weeks, months and years that followed, plastic, chemical and fossil fuel companies referenced the presentation and discussion, according to documents reviewed by The Times. The documents, mostly produced by companies in lawsuits over tobacco, asbestos and industrial chemicals, are publicly archived in the UC San Francisco Industrial Documents Library and in ToxicDocs, a project of Columbia University and the City University of New York.
On May 17, 1974, an executive with Firestone Plastics Co. – a division of Firestone Tire and Rubber Co. – wrote a memo summarizing the meeting for company president Todd Walker and said “that when PVC (not VCM) was fed to animals, it was retained by various organs.” VCM is the acronym for vinyl chloride monomer.
Shell Oil Co. industrial hygiene manager Howard Kusnetz sent a summary of the meeting to the company’s medical director, Roy Joyner, and others. Kusnetz knew the federal side well: until 1971, he had been deputy director of NIOSH, before Shell hired him to build its industrial hygiene program. “Volkheimer claims that these particles have also been found in the spinal fluid of dogs,” he writes. “Volkheimer noted that it takes four minutes for starch to appear in the blood after ingestion, peaking at 10 minutes.”
In a 1975…
Gn Health
