Autism linked to PCBs (thank you, Monsanto)
By Jeremy Bloom
We’re still a long way from finding out what causes autism, but a new study seems to have identified one piece of the puzzle: Exposure to a class of chemicals called PCBs (Polychlorinated Biphenyls).
The researchers were able to examine records of women who had had blood drawn during pregnancy to assess whether there were PCBs present (the tend to stay in the system and build up after being ingested), and correlate PCB presences with later Autism diagnosis.
It was determined that two compounds in particular — PCB 138/158 and PCB 153 — stood out as being significantly linked with autism risk. Children with the highest in utero levels (exposure during their mother’s pregnancy) of these two forms of PCBs were between 79 and 82 percent more likely to have an autism diagnosis than those found to be exposed to the lowest levels. High levels of two other compounds, PCB 170 and PCB 180, were also associated with children being approximately 50 percent more likely to be diagnosed — again, this is relative to children with the lowest prenatal exposure to these PCBs.
They also found that lower exposure increased the risk of children being diagnosed with intellectual disabilities.
PCBs are a potent neurotoxin and were banned in 1979, but were so widely used in the previous 50 years that they remain ubiquitous – from spilled PCBs that still contaminate the Hudson River, to insulation in electrical transformers all over the world.
Who manufactured PCBs? Before they switched over to agribusiness (at the behest of a corporate makeover consultant named Mitt Romney), the largest US PCB manufacturer was our old friend Monsanto.
Think Progress reported:
In a 1970 internal memo, agrochemical giant Monsanto alerted its development committee to a problem: Polychlorinated Biphenyls—known as PCBs—had been shown to be a highly toxic pollutant.
PCBs—sold under the common name Aroclor—were also huge business, raking in some $10 million in profits. Not wanting to lose all of these profits, Monsanto decided to continue its production of Aroclor while alerting its customers to its potentially adverse effects. Monsanto got out of the PCB business altogether in 1977—two years before the chemicals were banned by the EPA—but just because the company no longer produces the toxic substances doesn’t mean it can forget about them completely.
“We know Aroclors [PCBs] are toxic but the actual limit has not been precisely defined,” stated one document, dated September 20, 1955…