Environment and autism; and opposition to TPP

 Dear EarthTalk: What is the latest thinking on the environmental causes (if any) of autism? I hear so much conflicting information I don’t know what to believe.

Bill Stribling

Austin, Texas

In the 1980s, about one in 2,000 American kids was diagnosed with autism. Today the number is around one in 68, according to estimates from the U.S. Centers for Disease Control and Prevention’s Autism and Developmental Disabilities Monitoring Network. This disconcerting increase has led to intensified examination into what environmental factors may play a role in the disorder’s development. A wide range of exposures have been scientifically linked to autism, including air pollutants, phthalates and other endocrine disruptors, pesticides such as Chlorpyrifos, and many more. Vaccines were considered a leading culprit, but more recent research has proven this connection wrong — although the subject still engenders much debate.

A 2014 study by researchers at the Harvard School of Public Health found a strong link between autism and in utero exposure to air pollution: the risk of autism was doubled among children of women exposed to high levels of particulate air pollution during pregnancy. Another 2014 study out of the University of California, Davis determined that pregnant women living in close proximity to fields and farms where chemical pesticides are applied experience a 66 percent increased risk of having a child with autism or a developmental delay. The advocacy group Autism Speaks, which contributed to the funding of the Harvard study, believes that despite all the emerging data linking toxic exposures to autism, no environmental influence appears to cause or prevent autism by itself — rather they appear to influence risk in those genetically predisposed to the disorder.

“It’s important to remember that not all mothers exposed to air pollution during pregnancy will have a child with autism and not all children with autism were necessarily exposed to air pollution in utero,” said epidemiologist Michael Rosanoff, associate director for public health at Autism Speaks. “We know autism is a complex disorder and underlying genetic and biological factors interact to influence susceptibility. The next step is to identify the biological mechanisms that connect air pollution to autism and identify ways to treat if not prevent the harm to brain development.”

While many studies linking environmental toxins and autism have been inconclusive, one developing research approach appears to hold great promise. Remarkably, fallen baby teeth can be used to track a child’s prenatal and infant exposure to chemicals — thus allowing scientists to determine what environmental causes may have contributed to the disorder’s development.

“As a result, we can use teeth like an archeological record,” says Dr. Raymond Palmer of the University of Texas Health Science Center. “The enamel of different types of teeth begins to form at different points during prenatal development. In infancy, the enamel continues to absorb chemicals circulating through the baby’s body.” Palmer says the greatest insights from dental analysis may come from looking at chemical exposures along with gene abnormalities, which may affect one’s vulnerability to potentially toxic chemicals. “It’s not necessarily genes or environment,” he adds. “It’s likely to be both.”

Alysson Muotri at the University of California San Diego Department of Pediatrics is using teeth analysis to identify gene abnormalities in children with autism, even in cases with no previous known genetic cause. Parents of an 8-year-old autistic boy mailed Muotri’s team one of the boy’s baby teeth, and the researchers were able to detect a mutation in a gene known as TRPC6. The researchers treated the autistic boy with hyperforin, the active ingredient in St. John’s Wort. Dental analysis could potentially lead to personalized treatment for autism, whether the cause be identified as genetic, environmental or both.

Contacts: CDC Autism Spectrum Disorder Page, www.cdc.gov/ncbddd/autism/; Autism Speaks, www.autismspeaks.org; Muotri Lab at UCSD, www.pediatrics.ucsd.edu/research/muotri-lab; UT Health Science Center, www.uthscsa.edu.

Dear EarthTalk: Why do many green groups oppose the Trans-Pacific Partnership (TPP) governing trade in the Pacific?

Jane Donahue

Larchmont, N.Y.

The Trans-Pacific Partnership (TPP) is an international agreement that seeks to unite the economic interests of 12 countries that border the Pacific Ocean by lowering trade tariffs and establishing an international trade court to settle disputes. TPP emerged as a West Coast equivalent to the proposed Trans-Atlantic Trade and Investment Partnership, designed to ease trade restrictions between the U.S. and Europe. But TPP has progressed much faster thanks to the willingness of Pacific nations to “play ball.” 

International negotiators released a draft of the TPP agreement in October 2015 and are awaiting approvals from participating governments. However, despite the theoretical advantages of more fluid international trade, the current draft has several complications that could lead to a variety of problems for participating nations and others, meaning its implementation is far from a sure thing at this point.

Green leaders criticize the Obama administration and negotiators from other countries for keeping early talks on the formation of the TPP closed to observers and media. Many individuals and public interest groups requested access to the discussions, fearing that the agreement would unfairly favor large corporations. However, those appeals were ignored and the drafted document revealed what many feel was a prioritization of corporate interests over health and environmental concerns. Without any enforceable guarantees for environmental protection, the TPP could actually significantly contribute to global warming through increased exportation of U.S. fossil fuel supplies.

Additionally, differences in national policies regulating chemical use, artificial fertilizers and seeds from genetically modified organisms (GMOs) have yielded an agreement that encourages minimal protection. The nonprofit Public Citizen points out that existing U.S. regulation of pesticide and GMO labeling on packaging could be challenged in the international court as “trade barriers.” Another point of contention is the distinct advantage given to foreign corporations under the current TPP model. Overseas firms would be able to sue the U.S. government over new policies that disrupt the company’s “expectations.”

Perhaps more troubling is what’s not included in the document, which fails to mention how it will protect from over-harvesting of limited natural resources. Green groups point out that, while the TPP accounts for nearly a third of global fish harvest, there are no provisions to protect against overfishing. The draft also barely mentions enforceable safeguards of endangered species products, such as elephant ivory. 

Yet another issue critics say is woefully ignored is social justice. With free-trade opening up, even more American jobs would be sent overseas to reduce costs. Economists estimate that 5 million U.S. jobs could shift oversees under the TPP, resulting in serious pay cuts for American workers. Meanwhile, the richest 10 percent would profit at even higher rates, adding to an already drastic U.S. wealth inequality. 

Clearly, the current draft of the TPP agreement needs a lot of work before Congress should even consider it. Those opposed to the current version of the TPP can voice their dissatisfaction by signing onto the Stop the Trans-Pacific Partnership petition on MoveOn.org, or by urging your representatives in Congress to vote against it altogether.

Contacts: TPP Page, https://ustr.gov/tpp; Public Citizen, www.citizen.org; MoveOn.org’s Stop the Trans-Pacific Partnership Petition, petitions.moveon.org/sign/stop-the-trans-pacific.

EarthTalk is produced by Doug Moss and Roddy Scheer and is a registered trademark of Earth Action Network Inc. Email questions to earthtalk@emagazine.com.