Environment and Developmental Disorders

The August 2014 Scientific American article, “A New Kind of Inheritance” got me thinking about the tragedies of autism and similar developmental disorders. Autism is a fearsome condition which seems to have no attributable cause and no effective treatment. In too many cases, children are sentenced to a disability that thwarts a promising life, including extra care needs by parents, and communication disorders.

In other words, its cause and cure have stumped science, helping to launch suspicion and distrust of once accepted common practices, such as, for example, vaccinations against diseases like measles and smallpox. Looking for its cause and fearful of its occurrence in their young, parents are looking for answers, answers not forthcoming from scientists and doctors whom parents figure should know.

With soaring diagnosis of the disease, many parents are driven to refuse inoculations for their children, a practice that even serious medical practitioners have – at one time — suggested could be associated with disorders like autism, whose roots lie in the development of the human brain.  Other scientists had associated environmental influences, such as exposure to chemicals and the stresses of urban life with autism, but such connections seemed sketchy at the time. Now such environmental ties are more effectively made.

Without naming specific conditions like autism, this Scientific American article provides revelatory research about “epigenetic” changes being passed down to – and causing disease in – future generations, all due to environmental effects of harmful chemicals and stress situations. “Biologists have debated whether epimutations – abnormal epigenetic changes – can be passed down through many generations in mammals1,” Michael K. Skinner states. But his experiments strongly suggest epimutations can be transmitted through many generations.

In other words, epigenetic (epi, a prefix meaning over or above) and (genetic, that which we inherit in genes) information is present in our chromosomes. But epigenetic information is separate from DNA sequence and is affected by the environment. Such information is often carried in small molecules chemically attached to the DNA or to protein structures in chromosomes. Research on rats and mice show that exposure to certain pollutants, those identified as endocrine disruptors, can cause disease and reproductive problems, this without changing the animal’s DNA.

The greatest risk of exposure to such chemicals (the list includes some pharmaceuticals, dioxin, DDT, pesticides, jet fuel, detergents, some cosmetics, some toys, and plasticizers) is during prenatal and early postnatal development when organ and neural systems are forming.
Accordingly, exposure can be widespread, considering that recent blood tests of pregnant women revealed the presence of endocrine disruptors in 99% of the women. Add the research that shows epimutations can be passed down through generations, and we open the possibility of troubling developmental risks for many in our current and future generations.

Consider how we treat our planet like a dumping ground. For example, jet fuel, recognized as a harmful chemical in the endocrinal mix, is sometimes dumped in areas where planes land.  If a strong jet stream saves hundreds of gallons of fuel on a long trip, pilots may choose to dump fuel in order to “land light.” Hundreds of gallons amount to thousands of pounds of weight. In many ways such as this, we, without much thought, add to chemical exposure.

The epigenetic research was done using mice, but some studies did involve people tragically exposed to suspect chemicals. Like I said no distinct part of the study specified autism but did mention widespread issues such as the obesity epidemic, sexual abnormalities, pubertal abnormalities, and diseases of the ovaries, kidneys and prostate. But this was all in mice, relating to exposure to the pollutant dioxin, jet fuel, insect repellent, or chemical components of plastics in food containers and tooth fillings.

In 1976 an explosion at a chemical plant in Seveso, Italy, exposed some residents to the highest concentrations of dioxin ever recorded in a public release of this chemical. A long term study of 1000 women exposed to the chemical reported in 2010 that for those with a 10-fold exposure, the average time to get pregnant rose by 25% and the risk of infertility doubled. By 2013 women younger than 13 years at the time of the accident, had double the normal risk of developing metabolic syndrome – like elevated blood pressure and blood glucose and also had abnormal results on thyroid tests for granddaughters.

All studies have not been focused enough to even cite autism relationships, but do show a distinct connection of pollutant exposure and reproductive and metabolic disorders, and we are talking about long-term generation to generation causes and connections.

This particular study even seems to tie practices like fogging with DDT, a common mosquito-control practice in the 1940s and 1950s, with present disorders in current generations. It suggested that such practices in the distant past might have caused epimutations that persist in some babies even born today.

Too many with an agenda in contemporary culture try to minimize the message and influence of science, even stifle research that is sorely needed. One day, detractors of science may find that science can help explain impairments in the health of their own children, perhaps even point to actions that can ensure humankind’s continued survival.

And one of the most daunting conditions to strike the young might have answers – a cause, a treatment, and hopefully even prevention. But such focused research might lead to more environmental constraints on practices that contribute to record profits among large corporations.

  1. Michael K. Skinner, Scientific American, August 2014, page 46. []

James Hoover is a recently retired systems engineer. He has advanced degrees in Economics and English. Prior to his aerospace career, he taught high school, and he has also taught college courses. He recently published a science fiction novel called Extraordinary Visitors and writes political columns on several websites. Read other articles by James.