When the phenomenon of toxic exposures first hit the popular culture, it was all about cancer risks. This or that chemical or product increased your cancer risks. Cancer risks still define the way the EPA regulates chemicals with a theoretical safe threshold of one cancer case in a million. Cancer is the headliner of environmental health impacts. It's the bluntest short cut to labeling a substance as toxic.
But the last twenty years of research have been all about examining the less well-known, but perhaps more insidious non-cancer impacts on the human body of toxic chemical exposures. Damage to immune systems that then lead to more serious illness, links to debilitating diseases like Parkinson's and Alzheimer's, more abrupt consequences like strokes and heart attacks. And birth defects.
Birth defects are one of the most underrated impacts of toxic exposure, but they're capable of slowly but surely changing the characteristics of humanity itself.
There is now a whole new school of study, "Epigenetics," that didn't even exist a decade ago. It examines how damage of a person's DNA, or the factors influencing how that DNA works, are passed down to subsequent generations. Such damage can skip a generation, or two, so that your grandfather's or great grandfather's exposure to really bad stuff at his workplace affects your DNA and physiology today.
By allowing so many untested chemicals into the marketplace and making citizens swim through them as they go about their lives, industry and government are conducting a planet-size laboratory experiment that we are always trying to understand after the fact.
Another example of new knowledge is the discovery and labeling of certain chemicals as "Endocrine-Disruptors." Before the mid-1990's, we didn't even have such a phrase.
Our endocrine system is the network of glands and hormones that regulates many of the body's functions, including growth, development and maturation, as well as the way various organs operate. The endocrine glands — including the pituitary, thyroid, adrenal, thymus, pancreas, ovaries, and testes –– release carefully-measured amounts of hormones into the bloodstream that act as natural chemical messengers, traveling to different parts of the body in order to control and adjust many life functions.
Endocrine disruptors are chemicals that interfere with that signaling and regulation of body functions, and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife. They include Dioxins, Phthalates, DDT, PCBs, and Bisphenol A (BPA), and pose the greatest risk during prenatal and early postnatal development when organ and neural systems are forming.
Past studies of the effects of endocrine disrupting chemicals have often focused on the vulnerablity of reproductive systems to exposure to endocrein disruptors, producing the now familiar stories of male fish with female characteristics or via versa. In uterus, a fetus' chemical wiring can be crossed or short-circuited.
A new study from France involving over 600 boys looks to add to this trend, concluding that a expectant mother's exposure to Endocrine-disrupting chemicals raises the risk to a specific male birth defect, Hypospadias, by almost 70%.
Hypospadias is a condition where the opening of the urethra is on the underside of the penis rather than at the tip. The defect, which can be minor or quite severe depending on how far the opening is from the tip, can lead to problems with urination and, later in life, sexual difficulty.
The risk for those boys whose mothers were exposed to Endocrine disrupting chemicals was 68 percent higher than the unexposed boys. The researchers ruled out baby boys with known genetic risks for such defects. Working with hormone disrupting chemicals and living in homes near heavy polluters were both linked to more baby boys having the defect. Mothers were most likely to have boys with hypospadias if they worked as a cleaner, hairdresser or beautician. However, the researchers did say a limit of the study was attempting to estimate fetal exposure to such chemicals.
In a previous study, mothers in southeast England who were heavily exposed to endocrine disrupting phthalates on the job were about three times more likely to have a baby boy with hypospadias. Phthalates are used in some cosmetics, fragrances, food packaging and PVC plastics.
Hypospadias is one of the most common genital defects in baby boys, and most cases require surgery, often done before they reach two years old. In the United States, an estimated five out of 1,000 boys are born annually with hypospadias, while Europe’s rate is slightly less than two out of 1,000. “Nobody dies from hypospadias," said one of the researchers. "Most are cured with surgery, but if we can come up with some kind of prevention protocol, it could prevent a lot of surgeries and anxiety for families.”