The common belief within the toxic illness community seems to be that women are more likely than men to develop the condition. This belief is reinforced by the fact that online support groups appear to have a greater percentage of female than male participants. I was somewhat surprised, then, to read an article this week that detailed ways in which boys may be more vulnerable to environmental pollutants than their female counterparts are.
The article, published in Environmental Health News, makes the following points:
- There’s a stronger link between air pollution and autism in boys.
- The insecticide chlorpyrifos, found in Dursban and other products, seems to reduce the IQs of boys more than girls.
- Boys are more susceptible to damage from low-level lead exposure.
- Phthalates, found in vinyl and many other products, have been linked to larger behavioral changes, primarily aggression and attention disorders, in boys
- A study found that high in-utero exposure to Bisphenol A (BPA), another ubiquitous chemical, caused hyperactivity, aggression, and anxiety in boys, but not girls. The boys were also born with lower thyroid hormones, while female levels were normal.
The author explains the findings by noting that the pre-birth development of a female is simpler than that of a male. It takes a greater number of cell divisions to make a male, and with each division comes a greater vulnerability to toxic exposures.
After birth, these vulnerabilities continue. In females, the XX chromosome offers a bit of back-up protection, with a healthy X able to take over for one with a genetic defect. Males, with their XY makeup, have no such backup system. The article also notes that X chromosomes carry more genetic information, so the XY combination may mean a loss of brain development proteins or repair mechanisms.
In addition, estrogen protects the brain. Their lower estrogen levels mean that male brains are more fragile and prone to injury. Hormone imbalances may contribute to a wide range of chemical-related health effects, because many chemicals are endocrine disruptors which suppress or mimic hormones.
If it’s true that the common belief is that women are more vulnerable to chemical illness and the truth is the opposite, why is that? Perhaps it’s because we still have a lot to learn as a culture about all the possible symptoms that toxic exposures can cause. There will always be differences between boys and girls, but maybe some of the “natural boy” traits we’ve assigned to the gender, such as aggression, hyperactivity, and lack of focus, aren’t entirely natural after all.