In studies involving the drug diethylstilbestrol (DES), the scientific community was compelled to acknowledge the very real possibility that toxic exposure could have trans-generational effects. DES was a synthetic estrogen, manufactured by a number of pharmaceutical companies between the 1940s and 1970s designed to prevent miscarriages.
Unfortunately, the drug has had a devastating effect on the female offspring (and possibly even the grandchildren) of women who took DES. Cancer, infertility, and other permanent injuries have been linked to DES. There is also growing suspicion that DES may also have had adverse effects on male children of DES mothers.
Now, an animal (rat) study published in the journal Science has produced evidence that certain toxins may poison and pass diseases down for up to four generations. The researchers from Washington State University (led by Dr. Michael Skinner) exposed pregnant rats to a commonly used vineyard fungicide (vinclozolin) and a pesticide (methoxycchlor) during the period when the sex of the offspring was being determined. The exposed rats produced male offspring with low sperm counts and impaired fertility.
When these offspring were mated with healthy females, the male offspring had the same problems. This pattern persisted through at least four generations and affected over 90% of the male offspring in each of those generations. Dr. Skinner believes diseases like breast and prostate cancer, which are becoming more common, may be linked to similar trans-generational toxic exposure. It may also mean that exposure to environmental toxins may play an important role in the evolutionary process itself.
Since the levels of toxic exposure in the study were very high, the extent to which the effect may be concentration related is unclear. Thus, research needs to be done with much lower doses. Nonetheless, Dr. Skinner sees the study as "a new way to think about disease."