A study presented yesterday at the Experimental Biology 2005 conference in San Diego revealed that many autistic children have low levels of glutathione, an antioxidant that protects against cell damage from oxygen free radicals.
According to the Boston Globe,
The finding is suggestive… because glutathione… is crucial for neutralizing toxic heavy metals such as mercury. [Lead author S. Jill James said,] “One interpretation of this finding is that children with autism would be less able to detoxify and eliminate these heavy metals.”
There is a long-running controversy about whether mercury contributes to autism, and I’ve posted recently about another study that demonstrated a correlation between autism and mercury emission levels in Texas school districts.
Assume for a moment that the findings from the new study hold up, and that a small percentage of people are vulnerable to low levels of mercury in the environment. It provokes some serious questions for environmental regulation:
- Do we try to set mercury emissions levels so low that no one is harmed? Do we attempt to balance economic benefits with harm done to peoples’ health?
- Do we expect everyone to get tested to learn their predisposition to mercury poisoning and take steps on their own to avoid mercury (e.g., from fish)? Who pays for the testing?
There are close parallels in pharmaceutical safety:
- How many moderate, severe, and fatal side effects should we tolerate before a drug that works for some people is pulled from the market?
- With the advent of pharmacogenomics, can we identify the people who would be harmed by a drug and help them avoid it? Who will pay for the tests?