On ‘Eating Arsenic’

Thanks for a May 6 issue so chock-full of interesting and useful articles. I’d like to comment on “Eating Arsenic” (page 36). My small community in California was forced by the state to install two arsenic-removal systems a few years ago, at a cost of about $20 million, because a couple of our wells were a little over the arsenic maximum allowed by law.

This is what I recall on the standard-setting process: President Bill Clinton’s National Academy of Sciences’ committee looked at data from around the world on cancer incidence versus arsenic levels in the water and found that only two data sets had any significance—one from Taiwan and one from Bangladesh. The committee drew a line through those two data points and extrapolated to zero. Then they picked an arsenic level “standard” that corresponded to about the same incidence of skin cancer caused by exposure to the sun.

I wonder what standard we would choose after correcting those data for cancers caused by eating arsenic-laced rice in Taiwan and Bangladesh. I understand that arsenic gets into the rice from the water, but surely people in those countries eat more rice per capita than people in our little town. But maybe we drink more water?

Geoffrey Lindsay
Ridgecrest, Calif.