3 April 2014. Arsenic is one of the three trace elements (the others being lead and mercury) that have served as paradigm brain drainers. Whole generations of children have suffered adverse effects during brain development. However, little attention has been paid to the neurotoxic risks from contaminated drinking water outside of the countries with the most serious problems, such as Chile, Bangladesh, India, and China.
New research from the United States now reports brain toxicity associated with arsenic in drinking water in the state of Maine. The study included 272 children in grades 3-5 from three school districts. Although few children had stayed at their present home for their entire life, they had lived there for an average of 7.3 years. Thus, the current water-arsenic content is a reasonable reflection of the children’s life-time exposures. After adjustment for other factors, a higher arsenic level was negatively associated with Full Scale IQ as well as with Perceptual Reasoning, Working Memory and Verbal Comprehension scores.
The exposure levels in Maine were much lower than those that are common, e.g., in Bangladesh. Nonetheless, children exposed to arsenic concentrations above 5 µg/L had a 5-6 point lower average IQ, a difference that is statistically significant. Nearly 20 percent of private wells in Maine exceed this level, which is half of the current U.S. EPA limit for public drinking water supplies. However, there is no federal mandate for concentrations in private wells, and no testing is required.
Very little is being done to remedy the fact that drinking water at many locations contains a documented brain drainer. One can understand that the cholera epidemics in south-east Asia generated an acute need for safe drinking water and that chemical contamination was ignored at first (see “Only one chance”, Chapter 5). But increased arsenic concentrations occur in drinking water in many parts of the United States as well as in other countries like Argentina, Canada, Denmark, Hungary, Japan, Mexico, New Zealand, Poland, Spain, and Sri Lanka.
Ignoring arsenic in drinking water is even more surprising, as remedies are available that are much less expensive than digging new wells or piping in water from other locations. A filtration system that removes the arsenic costs $800 for each household, and replacing the filter adds more than $100 every several months, depending on the arsenic content and the amount of water used. But compared to a loss of 5 IQ points, this expense seems trivial.