Swine Flu Susceptibility Linked to Arsenic Exposure

Josh Hamilton, Ph.D.,
Marine Biological Laboratory and Dartmouth Medical School
NIEHS Grant P42ES007373

Low-level exposure to arsenic at concentrations found commonly in US drinking water compromises the initial immune response to H1N1 or swine flu infection according to NIEHS-supported scientists. The study, conducted in laboratory mice, suggests that people exposed to arsenic in their drinking water may be at increased risk for more serious illness or death in response to infection from the virus.

Laboratory mice were exposed to arsenic at a concentration of 100 parts per billion in their drinking water. The mice initially showed a weak immune response to the virus, and when the immune response fully developed, it was “too robust and too late” according to the study’s senior author, Josh Hamilton. The late influx of immune cells to the lung and the inflammatory response caused lung damage and bleeding not seen in the control animals. Over the course of the infection, the death rate in arsenic exposed animals was much higher than the non-exposed mice.

The current US EPA drinking water standard is 10 parts per billion; however, 100 parts per billion levels are commonly found in well water in areas where arsenic is geologically abundant such as New England, Florida, large portions of the Midwest, the Southwest, and the Rocky Mountains. The study authors also point out that high levels of arsenic in drinking water are common in the areas of Mexico where swine flu was initially reported.

Citation: Courtney D. Kozul, Kenneth H. Ely, Richard I. Enelow, and Joshua W. Hamilton. Low Dose Arsenic Compromises the Immune Response to Influenza A Infection in vivo. Environ Health Perspect. doi: 10.1289/ehp.0900911.