Coordinator, CHE’s Diabetes – Obesity Spectrum Working Group
This essay is reprinted with the author’s permission from her website: Diabetes and the Environment. See also CHE’s March 11th Partnership call: The Link Between Arsenic Exposure and Diabetes: A Review of the Current Research
Arsenic can be found naturally in drinking water. Millions of people worldwide rely on drinking water sources containing arsenic; in the U.S., about 13 million people live where arsenic levels in public drinking water supplies exceed the U.S. Environmental Protection Agency’s standard (Navas-Acien et al. 2008). In 2001, the US EPA lowered the drinking water standard for arsenic from 50 µg/L to 10 µg/L (10 ppb) (EPA). Arsenic has also been found in food, such as rice and conventional chicken (Nachman et al. 2013).
High Levels of Exposure: Human Studies
Numerous studies of people exposed to arsenic from Taiwan, Bangladesh, Mexico, and Sweden have shown that high levels of arsenic are associated with diabetes (Navas-Acien et al. 2006; Coronado-Gonzalez 2007; Del Razo et al. 2011), including one long-term prospective study (Tseng et al. 2000). A meta-analysis of data from 17 published articles with over 2 million participants found that arsenic in drinking water and in urine was associated with diabetes, with a 13% increased risk for every 100 µg arsenic/L in drinking water (Wang et al. 2014).
A review of the evidence by a panel of experts convened by the U.S. National Toxicology Program (NTP) concluded that, “Existing human data provide limited to sufficient support for an association between arsenic and diabetes in populations with relatively high exposure levels (≥ 150 µg arsenic/L in drinking water)” (Maull et al. 2012). (In science-speak, that is actually pretty strong evidence).