In January 2016, the Alaska Section of Epidemiology (SOE) received a report of a markedly elevated urine total arsenic concentration (500 ug/L; normal <35 ug/L) from a resident of Community A, located in the greater Fairbanks area. This person’s well water was subsequently tested and found to be 1,000 ppb of arsenic. By comparison, the Maximum Contaminant Level (MCL) of the Environmental Protection Agency (EPA) for public water systems is 10 ppb. These concerning findings prompted a public health investigation to determine if other community residents might be exposed to harmful arsenic levels from their well water.
METHODS:
SOE collaborated with the Section of Public Health Nursing (SOPHN), the Department of Environmental Conservation, and the Department of Natural Resources to organize a public meeting in Community A on March 16, 2016 to inform residents about naturally occurring arsenic, its potential health effects, and water treatment methods. Over the next two days, SOE and PHN staff visited a convenience sample of homes in Community A to assess residents’ arsenic exposure. The team administered a questionnaire to household members, characterizing each household’s drinking water source, and collected drinking water and urine samples for arsenic testing. Samples were analyzed at the Public Health Laboratory in Anchorage.
RESULTS:
The team visited 68 homes, thirty of which were empty at the time of visit; 19 homes reportedly had no well. From the remaining 19 homes, 36 residents reported drinking well water. From these homes, the team collected 32 urine samples and 19 water samples. Three wells had arsenic levels 20- to 110-times higher than EPA’s MCL. Four residents belonging to two of these households had high urine arsenic levels ranging from 200 to 1150 ppb. Three of the people with the highest levels were already aware that their well water had elevated arsenic concentrations and were treating it by reverse osmosis.
CONCLUSIONS:
This investigation identified several private wells in Community A with concerning arsenic concentrations, and identified at least five persons with elevated urine arsenic levels. The public meeting helped raise community awareness about the existence of naturally occurring arsenic in Community A groundwater, the potential health risks associated with arsenic toxicity, and methods for treating water. The investigation also identified one household where people were exposed to high levels of arsenic despite having a reverse osmosis treatment system. These findings highlight the importance of testing private wells to reduce or prevent exposure to potentially harmful toxins.