Showering and taking a bath in well water high in arsenic are not significant arsenic exposure sources for children and adults, according to a new study by the Maine CDC and US CDC.
This is good news for the tens of thousands of Maine residents who likely have too much arsenic in their well water. Bathing in contaminated well water is one of the top concerns voiced by the more than 700 Mainers who seek well water advice from Maine CDC experts each year.
The study also shows that switching to bottled water or installing an arsenic treatment system at the kitchen sink—real-world solutions used by many Maine residents—effectively reduce arsenic exposure when arsenic levels are below 40 micrograms per liter. This is more good news because these strategies may be less expensive than systems that treat all of the water used in the house.
Reducing exposure is more complicated for people when their well has an arsenic level above 40 micrograms per liter, especially if there are young children in the home. For these residents, the study confirms the importance of using bottled or treated water not only for drinking, but for all beverage and food preparation as well.
Less than 2 percent of Maine wells have arsenic levels above 40 micrograms per liter.
The study examined the amount of arsenic in individuals’ urine in relation to their untreated water arsenic concentration, daily water and food consumption and time spent bathing. Participants were children and adult volunteers from 167 Maine households with well water arsenic levels greater than 10 micrograms per liter, and where residents drank bottled water or water treated at the kitchen sink.
Authored by Maine’s State Toxicologist, Andrew Smith, and colleagues, the study appears in the February 15 edition of Science of the Total Environment.
The Maine CDC thanks all of the study volunteers for their participation and contribution to public health.