BROOKSVILLE — A months-long study of residents in southeastern Hernando County showed no significant differences in the level of arsenic in the bodies of people whose private wells are known to be contaminated with the element, but where faucets are equipped with filtering devices, compared with those whose wells contain safe levels of arsenic.
A report released by the Hernando County Health Department last week showed that urine samples collected from adults and children participating in the study showed only a marginal difference between the two groups. Further testing showed that 94.4 percent of the total arsenic levels likely came from a nontoxic organic source. Organic arsenic is typically found in food.
A total of 360 individuals from 166 households participated in the $60,000 study, which was funded by the U.S. Centers for Disease Control and Prevention and authored by the Florida Department of Health Bureau of Epidemiology. Testing was done between April and July, and included homes where a point-of-use filter had been installed on the kitchen tap as well as homes where higher levels of arsenic are not found.
County environmental health manager Al Gray said the study helped his department learn how well filter systems protect the bodies of adults and children.
"The numbers show that they are definitely doing what they are designed to do," Gray said. "As long as people use them, it appears that the danger of arsenic contamination is minimal."
County health officials have long had concerns over high arsenic levels in groundwater in some rural areas where the chemical was once used as an agricultural pesticide. Tests conducted between 2007 and 2012 identified 312 Hernando properties where samples showed higher concentrations of the element than both the state and federal governments deem safe. As a result, those residences qualified for help from the state Department of Environmental Protection, which provided affected homes with a small filter that could be installed next to the kitchen sink to provide water for drinking and cooking.
Participants in the Health Department study were asked to provide regular urine samples to test for accumulated arsenic levels. In addition, they completed a questionnaire on individual daily water consumption and exposure patterns, dietary history and other possible sources of arsenic exposure.
Nearly 50 percent of the participants were from "control" households with well water that had arsenic levels below 8 micrograms per liter, while the other half were classified as "case" households with arsenic levels exceeding 10 micrograms per liter of water.
Gray said that Hernando County was selected to participate in the study because it is known to have a large number of wells with arsenic levels above the normal limit, and that the data collected will be used in a peer review study that will eventually be published.
Logan Neill can be reached at firstname.lastname@example.org or (352) 848-1435.