CHARACTERIZING LEAD EXPOSURE IN HOUSEHOLDS THAT DEPEND ON PRIVATE WELLS FOR DRINKING WATER

Abstract

Evidence accumulated over the past several decades indicates that there is no safe level of exposure to lead for young children. Although the Safe Drinking Water Act has safety measures in place to maintain the safety of municipal water supplies, no such protection exists for private wells. Recent research suggests U.S. children relying on private well water may be at increased risk from lead exposure compared to those with access to a regulated community water supply. However, no prior studies have investigated this risk through concurrent collection of water and blood samples to test for associations between lead in water and lead in blood. To assess these associations, we collected blood and water samples from 89 participants in North Carolina homes relying on private wells for their drinking water. We also collected dust samples to account for the potential risk of exposure to lead from paint and from lead-containing dirt tracked into the home. All environmental samples were analyzed for lead using inductively coupled plasma mass spectrometry. A multivariable regression was performed to examine the association between well water and blood lead, controlling for lead in dust and other factors that may be associated with lead exposure risk. We found that although water lead levels were not directly associated with blood lead, use of a water filter was associated with a decrease of 32% in blood lead (p<0.05). Additionally, use of a filter was significantly associated with a decreased risk of the occurrence of high lead levels drinking water (p=0.01). Furthermore, we found significant racial disparities in access to water filters. Among participants identifying as African American or Native American, 38% had a water filter, compared to 83% of those identifying as other races (p<0.001). This study highlights that those who get their drinking water from a private well and do not filter their water may be at increased risk of exposure to lead. Further research will be required to understand the association more fully between lead exposure and well water, with a focus on communities who do not have access to water filters.