![[ Visit Client Website ]](images/banner.png)
BACKGROUND: General population exposure to inorganic arsenic most commonly occurs through contaminated ground water. USGS data of sampled private wells found a significant number of areas in the US exceeded EPA’s acceptable Maximum Contaminant Level (MCL) for arsenic, including some private wells in Louisiana. In addition, several Louisiana communities have recently been affected by arsenic-contaminated well water. Given the increase in people who rely on domestic well water, and the minimal private well testing requirements in many states, public health agencies need to evaluate existing arsenic and water use data to identify possible data gaps and areas for targeted outreach.
METHODS: Seven separate data sources characterizing either potential arsenic hazard or exposure were evaluated to identify highrisk areas in Louisiana. Evaluation criteria include sample size, temporal and geographic coverage, timeliness, data descriptors (e.g., sample date, detection limit, etc.), and data management resources. “Potential hazard” was characterized by the geographic distribution and magnitude of arsenic in groundwater and soil/sediment; “potential exposure” was characterized by the location of private wells, volume of well water for domestic use, and results of clinical laboratory tests.
RESULTS: About 4% of all arsenic raw source well water samples in Louisiana exceeded the MCL. Approximately 12% of Louisiana residents use ground water for domestic use. The number of private wells per parish ranges from 9 to 5070 (average=1041). Two parishes had both a potential hazard (elevated groundwater arsenic levels) and potential exposure (high domestic water use). There was an annual average of 1600 arsenic biomonitoring tests: 48% blood and 52% urine. Men were more likely than women to have an arsenic lab test (59% vs. 41%); average age was 49 (men) and 53 (women). Four cases had a urine test above the biological exposure index. There were no elevated blood tests.
CONCLUSIONS: State agencies can use these methods to catalog available data and identify areas of concern related to arsenic and domestic well use; results, however, are compromised without additional well water monitoring data. In Louisiana, and many other states, there are no state regulations mandating monitoring and reporting of private well water tests. Enacting policies to require routine testing and reporting to health authorities would have many benefits: 1) protect the health of well owners and their families; 2) support state groundwater surveillance to identify problem areas; and 3) enable targeted outreach, such as promoting the use of cheap, sustainable filtration technologies.