Tom Neltner, J.D., is Chemicals Policy Director
Health professionals periodically ask me how they should advise parents who ask about what constitutes a dangerous level of lead in drinking water. They want a number similar to the one developed by the Environmental Protection Agency (EPA) for lead in dust and soil (which is the primary source of elevated blood lead levels in young children). I usually remind them that EPA’s 15 parts per billion (ppb) Lead Action Level is based on the effectiveness of treating water to reduce corrosion and the leaching of lead from plumbing; it has no relation to health. Then I tell them that EPA is working on one and to hold tight. Admittedly, that is not very satisfying to someone who must answer a parent’s questions about the results of water tests today.
On January 12, EPA released a draft report for public comment and external peer review that provides scientific models that the agency may use to develop potential health-based benchmarks for lead in drinking water. In a blog last month, I explained the various approaches and options for benchmarks that ranged from 3 to 56 ppb. In another blog, I described how EPA’s analysis provides insight into the amounts of lead in food, water, air, dust and soil to which infants and toddlers may be exposed. In this blog, I provide our assessment of numbers that health professionals could use to answer a parent’s questions. Because the numbers are only a start, I also suggest how health professionals can use the health-based benchmarks to help parents take action when water tests exceed those levels.
EDF’s read on an appropriate health-based benchmark for individual action on lead in drinking water
When it comes to children’s brain development, EDF is cautious. So we drew from the agency’s estimates calculated by its model to result in a 1% increase in the probability of a child having a blood lead level (BLL) of 3.5 micrograms of lead per deciliter of blood (µg/dL).
|EDF's assessment of a health-based benchmark for individual action on lead in drinking water|
|Age of child in home and type of exposure||Houses built before 1950¹||Houses built 1950 to 1978²||Tests show no lead in dust or soil³|
|Formula-fed infant||3.8 ppb||8.2 ppb||11.3 ppb|
|Other children 7 years or younger||5.9 ppb||12.9 ppb||27.3 ppb|