Association between children's blood lead levels, lead service lines, and water disinfection, Washington, DC, 1998-2006.
OBJECTIVE
Evaluate the effect of changes in the water disinfection process, and presence of lead service lines (LSLs), on children's blood lead levels (BLLs) in Washington, DC.


METHODS
Three cross-sectional analyses examined the relationship of LSL and changes in water disinfectant with BLLs in children <6 years of age. The study population was derived from the DC Childhood Lead Poisoning Prevention Program blood lead surveillance system of children who were tested and whose blood lead test results were reported to the DC Health Department. The Washington, DC Water and Sewer Authority (WASA) provided information on LSLs. The final study population consisted of 63,854 children with validated addresses.


RESULTS
Controlling for age of housing, LSL was an independent risk factor for BLLs ≥ 10 μg/dL, and ≥ 5 μg/dL even during time periods when water levels met the US Environmental Protection Agency (EPA) action level of 15 parts per billion (ppb). When chloramine alone was used to disinfect water, the risk for BLL in the highest quartile among children in homes with LSL was greater than when either chlorine or chloramine with orthophosphate was used. For children tested after LSLs in their houses were replaced, those with partially replaced LSL were >3 times as likely to have BLLs ≥ 10 μg/dL versus children who never had LSLs.


CONCLUSIONS
LSLs were a risk factor for elevated BLLs even when WASA met the EPA water action level. Changes in water disinfection can enhance the effect of LSLs and increase lead exposure. Partially replacing LSLs may not decrease the risk of elevated BLLs associated with LSL exposure.
Lead Poisoning Prevention Branch, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway NE, Atlanta, GA 30348, USA. mjb5@cdc.gov
Mary Jean
MJ
Brown
Jaime
J
Raymond
David
D
Homa
Chinaro
C
Kennedy
Thomas
T
Sinks
D002648:Child; D002675:Child, Preschool; D002700:Chloramines / Q000737:chemistry; D002713:Chlorine / Q000737:chemistry; D003430:Cross-Sectional Studies; D004219:District of Columbia; D006801:Humans; D007223:Infant; D007854:Lead / Q000097:blood*; D016015:Logistic Models; D008297:Male; D010710:Phosphates / Q000737:chemistry; D014105:Tosyl Compounds / Q000737:chemistry; D014505:Urban Population; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis*
D002700:Chloramines; D010710:Phosphates; D014105:Tosyl Compounds; C016300:chloramine-T; D007854:Lead; D002713:Chlorine