Any detectable blood lead level harmful in children, finds JAMA study
Lead has no biological role in the body and no safe level of exposure to lead for children has been identified. Any detectable lead level is abnormal and potentially harmful, particularly in young children. Understanding individual and neighborhood level risk factors that are associated with any exposure to lead in children may be important in targeting efforts to mitigate adverse effects.
Hauptman et al from Boston Children's Hospital conducted a study to evaluate individual and community-level factors associated with detectable and elevated blood lead levels (BLLs) in children that may guide in implementing health policies.
In this cross-sectional study , 141 441 children younger than 6 years living in all 50 US states and the District of Columbia who underwent blood lead testing during the study period were enrolled. If the first specimen was from capillary blood and the result was 5.0 μg/dL or more, a confirmatory specimen was required within 90 days; in this case, only the results from the confirmatory specimens were considered in this analysis, consistent with the CDC definition of "confirmed elevated BLL." Children who underwent lead testing of unknown source and those with elevated BLLs who received capillary blood lead testing without confirmatory venous testing were excluded.Researchers had a special interest on pre-1950's housing because paint produced after the 1950s tended to have lower concentrations of lead than that produced earlier.
Important findings of the study are:
-Of the 1141441 children in the study, more than half of the children tested (576 092 [50.5%]) had detectable BLLs, and 21 172 children (1.9%[95%CI, 1.8%-1.9%]) had BLLs of 5.0 μg/dL or more.
-The proportion of children with detectable and elevated BLLs increased significantly for progressive pre-1950s housing and poverty quintiles (P < .001).
-Children from predominately Black populations had significantly higher proportions of children with detectable BLLs and BLLs of 5.0 μg/dL than those belonging to white population.
-The odds of detectable BLLs were significantly higher among children in the highest vs lowest quintile of pre-1950s housing and of poverty.
This large, cross-sectional, retrospective national study demonstrates that there is an association between where a child lives and the risk of any lead exposure, an important health issue with long-term outcomes at a population level.
Authors conclude-"this study demonstrates that there are still substantial individual- and community-level disparities that have important implications for addressing childhood lead exposure."