Cross-sectional associations of self-reported firearm use with blood lead concentrations in a nationally representative cohort of US adults.

Background: Firearm-related lead exposure could occur when firearms discharge lead ammunition particles. Prior studies were primarily among military or police participants, but this relation has not been examined in civilian populations. Thus, among noninstitutionalized United States (US) adult civilians, we examined the association of self-reported firearm noise exposure (proxy for firearm-related lead exposure) and firearm use with blood lead concentrations. Methods: We used 5 cycles of the National Health and Nutrition Examination Survey. Using lead biomarkers and questionnaires related to firearm noise exposure (1999-2004, n = 9,606) and firearm use (2011-2012 and 2015-2016, n = 5,972), we calculated survey-weighted and covariate-adjusted percent differences in blood lead concentrations. We adjusted for gender, age, race/ethnicity, and education. Sensitivity analyses separately examined whether former military status, pre-1978 housing, or occupation confounded these associations. Results: Self-reported firearm noise exposure was associated with blood lead concentrations (percent difference 15%; 95% CI = 7%, 23%), but firearm use was not (percent difference 1%; 95% CI = -5%, 9%). However, blood lead concentrations were 9% (95% CI = -5%, 25%) and 21% (95% CI = -5%, 54%) higher among those who reported shooting 1,000-10,000 and 10,000+ rounds, respectively (P value for trend = 0.07), compared with those who reported shooting 0 rounds. Results were similar after separate adjustment for former military status, pre-1978 housing, and occupation. Conclusion: In this representative sample of US civilians, individuals who used firearms more frequently (10,000+ rounds) had increased blood lead concentrations.