Federal Housing Assistance and Blood Lead Levels in a Nationally Representative US Sample Age 6 and Older: NHANES, 1999–2018

BACKGROUND: Federal housing assistance is an important policy tool to ensure housing security for low-income households. Less is known about its impact on residential environmental exposures, particularly lead. OBJECTIVES: We conducted a quasi-experimental study to investigate the association between federal housing assistance and blood lead levels (BLLs) in a nationally representative US sample age 6 y and older eligible for housing assistance. METHODS: We used the 1999–2018 National Health and Nutrition Examination Survey (NHANES) linked with US Department of Housing and Urban Development (HUD) administrative records to assess BLLs of NHANES participants with concurrent HUD housing assistance (i.e., current recipients, n = 3,071) and those receiving assistance within 2 y after the survey (i.e., pseudo-waitlist recipients, n = 1,235). We estimated BLL least squares geometric means (LSGMs), odds ratio (OR) for BLL ≥3:5 lg/dL, and percent differences in LSGMs by HUD housing assistance status adjusting for age, sex, family income-to-poverty ratio, education, country of birth, race/ethnicity, region, and survey year. We also examined effect modification using interaction terms and stratified analyses by program type [i.e., public housing, multifamily, housing choice vouchers (HCV)], and race/ethnicity. RESULTS: Current HUD recipients had a significantly lower LSGM [1:07 lg/dL; 95% confidence interval (CI): 1.02, 1.12] than pseudo-waitlist recipients (1:21 lg/dL; 95% CI: 1.14, 1.28), with an adjusted OR of 0.60 (95% CI: 0.42, 0.87) for BLL ≥3:5 lg/dL. Some effect modification were observed: The protective association of HUD assistance on BLL was strongest among public housing (−19:5% LSGM; 95% CI: −27:5%, −10:7%), multifamily (−12:5% LSGM; 95% CI: −20:7%, −3:5%), and non-Hispanic White (−20:6% LSGM; 95% CI: −29:8%, −10:3%) recipients. It was weaker to null among HCV (−5:7% LSGM; 95% CI: −12:7, 1.7%), non-Hispanic Black (−1:6% LSGM; 95% CI: −8:1%, 5.4%), and Mexican American (−12.5% LSGM; 95% CI: −31:9%, 12:5%) recipients.