Neighborhood deprivation, race/ethnicity, and urinary metal concentrations among young girls in California

Abstract

Background: Although metals can adversely impact children's health, the distribution of exposures to many metals, particularly among vulnerable subpopulations, is not well characterized.

Objectives: We sought to determine whether neighborhood deprivation was associated with urinary concentrations of thirteen metals and whether observed relationships varied by race/ethnicity.

Methods: We obtained neighborhood characteristics from the 2005-2009 American Community Survey. Demographic information and urine samples from 400 healthy young girls in Northern California were obtained during a clinical visit. Urine samples were analyzed for metals using inductively-coupled plasma-mass spectrometry and levels were corrected for creatinine. We ran analysis of variance and generalized linear regression models to estimate associations of urinary metal concentrations with neighborhood deprivation and race/ethnicity and stratified multivariable models to evaluate possible interactions among predictors on metals concentrations.

Results: Urinary concentrations of three metals (barium, lead, antimony) varied significantly across neighborhood deprivation quartiles, and four (barium, lead, antimony, tin) varied across race/ethnicity groups. In models adjusted for family income and cotinine, both race/ethnicity (F3,224=4.34, p=0.01) and neighborhood deprivation (F3,224=4.32, p=0.01) were associated with antimony concentrations, but neither were associated with lead, barium, or tin, concentrations. Examining neighborhood deprivation within race/ethnicity groups, barium levels (pinteraction<0.01) decreased with neighborhood deprivation among Hispanic girls (ptrend<0.001) and lead levels (pinteraction=0.06) increased with neighborhood deprivation among Asian girls (ptrend=0.04).

Conclusions: Our results indicate that children's vulnerability to some metals varies by neighborhood deprivation quartile and race/ethnicity. These differential distributions of exposures may contribute to environmental health disparities later in life.

Keywords: Children; Environmental health disparities; Lead; Metals; Vulnerability.