Individuals living in areas with the potential for elevated metal exposure from industrial sources may have reduced pulmonary function. We evaluated cross-sectional associations of toenail concentrations of 17 metals within a community area of residence and asthma control in 75 children, and pulmonary function measures [forced expiratory volume in one second (FEV1; liters), forced vital capacity (FVC; liters), FEV1 to FVC ratio (FEV1:FVC), and mid-exhalation forced expiratory flow rate (FEF 25-75%; liters/second)], in a subsample of 39 children with diagnosed asthma in Chicago, Illinois. Linear regression models were used to estimate adjusted regression coefficients and standard errors (SE) for the associations between ≥ median versus <median metal exposures and natural log-transformed (ln) pulmonary function test parameters. Toenail levels of cadmium, cobalt, iron, manganese, and vanadium were higher among children residing near an industrial corridor than those in a comparison community. Copper concentrations were inversely associated with lnFEV1 (β = -0.10, SE = 0.04, p = 0.01), lnFEV1:FVC (β = -0.07, SE = 0.03, p = 0.02) and lnFEF 25-75% (β = -0.25, SE = 0.09, p = 0.01); manganese concentrations were inversely associated with lnFEV1 (β = -0.11, SE = 0.04, p = 0.01), lnFEV1:FVC (β = -0.07, SE = 0.03, p = 0.02), and lnFEF 25-75% (β = -0.28, SE = 0.10, p = 0.004), and vanadium concentrations were inversely associated with lnFEV1 (β = -0.08, SE = 0.04, p = 0.05) and lnFVC (β = -0.07, SE = 0.03, p = 0.03). Nickel and copper were associated with uncontrolled asthma (OR = 6.8; 95% CI 2.0, 22.8 and OR = 4.6; 95% CI 1.0, 21.0, respectively). These data suggest that selected metal exposures may be associated with impaired pulmonary function parameters and reduced asthma control among children with preexisting asthma.
Keywords: asthma; children; metals; pulmonary function; respiratory function.