Linking soil-metal concentrations with children's blood and urine biomarkers in Syracuse, NY

This study investigates the relationship between trace element concentrations of lead (Pb), arsenic (As), cobalt (Co), manganese (Mn), molybdenum (Mo), and mercury (Hg) in soil on blood and urine biomarkers in a cohort of children from Syracuse, New York. The cohort data were collected as part of the Environmental Exposures and Child Health Outcomes project investigating the body burden of trace metals in children and where those metals come from. This study specifically investigates exposure to trace metals in soil. Cohort data were collected between 2013 and 2017 and soil samples were obtained from a separate study conducted in 2003-2004. We used linear and spatial-error models to test if daily dose exposure to soil concentrations of trace metals were associated with blood and urine levels of those same metals. We controlled for race, gender, socioeconomic status (index calculated from income and parent education level), age, body mass index, diet (index of daily dietary patterns of different food groups), smoking status of parents, distance to nearest highway, and air concentration of metal pollution. We found that a one standard deviation increase in soil-Pb may be associated with a 12 percent (95 % CI [2.5 %, 21 %]), rise in blood-Pb, and a one standard deviation increase in nearby soil-Hg levels may be associated with a 22.5 percent (90 % CI [1 %-49 %]) rise in blood-Hg. On average, participants had 2.5 μg/dL (95 % CI [1.6 μg/dL, 3.4 μg/dL]) higher blood-Pb levels for every 1000 mg/kg of soil-Pb. Participants also had 1.5 μg/g (95 % CI [0.78 μg/g, 2.2 μg/g]) creatinine higher adjusted urine-Co levels for every 1 μg/kg/day of soil-Co exposure with 10 percent variance explained by soil-Co dose (R² = 0.1). These results highlight that soil-metal concentrations can pose a risk to child health even when accounting for other exposures.