Associations between metals in residential environmental media and exposure biomarkers over time in infants living near a mining-impacted site

Abstract

Infant exposures to metals are a concern for mining-impacted communities, although limited information is available to assess residential exposures over the first year of life. We measured lead (Pb), manganese, arsenic, and cadmium in indoor air, house dust, yard soil, and tap water from 53 infants’ homes near the Tar Creek Superfund Site (Oklahoma, USA) at two time points representing developmental stages before and during initial ambulation (age 0–6 and 6–12 months). We measured infant metal biomarkers in: umbilical cord blood (n = 53); 12- (n = 43) and 24- (n = 22) month blood; and hair at age 12 months (n = 39). We evaluated cross-sectional and longitudinal associations between infant residential and biomarker concentrations. A doubling of mean dust Pb concentration was consistently associated with 36–49% higher 12-month blood Pb adjusting for cord blood Pb (P≤ 0.05). Adjusted dust concentration explained 29–35% of blood Pb variance, and consistent associations with other media were not observed. Although concentrations in dust and blood were generally low, strong and consistent associations between dust and body burden suggest that house dust in mining-impacted communities may impact children’s health. These relationships were observed at a young age, typically before blood Pb levels peak and when children’s development may be particularly vulnerable to toxic insult.

Maternal and Cord Blood Manganese Concentrations and Early Childhood Neurodevelopment among Residents near a Mining-Impacted Superfund Site

“…In this cohort, the routes of exposure likely include ingestion of manganese in dusts. We have previously reported positive associations between child hair manganese levels and house dust, but not indoor air, yard soil or tap water, in a subset of this cohort ( Zota et al 2015 ). Our observation that the median manganese level in cord blood was about twice as high as in maternal blood likely reflects active transport of manganese across the placenta ( Krachler et al 1999 ; Nandakumaran et al 2016 ).…”

Assessing the contributions of metals in environmental media to exposure biomarkers in a region of ferroalloy industry

“…Although there is strong evidence that exposure to metals is higher among individuals living near ferroalloy facilities and that adverse health effects may be linked with exposure to these metals, less is known about sources and pathways of exposure from environmental samples to internal dose (32). There is a need to better understand the relative contributions of different environmental media to metals biomarkers in order to support preventive strategies, even after industrial facilities close (33, 34).…”

Mining is bad for health: a voyage of discovery

“…Mining activities play an important but underappreciated role in the generation of contaminated atmospheric dust and aerosol and the transport of metal and metalloid contaminants (Csavina et al 2012a;Meyer et al 2015). Coarse particles form a large proportion of resulting dust particles and are usually too heavy to travel far, although they may still contribute to exposure of workers and nearby residents (Barbieri et al 2014;Zota et al 2016). The combination of mining activities and mechanical dispersion via water and wind has moved heavy metals around 4 km from a mine site in Iran (Mokhtari et al 2018), while in Hunan Province, China, metal aerial contamination peaked around the 1 km mark.…”

“…The poor may not have a lot of choice in housing, often living close to mines or on top of mine waste (Demetriades 2011). House dust can be the main route of exposure of families, including children and pregnant women, who are usually the most vulnerable (Martin et al 2014;Zota et al 2016;Lewis et al 2017).…”