Association of Children's Urinary CC16 Levels with Arsenic Concentrations in Multiple Environmental Media

Abstract

Arsenic exposure has been associated with decreased club cell secretory protein (CC16) levels in adults. Further, both arsenic exposure and decreased levels of CC16 in childhood have been associated with decreased adult lung function. Our objective was to determine if urinary CC16 levels in children are associated with arsenic concentrations in environmental media collected from their homes. Yard soil, house dust, and tap water were taken from 34 homes. Urine and toenail samples were collected from 68 children. All concentrations were natural log-transformed prior to data analysis. There were associations between urinary CC16 and arsenic concentration in soil (b = -0.43, p = 0.001, R² = 0.08), water (b = -0.22, p = 0.07, R² = 0.03), house dust (b = -0.37, p = 0.07, R² = 0.04), and dust loading (b = -0.21, p = 0.04, R² = 0.04). In multiple analyses, only the concentration of arsenic in soil was associated with urinary CC16 levels (b = -0.42, p = 0.02, R² = 0.14 (full model)) after accounting for other factors. The association between urinary CC16 and soil arsenic may suggest that localized arsenic exposure in the lungs could damage the airway epithelium and predispose children for diminished lung function. Future work to assess this possible mechanism should examine potential associations between airborne arsenic exposures, CC16 levels, lung function, and other possible confounders in children in arsenic-impacted communities.

Keywords: CC16; arsenic; children; drinking water; multi-route exposure assessment; respiratory health; soil; uteroglobulin.

Figure 1

Potential for arsenic exposure in the US. Maps derived from data contained in Focazio et al. [16] and Smith et al. [17]. Yavapai County, where the study is located, is outlined. (a) Well water concentration above US EPA drinking water guideline for arsenic of 10 ppb; (b) soil concentration above Arizona Department of Environmental Quality Soil Remediation Level of 10 ppm.

Figure 2

Relationship between concentration of CC16 in urine and arsenic in soil. Individual households are indicated by the same shape and color scheme. Both variables have been natural-log transformed.

Figure 3

Partial correlations between urinary CC16 and the concentration of arsenic in soil, dust, toenails, urine, and water. Arrows are used to depict partial correlations with a p ≤ 0.10.