Using Silicone Wristbands to Assess Children's Exposure to Organophosphate Esters and Brominated Flame Retardants

Abstract

Organophosphate esters (OPEs) are often used as flame retardants and plasticizers and, like brominated flame retardants (BFRs), are frequently detected in indoor environments. Human exposure to semi-volatile organic compounds (SVOCs), including OPEs and BFRs, is widespread, which is particularly concerning for children who often experience higher exposures than adults and are especially vulnerable to long-term negative health impacts. Silicone wristbands have been used as personal passive samplers to examine adult ambient and occupational exposures to a suite of SVOCs and have the potential to be used as a non-invasive and inexpensive method of measuring personal exposures to chemical mixtures. Previously, among adults, OPEs and polybrominated diphenyl ethers (PBDEs, a class of BFRs) on bands have been significantly and positively associated with metabolites in pooled urine samples and serum biomarkers, respectively (rs=0.4-0.7; p<0.01). Here, we examine the utility of wristbands for assessing children’s exposure to 6 OPEs and several classes of BFRs. Children ages 3-6 and their families were recruited in 2014-16 as part of a study examining children’s exposures to SVOCs. Paired passive air samplers, hand wipes, and dust from the home were collected and analyzed; OPEs on hand wipes were significantly correlated with biomarkers from pooled urine samples (rs=0.2-0.4, p<0.05). Wristbands (n=75) were also deployed among these children and will be analyzed for OPEs and BFRs. Levels on the bands will also be compared to OPE urinary metabolites, which were previously analyzed in our laboratory, and serum PBDEs. Preliminary analyses among wristbands worn by children in a similar age range indicate that OPEs and BFRs are ubiquitously detectable on the bands (GM=2.6-187.5 ng/g). Results from this study will be used to validate wristbands as a tool for assessing personal exposure among children.