Open AccessTemporal Trends in Exposure to Organophosphate Flame Retardants in the United States
Author(s) -
Kate Hoffman,
Craig M. Butt,
Thomas F. Webster,
Emma V. Preston,
Stephanie C. Hammel,
Colleen M. Makey,
Amelia Lorenzo,
Ellen M. Cooper,
Courtney C. Carignan,
John D. Meeker,
Russ Hauser,
Adelheid Soubry,
Susan K. Murphy,
Thomas M. Price,
Cathrine Hoyo,
Emma Mendelsohn,
Johanna Congleton,
Julie L. Daniels,
Heather M. Stapleton
Publication year - 2017
Publication title -
environmental science and technology letters
Language(s) - English
Resource type - Journals
ISSN - 2328-8930
DOI - 10.1021/acs.estlett.6b00475
Subject(s) - organophosphate , triphenyl phosphate , environmental chemistry , phosphate , chemistry , exposure assessment , confidence interval , population , toxicology , fire retardant , environmental health , medicine , pesticide , biology , organic chemistry , ecology
During the past decade, use of organophosphate compounds as flame retardants and plasticizers has increased. Numerous studies investigating biomarkers (i.e., urinary metabolites) demonstrate ubiquitous human exposure and suggest that human exposure may be increasing. To formally assess temporal trends, we combined data from 14 U.S. epidemiologic studies for which our laboratory group previously assessed exposure to two commonly used organophosphate compounds, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP). Using individual-level data and samples collected between 2002 and 2015, we assessed temporal and seasonal trends in urinary bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), the metabolites of TDCIPP and TPHP, respectively. Data suggest that BDCIPP concentrations have increased dramatically since 2002. Samples collected in 2014 and 2015 had BDCIPP concentrations that were more than 15 times higher than those collected in 2002 and 2003 (10 β = 16.5; 95% confidence interval from 9.64 to 28.3). Our results also demonstrate significant increases in DPHP levels; however, increases were much smaller than for BDCIPP. Additionally, results suggest that exposure varies seasonally, with significantly higher levels of exposure in summer for both TDCIPP and TPHP. Given these increases, more research is needed to determine whether the levels of exposure experienced by the general population are related to adverse health outcomes.