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Trends in Cumulative Exposures of Six Phthalates in the United States from 2005 to 2014
Citation:
Reyes, J. AND P. Price. Trends in Cumulative Exposures of Six Phthalates in the United States from 2005 to 2014. 2017 ISES Annual Meeting, RTP, North Carolina, October 15 - 19, 2017.
Impact/Purpose:
The presentation will describe ORD's research on declining trends in combined exposures to six phthalates using NHANES bio-monitoring data.
Description:
Phthalates are utilized in a wide range of consumer goods and are common contaminants in food. Exposures and resulting dosages of individual phthalates vary over time as a result of changes in their use in consumer products and food contact materials. We calculated the trends in screening estimates of daily dose, Hazard Quotient (HQ), Hazard Index (HI), and Maximum Cumulative Ratio (MCR) for a group of six phthalates using the tolerable daily intakes for the compounds and biomonitoring data collected from 2005 to 2014 under the National Health and Nutrition Examination Survey. HQ is the ratio of an individual’s dose of a chemical and the chemical’s permitted dose. HI is the summation of an individual’s HQs. The MCR is the ratio of the HI to the largest HQ for each individual. There was a 2.2-fold decrease in the mean HI over this period (0.34 to 0.15) and a 7.2-fold decrease in the percentage of participants with an HI greater than 1 (5.7% to 0.8%). Decreases in HI were due to the decreases of diethylhexyl phthalate (DEHP) and dibutyl phthalates (DBP). Diisononyl phthalate (DINP) exposure increased between 2005 and 2014 and the remaining three phthalates remained approximately constant during this period. The phthalate with the greatest frequency of maximum HQ among individuals with HI values greater than 1 in 2005 was DEHP and in 2014 was DINP. While the individual HI values decreased over time, the values of MCRs increased, indicating that the need to consider cumulative exposures has become more important. These findings suggest that there has been a shift in phthalate exposures in the US population, leading to a decrease in HI values. These secular decreases were most pronounced in the groups experiencing the highest phthalates exposures and occurred due to the declines in HQs for DEHP and DBP out weighing the increases in DINP HQs. The views expressed in this abstract are those of the authors and do not necessarily reflect the views or policies of the U.S. EPA.
