Descriptive analysis of exposure levels of organophosphate esters among firefighters, paramedics, and office workers.

backgroundOrganophosphate esters (OPEs) are a class of chemicals used as flame retardants and plasticizers in many products and industries. While research shows that OPE exposure is widespread in the general population, studies on the working population are scarce, despite their potential of being at higher risk of exposure due to their handling of OPE containing materials and products across their lifecycle.

objectivesThis study aims to characterize OPE exposure among firefighters, paramedics, and office workers, to describe internal exposure levels, evaluate changes over a 24-h period including a work shift, and determine whether levels differ between occupational groups.

methodsParticipants provided two spot urine samples over the sampling period; one at the beginning of their shift (day 1) and another after 24 h (day 2). Twelve urinary OPE metabolites (mOPEs) were quantified. mOPE levels were described, and differences between groups and changes over time were examined using ANOVA and bivariate statistics.

resultsForty firefighters, 12 paramedics, and 13 office workers participated (78.5% male; mean age = 41 years). The highest geometric mean (GM) concentrations were observed for diphenyl phosphate (DPhP) (day 1: 1.09 µg/g-creatinine [GSD: 2.38], day 2: 1.20 µg/g-creatinine [GSD: 2.22]) and bis (1,3-dichloro-2-propyl) phosphate (BDCIPP) (day 1: 0.91 µg/g-creatinine [GSD: 3.04], day 2: 0.84 µg/g-creatinine [GSD: 3.17]). BDCIPP GM levels were significantly higher among firefighters (day 1: 1.25 µg/g-creatinine, day 2: 1.09 µg/g-creatinine; P-values < 0.001) and paramedics (day 1: 1.15 µg/g-creatinine, day 2: 1.23 µg/g-creatinine: P-values < 0.01) compared with office workers. While firefighters tended to have higher levels of mOPEs than other groups, not all differences reached statistical significance. Office workers tended to have higher DPhP levels than paramedics (day 1: office workers: 1.13 µg/g-creatinine, paramedics: 0.79 µg/g-creatinine, P = 0.565; day 2: office workers: 1.05 µg/g-creatinine, paramedics: 0.78 µg/g-creatinine, P = 0.597).

conclusionsOur results confirm consistent exposure to a subset of measured OPEs among these occupational groups. Concentrations of BDCIPP differed across occupations, suggesting potential exposure to different sources in those workplaces. However, the personal and work-related factors that contribute to these differences remain unclear. Given the concerns regarding possible adverse health effects related to OPE exposure (eg TDCIPP), more effort is needed to identify determinants and reduce occupational exposure to OPEs.