Gas-particle partition and size-segregated distribution of flame retardants in indoor and outdoor air: Reevaluation on the role of fine particles in human exposure

Self Cite

Herein, 16 traditional and 13 novel organophosphate esters (OPEs) in skin wipes, personal PM 2.5 , sputum, and nails (fingernails and toenails) and 7 OPE metabolites in urine synchronously obtained from 64 college students were analyzed. Similar compositional profiles of the OPEs were found in skin wipes and nails and in personal PM 2.5 and induced sputum. Significant correlations were observed between the concentrations of high-lipophilicity low-volatility OPEs in skin wipes and nails and between the concentrations of high-volatility low-lipophilicity OPEs in personal PM 2.5 and sputum. These results imply that OPEs in fingernails and toenails may mainly come from external sources rather than internal exposure, and human nails and sputum can be used as indicators of human exposure to OPEs. A comparison between the daily exposure doses of the OPEs in personal PM 2.5 and sputum shows that more volatile compounds may have higher inhalation bioavailability, which should be considered to improve the accuracy of inhalation exposure assessments. According to comprehensive external and internal exposure assessment, dermal absorption may be a more dominant pathway than inhalation, and skin wipes may be the best representative environmental matrix of human exposure to OPEs.

Section: Resultsmentioning

confidence: 99%

Section: Sampling Informationmentioning

confidence: 99%

Assessment of Human Exposure to Traditional and Novel Organophosphate Esters via Multiple Personal Matrices

Zhao,

Fan,

et al. 2024

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“…Based on prediction models, TDCIPP with a high log K oa (11) tends to bind with airborne particles, and TCEP with a low log K oa (7.6) is more likely to be detected in the gas phase. However, due to the strong polarity, TCEP is strongly adsorbed on the glass/quartz fiber filters used for air sampling or on the particles on those filters, which causes the high measured levels of TCEP in the atmospheric particles. − In addition, the inhalation bioaccessibility of TCEP in PM 2.5 (84.1%) is higher than that of TDCIPP (61.9%), which also contributes to the higher exposure levels of TCEP than TDCIPP through the inhalation of PM 2.5 .…”

Section: Resultsmentioning

confidence: 99%

Integrating Physiologically Based Pharmacokinetic Modeling-Based Forward Dosimetry and in Vitro Bioassays to Improve the Risk Assessment of Organophosphate Esters on Human Health

Wang

Zhao

Shi

et al. 2023

The ability to accurately assess the health risks of contaminants is limited by the shortcomings of toxicological standards. Using organophosphate esters (OPEs) as an example, this study attempted to integrate physiologically based pharmacokinetic (PBPK)-based forward dosimetry and in vitro bioassays to assess the likelihood of contaminants inducing biological effects in humans. The total exposure level of OPEs for Chinese residents was 19.5 ± 8.71 ng/kg/day with inhalation being the main exposure pathway. Then, human PBPK models were developed for individual OPEs to predict their steady-state concentrations in human tissues, and the predicted median levels in blood were close to the measurements. The reference doses (RfDs) of OPEs based on in vitro bioassays were comparable to in vivo animal-derived RfDs, demonstrating the reliability of in vitro bioassays. Therefore, the likelihood of OPEs inducing bioactivities in humans (RQin‑vitro) was calculated using in vitro toxicity data and OPE levels in human tissues. The RQin‑vitros of tris(2-chloroisopropyl) phosphate, tris(1,3-dichloropropyl) phosphate, and triphenyl phosphate (7.68 × 10–5–3.18 × 10–3) were comparable to the risks assessed using traditional RfDs (5.22 × 10–5–1.94 × 10–3), indicating the credibility of the method proposed in this study. This study establishes a new framework to improve the health risk assessment of contaminants without sufficient toxicity data and minimize the need for animal experimentation.

“…Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD) are two classes of brominated flame retardants (BFRs) which have been ubiquitously used in commercial products. Following the frequent detection of these BFRs in environmental media, − biota samples, − and even human samples, ,− along with reports of adverse effects of these BFRs on the environment and human health, − commercial formulations of penta-/octa-BDEs and deca-BDE were banned in Europe in 2004 and 2008, respectively . Subsequently, penta-/octa-BDEs, HBCDD, and deca-BDE were listed under the Stockholm Convention in 2009, 2014, and 2017, respectively, leading to global phase-out of commercial production and use of these legacy BFRs .…”

Section: Introductionmentioning

confidence: 99%

Impact of Legislation on Brominated Flame Retardant Concentrations in UK Indoor and Outdoor Environments: Evidence for Declining Indoor Emissions of Some Legacy BFRs

Ma,

Stubbings,

Jin

et al. 2024

Concentrations of polybrominated diphenyl ethers, hexabromocyclododecane (HBCDD), and novel brominated flame retardants (NBFRs) were measured in indoor dust, indoor air, and outdoor air in Birmingham, UK. Concentrations of ΣBFRs ranged from 490 to 89,000 ng/g, 46−14,000 pg/m 3 , and 22−11,000 pg/m 3 , respectively, in UK indoor dust, indoor air, and outdoor air. BDE-209 and decabromodiphenyl ethane (DBDPE) were the main contributors. The maximum concentration of DBDPE (10,000 pg/m 3 ) in outdoor air is the highest reported anywhere to date. In contrast with previous studies of outdoor air in Birmingham, we observed significant correlations between concentrations of tri-to hepta-BDEs and HBCDD and temperature. This may suggest that primary emissions from ongoing use of these BFRs have diminished and that secondary emissions (e.g., evaporation from soil) are now a potentially major source of these BFRs in outdoor air. Conversely, the lack of significant correlations between temperature and concentrations of BDE-209 and DBDPE may indicate that ongoing primary emissions from indoor sources remain important for these BFRs. Further research to clarify the relative importance of primary and secondary sources of BFRs to outdoor air is required. Comparison with earlier studies in Birmingham reveals significant (p < 0.05) declines in concentrations of legacy BFRs, but significant increases for NBFRs over the past decade. While there appear minimal health burdens from BFR exposure for UK adults, dust ingestion of BDE-209 may pose a significant risk for UK toddlers.