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Inhalation exposure to flame retardants used as additives to minimize fire risk and plasticizers is ubiquitous in human daily activities, but has not been adequately assessed. To address this research gap, the present study conducted an assessment of human health risk for four age groups through inhalation exposure to size fractionated particle-bound and gaseous halogenated flame retardants (polybrominated diphenyl ethers (PBDEs) and alternative halogenated flame retardants (AHFRs)) and organophosphate esters (OPEs) at indoor and outdoor environments (school, office, and residence) in three districts of a megacity (Guangzhou, China). Results demonstrated that OPEs were the dominant components among all targets. Indoor daily intakes of PBDEs and OPEs were 13–16 times greater than outdoor levels for all age groups. Gaseous OPEs contributed significantly greater than particle-bound compounds to daily intakes of all target compounds. Based on the different life scenarios, hazard quotient (HQ) and incremental life cancer risk (ILCR) from adults exposure to PBDEs and OPEs in indoor and outdoor settings were the greatest, followed by adolescents, children, and seniors. The estimated HQ and ILCR for all age groups both indoors and outdoors were lower than the safe level (HQ = 1 and ILCR = 10−6), indicating that the potential health risk for local residents in Guangzhou via inhalation exposure to atmospheric halogenated flame retardants and OPEs was low. Image 1 • Indoor daily intakes of PBDEs and OPEs were 13–16 times greater than outdoor levels. • Daily intakes of gaseous OPEs were greater than particle-bound OPEs. • Inhalation exposure health risk for residents in Guangzhou to PBDEs and OPEs was low. Comprehensive investigation of indoor and outdoor polybrominated diphenyl ethers and organophosphate esters are conducted to provide new insight in risk assessment of human inhalation exposure to atmospheric halogenated flame retardants and plasticizers in an urban zone. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Crude e-waste recycling was simulated in closed chamber. • Emissions of OPFRs were large in both thermal treatment and open burning. • OPFRs were probably emitted in association with particles. • The abundances of OPFRs were lower in coarse particles than in fine particles. Abstract Organophosphate flame retardants (OPFRs) have been increasingly produced and consumed since the gradual phase-out of polybrominated diphenyl ethers. Primitive recycling of e-waste can be a significant input source of OPFRs to the environment. Thermal treatment and open burning of typical e-wastes were conducted in a closed chamber to examine the emissions and the size distribution patterns of particle-bound OPFRs from these processes. The sum emission factors of OPFRs were 3.70 × 104–3.65 × 105 ng g−1 by thermal treatment and 5.22 × 103–9.27 × 104 ng g−1 by open burning. The output-input mass ratios of OPFRs for plastic casings were 0.030–116 and 0.012–7.1 by thermal treatment and open burning, respectively, and were 0.11–40 and 0.0014–6.7 for printed circuit boards. The size distribution patterns of OPFRs were characterized by one unimodal peak (0.56–1.0 μm) for thermal treatment and bimodal peaks (0.56–1.0 or 1.0–1.8 and 10–18 μm) for open burning. Particle-bound OPFRs appeared to form in affiliation with particles rather than by adsorption or deposition from the gaseous phase to particulate organic matter. With increasing amounts of OPFRs used in a variety of consumer products, the emissions of OPFRs to the environment are expected to increase continuously in the future. [ABSTRACT FROM AUTHOR]

A total of 53 feeds from 23 brands for four types of animals, i.e., fish, chicken, duck, and pig, as well as six types of raw materials, were bought from Guangxi, Hubei, Anhui, and Guangdong provinces in China and analyzed for polybrominated diphenyl ethers (PBDEs). The raw materials including super fish meal, ordinary fish meal, poultry ore, soybean, stone powder, and rapeseed were selected because they were added to all the animal feeds manufactured. The occurrence of PBDEs was ubiquitous in the feeds and raw materials, with BDE-209 as the most abundant congener. The average concentration of ∑8PBDE was 1.1 and 0.44 ng g−1 dry weight in feeds (range 0.25-5.7) and raw materials (range 0.27-0.84), respectively. No statistically significant differences in ∑8PBDE concentrations were observed among the four groups of animal feeds. Feeds from Yangzhiyuan Brand (n = 11) contained statistically (p < 0.01) lower ∑8PBDE concentrations than all other brands except for Baoshun Brand. Chicken was selected as a representative animal to assess health risk for human exposure to PBDEs via the consumption of chicken raised by the feeds under investigation. Hazard quotients based on per-capita consumption of chicken were all below 1, indicating low potential risk to humans consuming chicken raised with the feeds.Graphical abstract [ABSTRACT FROM AUTHOR]

Atmospheric size-fractionated particles were collected at different heights in an e-waste recycling zone (QY) and urban Guangzhou (GZ), China and analyzed for organophosphate flame retardants (OPFRs). The total air concentrations of eight OPFRs were 130 ± 130 and 138 ± 127 ng m −3 in QY and GZ, respectively. Compositional profiles of chlorinated OPFRs were different between QY and GZ, but the size distribution patterns of all OPFRs were not significantly different at different heights. Estimated atmospheric deposition fluxes of OPFRs were 51 ± 67 and 55 ± 13 μg m −2 d −1 in QY and GZ, respectively, and the coarse particles ( D p > 1.8 μm) dominated both the dry and wet deposition fluxes. Moreover, not all particle-bound OPFRs were inhalable and deposited in the human respiratory tract. The calculated inhalation doses of OPFRs were much lower than the reference doses, suggesting that potential health risk due to inhalation exposure to particle-bound OPFRs in the e-waste recycling zone and urban site was low. [ABSTRACT FROM AUTHOR]

• Dissolved PBDEs and OPFRs were concentrated in porewater and overlying water. • Sediment is interchanged with sink and source for riverine transport of OPFRs. • Sediment-water diffusion of PBDEs and OPFRs was not significant compared to riverine transport. Despite ample evidence on spreading of e-waste derived hazardous materials, riverine transport of organic contaminants from e-waste recycling zones to surrounding areas has not been evaluated. To address this issue, passive and grab sampling methods were used to assess sediment-water diffusion and horizontal transport of polybrominated diphenyl ethers (PBDEs) and organophosphorus flame retardant (OPFRs) at upstream and downstream sites of two rivers in a typical e-waste recycling zone. Sediment acted as a source of BDE-17 with fluxes of 0.007−0.04 ng m−2 d−1 at all sampling sites. BDE-47 and BDE-99 reached equilibrium between overlying water and sediment porewater. Sediment interconverted from a sink at the upstream site to a source of OPFRs at the downstream site with a flux varying between −7.3 and 234 ng m−2 d−1. The amounts of OPFRs (11−45 g d−1) via horizontal riverine transport were greater than those of PBDEs (0.68−2 g d−1). The vertical sediment-water diffusion of PBDEs and OPFRs was not significant compared to horizontal riverine transport. The annual riverine outputs of PBDEs and OPFRs from the downstream sites were 250–330 g and 12,000–16,500 g, respectively, indicating the significance of riverine transport of organic contaminants from e-waste recycling zones to surrounding areas. [Display omitted] [ABSTRACT FROM AUTHOR]

The partition coefficient (K pew) of an analyte between low-density polyethylene (LDPE) film and water is a critical parameter for measuring freely dissolved concentrations of the analyte with PE passive sampling devices. Measuring log K pew for super hydrophobic organic chemicals (HOCs) have been proven extremely difficult. The present study developed a large volume model for measuring log K pew of super HOCs, i.e., novel halogenated flame retardants (NHFRs). Results showed that the measured log K pew values of selected PAHs and PCBs obtained by the large volume model were in line with those from the co-solvent model and the literature data within less 0.3 log units of difference, while those of NHFRs (6.27–7.34) except for hexachlorocyclopentadienyldibromocyclooctane (HCDBCO) and Decabromodiphenyl ethane (DBDPE) were significantly lower than those (6.51–8.89) from the co-solvent model. A curvilinear relationship was observed between log K pew and log K ow of all target compounds, with the turning point at log K ow = ∼8.0 in the large volume model, but that was not found for the co-solvent model. These can be attributed to the large molecular volumes (> 450 Å3) for NHFRs, which require high Gibbs free energy to penetrate into the inside structures of LDPE in the large volume model. However, the solvent swelling effects in the co-solvent model needs to be investigated. Therefore, the large volume model is robust to determine the K pew values of super HOCs for facilitating the application of aquatic passive sampling techniques. • The large volume model is feasible to measure the K pew values of super HOCs. • The K pew values of HOCs from the co-solvent model were greater than other models. • The K pew values of NHFRs decreased with increasing molecular volumes. [ABSTRACT FROM AUTHOR]