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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]

Although a number of studies have assessed the occurrence of atmospheric polycyclic aromatic hydrocarbons (PAHs) in indoor environment, few studies have systemically examined the indoor-outdoor interplay of size-dependent particulate PAHs and potential health risk based on daily lifestyles. In the present study, size-dependent particle and gaseous samples were collected both indoors and outdoors within selected schools, offices and residences located in three districts of Guangzhou, China with different urbanization levels during the dry and wet weather seasons. Results from measurements of PAHs showed that higher total PAH concentrations occurred in residential areas than in other settings and in indoor than in outdoor environments. Compositional profiles and size distribution patterns of particle-bound PAHs were similar indoors and outdoors, predominated by 4-and 5-ring PAHs and the 0.56–1.0 μm particle fraction. Statistical analyses indicated that outdoor sources may have contributed to 38–99% and 62–100% of the variations for indoor particle-bound and gaseous PAH concentrations, respectively. Incremental life cancer risk ( ILCR ) from human exposure to indoor and outdoor PAHs based on different lifestyles followed the order of adults > children > adolescents > seniors. All average ILCR values for four age groups were below the lower limit of the Safe Acceptable Range (10 −6 ). In addition, the ILCR value for adults (average: 7.2 × 10 −7 ; 95% CI: 5.4 × 10 −8 ‒2.5 × 10 −6 ), estimated from outdoor air PAH levels with 24-h exposure time, was significantly higher than our assessment results (average: 5.9 × 10 −7 ; 95% CI: 6.3 × 10 −8 ‒1.9 × 10 −6 ), suggesting the significance of assessing human inhalation exposure risks of indoor and outdoor PAHs in urban air based on daily lifestyles. [ABSTRACT FROM AUTHOR]

Understanding particle size distribution and size-resolved gas-particle partitioning of semi-volatile organic compounds (SVOCs) is important for characterizing their fate in atmosphere. However, the size-resolved gas-particle partitioning characteristics of SVOCs has not been adequately considered. To address this issue, the present study collected gaseous and size-fractioned particulate samples both in and outside of schools, offices, and residences in three districts of different urbanization levels in a megacity, Guangzhou, South China during two seasons. Typical SVOCs, including 15 polycyclic aromatic hydrocarbons (PAHs), six organophosphate esters and seven phthalic acid esters were measured. Emission sources, physicochemical properties, and environmental conditions at the sampling sites considerably impacted the spatiotemporal distribution patterns and particle size distribution of target SVOCs. Not all observed gas-particle partition coefficients (K p) of target SVOCs were negatively correlated with subcooled liquid-vapor pressures (P L 0), probably because certain factors, such as the non-exchangeable part of the particle-bound SVOCs, were not considered in traditional gas-particle partition theories. Particle size was an important factor affecting gas-particle partitioning. Adsorption was the dominant mechanism for PAHs with high molecular weight in different particle modes. A new model was established to predict size-resolved K p of PAHs with high molecular weight based on P L 0 and particle size. [Display omitted] • Observed log K p of PAEs and OPEs were not well correlated with log P L 0. • Observed log K p of 3- and 4-rings PAHs were negatively related with log P L 0. • Adsorption was the dominant gas-particle partition mechanism of 3- and 4-rings PAHs. • Particle size affects gas-particle partitioning of semi-volatile organic compounds. • The established model greatly predicted size-resolved K p of 3- and 4-rings PAHs. [ABSTRACT FROM AUTHOR]

Health risk of residents dwelling around e-waste recycling zones has been a global concern, but has not been adequately examined. The present study was intended to evaluate the potential health risk of residents through inhalation exposure to size-fractionated particle-bound heavy metals in a typical e-waste recycling zone, South China. Anthropogenic metals (Zn, Se, Pb, Sb, As, and Cd) were predominantly enriched in fine particles ( D p < 1.8 μm), whereas the crustal elements (Ti, Fe, and Co) tended to accumulate in coarse particles ( D p > 1.8 μm). Although the daily inhalation intakes of the target metals were significantly lower than those through food consumption and ingestion of house dust, the hazard quotients of total metals for adults (95% CI: 1.0–5.5) and children (95% CI: 3.0–17) were greater than 1. Moreover, the incremental lifetime cancer risks of five carcinogenic metals (Cr, Co, Ni, As, and Cd) for adults and children were 1.3 × 10 −3 (95% CI: 4.1 × 10 −4 –3.0 × 10 −3 ) and 3.9 × 10 −3 (95% CI: 1.3 × 10 −3 –8.6 × 10 −3 ), respectively, substantially higher than the acceptable cancer risk range of 10 −6 –10 −4 . All these findings suggested that health risks were high for local residents dwelling around the e-waste recycling zone through inhalation exposure to particle-bound heavy metals, for both adults and children. [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]