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Barbecue (BBQ) is one of the most popular cooking activities with charcoal worldwide and produces abundant polycyclic aromatic hydrocarbons (PAHs) and particulate matter. Size distribution and clothing-air partitioning of particle-bound PAHs are significant for assessing potential health hazards to humans due to exposure to BBQ fumes, but have not been examined adequately. To address this issue, particle and gaseous samples were collected at 2-m and 10-m distances from a cluster of four BBQ stoves. Personal samplers and cotton clothes were carried by volunteers sitting near the BBQ stoves. Particle-bound PAHs (especially 4–6 rings) derived from BBQ fumes were mostly affiliated with fine particles in the size range of 0.18–1.8 μm. High molecular-weight PAHs were mostly unimodal peaking in fine particles and consequently had small geometric mean diameters and standard deviations. Source diagnostics indicated that particle-bound PAHs in BBQ fumes were generated primarily by combustion of charcoal, fat content in food, and oil. The influences of BBQ fumes on the occurrence of particle-bound PAHs decreased with increasing distance from BBQ stoves, due to increased impacts of ambient sources, especially by petrogenic sources and to a lesser extent by wind speed and direction. Octanol-air and clothing-air partition coefficients of PAHs obtained from personal air samples were significantly correlated to each other. High molecular-weight PAHs had higher area-normalized clothing-air partition coefficients in cotton clothes, i.e., cotton fabrics may be a significant reservoir of higher molecular-weight PAHs. Capsule Particle-bound PAHs from barbecue fumes are generated largely from charcoal combustion and food-charred emissions and mainly affiliated with fine particles. [ABSTRACT FROM AUTHOR]

Natural organic matter and grain size are considered as important parameters dictating the transport and fate of organic compounds in sediment. However, increasing evidence suggested that manufactured debris may alter the underlying mechanisms for biogeochemical cycling of organic compounds. To examine this assumption, estuarine sediment and embedded debris were collected from a fishery base in Guangdong Province of South China and analyzed for organophosphorus flame retardants (OPFRs), phthalates (PAEs), organotin compounds (OTs) and dichlorodiphenyltrichloroethanes (DDTs). Coarse-size debris (> 200 μm) were heterogeneously distributed in sediment, and most abundant near the boat maintenance facilities, aquaculture zone and shipping channel. The median concentrations of OPFRs, OTs, PAEs and DDTs in debris were 11 , 0.2, 11 and 3.9 μg g −1 dry sample weight −1 , respectively, 1 to 3 orders of magnitude greater than those in bulk sediment (19, 60, 240 and 570 ng g −1 dry sample weight −1 , respectively). Furthermore, OPFRs, OTs and PAEs were mostly (> 99%) enriched in coarse-size (63–2000 μm) sediment, and there was no significant correlation ( p > 0.05) between the concentrations of OPFRs, OTs and PAEs in bulk and size-fractioned sediment samples and total organic carbon or grain size, similar to the distribution pattern of DDTs reported previously. When distinct debris were removed from the light-density (< 1.7 g cm −3 ) fraction of coarse-size (200–2000 μm) sediment, the concentration levels of OPFRs, OTs, PAEs and DDTs declined by 84%, 59%, 55% and 7%, respectively. Obviously, debris irregularly distributed in sediment can alter the sediment sorption capacity for OPFRs, OTs and PAEs, and thus may undermine the significance of organic matter and grain size to the distribution of organic chemicals in sediment. Finally, commonly used procedures for preparing sediment samples and screening of debris may disturb the grain size distribution or underestimate the abundance of heavy-density debris, resulting in flawed sediment quality assessment. [ABSTRACT FROM AUTHOR]

To investigate the effects of human activity on contaminants in regional soil, hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were measured in 187 surface soil samples of different land-use types collected from the Pearl River Delta (PRD), South China. The concentrations of Σ 9 OH-PAH (sum of nine target analytes) ranged from 0.36 to 252 ng/g (median: 5.98 ng/g), with phenanthrene derivatives as the dominant components, accounting for ~70%. Among different land-use types, residency soil contained the highest levels of Σ 9 OH-PAH (median: 11.3 ng/g), followed by landfill soil (9.28 ng/g), industry soil (7.51 ng/g), agriculture soil (6.04 ng/g), forestry soil (4.28 ng/g) and drinking water source soil (4.20 ng/g). A higher value was also observed in soil from the central PRD (6.94 ng/g) than the surrounding areas (5.94 ng/g), which indicated a significant impact of human activity on OH-PAH contamination in soil. Correlation and principal component analysis indicated that OH-PAHs in PRD soil are likely derived from the degradation of their parent PAHs in the atmosphere and/or soil and not directly from the same source as the parent PAHs. The ratios of OH-PAHs to their parent PAHs also varied among different land-use types, which may be partly attributed to the different populations of microorganisms in different soil types or the different chemical properties of PAHs and their metabolites. Unlabelled Image • High levels of OH-PAHs were mainly concentrated in area with heavy human activities. • OH-PAHs are likely from degradation, not the same source together with parent-PAHs. • High concentration ratio of OH-PAHs/parent-PAHs was found in some soil samples. • Easier to get high above ratio for light PAHs in area with heavy human activities [ABSTRACT FROM AUTHOR]

To evaluate the impacts of anthropogenic events on the rapid urbanized environment, the levels of legacy organochlorine pesticides (OCPs) and current-use insecticides (CUPs), i.e., dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), pyrethroids and organophosphates in soil of the Pearl River Delta (PRD) and surrounding areas were examined. Spatial concentration distributions of legacy OCPs and CUPs shared similar patterns, with higher concentrations occurred in the central PRD with more urbanization level than that in the PRD's surrounding areas. Furthermore, relatively higher concentrations of OCPs and CUPs were found in the residency land than in other land-use types, which may be attributed to land-use change under rapid urbanization. Moderate correlations between gross domestic production or population density and insecticide levels in fifteen administrative districts indicated that insecticide spatial distributions may be driven by economic prosperity. The soil–air diffusive exchanges of DDTs and HCHs demonstrated that soil was a sink of atmospheric o , p ′-DDE, o , p ′-DDD, p , p ′-DDD and o , p ′-DDT, and was a secondary source of HCHs and p , p ′-DDT to atmosphere. The soil inventories of DDTs and HCHs (100 ± 134 and 83 ± 70 tons) were expected to decrease to half of their current values after 18 and 13 years, respectively, whereas the amounts of pyrethroids and organophosphates (39 and 6.2 tons) in soil were estimated to decrease after 4 and 2 years and then increase to 87 and 1.0 tons after 100 years. In this scenario, local residents in the PRD and surrounding areas will expose to the high health risk for pyrethroids by 2109. Strict ban on the use of technical DDTs and HCHs and proper training of famers to use insecticides may be the most effective ways to alleviate the health effect of soil contamination. [ABSTRACT FROM AUTHOR]

Abstract: The occurrence of polycyclic aromatic hydrocarbons (PAHs) in soil of the Pearl River Delta (PRD) and surrounding areas was examined on a basis of six land-use types and four geographic regions, from which the impacts of anthropogenic events on the terrestrial environment were evaluated. No significant difference in the concentrations of Σ28PAH and Σ15PAH (sums of 28 and 15 PAHs, respectively) was found among the land-use types of industry, landfill and residency. On the other hand, higher soil PAH concentrations occurred in the central PRD characterized by dense population and high urbanization level, compared to other geographic regions. Source diagnostics implicated the combustions of coal and refined petroleum as the major input sources of anthropogenic PAHs. Furthermore, low molecular weight PAHs tended to volatilize from soil to air while the opposite was prevailing for high molecular weight PAHs. The mean annual diffusive flux of Σ15PAH (852μgm−2 yr−1) from the soil to the atmosphere in the central PRD was greater than those in the PRD's periphery (195μgm−2 yr−1), West region (322μgm−2 yr−1) and East region (84.9μgm−2 yr−1), suggesting that the central PRD may have become a secondary source of PAHs to the surrounding areas. Finally, ecological risk assessment based on the classification from Maliszewska-Kordybach showed that 3.5% of soil within the central PRD was heavily contaminated by PAHs and 5.2million residents may be subjected to high health risk. [Copyright &y& Elsevier]

The effect of periphyton propagation in paddy fields on phosphorus biogeochemical cycling has received little attention. In this phytotron study, inorganic phosphorus (P i ) accumulation by periphyton was investigated for varying inputs of calcium [Ca(II)] or ferrous‑iron [Fe(II)], and lighting conditions. Results indicated that additions of Ca(II) or Fe(II) enhanced abiotic accumulation of P i by up to 16 times, and decreased solution P i concentration by up to 50%, especially under light condition. The enhanced P i accumulation into periphyton intensified with increasing P i concentration, and P i accumulation showed a positive linear relationship with Ca or Fe accumulation. Abiotic accumulation of P i induced by Ca(II) was mainly through Ca-phosphate precipitation, and co-precipitation of P with carbonates at pH > 8. Accumulation with added Fe(II) was mainly considered to be through Fe(III) phosphate precipitation coupled with adsorption of P i by ferric hydroxides. Moreover, Fe(II) was more effective than Ca(II) in promoting abiotic accumulation of P i by periphyton. Our results indicate the potential for controlling environmental factors to enhance the role of periphyton in biogeochemical cycling and P-use efficiency in paddy rice fields and to reduce P discharged to neighboring water bodies. [ABSTRACT FROM AUTHOR]

Measurements of atmospheric particulate mercury (PHg) were conducted at a suburban site in Jinan, China from June 2014 to December 2015. The average PHg concentration was 508.5 ± 402.7 pg m − 3 , and the average Hg content in PM 2.5 (particles with a diameter of 2.5 μm or less) was 6.60 ± 5.82 μg g − 1 . Both PHg and Hg content in PM 2.5 aerosols were comparable to levels in some cities in China and were much higher than in cities in North America and Europe. Weak correlations were found between PHg and meteorological parameters. The correlations between PHg and other pollutants in ambient air, including SO 2 , CO and NO χ , together with their wind dependence were used for source analysis, which suggested coal-fired industries, cement plants and traffic emissions as potential local sources for the site. Cluster analysis of 36-h backward trajectories suggested that the regional transport from southwestern Shandong Province also contributed to PHg in Jinan. [ABSTRACT FROM AUTHOR]

Human health concerns are rising with polybrominated diphenyl ethers' (PBDEs) analogues, methoxylated and hydroxylated PBDEs (MeO-PBDEs and OH-PBDEs), due to their occurrences in foods and greater potential toxicological effects than PBDEs. While the oral bioaccessibilities (BA%) of PBDEs in foods are available, such information on MeO-PBDEs and OH-PBDEs, and the effects of cooking on them have not been adequately addressed. The present study was conducted with fish and chicken egg as typical foods to assess the bioaccessibility (BA%) of PBDEs, MeO-PBDEs, and OH-PBDEs using the colon extended physiologically based extraction test and examine the effects of cooking processes (boiling, frying, and steaming) on them. The results showed that thermal degradation or transformation of the target compounds did not occur during boiling and frying of fish. The BA% of individual PBDEs, MeO-PBDEs, and OH-PBDEs were 20–51% for boiled fish, 11–20% for pan-fried fish, 15–77% for steamed egg, and 42–68% for pan-fried egg. Cooking decreased the BA% of all target compounds in fish due to protein denaturation. However, the BA% of OH-PBDEs in pan-fried egg were greater than those in steamed egg. In addition, the substituent groups of CH 3 O- and OH- did not pose any effects on the BA% of BDE-47 in fish, but OH-group decreased its BA% in egg. These findings suggested that MeO-PBDEs and OH-PBDEs exhibited the similar oral BA% in fish to PBDEs, but the underlying mechanism for the effects of cooking on BA% of OH-PBDEs in egg needs to be further investigated. Unlabelled Image • MeO- and OH-PBDEs exhibited the similar bioaccessibility in fish and egg to PBDEs. • Cooking decreased the bioaccessibility of PBDEs, MeO-PBDEs, and OH-PBDEs in fish. • PBDEs and MeO- and OH-PBDEs were more bioaccessible in fried egg than fried fish. [ABSTRACT FROM AUTHOR]

• Sufficient P further improves biodiesel production under N starvation in glucose. • Soybean processing wastewater (SPW) is suitable for applying N and P regulation. • N-sufficient stage (stage 1) and N-starvation stage (stage 2) are naturally formed. • S. obliquus grows rapidly in stage 1 and accumulates lipids quickly in stage 2. • High fatty acids productivity in SPW verifies N and P regulation in glucose. In this study, the effects of nitrogen and phosphorus supply on biodiesel production from Scenedesmus obliquus with glucose as the carbon source were investigated. It was found that sufficient phosphorus could further improve biodiesel production under nitrogen starvation. S. obliquus was cultivated in soybean processing wastewater. The removal efficiencies of carbon oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) after 8-day cultivation were 72%, 95%, and 54%, respectively. Moreover, the fatty acid productivity after eight-day cultivation reached as high as 99.3 mg·L−1·d−1, which was 1.15 times higher than the highest efficiency using a glucose culture. This result was due to two naturally-formed stages occurring with sufficient phosphorus: nitrogen sufficiency stage for biomass and nitrogen starvation stage for lipid accumulation. It verified the conclusion of the roles of nitrogen and phosphorus obtained in the glucose culture and provided an economic and environmentally friendly choice for biodiesel production with efficient soybean wastewater treatment. [ABSTRACT FROM AUTHOR]