Cities and contaminated areas can be primary or secondary sources of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and other chemicals, into air and soil and can influence the regional level of some of these pollutants. In a contaminated site, the evaluation of such emissions can be crucial in the choice of the remediation technology to be adopted. In the city of Brescia (Northern Italy), more than 100 ha of agricultural areas were contaminated with PCBs, PCDD/Fs and heavy metals, originating from the activities of a former PCB factory. In order to evaluate the current emissions of PCBs and PCDD/Fs from the contaminated site, in a location where other current sources are present, we compared measured and predicted air concentrations, resulting from chemical volatilization from soils as well as fingerprints of Brescia soils and of soils contaminated by specific sources. The results confirm that the contaminated area is still a current and important secondary source of PCBs to the air, and to a lesser extent of PCDFs (especially the more volatile), but not for PCDDs. PCBs in soils have fingerprints similar to highly chlorinated mixtures, indicating contamination by these mixtures and/or a long weathering process. PCB 209 is also present at important levels. PCDD fingerprints in soil cannot be related to current emission sources, while PCDFs are compatible to industrial and municipal waste incineration, although weathering and/or natural attenuation may have played a role in modifying such soil fingerprints. Finally, we combined chemical and microbiological analyses to provide an integrated approach to evaluate soil fingerprints and their variation in a wider perspective, which accounts for the mutual effects between contamination and soil microbiota, a pivotal hint for addressing in situ bioremediation activities.

Concentrations of alternative flame retardants and polybrominated diphenyl ethers (PBDEs) were analyzed in ringed seal (Phoca hispida) blubber collected across the Canadian Arctic during subsistence hunts between 1998 and 2013. More than 80% of sampled animals were females and juvenile males. The highest mean ΣPBDE concentrations (sum of 13 congeners) were found in seals from Nain (Nunatsiavut) as well as Inukjuaq and Arviat (Hudson Bay) and the lowest mean levels were found in seals from Lancaster Sound. BDE-47 and -99 were the predominant PBDE congeners quantified in ringed seals. The most frequently detected non-PBDE flame retardants were polybrominated biphenyl 101 (BB-101, 57% of samples analyzed for this chemical), hexabromocyclododecane (HBCDD; 38%), hexabromobenzene (HBB, 30%), and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTeBB, 23%). The relative trophic position of seals, estimated using stable isotopes, did not vary over time and did not influence flame retardant blubber concentrations. The relative carbon source increased over time at Arviat and Resolute Bay and weak relationships were observed with ΣPBDEs in blubber of seals. ΣPBDEs increased significantly from 1998 to 2008 in ringed seals from East Baffin and subsequently decreased in recent years. PBDE levels at other sites fluctuated slightly over time. HBCDD concentrations increased at several sites over the past decade. The presence of flame retardants in ringed seals suggests their persistence and their continuous inputs in the Canadian Arctic environment. Monitoring and research on the effects of these contaminants in seals are warranted given the importance of this species in the arctic marine food web and for local communities.

Increased use of commercial titanium dioxide nanoparticles (TiO2 NPs) in consumer products most likely leads to their additional environmental release. Aggregation and disaggregation processes are expected to play an important role in the fate and transport of TiO2 NPs in natural aquatic ecosystems. Therefore, in this work, we have studied the colloidal stability of TiO2 NPs in the presence of extracellular polymeric substances (EPS) from Bacillus subtilis and the adsorption behavior of EPS on TiO2 NPs in aqueous solutions at different pH values and ionic strengths (IS). The adsorption and aggregation processes were found to depend on the solution chemistry. The mass fraction of EPS on TiO2 NPs decreased with increased pH and NaCl concentrations, which was verified by Fourier transform infrared spectroscopy. The presence of EPS can substantially influence the colloidal stability of TiO2 NPs. In deionized water, the aggregation of NPs was induced by the addition of EPS only when the pH was below the TiO2 NP point of zero charge (≈6). When the pH was equal to pHPZC, TiO2, the TiO2 NPs would rapidly form large aggregates, but the adsorption of EPS leads to partial fragmentation via electrostatic repulsion and steric hindrance. When the pH was greater than pHPZC, TiO2, the aggregation rate was minimally affected by the increased EPS concentration. In NaCl solution, the aggregation rate of TiO2 NPs obviously increased with increased NaCl concentration. The critical coagulation concentration (CCC) of TiO2 NPs is 13.9 mM in the absence of EPS and increases to 155.6, 213.7 and 316.4 mM in the presence of 1, 5 and 10 mg/L EPS in NaCl solution, respectively, which indicates that the steric hindrance occurs after the addition of EPS. This study suggests that environmental conditions and EPS concentration greatly modify the colloidal stability of TiO2 nanoparticles.

We investigated the associations between exposure to polycyclic aromatic hydrocarbons (PAHs) and selected respiratory physiologic measures in cycles 2 and 3 of the Canadian Health Measures Survey, a nationally representative population sample. Using generalized linear mixed models, we tested the association between selected PAH metabolites and 1-second forced expiratory volume (FEV1), forced vital capacity (FVC), and the ratio between the two (FEV1/FVC) in 3531 people from 6 to 79 years of age. An interquartile change in urinary PAH metabolite was associated with significant decrements in FEV1 and FVC for eight PAHs, 2-hydroxynapthalene, 1-, and 2-hydroxyphenanthrene, 2-, 3-, and 9-hydroxyfluorene and 3- and 4-hydroxyphenanthrene. Exposure to PAH may negatively affect lung function in the Canadian population.

We assessed mercury (Hg) pollution in China's coastal waters, including the Bohai Sea, the Yellow Sea, the East China Sea and the South China Sea, based on a nationwide dataset from 301 sampling sites. A methylmercury (MeHg) intake model for humans based on the marine food chain and human fish consumption was established to determine the linkage between water pollutants and the pollutant intake by humans. The predicted MeHg concentration in fish from the Bohai Sea was the highest among the four seas included in the study. The MeHg intake through dietary ingestion was dominant for the fish and was considerably higher than the MeHg intake through water respiration. The predicted MeHg concentrations in human blood in the coastal regions of China ranged from 1.37 to 2.77 μg/L for pregnant woman and from 0.43 to 1.00 μg/L for infants, respectively, based on different diet sources. The carnivorous fish consumption advisory for pregnant women was estimated to be 288–654 g per week to maintain MeHg concentrations in human blood at levels below the threshold level (4.4 μg/L established by the US Environmental Protection Agency). With a 50% increase in Hg concentrations in water in the Bohai Sea, the bioaccumulated MeHg concentration (4.5 μg/L) in the fish consumers will be higher than the threshold level. This study demonstrates the importance in controlling Hg pollution in China's coastal waters. An official recommendation guideline for the fish consumption rate and its sources will be necessary for vulnerable populations in China.

The presence of organic pollutants in the aquatic environment, usually found at trace concentrations (i.e., between ng L−1 and μg L−1 or even lower, known as micropollutants), has been highlighted in recent decades as a worldwide environmental concern due to their difficult elimination by conventional water and wastewater treatment processes. The relevant information on constructed wetlands (CWs) and their application for the removal of a specific group of pollutants, 41 organic priority substances/classes of substances (PSs) and 8 certain other substances with environmental quality standards (EQS) listed in Directive 2013/39/EU as well as 17 contaminants of emerging concern (CECs) of the Watch List of Decision 2015/495/EU, is herein reviewed. Studies were found for 24 PSs and 2 other substances with EQS: octylphenol, nonylphenol, perfluorooctane sulfonic acid, di(2-ethylhexyl)phthalate, trichloromethane, dichloromethane, 1,2-dichloroethane, pentachlorobenzene, benzene, polychlorinated dibenzo-p-dioxins, naphthalene, fluoranthene, trifluralin, alachlor, isoproturon, diuron, tributyltin compounds, simazine, atrazine, chlorpyrifos (chlorpyrifos-ethyl), chlorfenvinphos, hexachlorobenzene, pentachlorophenol, endosulfan, dichlorodiphenyltrichloroethane (or DDT) and dieldrin. A few reports were also published for 8 CECs: imidacloprid, erythromycin, clarithromycin, azithromycin, diclofenac, estrone, 17-beta-estradiol and 17-alpha-ethinylestradiol. No references were found for the other 17 PSs, 6 certain other substances with EQS and 9 CECs listed in EU legislation.

Vehicle emissions have become one of the key factors affecting the urban air quality and climate change in the Pearl River Delta (PRD) region, so it is important to design policies of emission reduction based on quantitative Co-benefits for air pollutants and greenhouse gas (GHG). Emissions of air pollutants and GHG by 2020 was predicted firstly based on the no-control scenario, and five vehicle emissions reduction scenarios were designed in view of the economy, technology and policy, whose emissions reduction were calculated. Then Co-benefits between air pollutants and GHG were quantitatively analyzed by the methods of coordinate system and cross-elasticity. Results show that the emissions reduction effects and the Co-benefits of different measures vary greatly in 2015–2020. If no control scheme was applied, most air pollutants and GHG would increase substantially by 20–64% by 2020, with the exception of CO, VOC and PM2.5. Different control measures had different reduction effects for single air pollutant and GHG. The worst reduction measure was Eliminating Motorcycles with average reducing rate 0.09% for air pollutants and GHG, while the rate from Updated Emission Standard was 41.74%. Eliminating Yellow-label Vehicle scenario had an obvious reduction effect for every single pollutant in the earlier years, but Co-benefits would descent to zero in later by 2020. From the perspective of emission reductions and co-control effect, Updated Emission Standard scenario was best for reducing air pollutants and GHG substantially (tanα=1.43 and Els=1.77).

Measuring black carbon (BC) is critical to understand the impact of combustion aerosols on air quality and climate change. In this study, BC was measured in 2014 at a unique community formed with rapid economic development and urbanization in an urban-rural fringe area of Beijing. Hourly BC concentrations were 0.1–33.5 μg/m3 with the annual average of 4.4 ± 3.7 μg/m3. BC concentrations had clear diurnal, weekly, and seasonal variations, and were closely related with atmospheric visibility. The absorption coefficient of aerosols increased while its contribution to extinction coefficient decreased with the enhancement of PM2.5 concentration. The high mass absorption efficiency (MAE) of EC was attributed to a combination of coal combustion, vehicular emission and rapidly coating by water-soluble ions and organic carbon (OC). BC concentrations followed a typical lognormal pattern, with over 88% samples in 0.1–10.0 μg/m3. Low BC levels were mostly bounded up with winds from north and northwest. Coal combustion and biomass burning were closely associated with severe haze pollution events. Firework discharge had significant UV absorption contribution. During the Asia-Pacific Economic Cooperation (APEC) forum in November 2014, air quality obviously improved due to various control strategies.

Perfluorooctane sulfonate (PFOS), a hepatic toxicant and a potential hepatocarcinogen, is commonly used in industrial products. The widespread contamination of PFOS in human maternal and cord blood has raised concerns about its potential risks to the fetus. It is believed that adverse environmental exposure during the critical period of embryo development can have long-lasting consequences in later life. In this report, we used transcriptome sequencing, followed by bioinformatics analysis, to elucidate the potential hepatotoxic and hepatocarcinogenic effects of prenatal PFOS exposure in the fetus. Our results demonstrated that prenatal PFOS exposure could activate the synthesis and metabolism of fatty acids and lipids, leading to liver damage and interference with liver development in the fetus. In addition, a number of cancer-promoting signaling pathways, including Wnt/β-catenin, Rac, and TGF-β, were found to be activated in the fetal liver. More importantly, hepatic transaminase activity, including aspartate aminotransferase and alanine transaminase activity, was induced in the liver of mice offspring after prenatal PFOS exposure. For the first time, our results demonstrate that the hepatotoxic effects of prenatal exposure to PFOS may predispose to a long-term liver disorder in the offspring.

Although organophosphate esters (OPEs) have been detected with growing frequency in water ecosystems, the underlying accumulation mechanisms of these compounds in fish are still unknown. Here, we investigated the tissue-specific accumulation and depuration of seven OPEs in adult zebrafish at three levels (0, 1/150 LC50 (environmentally relevant level), and 1/30 LC50 per OPE congener) in laboratory after 19 days exposure and 3 days depuration. The bioaccumulation of OPEs varied among tissues. Muscle contained the lowest level of OPEs and liver had the highest level of two (TPP and TCEP) of the seven OPEs at steady state. The high levels and slow depuration rates of TDCIPP, TPHP, and TCP observed in roe indicated that the accumulated OPEs were potentially stored in roe and transferred to the next generation. After examination of the major metabolites (organophosphate diesters) in selected tissues, a physiologically based toxicokinetic (PBTK) model used in fish was adopted to explore the key factors affecting the bioaccumulation of OPEs in zebrafish. Biotransformation of OPEs with polychlorinated alkyl moieties (i.e. TDCIPP) and aryl moieties (i.e. TPHP and TCP) has more significant impacts on the accumulation than those of OPEs with alkyl or short chain chlorinated alkyl moieties. Furthermore, the partition process between tissues and blood was also investigated, and was demonstrated to be the dominant process for OPEs accumulation in zebrafish. This study provides critical information on the bioaccumulation, tissue distribution, and metabolization of OPEs in relation with OPE structures in fish, as well as the underlying bioaccumulation mechanisms/pathways of OPEs in aquatic life.