The production and use of pentachlorophenol (PCP) was recently prohibited/restricted by the Stockholm Convention on persistent organic pollutants (POPs), but environmental data are few and of varying quality. We here present the first extensive dataset of the continent-wide (Eurasia and Canada) occurrence of PCP and its methylation product pentachloroanisole (PCA) in the environment, specifically in pine needles. The highest concentrations of PCP were found close to expected point sources, while PCA chiefly shows a northern and/or coastal distribution not correlating with PCP distribution. Although long-range transport and environmental methylation of PCP or formation from other precursors cannot be excluded, the distribution patterns suggest that such processes may not be the only source of PCA to remote regions and unknown sources should be sought. We suggest that natural sources, e.g., chlorination of organic matter in Boreal forest soils enhanced by chloride deposition from marine sources, should be investigated as a possible partial explanation of the observed distributions. The results show that neither PCA nor total PCP (ΣPCP = PCP + PCA) should be used to approximate the concentrations of PCP; PCP and PCA must be determined and quantified separately to understand their occurrence and fate in the environment. The background work shows that the accumulation of airborne POPs in plants is a complex process. The variations in life cycles and physiological adaptations have to be taken into account when using plants to evaluate the concentrations of POPs in remote areas.

Uptake of selenium (Se) by plants largely depend on the availability of Se in soil. Soils and plants were sampled four times within 8 weeks of plant growth in pot experiments using four plant species. Sequential extraction and diffusive gradients in thin-films (DGT) method were employed to measure Se concentrations in potted soils in selenite- or selenate-amended soils. Results showed that DGT-measured Se concentrations (CDGT−Se) were generally several folds higher for selenate than selenite amended soils, which were obviously affected by the plant species and the duration of their growth. For example, the folds in soil planted with mustard were 1.49–3.47 and those in soils planted with purple cabbage and broccoli, which grew for 3 and 4 weeks after sowing, were 1.06–2.14 and only 0.15–0.62 after 6 weeks of growth. The selenate-amended soil planted with wheat showed an extremely high CDGT−Se compared with selenite-amended soil, except the last harvest. Furthermore, minimal changes in CDGT−Se and soluble Se(IV) were found in selenite-amended soils during plant growth, whereas significant changes were observed in selenate-amended soils (p < 0.05). Additionally, Se distribution in various fractions of soil remarkably changed; the soils planted with purple cabbage and broccoli showed the most obvious change followed by wheat and mustard. Soluble Se(VI) and exchangeable Se(VI) were likely the major sources of CDGT−Se in selenate-amended soils, and soluble Se(IV) was the possible source of CDGT−Se in selenite-amended soils. In selenate-amended soils, soluble Se(VI) and exchangeable Se(VI) were significantly correlated with Se concentrations in purple cabbage, broccoli, and mustard; in wheat, Se concentration was significantly correlated only with soluble Se(VI) but not with exchangeable Se. CDGT−Se eventually became positively correlated with Se concentrations accumulated by different plants, indicating that DGT is a feasible method in predicting plant uptake of selenate but not of selenite.

The association between ambient temperature and mortality has been well documented worldwide. However, limited data are available on nonfatal health outcomes, such as emergency department visits (EDVs), particularly from China.To examine the temperature-EDV association in 12 Chinese cities; and to assess the modification effects by region, gender and age.Daily meteorological data and non-accidental EDVs were collected during 2011–2014. Poisson regression with distributed lag non-linear model was applied to examine the temperature-lag-EDV association in each city. The effect estimates were pooled using multivariate meta-analysis at the national and regional level. Stratified analyses were performed by gender and age-groups. Sensitivity analyses adjusting for air pollution and relative humidity were conducted.A total of 4,443,127 EDVs were collected from the 12 cities. Both cold and hot temperatures were associated with increased risk of EDVs, with minimum-mortality temperature located at 64th percentile of temperature. The effect of cold temperature appeared on day 2 and persisted until day 30, causing a cumulative relative risk (RR) of 1.80 (1.54, 2.11). The effect of hot temperature appeared immediately and lasted until day 3, with a cumulative RR of 1.15 (1.03, 1.29). The effect of temperature on EDVs was similar in male and female but was attenuated with increasing age. The effect of cold temperature on EDVs was greater in southern areas of the country whereas the hot effect was greater in northern cities. The association was robust to a large range of sensitivity analyses.In China, there is a U-shaped association between temperature and risk of EDVs that is independent of air pollution and humidity. The temperature-EDV association varies with latitude and age-groups but is not affected by gender. Forecasting models for hospital emergency departments may be improved if temperature is included as an independent predictor.

Understanding the phytoavailability of bound residues of polycyclic aromatic hydrocarbons (PAHs) in soils is essential to assessing their environmental fate and risks. This study investigated the release and plant uptake of bound PAH residues (reference to parent compounds) in field contaminated soils after the removal of extractable PAH fractions. Plant pot experiments were performed in a greenhouse using ryegrass (Lolium multiflorum Lam.) to examine the phytoavailablility of bound PAH residues, and microcosm incubation experiments with and without the addition of artificial root exudates (AREs) or oxalic acid were conducted to examine the effect of root exudates on the release of bound PAH residues. PAH accumulation in the ryegrass after a 50-day growth period indicated that bound PAH residues were significantly phytoavailable. The extractable fractions, including the desorbing and non-desorbing fractions, dominated the total PAH concentrations in vegetated soils after 50 days, indicating the transfer of bound PAH residues to the extractable fractions. This transfer was facilitated by root exudates. The addition of AREs and oxalic acid to test soils enhanced the release of bound PAH residues into their extractable fractions, resulting in enhanced phytoavailability of bound PAH residues in soils. This study provided important information regarding environmental fate and risks of bound PAH residues in soils.

A warming climate is anticipated to increase the future heat-related total mortality in urban areas. However, little evidence has been reported for cause-specific mortality or nonurban areas. Here we assessed the impact of climate change on heat-related total and cause-specific mortality in both urban and rural counties of Jiangsu Province, China, in the next five decades. To address the potential uncertainty in projecting future heat-related mortality, we applied localized urban- and nonurban-specific exposure response functions, six population projections including a no population change scenario and five Shared Socioeconomic Pathways (SSPs), and 42 temperature projections from 21 global-scale general circulation models and two Representative Concentration Pathways (RCPs). Results showed that projected warmer temperatures in 2016–2040 and 2041–2065 will lead to higher heat-related mortality for total non-accidental, cardiovascular, respiratory, stroke, ischemic heart disease (IHD), and chronic obstructive pulmonary disease (COPD) causes occurring annually during May to September in Jiangsu Province, China. Nonurban residents in Jiangsu will suffer from more excess heat-related cause-specific mortality in 2016–2065 than urban residents. Variations across climate models and RCPs dominated the uncertainty of heat-related mortality estimation whereas population size change only had limited influence. Our findings suggest that targeted climate change mitigation and adaptation measures should be taken in both urban and nonurban areas of Jiangsu Province. Specific public health interventions should be focused on the leading causes of death (stroke, IHD, and COPD), whose health burden will be amplified by a warming climate.

There are limited ambient air measurements of extended (beyond EPA Priority 16) lists of polycyclic aromatic hydrocarbons (PAHs). We measured air concentrations of 45 PAHs using passive and active air sampling at 15 sites in a central urban community and one rural site for two years. Passive sampling was conducted with cylindrical XAD-based samplers deployed to capture spatial variability. High volume active samplers with quartz fiber filters for particles and XAD-4 absorbent for gases were deployed at two urban sites and the rural site to calibrate the passive measurements directly. Estimated passive sampling rates (PSRs) were evaluated as functions of meteorological data, seasons, locations, study year, and compared with other studies. Possible particle collection by the passive samplers was evaluated using a variety of particle measurements (TSP, PM10, PM2.5 and ultrafines <100 nm). Total PAHs were statistically associated with ultrafine particle concentrations and to a lesser extent PM2.5 and PM10, but not TSP. PSRs were more variable when PAH mass loadings were lower and near method detection limits; this occurred more often at the rural site. The PSRs were not statistically associated with meteorological conditions in this study, but wind speed had the highest potential to impact PSR results. The resulting passive PAH measurements are reported with respect to proximity to major roadways and other known air emissions types. PSRs were quantifiable for some PAHs that were found predominantly in the particulate phase in active sampling. This information, together with particle fraction calculations from active sampling, were used to estimate the particulate PAH capture of the passive sampler. Summed PAH (∑PAH) passive concentrations were measured within the range of 10–265 ng/m3, with the highest concentrations from naphthalene and the lowest detected concentrations from anthracene. These results indicated a stronger seasonal signal within 200 m of a major roadway.

Samples of microplastic (n = 924) from two beaches in south west England have been analysed by field-portable-x-ray fluorescence (FP-XRF) spectrometry, configured in a low-density mode and with a small-spot facility, for the heavy metals, Cd and Pb, and the halogen, Br. Primary plastics in the form of pre-production pellets were the principal type of microplastic (>70%) on both beaches, with secondary, irregularly-shaped fragments representing the remainder of samples. Cadmium and Pb were detected in 6.9% and 7.5% of all microplastics, respectively, with concentrations of either metal that exceeded 103 μg g−1 usually encountered in red and yellow pellets or fragments. Respective correlations of Cd and Pb with Se and Cr were attributed to the presence of the coloured, inorganic pigments, cadmium sulphoselenide and lead chromate. Bromine, detected in 10.4% of microplastics and up to concentrations of about 13,000 μg g−1, was mainly encountered in neutrally-coloured pellets. Its strong correlation with Sb, whose oxides are effective fire suppressant synergists, suggests the presence of a variety of brominated flame retardants arising from the recycling of plastics originally used in casings for heat-generating electrical equipment. The maximum bioaccessible concentrations of Cd and Pb, evaluated using a physiological extraction based on the chemical characteristics of the proventriculus-gizzard of the northern fulmar, were about 50 μg g−1 and 8 μg g−1, respectively. These concentrations exceed those estimated for the diet of local seabirds by factors of about 50 and 4, respectively.

The Midwest United States is an intensely agricultural region where pesticides in streams pose risks to aquatic biota, but temporal variability in pesticide concentrations makes characterization of their exposure to organisms challenging. To compensate for the effects of temporal variability, we deployed polar organic chemical integrative samplers (POCIS) in 100 small streams across the Midwest for about 5 weeks during summer 2013 and analyzed the extracts for 227 pesticide compounds. Analysis of water samples collected weekly for pesticides during POCIS deployment allowed for comparison of POCIS results with periodic water-sampling results. The median number of pesticides detected in POCIS extracts was 62, and 141 compounds were detected at least once, indicating a high level of pesticide contamination of streams in the region. Sixty-five of the 141 compounds detected were pesticide degradates. Mean water concentrations estimated using published POCIS sampling rates strongly correlated with means of weekly water samples collected concurrently, however, the POCIS-estimated concentrations generally were lower than the measured water concentrations. Summed herbicide concentrations (units of ng/POCIS) were greater at agricultural sites than at urban sites but summed concentrations of insecticides and fungicides were greater at urban sites. Consistent with these differences, summed concentrations of herbicides correlate to percent cultivated crops in the watersheds and summed concentrations of insecticides and fungicides correlate to percent urban land use. With the exception of malathion concentrations at nine sites, POCIS-estimated water concentrations of pesticides were lower than aquatic-life benchmarks. The POCIS provide an alternative approach to traditional water sampling for characterizing chronic exposure to pesticides in streams across the Midwest region.

Thallium (Tl) is a highly toxic rare element. Severe Tl poisoning can cause neurological brain damage or even death. The present study was designed to investigate contents of Tl and other associated heavy metals in arable soils and twelve common vegetables cultivated around a steel plant in South China, a newly-found initiator of Tl pollution. Potential health risks of these metals to exposed population via consumption of vegetables were examined by calculating hazard quotients (HQ). The soils showed a significant contamination with Tl at a mean concentration of 1.34 mg/kg. The Tl levels in most vegetables (such as leaf lettuce, chard and pak choy) surpassed the maximum permissible level (0.5 mg/kg) according to the environmental quality standards for food in Germany. Vegetables like leaf lettuce, chard, pak choy, romaine lettuce and Indian beans all exhibited bioconcentration factors (BCF) and transfer factors (TF) for Tl higher than 1, indicating a hyperaccumulation of Tl in these plants. Although the elevated Tl levels in the vegetables at present will not immediately pose significant non-carcinogenic health risks to residents, it highlights the necessity of a permanent monitoring of Tl contamination in the steel-making areas.

Wet deposition is not only a mechanism for removing atmospheric pollutants, but also a process which reflects loadings of atmospheric pollutants. Our previous study on wet deposition examined the effectiveness of short-term control measures on atmospheric particulate pollution, which were partly effective for organic pollutants of current input sources. In the present study, dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs), representative of legacy contaminants, were measured in the same samples collected throughout the entire year of 2010 in Guangzhou, a large urban center in South China. Concentrations of ∑DDT (sum of o,p′ and p,p′-DDT, o,p′ and p,p′-DDE, o,p′ and p,p′-DDD, and p,p′-DDMU) and ∑HCH (sum of α-, β-, γ-, and δ-HCH) in wet deposition were in the ranges of nd–69 (average: 1.8 ng L−1) and nd–150 ng L−1 (average: 5.1 ng L−1), respectively. In addition, the results of source diagnostics and backward air mass trajectories appeared to suggest the transport of antifouling paint derived DDTs from the coastal region off South China to Guangzhou. The combined wet and dry deposition flux of ∑HCH in the first quarter (January to March) was greater than that in the fourth quarter (October to December), while those of ∑DDT were comparable in the first and fourth quarters. Similar trends were also observed for the concentrations of ∑HCH and ∑DDT in aerosol samples. These results suggested the short-term pollution control measures implemented during the 16th Asian Games and 10th Asian Para Games (held in November and December 2010, respectively) did not work well for DDTs. The reduced input of HCHs during the fourth quarter was probably associated with the strict ban on lindane for food safety, which also exposed the weakness of control measures focusing mainly on the removal of atmospheric particulate matter.