Seawater flue gas desulfurization (SFGD) systems are commonly used to remove acidic SO2 from the flue gas with alkaline seawater in many coastal coal-fired power plants in China. However, large amount of mercury (Hg) originated from coal is also transferred into seawater during the desulfurization (De-SO2) process. This research investigated Hg isotopes in seawater discharged from a coastal plant equipped with a SFGD system for the first time. Suspended particles of inorganic minerals, carbon residuals and sulfides are enriched in heavy Hg isotopes during the De-SO2 process. δ202Hg of particulate mercury (PHg) gradually decreased from −0.30‰ to −1.53‰ in study sea area as the distance from the point of discharge increased. The results revealed that physical mixing of contaminated De-SO2 seawater and uncontaminated fresh seawater caused a change in isotopic composition of PHg isotopes in the discharging area; and suggested that both De-SO2 seawater and local background contributed to PHg. The impacted sea area predicted with isotopic tracing technique was much larger than that resulted from a simple comparison of pollutant concentration. It was the first attempt to apply mercury isotopic composition signatures with two-component mixing model to trace the mercury pollution and its influence in seawater. The results could be beneficial to the coal-fired plants with SFGD systems to assess and control Hg pollution in sea area.

Elevated nitrogen (N) deposition impacts the structure and functioning of heathland ecosystems across Europe. Calluna plants under high N-inputs are very sensitive to secondary stress factors, including defoliation attacks by the heather beetle. These attacks result in serious damage or death of Calluna, its rapid replacement by grasses, and the subsequent loss of heathland. We know very little about the mechanisms that control the populations and trigger outbreaks of the heather beetle, impeding proper management measures to mitigate the damage. We investigated the effects of N deposition on the relationships between the heather beetle, its host plant, and two arthropod predators at building (rejuvenated through fire) and mature heathlands. The study combines field manipulation experiments simulating a range of N deposition rates (0, 1, 2, 5 g N m−2 year−1 for 2 years, and 5.6 g N m−2 year−1 for 10 years), and food-choice laboratory experiments testing the preferences of adults and larvae of the heather beetle for N-treated Calluna plants, and the preferences of predators for larvae grown on plants with different N-content. The larvae of the heather beetle achieved the highest abundances after the long-term (10-year) addition of N at mature Calluna plots in the field. Contrary to the adults, the larvae foraged preferentially on the most N-rich Calluna shoots under laboratory conditions. Predators showed no aggregative numerical responses to the accumulation of heather beetle larvae at high N-input experimental plots. During the feeding trials, predators consumed a small number of larvae, both in total and per individual, and systematically avoided eating the larvae reared on high-N Calluna shoots. Our study showed that the most severe defoliation damage by the heather beetle is inflicted at the larval stage under prolonged availability of high-N inputs, and that arthropod predators might not act as effective regulators of the beetle's populations.

Atmospheric nitrogen deposition is one of the main threats for biodiversity and ecosystem functioning. Measurement techniques like ion-exchange resin collectors (IECs), which are less expensive and time-consuming than conventional methods, are gaining relevance in the study of atmospheric deposition and are recommended to expand monitoring networks. In the present work, bulk and throughfall deposition of inorganic nitrogen were monitored in three different holm oak forests in Spain during two years. The results obtained with IECs were contrasted with a conventional technique using bottle collectors and with a literature review of similar studies. The performance of IECs in comparison with the conventional method was good for measuring bulk deposition of nitrate and acceptable for ammonium and total dissolved inorganic nitrogen. Mean annual bulk deposition of inorganic nitrogen ranged 3.09–5.43 kg N ha−1 according to IEC methodology, and 2.42–6.83 kg N ha−1 y−1 using the conventional method. Intra-annual variability of the net throughfall deposition of nitrogen measured with the conventional method revealed the existence of input pulses of nitrogen into the forest soil after dry periods, presumably originated from the washing of dry deposition accumulated in the canopy. Important methodological recommendations on the IEC method and discussed, compiled and summarized.

Polycyclic aromatic hydrocarbons (PAHs) derivatives like nitrated and oxygenated PAHs are of growing concerns because of considerably higher toxicity and important roles during atmospheric chemical reactions. Residential solid fuel combustion is likely to be one large primary source of these pollutants in developing countries. In this study, inhalation exposure to nitrated and oxygenated PAH derivatives was evaluated among rural residents using carried samplers. The exposure levels of individual nitrated PAHs ranged from 4.04 (9-nitrated phenanthrene) to 89.8 (9-nitrated anthracene) pg/m3, and of oxy-PAHs were 0.570 (benzo[a]anthracene-7, 12-dione) to 7.99 (Benzanthrone) ng/m3, generally higher in wood user than that in anthracite user. A majority of derivatives in particle presented in PM2.5 (80% for nitrated naphthalene and over 90% for other targets) and even fine PM1.0. Mass fractions of PAH derivatives in fine and ultra-fine particles were significantly higher than the fractions of corresponding parent PAHs, indicating more adverse health outcomes induced by these derivatives. The inhalation exposure levels for residents adopting wood gasifier burners was significantly lower than the documented results for those burning wood in typical built-in brick stoves, and comparable to those using LPG and electricity, which provided vital information for clean stove development and intervention programs.

The sorption of PAH on 12 different sediments was investigated and was correlated to their corresponding organic matter (OM) content and quality. For this purpose, the OM was precisely characterized using thermal analysis consisting in the successive combustion and quantification of the increasingly thermostable fractions of the OM. Simultaneously, the water-exchangeable fraction of the sorbed PAH defined as the amount of PAH freely exchanged between the water and the sediment (by opposition to the PAH harshly sorbed to the sediments particles) was determined using a passive sampler methodology recently developed. The water concentrations, when the sediment-water system is equilibrated, were also assessed which allows the determination of the sediment-water distribution coefficients without artifacts introduced by the non water-exchangeable fraction of PAH. Hence, the present study provides the distribution coefficients of PAH between the water and 4 different OM fractions combusted at a specific temperature range. The calculated distribution coefficients demonstrate that the sedimentary OM combusted at the intermediate temperature range (between 300 °C and 450 °C) drives the reversible sorption of PAH while the inferred sorption to the OM combusted at a lower and higher temperature range does not dominate the partitioning process.

Airborne fine particulate matter (PM2.5) is a risk factor for respiratory diseases. However, little is known about the effects of PM2.5 on bronchi. The present study investigated the effect of airborne PM2.5 on rat bronchi and the underlying mechanisms. Isolated rat bronchial segments were cultured for 24 h. Endothelin (ET) receptor-mediated contractile responses were recorded using a wire myograph. The mRNA and protein expression levels of ET receptors were studied using quantitative real-time PCR, Western blotting, and immunohistochemistry. The results demonstrated that ETA and ETB receptor agonists induced remarkable contractile responses on fresh and cultured bronchial segments. PM2.5 (1.0 or 3.0 μg/ml) significantly enhanced ETA and ETB receptor-mediated contractile responses in bronchi with a markedly increased maximal contraction compared to the DMSO or fresh groups. PM2.5 increased the mRNA and protein expression levels of ETA and ETB receptors. U0126 (a MEK1/2 inhibitor) and SB203580 (a p38 inhibitor) significantly suppressed PM2.5-induced increases in ETB receptor-mediated contractile responses, mRNA and protein levels. SP600125 (a JNK inhibitor) and SB203580 significantly abrogated the PM2.5-induced enhancement of ETA receptor-mediated contraction and receptor expression. In conclusion, PM2.5 upregulates ET receptors in bronchi. ETB receptor upregulation is associated with MEK1/2 and p38 pathways, and the upregulation of ETA receptor is involved in JNK and p38 pathways.

Exposure to ambient air pollution has been clearly linked to adverse reproductive outcome and fecundation index, but its effects on male semen quality are still uncertain. In this study, we reviewed information from ten studies to get the qualitative evidence of the influence of the ambient air pollution on sperm quality and collected data from six of the ten studies to conduct meta-analysis. The original studies classified participants into different exposure levels and the highest and lowest expose levels were chosen as high expose and low expose groups, respectively. The random-effect model was used in the meta-analysis with the weight mean difference (WMD) as the measure indicator. The WMDs (95% confidence intervals, CIs) of sperm volume, sperm count, semen concentration, sperm progressive motility, total motility, and normal morphology were 0.09 (−0.04, 0.23), 0.46 (−4.47, 5.39), −8.21 (−20.38, 3.96), −7.76 (−16.26, 0.74), −7.61 (−16.97, 1.74) and −3.40 (−7.42, 0.62), respectively. In conclusion, although the differences are not statistically significant between the two groups, the overall trends and evidence from this review indicate the chronic exposure to ambient pollutants at high level may alter men sperm quality.

Using a global database of contaminated sites, toxic hotspots in eight former Soviet countries were analyzed to identify the prevalence, types and sources of toxic pollution, as well as their associated potential public health impacts. For this analysis, polluted sites in Armenia, Azerbaijan, Kazakhstan, Kyrgyzstan, Russia, Tajikistan, Ukraine, and Uzbekistan were compiled and analyzed. The levels of contamination of seven key pollutants were assessed in each country. 424 contaminated sites were identified using data from Blacksmith Institute. Pesticides, lead (Pb), radioactive metals, arsenic (As), mercury (Hg), chromium (Cr), and cadmium (Cd) were the most commonly identified key pollutants. Collectively, these sites pose health risks to an estimated 6.2 million residents. The existing data on toxic hotspots in former Soviet countries likely captures only a small percentage of actual contaminated sites, but suggests potentially severe public health consequences. Additional assessments are needed to understand the risks posed by toxic pollution in the region.

Environmental contamination with radioactive materials of geogenic and anthropogenic origin is a global problem. A variety of mutagenicity test procedures has been developed which enable the detection of DNA damage caused by ionizing radiation which plays a key role in the adverse effects caused by radioisotopes. In the present study, we investigated the usefulness of the Tradescantia micronucleus test (the most widely used plant based genotoxicity bioassay) for the detection of genetic damage caused by environmental samples and a human artifact (ceramic plate) which contained radioactive elements. We compared the results obtained with different exposure protocols and found that direct exposure of the inflorescences is more sensitive and that the number of micronuclei can be further increased under “wet” conditions. The lowest dose rate which caused a significant effect was 1.2 μGy/h (10 h). Comparisons with the results obtained with other systems (i.e. with mitotic cells of higher plants, molluscs, insects, fish and human lymphocytes) show that the Tradescantia MN assay is one to three orders of magnitude more sensitive as other models, which are currently available. Taken together, our findings indicate that this method is due to its high sensitivity a unique tool, which can be used for environmental biomonitoring in radiation polluted areas.

Illicit drugs have been recognized as a group of emerging contaminants. In this work, occurrence of common illicit drugs and their metabolites in Chinese surface waters was examined by collecting samples from 49 lakes and 4 major rivers across the country. Among the drugs examined, methamphetamine and ketamine were detected with highest frequencies and concentration levels, consistent with the fact that these are primary drugs of abuse in China. Detection frequencies and concentrations of other drugs were much lower than in European lakes and rivers reported in the literature. In most Chinese surface waters methamphetamine and ketamine were detected at concentrations of several ng L−1 or less, but in some southern lakes and rivers, these two drugs were detected at much higher concentrations (up to several tens ng L−1). Greater occurrence of methamphetamine and ketamine in southern surface waters was attributed to greater abuse and more clandestine production of the two drugs in southern China.