Underground coal fires start naturally or as a result of human activities. Besides burning away the important non-renewable energy resource and causing financial losses, burning coal seams emit carbon dioxide, carbon monoxide, sulfur oxide and methane, and is a leading cause of smog, acid rain, global warming, and air toxins. In the U.S. alone, the combined cost of coal-fire remediation projects that have been completed, budgeted, or projected by the U.S. Department of the Interior's Office of Surface Mining Remediation and Enforcement (OSM), exceeds $1 billion. It is estimated that these fires generate as much as 3% of the world's annual carbon dioxide emissions and consume as much as 5% of its minable coal. Considering the magnitude of environmental impact and economic loss caused by burning underground coal seams, we have developed a new, safe, reliable surface measurement of coal fire gases to assess the nature of underground coal fires. We use a drone mounted with gas sensors. Drone collected gas concentration data provides a safe alternative for evaluating the rank of a burning coal seam. In this study, a new method of determining coal rank by gas ratios is developed. Coal rank is valuable for defining parameters of a coal seam such as burn temperature, burn rate, and volume of burning seam.

The contamination levels and patterns of perfluoroalkyl acids (PFAAs) and their precursors in indoor air of children's bedrooms in Finland, Northern Europe, were investigated. Our study is among the most comprehensive indoor air monitoring studies (n = 57) and to our knowledge the first one to analyse air in children's bedrooms for PFASs (17 PFAAs and 9 precursors, including two acrylates, 6:2 FTAC and 6:2 FTMAC). The most frequently detected compound was 8:2 fluorotelomer alcohol (8:2 FTOH) with the highest median concentration (3570 pg/m3). FTOH concentrations were generally similar to previous studies, indicating that in 2014/2015 the impact of the industrial transition had been minor on FTOH levels in indoor air. However, in contrast to earlier studies (with one exception), median concentrations of 6:2 FTOH were higher than 10:2 FTOH. The C8 PFAAs are still the most abundant acids, even though they have now been phased out by major manufacturers. The mean concentrations of FOSE/As, especially MeFOSE (89.9 pg/m3), were at least an order of magnitude lower compared to previous studies. Collectively the comparison of FTOHs, PFAAs and FOSE/FOSAs with previous studies indicates that indoor air levels of PFASs display a time lag to changes in production of several years. This is the first indoor air study investigating 6:2 FTMAC, which was frequently detected (58%) and displayed some of the highest maximum concentrations (13 000 pg/m3). There were several statistically significant correlations between particular house and room characteristics and PFAS concentrations, most interestingly higher EtFOSE air concentrations in rooms with plastic floors compared to wood or laminate.

The exposures of pharmaceutical antibiotics in water solution caused potential risks for ecological environment and human health. In the present study, porous covalent triazine frameworks (CTFs) were synthesized and the adsorption behavior of sulfamethoxazole (SMX) and tylosin (TL) was investigated. The CTFs were characterized by X-ray diffraction, transform infrared and N2 adsorption/desorption. Sulfamethoxazole displayed much stronger adsorption than tylosin on microporous CTF-1 adsorbent due to the pore-filling effect. While the adsorption of bulky tylosin on microporous CTF-1 was suppressed because of the size exclusion effect. Additionally, the porous CTFDCBP showed stronger adsorption affinity and faster adsorption kinetics than other porous adsorbents, which was attributed to wide pore size distribution and open pore structure. Findings in this study highlight the potential of using porous CTFs as a potential adsorbent to eliminate antibiotics from water, especially for selective adsorption of bulky molecular pollutant.

A total of 82 aerosol samples (PM10-2.5) were collected from June 18, 2015 to October 1, 2016 at the remote sea site, the Ieodo Ocean Research Station (IORS), in the East China Sea. Samples were analyzed for 10 elements (Al, Fe, Cu, Zn, As, Mo, Cd, Sb, Tl, and Pb) as well as Pb isotopic composition to characterize temporal variations in elemental concentration levels, and to identify the potential source regions of atmospheric pollutants transported over the remote East China Sea. The results showed that the annual average element concentrations were lowest compared to those at different sites in East Asia, suggesting a very clean background area of IORS, with values ranging from 114 ng m⁻³ for Al to 0.045 ng m⁻³ for Tl. Concentrations averaged seasonally for all the elements revealed the highest levels occurring between winter and spring, and the lowest levels in summer. High enrichment factors (EF) of more than 100 for trace elements suggest that these elements originated mostly from anthropogenic sources. Coupling the Pb isotopic composition with a back trajectory analysis identified the potential source regions for each sample. Our approach identified China as a dominant contributor affecting atmospheric composition changes at IORS, the remote area of the East China Sea. As the largest anthropogenic emission source in East Asia, China contributed to almost 100% of the elemental concentration levels in winter and spring, ∼53% in summer and ∼63% in autumn. Because IORS's ambient air is sensitive to even slight changes in pollutant loading due to the significantly low pollution levels, long-term monitoring of air quality at IORS will provide invaluable information on the progress and efforts of atmospheric pollution management linked to emission controls in East Asian countries, especially China.

Based on the 5th Chinese Total Diet Study (TDS) carried out in 2011, the dietary exposure of Chinese population to three currently used brominated flame retardants (BFRs), tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) and decabrominated diphenyl ether (BDE-209), was estimated and the related health risks were assessed. Levels of the three BFRs were determined in 80 composite samples from four animal-origin food groups. The average levels of BFRs in various food groups ranged from 0.671 to 5.76 ng/g lipid weight (lw). The levels of TBBPA were lower than those of HBCD but higher than those of BDE-209. Moreover, average contamination levels of TBBPA and HBCD in TDS 2011 were found to be 3 to 30 times higher than those observed in TDS 2007 in the four food groups, indicating an increase in TBBPA and HBCD in the environment during 2007–2011. The average estimated daily intakes (EDIs) of TBBPA, HBCD and BDE-209 via food consumption for a “standard Chinese man” were 1.34, 1.51 and 0.96 ng/kg bw/day, respectively. Meat and meat products were found to be the major contributor to the daily dietary intake because the consumption of meat and meat products were significantly higher than that of other food groups in China. In comparison, the levels and EDIs of BFRs in this study were found to be higher than those in most studies worldwide. However, the large margin of exposure (MOE), with at least 1.1 × 105 calculated following the European Food Safety Authority (EFSA) approach, indicates that the estimated dietary exposure to these three BFRs is unlikely to raise significant health concerns. In addition, a comparison between the contamination levels of TBBPA, HBCD, BDE-209 and some novel BFRs in food samples from TDS 2011 indicated an obvious shift in the industrial production and usage pattern between PBDE and non-PBDE BFRs in China.

Flue gas desulfurization (FGD) and selective catalytic reduction (SCR) technologies have been widely used to control the emissions of sulphur dioxide (SO2) and nitrogen oxides (NOX) from coal-fired power plants (CFPPs). Field measurements of emission characteristics of four conventional CFPPs indicated a significant increase in particulate ionic species, increasing PM2.5 emission with FGD and SCR installations. The mean concentrations of PM2.5 from all CFPPs tested were 3.79 ± 1.37 mg/m3 and 5.02 ± 1.73 mg/m3 at the FGD inlet and outlet, respectively, and the corresponding contributions of ionic species were 19.1 ± 7.7% and 38.2 ± 7.8%, respectively. The FGD was found to enhance the conversion of NH3 slip from the SCR to NH4+ in the PM2.5, together with the conversion of SO2 to SO42-, and increased the primary NH4+ and SO42- aerosol emissions by approximately 18.9 and 4.2 times, respectively. This adverse effect should be considered when updating the emission inventory of CFPPs and should draw the attention of policy-makers for future air pollution control.

Exposure experiments were conducted to evaluate the influence of dissolved organic matter (DOM) on the toxicity of ZnO-NPs (10–30 nm) and dissolved Zn at sub-lethal doses (50 and 5 ppm, respectively) to zebrafish (Danio rerio). Humic acid, alginic acid, bovine serum albumin and various natural DOM isolated from rivers as the Milwaukee River-WI (NOMW), Yukon River-AK (NOMA) and Suwannee River-GA DOM (NOMS) were used to represent humic substances (HA), carbohydrates (CHO), proteins (PTN), and natural organic matter (NOM), respectively. Initial experiments were carried out to confirm the toxic effect of ZnO-NPs at 50 ppm, followed by mitigation experiments with different types and concentrations of DOM (0.4–40 mg-C/L). Compared to 0% hatch of 50 ppm ZnO-NPs exposed embryos at 72 h post fertilization (hpf), NOMS, NOMW and HA had the best mitigative effects on hatching (53–65%), followed by NOMA, CHO and PTN (19–35%); demonstrating that the mitigation effects on ZnO-NPs toxicity were related to DOM's quantity and composition. At 96 hpf, 20% of embryos exposed to 50 ppm ZnO-NPs hatched, 100% of embryos reared in embryo medium hatched, and close to 100% of the embryos hatched upon mitigation, except for those mitigated with PTN which had less effect. Dissolved Zn (5 ppm) also exhibited the same toxicity on embryos as ZnO-NPs (50 ppm). However, in the presence of HA, NOM and CHO, the hatching rates at 72 and 96 hpf increased significantly compared to 5% hatch without DOM. The overall mitigation effects produced by DOM followed the order of HA ≥ NOMS > NOM (A&W) > CHO >> PTN, although specific mitigation effects varied with DOM concentration and functionalities. Our results also indicate that the toxicity of ZnO-NPs to embryos was mostly derived from NPs although dissolved Zn released from ZnO-NPs also interacted with embryos, affecting hatching, but to a less extent.

Benzene exposure represents a potential risk for children's health. Apart from being a known carcinogen for humans (group 1 according to IARC), there is scientific evidence suggesting a relationship between benzene exposure and respiratory problems in children. But results are still inconclusive and inconsistent. This study aims to assess the determinants of exposure to indoor and outdoor residential benzene levels and its relationship with respiratory health in infants. Participants were 1-year-old infants (N = 352) from the INMA cohort from Valencia (Spain). Residential benzene exposure levels were measured inside and outside dwellings by means of passive samplers in a 15-day campaign. Persistent cough, low respiratory tract infections and wheezing during the first year of life, and covariates (dwelling traits, lifestyle factors and sociodemographic data) were obtained from parental questionnaires. Multiple Tobit regression and logistic regression models were performed to assess factors associated to residential exposure levels and health associations, respectively. Indoor levels were higher than outdoor ones (1.46 and 0.77 μg/m3, respectively; p < 0.01). A considerable percentage of dwellings, 42% and 21% indoors and outdoors respectively, surpassed the WHO guideline of 1.7 μg/m3 derived from a lifetime risk of leukemia above 1/100 000. Monitoring season, maternal country of birth and parental tobacco consumption were associated with residential benzene exposure (indoor and outdoors). Additionally, indoor levels were associated with mother's age and type of heating, and outdoor levels were linked with zone of residence and distance from industrial areas. After adjustment for confounding factors, no significant associations were found between residential benzene exposure levels and respiratory health in infants. Hence, our study did not support the hypothesis for the benzene exposure effect on respiratory health in children. Even so, it highlights a public health concern related to the personal exposure levels, since a considerable number of children surpassed the abovementioned WHO guideline for benzene exposure.

Hexabromocyclododecane (HBCD) contamination and its diastereomeric profile were investigated in a multi-media environment along a river at the local scale in air, soil, sludge, sediment, and fish samples. The spatial distribution of HBCD in each matrix showed a different result. The highest concentrations of HBCD in air and soil were detected near a general industrial complex; in the sediment and sludge samples, they were detected in the down-stream region (i.e., urban area). Each matrix showed the specific distribution patterns of HBCD diastereomers, suggesting continuous inputs of contaminants, different physicochemical properties, or isomerizations. The particle phases in air, sludge, and fish matrices were dominated by α-HBCD, owing to HBCD's various isomerization processes and different degradation rate in the environment, and metabolic capabilities of the fish; in contrast, the sediment and soil matrices were dominated by γ-HBCD because of the major composition of the technical mixtures and the strong adsorption onto solid particles. Based on these results, the prevalent and matrix-specific distribution of HBCD diastereomers suggested that more careful consideration should be given to the characteristics of the matrices and their effects on the potential influence of HBCD at the diastereomeric level.

Indoor air pollution is an important environmental factor that contributes to the burden of various diseases. Long-term exposure to ambient air pollution is associated with telomere shortening. However, the association between chronic indoor air pollution from household fuel combustion and leukocyte telomere length has not been studied. In our study, 137 cancer-free non-smokers were recruited. Their exposure levels to indoor air pollution from 1985 to 2014 were assessed using a face-to-face interview questionnaire, and leukocyte telomere length (LTL) was measured using a monochrome multiplex quantitative PCR method. Accumulative exposure to solid fuel usage for cooking was negatively correlated with LTL. The LTL of residents who were exposed to solid fuel combustion for three decades (LTL = 0.70 ± 0.17) was significantly shorter than that of other populations. In addition, education and occupation were related to both exposure to solid fuel and LTL. Sociodemographic factors may play a mediating role in the correlation between leukocyte telomere length and environmental exposure to indoor air pollution. In conclusion, long-term exposure to indoor air pollution may cause LTL dysfunction.