The potential arsenite bioteansformation activity of arsenic was investigated by examining bacterial arsenic arsenite-oxidizing gene such as aoxS, aoxR, aoxA, aoxB, aoxC, and aoxD in high arsenic-contaminated drinking water produced from the surface water of floating houses. There is a biogeochemical cycle of activity involving arsenite oxidase aox system and the ars (arsenic resistance system) gene operon and aoxR leader gene activity in Alcaligenes faecalis SRR-11 and aoxS leader gene activity in Achromobacter xylosoxidans TSL-66. Batch experiments showed that SRR-11 and TSL-66 completely oxidized 1 mM of As (III) to As (V) within 35–40 h. The leaders of aoxS and aoxR are important for gene activity, and their effects in arsenic bioremediation and mobility in natural water has a significant ecological role because it allows arsenite oxidase in bacteria to control the biogeochemical cycle of arsenic-contaminated drinking water produced from surface water of floating houses.

Zebrafish were placed in the upper layer of aquariums to investigate the impacts of anatase and rutile nano-TiO2 on perfluorooctanesulfonate (PFOS) bioaccumulation in zebrafish. Both variations of particle hydrodynamic size and concentration in water column suggest that anatase was better dispersed than rutile. PFOS could be significantly adsorbed on nano-TiO2 to form TiO2-PFOS complexes, leading to reduced concentration of PFOS in upper layer. Due to enhanced exposure to PFOS by ingestion and adhesion of TiO2-PFOS complexes, the whole-body PFOS concentration in zebrafish was enhanced by 59.0% (95% CI: 55.9%, 61.9%) and 25.4% (95% CI: 24.8%, 25.6%) in the presence of anatase and rutile nano-TiO2 after equilibrium compared with the control with PFOS alone. The bioaccumulation of PFOS was much more promoted by anatase, which was attributed by greater adsorption capacity of PFOS to anatase, slower migration of their complex in water column, and slower elimination rate of anatase from fish.

In this work, agricultural and background soil concentrations of p,p′-DDT, p,p′-DDE, HCB, α-, β- and γ-HCH from 1993 to 2012 were collected from 73 peer-reviewed publications, and analysed statistically. For the period 2003–2012 and for all chemicals, the mean concentration in agricultural soil is significantly higher than the concentration in background soil. In addition to the statistical analysis, concentrations of p,p′-DDT and α-HCH in soils were calculated with a global environmental fate and transport model. A decrease in the mean soil concentration from the first decade to the second was observed with the model, but this decrease is not visible in the measured concentrations, which could result from ongoing use of p,p′-DDT and α-HCH Furthermore, modelled background soil concentrations are generally lower than measurements. This implies that background soil may have received p,p′-DDT and α-HCH through additional routes not described by the model such as spray drift.

Short-term effects of air pollution on mortality have been well documented in the literature worldwide. Less is known about which subpopulations are more vulnerable to air pollution. We conducted a case-only study in Hong Kong to examine the potential effect modification by personal characteristics and specific causes of death. Individual information of 402,184 deaths of non-external causes and daily mean concentrations of air pollution were collected from 2001 to 2011. For a 10 μg/m3 increase of pollution concentration, people aged ≥∇65 years (compared with younger ages) had a 0.9–1.8% additional increase in mortality related to PM, NO2, and SO2. People dying from cardiorespiratory diseases (compared with other non-external causes) had a 1.6–2.3% additional increase in PM and NO2 related mortality. Other subgroups that were particularly susceptible were females and those economically inactive. Lower socioeconomic status and causes of cardiorespiratory diseases would increase the likelihood of death associated with air pollution.

This study aims to identify and apportion multi-source and multi-phase heavy metal pollution from natural and anthropogenic inputs using ensemble models that include stochastic gradient boosting (SGB) and random forest (RF) in agricultural soils on the local scale. The heavy metal pollution sources were quantitatively assessed, and the results illustrated the suitability of the ensemble models for the assessment of multi-source and multi-phase heavy metal pollution in agricultural soils on the local scale. The results of SGB and RF consistently demonstrated that anthropogenic sources contributed the most to the concentrations of Pb and Cd in agricultural soils in the study region and that SGB performed better than RF.

Both China and UNEP recommend replacing raw coal chunks with coal briquettes in household sector as clean coal technology (CCT), which has been confirmed by the decreased emissions of particulate matter and black carbon. However, the clean effect has never been systematically checked by other pollutants like polycyclic aromatic hydrocarbons (PAHs). In this study, 5 coals with different geological maturities were processed as both chunks and briquettes and burned in 3 typical coal stoves for the measurement of emission factors (EFs) of particle-bound PAHs. It was found that the EFs of 16 parent PAHs, 26 nitrated PAHs, 6 oxygenated PAHs, and 8 alkylated PAHs for coal briquettes were 6.90 ± 7.89, 0.04 ± 0.03, 0.65 ± 0.40, and 72.78 ± 18.23 mg/kg, respectively, which were approximately 3.1, 3.7, 1.9, and 171 times those for coal chunks, respectively. Such significant increases in PAH emissions increased human health risk and challenged the policy of CCT.

Oil spill models are combined with bathymetric, meteorological, oceanographic, and geomorphological data to model a series of oil spill accidents in the Eastern Mediterranean Sea. A total of 104 oil spill simulations, computed for 11 different locations in the Levantine Basin, show that oil slicks will reach the coast of Cyprus in four (4) to seven (7) days in summer conditions. Oil slick trajectories are controlled by prevailing winds and current eddies. Based on these results, we support the use of chemical dispersants in the very few hours after large accidental oil spills. As a corollary, we show shoreline susceptibility to vary depending on: a) differences in coastline morphology and exposure to wave action, b) the existence of uplifted wave-cut platforms, coastal lagoons and pools, and c) the presence of tourist and protected environmental areas. Mitigation work should take into account the relatively high susceptibility of parts of the Eastern Mediterranean.

Ecological risk assessment of chemicals aims at quantifying the likelihood of adverse effects posed to non-target populations and the communities they constitute, often based on lethal concentration estimates for standard test species. There may, however, be intra- and interspecific differences in responses to chemical exposure. Here with the help of a toxicokinetic-toxicodynamic model, we explored whether differential body sizes might explain the observed variability in sensitivity between species and between life-stages of each individual species, for three model organisms, Daphnia magna, Chaoborus crystallinus and Mesocyclops leuckarti. While body size-dependent toxicokinetics could be used to predict intraspecies variation in sensitivity, our results also suggest that changes in both toxicokinetic and toxicodynamic parameters might be needed to describe differential species sensitivity. Accounting for biological traits, like body size, in mechanistic effect models will allow more accurate predictions of chemical effects in size structured populations, ultimately providing mechanistic explanations for species sensitivity distributions.

This study reports the occurrence and distribution of organophosphorus flame retardants and plasticizers (OPEs) in the Elbe and Rhine rivers. A special focus of this investigation concerns the potential impacts of a major flood event in 2013 on the OPE patterns and levels in the Elbe River. In this river, 6 of 13 OPEs were detected, with tris-ethyl-phosphate (TEP, 168 ± 44 ng/L), tris-1,3-dichloro-2-propyl-phosphate (TDCPP, 155 ± 14 ng/L) and tris-1-chloro-2-propyl phosphate (TCPP, 126 ± 14 ng/L) identified as the dominant compounds. Relative to previous studies, an increase in the concentrations and relative contributions of TDCPP to the total level of OPEs was observed, which was likely caused by its increased use as a replacement for the technical pentaBDE formulation. During the flood event, the concentrations of OPEs were similar to the normal situation, but the mass fluxes increased by a factor of approximately ten (∼16 kg/d normal versus ∼160 kg/d flood peak). No input hotspots were identified along the transects of the Elbe and Rhine rivers, and the mass flux of OPEs appeared to be driven by water discharge.

Stomata tend to narrow under ozone (O3) impact, leading to limitation of stomatal O3 influx. Here, we review stomatal response under recently conducted free-air O3 exposure experiments on two species of the same tree genus: Fagus sylvatica at Kranzberg Forest (Germany) and F. crenata at Sapporo Experimental Forest (Japan). Both beeches exhibited reduction in stomatal conductance (gs) by 10–20% under experimentally enhanced O3 regimes throughout the summer relative to ambient-air controls. Stomatal narrowing occurred, in early summer, in the absence of reduced carboxylation capacity of Rubisco, although photosynthetic net CO2 uptake rate temporarily reflected restriction to some minor extent. Observed stomatal narrowing was, however, diminished in autumn, suggesting gradual loss of stomatal regulation by O3. Monotonic decline in gs with cumulative O3 exposure or flux in current modeling concepts appear to be unrealistic in beech.