To estimate the health risk of haloacetonitriles in different kinds of drinking water, the concentrations of haloacetonitriles in tap water, boiled water and direct drinking water were detected. The physiologically based pharmacokinetic (PBPK) model was used to calculate internal dose in the human body for haloacetonitriles through ingestion, and the probability distributions of the non-carcinogenic risk of haloacetonitriles for human via drinking water were assessed. This study found that the mean concentrations of dichloroacetonitrile (DCAN) in tap water, boiled water and direct drinking water were 0.955 μg/L, 0.207 μg/L and 0.127 μg/L, and those of dibromoacetonitrile (DBAN) were 0.221 μg/L, 0.104 μg/L, 0.089 μg/L, respectively. In China, direct drinking water is used most frequently, so the concentrations of haloacetonitriles in direct drinking water were used to obtain data on the internal dose of haloacetonitriles. In addition, the simulation results for the PBPK model showed that the highest and lowest concentrations of DCAN occurred in the liver and venous blood, respectively. The peak concentrations of DBAN in each tissue were in the decreasing order liver > rapidly perfused tissue > kidney > slowly perfused tissues > fat > arterial blood (venous blood). In addition, the highest 95th percentile hazard quotients (HQ) value of haloacetonitriles via drinking water for humans was 8.89 × 10−3, much lower than 1. The 95th percentile hazard index (HI) was 0.046, which was also lower than 1, suggesting that there was no obvious non-carcinogenic risk.

Communities resident in urban areas located near active volcanoes can experience volcanic ash exposures during, and following, an eruption, in addition to sustained exposures to high concentrations of anthropogenic air pollutants (e.g., vehicle exhaust emissions). Inhalation of anthropogenic pollution is known to cause the onset of, or exacerbate, respiratory and cardiovascular diseases. It is further postulated similar exposure to volcanic ash can also affect such disease states. Understanding of the impact of combined exposure of volcanic ash and anthropogenic pollution to human health, however, remains limited.The aim of this study was to assess the biological impact of combined exposure to respirable volcanic ash (from Soufrière Hills volcano (SHV), Montserrat and Chaitén volcano (ChV), Chile; representing different magmatic compositions and eruption styles) and freshly-generated complete exhaust from a gasoline vehicle. A multicellular human lung model (an epithelial cell-layer composed of A549 alveolar type II-like cells complemented with human blood monocyte-derived macrophages and dendritic cells cultured at the air-liquid interface) was exposed to diluted exhaust (1:10) continuously for 6 h, followed by immediate exposure to the ash as a dry powder (0.54 ± 0.19 μg/cm2 and 0.39 ± 0.09 μg/cm2 for SHV and ChV ash, respectively). After an 18 h incubation, cells were exposed again for 6 h to diluted exhaust, and a final 18 h incubation (at 37 °C and 5% CO2). Cell cultures were then assessed for cytotoxic, oxidative stress and (pro-)inflammatory responses.Results indicate that, at all tested (sub-lethal) concentrations, co-exposures with both ash samples induced no significant expression of genes associated with oxidative stress (HMOX1, NQO1) or production of (pro-)inflammatory markers (IL-1β, IL-8, TNF-α) at the gene and protein levels. In summary, considering the employed experimental conditions, combined exposure of volcanic ash and gasoline vehicle exhaust has a limited short-term biological impact to an advanced lung cell in vitro model.

Although hexachlorobutadiene (HCBD) has been listed as a persistent organic pollutant (POP) under Annexes A and C of the Stockholm Convention, information about its unintentional production and emission is still very limited. We estimated the historical unintentional production and emission of HCBD during 1992–2016 in China based on aggregated activity data and emission functions. The unintentional production of HCBD increased from 60.8 (95% confidence interval, 38.2–88.5) MT/yr to 2871.5 (2234.2–3530.0) MT/yr during 1992–2016, representing an average annual growth rate of 17.4%. The main unintentional source of HCBD changed from carbon tetrachloride to trichloroethylene production during this period. We estimated that China's cumulative emissions of HCBD were 8211.3 (6131.5–10,579.5) MT during the same period. HCBD consumption and the chlorinated hydrocarbon production sector were the major contributors to total HCBD emissions. Owing to the long-range transport capability of HCBD (8784 km), such high emissions in China may cause adverse effects in other regions.

PM₂.₅ and its major chemical compositions were sampled and analyzed in January, April, July and October of 2014 at Beijing (BJ), Tianjin (TJ), Langfang (LF) and Baoding (BD) in order to probe the temporal and spatial characteristics as well as source apportionment of PM₂.₅ in the Beijing-Tianjin-Hebei (BTH) region. The results showed that PM₂.₅ pollution was severe in the BTH region. The average annual concentrations of PM₂.₅ at four sampling sites were in the range of 126–180 μg/m³, with more than 95% of sampling days exceeding 35 μg/m³, the limit ceiling of average annual concentration of PM₂.₅ regulated in the Chinese National Ambient Air Quality Standards (GB3095-2012). Additionally, concentrations of PM₂.₅ and its major chemical species were seasonally dependent and demonstrated spatially similar variation characteristics in the BTH region. Concentration of toxic heavy metals, such as As, Cd, Cr, Cu, Mn, Ni, Pb, Sb, Se, and Zn, were higher in winter and autumn. Secondary inorganic ions (SO₄²⁻, NO₃⁻, and NH₄⁺) were the three-major water-soluble inorganic ions (WSIIs) of PM₂.₅ and their mass ratios to PM₂.₅ were higher in summer and autumn. The organic carbon (OC) and elemental carbon (EC) concentrations were lower in spring and summer than in autumn and winter. Five factors were selected in Positive Matrix Factorization (PMF) model analysis, and the results showed that PM₂.₅ pollution was dominated by vehicle emissions in Beijing, combustion emissions including coal burning and biomass combustion in Langfang and Baoding, and soil and construction dust emissions in Tianjin, respectively. The air mass that were derived from the south and southeast local areas around BTH regions reflected the features of short-distant and small-scale air transport. Shandong, Henan, and Hebei were identified the major potential sources-areas of secondary aerosol emissions to PM₂.₅.

Biochar has potential for application for in situ metal-contaminated sediment remediation, mainly because of its cost-effectiveness. In this study, the effectiveness of Phyllostachys pubescens (PP) biochar for immobilization of cadmium (Cd) chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) by decreasing the bioavailable fraction was investigated using a series of laboratory sediment remediation microcosms. The results demonstrated that biochar could significantly reduce the bioavailable fraction of metals (except for Cr) by diffusive gradients in thin film (DGT) measurement in porewater. Additionally, amended sediment treated with 15% w/w biochar resulted in 79.71%, 73.20%, 54.86%, 49.75%, 31.16% and 0.99% reductions in the acid-soluble fraction for Cu, Pb, Ni, Zn, Cd, and Cr, respectively. Similarly, bioaccumulation of metals (except for Cr) by Limnodrilus hoffmeisteri was reduced by 18.45%–59.15% in biochar amended sediment. PP biochar at 15% could also reduce the inhibition or lethality rate by 37.5%, 18.1% and 36.3% for Chlorella vulgaris, Daphnia magna and luminescent bacteria Vibrio qinghaiensis, respectively. Overall, these results demonstrate the potential for biochar application for in situ sediment remediation.

The ecological toxicity of hexabromocyclododecane (HBCD) on animals, including fish and mice, has been reported, but its effects in plants, particularly its toxic mechanism, have rarely been investigated. An untargeted metabolomics approach for comprehensive assessment was selected to study the alterations in the metabolic profiles in pak choi leaves induced by exposure to trace-level amounts of HBCD diastereomers over 30 days. A supervised orthogonal partial least-squares-discriminant analysis (OPLS-DA) was performed to investigate differences between the HBCD and control groups. The discriminating metabolites were identified using public databases. The results indicated that the toxicity of the HBCD diastereomers was ordered as γ-HBCD > α-HBCD > β-HBCD. 13 metabolites were identified as potential biomarkers to discriminate the presence of HBCD toxicity. The lipid, carbohydrate, nucleotide and amino acid metabolic pathways affected were found in accordance with animals and humans, and also HBCD could induce the interference of the secondary metabolite pathways. The system of the stress defences was activated, including signalling pathway, antioxidant defence system, shikimate and phenylpropanoid metabolism. The carbohydrate and amino acid metabolism were disturbed by HBCD intervention, and the lipid, amino acid and secondary metabolite metabolism were regulated for HBCD stress prevention. These results provide insights into the mechanism and degree of HBCD phytotoxicity.

Imposex is a disorder caused by organotins, mainly tributyltin, which results in the appearance of male sexual characteristics in females of gastropod mollusks. The main objective of this work was to make a critical analysis of the relationship between imposex and butyltin body burdens in Nucella lapillus and Nassarius reticulatus. Specifically, this study evaluates possible additive effects among butyltins, proposes scales of effects based on robust statistical criteria as alternatives to existing ones and defines the body burdens of TBT in N. lapillus and N. reticulatus corresponding to the assessment classes (ACs) of the Vas Deferens Sequence Index (VDSI) established by OSPAR. Data of organotin body burdens and biological effects was retrieved from the ICES Dataset and from scientific literature. All responses, except the percentage of females displaying Imposex (IMPF) in Nucella lapillus, showed a sigmoidal profile regarding to the body burden of mono- (MBT), di- (DBT) and tributyltin and sum of butyltins (SumBTs). TBT and the SumBTs were better indicators of the VDSI or Relative Penis Size Index/Relative Penis Length Index (RPSI/RPLI) responses than MBT or DBT in most cases. From a statistical point of view, RPSI/RPLI and VDSI were better indicators of contamination by TBT than IMPF, although both RPSI and RPLI showed lower sensitivity than VDSI. The model used for describing the joint effect of butyltins provided a statistically significant fitting to the data assuming a null effect for both MBT and DBT for N. lapillus, and a lower toxic contribution of MBT and DBT with respect to TBT for N. reticulatus. RPSI or RPLI values, equivalent to the ACs for VDSI, were proposed as alternative criteria when measuring moderate to high levels of imposex. TBT concentrations in N. reticulatus and N. lapillus tissues, corresponding to the ACs were calculated and provided valuable information for cross-species comparisons.

Pyrethroid-resistant Hyalella azteca with voltage-gated sodium channel mutations have been identified at multiple locations throughout California. In December 2013, H. azteca were collected from Mosher Slough in Stockton, CA, USA, a site with reported pyrethroid (primarily bifenthrin and cyfluthrin) sediment concentrations approximately twice the 10-d LC50 for laboratory-cultured H. azteca. These H. azteca were shipped to Southern Illinois University Carbondale and have been maintained in pyrethroid-free culture since collection. Even after 22 months in culture, resistant animals had approximately 53 times higher tolerance to permethrin than non-resistant laboratory-cultured H. azteca. Resistant animals held in culture also lacked the wild-type allele at the L925 locus, and had non-synonymous substitutions that resulted in either a leucine-isoleucine or leucine-valine substitution. Additionally, animals collected from the same site nearly three years later were again resistant to the pyrethroid permethrin. When resistant animals were compared to non-resistant animals, they showed lower reproductive capacity, lower upper thermal tolerance, and the data suggested greater sensitivity to, 4, 4′-dichlorodiphenyltrichloroethane (DDT), copper (II) sulfate, and sodium chloride. Further testing of the greater heat and sodium chloride sensitivity of the resistant animals showed these effects to be unrelated to clade association. Fitness costs associated with resistance to pyrethroids are well documented in pest species (including mosquitoes, peach-potato aphids, and codling moths) and we believe that H. azteca collected from Mosher Slough also have fitness costs associated with the developed resistance.

Pesticides, in particular insecticides, can be very beneficial but have also been found to have harmful side effects on non-target insects. Butterflies play an important role in ecosystems, are well monitored and are recognised as good indicators of environmental health. The amount of information already known about butterfly ecology and the increased availability of genomes make them a very valuable model for the study of non-target effects of pesticide usage. The effects of pesticides are not simply linear, but complex through their interactions with a large variety of biotic and abiotic factors. Furthermore, these effects manifest themselves at a variety of levels, from the molecular to metapopulation level. Research should therefore aim to dissect these complex effects at a number of levels, but as we discuss in this review, this is seldom if ever done in butterflies. We suggest that in order dissect the complex effects of pesticides on butterflies we need to integrate detailed molecular studies, including characterising sequence variability of relevant target genes, with more classical evolutionary ecology; from direct toxicity tests on individual larvae in the laboratory to field studies that consider the potentiation of pesticides by ecologically relevant environmental biotic and abiotic stressors. Such integration would better inform population-level responses across broad geographical scales and provide more in-depth information about the non-target impacts of pesticides.

The fast economic development of southwest China has resulted in significant increases in the concentrations of reactive nitrogen (Nr) in the atmosphere. In this study, an urban (Chengdu, CD), suburban (Shifang, SF) and agriculture (Yanting, YT) – dominated location in the Sichuan Province, southwest China, were selected to investigate the atmospheric composition of Nr, their concentrations and deposition rates. We measured Nr concentrations in precipitation (NH₄⁺, NO₃⁻ and organic N (DON)), the gas phase (NH₃ and NO₂), and the aerosol particles (PM₂.₅), and calculated their fluxes over a two year period (2014–2016). Total annual N deposition rates were 49.2, 44.7 and 19.8 kg N ha⁻¹ yr⁻¹ at CD, SF and YT, respectively. Ammonia concentrations were larger at the urban and suburban sites than the agricultural site (12.2, 14.9, and 4.9 μg N m⁻³ at CD, SF and YT, respectively). This is consistent with the multitude of larger sources of NH₃, including city garbage, livestock and traffic, in the urban and suburban areas. Monthly NO₂ concentrations were lower in warmer compared to the colder months, but seasonal differences were insignificant. Daily PM₂.₅ concentrations ranged from 7.7 to 236.0, 5.0–210.4 and 4.2–128.4 μg m⁻³ at CD, SF and YT, respectively, and showed significant correlations with fine particulate NH₄⁺ and NO₃⁻ concentrations. Ratios of reduced to oxidized N were in the range of 1.6–2.7. This implies that the control of reduced Nr especially in urban environments is needed to improve local air quality.