Numerous epidemiological studies have indicated the adverse cardiovascular effects of air pollution on heart failure (HF) risk. However, little data are available directly evaluating the association of ambient volatile organic compounds (VOCs) with HF risk. We aimed to estimate the short-term effects of ambient VOCs on HF emergency hospitalizations in Hong Kong and to evaluate whether the associations were modified by sex and age.We collected the daily VOCs concentrations from the Hong Kong Environmental Protection Department between April 2011 to December 2014. HF emergency hospital admission data were obtained from the Hospital Authority of Hong Kong. Generalized additive model (GAM) integrated with the distributed lag model (DLM) was used to estimate the excess risks of HF emergency hospitalizations with ambient concentrations of each VOCs groups – alkane, alkene, alkyne, benzene and substituted benzene.We observed short-term effects of alkyne and benzene on an increased risk of HF emergency hospitalizations. The cumulative effect over 0–6 lag days (dlm₀₋₆) for an IQR increment of alkyne (1.17 ppb) was associated with 4.2% (95% CI: 1.18%–7.26%) increases of HF emergency hospitalizations, while the corresponding effect estimate over dlm₀₋₂ for benzene per IQR (0.43 ppb) was 2.7% (95% CI: 0.39%–5.04%). Each VOCs groups was significantly associated with HF emergency hospitalizations in men.Ambient volatile organic compounds, particularly alkyne and benzene, were associated with increased risks of heart failure in the Hong Kong population.

Paddy soil plays an essential role in contributing to the emission of methane (CH₄), a potent greenhouse gas, to the atmosphere. This study aimed to demonstrate the effects of straw incorporation and straw-derived biochar amendment on CH₄ emissions from double-rice cropping fields and to explore their potential mechanisms based on in-situ field measurements conducted for a period of three years (2012–2014) and model analysis. The results showed that the improved soil aeration due to biochar amendment resulted in low CH₄ emissions and that sufficient substrate carbon availability in straw amendment treatments caused high CH₄ emissions. The newly developed CH₄ emission module for the water and nitrogen management model (WNMM), a process-based biophysical model, performed well when simulating both daily CH₄ fluxes and the annual cumulative CH₄ emissions under straw incorporation and biochar amendment. Results of our study indicate that the model has a great potential for upscaling and could benefit mechanism analyses about the factors regulating CH₄ emissions. Application of biochar into paddy fields provides a great opportunity to reduce CH₄ emissions, and the decrease in CH₄ emissions following biochar amendment with repeated crop cycles would sustain for a prolonged period.

Decabromodiphenyl ether (BDE-209), as a major component of brominated flame retardants, has been detected in the agricultural soil in considerable amount. Given that BDE-209 is toxic, ubiquitous and persistent, BDE-209 might induce toxic effects on rice cultivars planted in contaminated soil. A comparative study was conducted on phytotoxicities and GC-MS based antioxidant-related metabolite levels to investigate the differences of phytotoxicities of BDE-209 to rice cultivars in Yangtze River Delta of China. Rice seedlings were treated with BDE-209 at 0, 10, 50, 100 and 500 μg/L in a hydroponic setup. Results showed that BDE-209-induced phytotoxicites were cultivar-dependent and that the antioxidant defense systems in the cultivars were disturbed differently. Among the three selected cultivars (Jiayou 5, Lianjing 7 and Yongyou 9), Jiayou 5 and Lianjing 7 displayed lower toxic effects than Yongyou 9 in terms of the growth inhibition, lipid peroxidation and DNA damage. The increases of antioxidant enzymes were significantly higher in Jiayou 5 and Lianjing 7 than those in Yongyou 9. Multivariate analysis of antioxidant-related metabolites in the three cultivars indicated that l-tryptophan and l-valine were the most important ones among 10 metabolites responsible for the separation of cultivars. The up-regulation of l-tryptophan and l-valine were likely plant strategies to increase their tolerance. The current results provided an insight into the development of rice cultivars with higher BDE-209 tolerance.

The use of dynamic membranes as a low-cost alternative for conventional membrane for the treatment of landfill leachate (LFL) was investigated in this study. For this purpose a lab-scale, submerged pre-anoxic and post-aerobic bioreactor configuration was used with nylon mesh as dynamic membrane support. The study was conducted at ambient temperature and LFL was fed to the bioreactor in gradually increasing concentration mixed with tap water (from 20% to 100%). The results of this study demonstrated that lower mesh pore size of 52 μm achieved better results in terms of solid-liquid separation performance (turbidity <10 NTU) of the formed dynamic membrane layer as compared to 200 and 85 μm meshes while treating LFL. Consistently high NH₄⁺-N conversion efficiency of more than 98% was achieved under all nitrogen loading conditions, showing effectiveness of the formed dynamic membrane in retaining slow growing nitrifying species. Total nitrogen removal reached more than 90% however, the denitrification activity showed a fluctuating profile and found to be inhibited by elevated concentrations of free nitrous acid and NO₂⁻-N at low pH values inside the anoxic bioreactor. A detailed metagenomic analysis allowed a taxonomic investigation over time and revealed the potential biochemical pathways involved in NH₄⁺-N conversion. This study led to the identification of a dynamic system in which nitrite concentration is determined by the contribution of NH₄⁺ oxidizers (Nitrosomonas), and by a competition between nitrite oxidizers (Nitrospira and Nitrobacter) and reducers (Thauera).

The prevalence of antibiotic resistance genes (ARGs) in waste sludge, especially for the pharmaceutical waste sludge, presents great potential risks to human health. Although ARGs and factors affecting their spreading are of major importance for human health, the factors influencing the fate of ARGs during sludge treatment, especially for pharmaceutical sludge treatment are not yet well understood. In order to be able to minimize ARGs spreading, it is important to find what is influencing their spreading. Therefore, certain factors, such as the sludge characteristics, bacterial diversity and community composition, and mobile genetic elements (MGEs) during the advanced AD of pharmaceutical sludge with different pretreatments were studied, and their affinity with ARGs was elucidated by Spearman correlation analysis. Furthermore, multiple linear regression was introduced to evaluate the importance of the various factors. Results showed that 59.7%–88.3% of the variations in individual ARGs and total ARGs can be explained by the corresponding factors. Bacterial diversity rather than specific bacterial community composition affected the fate of ARGs, whereas alkalinity was the most important factor on ARGs among all sludge characteristics investigated in this study. Besides, 66.4% of variation of total ARGs was driven by the changes of MGEs. Multiple linear regression models also reveal the collective effect of these factors on ARGs, and the contributions of each factor impact on ARGs. This study provides more comprehension about the factors impact on the fate of ARGs during pharmaceutical sludge treatment, and offers an approach to evaluate the importance of each factor, which method could be introduced for evaluation of factors influencing ARGs during other types of sludge or wastewater treatment.

Antibiotics have been widely used in human and veterinary medicine to both treat and prevent disease. Due to their high water solubility and low bioavailability, many antibiotic residues have been found in aquatic environments. Fish are an indispensable link between the environmental pollution and human health. However, the chronic effects of environmental concentrations of antibiotics in fish have not been thoroughly investigated. Sulfamethoxazole (SMX) and oxytetracycline (OTC) are frequently detected in aquatic environments. In this study, zebrafish were exposed to SMX (260 ng/L) and OTC (420 ng/L) for a six-week period. Results indicated that exposure to antibiotics did not influence weight gain of fish but increased the metabolic rate and caused higher mortality when treated fish were challenged with Aeromonas hydrophila. Furthermore, exposure to antibiotics in water resulted in a significant decrease in intestinal goblet cell numbers, alkaline phosphatase (AKP), acid phosphatase (ACP) activities, and the anti-oxidant response while there was a significant increase in expression of inflammatory factors. Antibiotic exposure also disturbed the intestinal microbiota in the OTC-exposed group. Our results indicated that environmental antibiotic concentrations can impair the gut health of zebrafish. The potential health risk of antibiotic residues in water should be evaluated in the future.

In this study, the accumulation and toxicity effect of 1–7 μM of Hg was determined during 24–72 h on two strains of Chlamydomonas reinhardtii, CC-125 and CC-503 as a cell wall-deficient mutant, by monitoring the growth rate and the maximum quantum yield of Photosystem II. In addition, the level of extracytoplasmic polyphosphates (polyP related to the cell wall) was determined to understand the polyP physiological role in Hg-treated algal cells. The results showed that the polyP level was higher in the strain CC-125 compared to CC-503. When algal cells were exposed to 1 and 3 μM of Hg, the accumulation of Hg was correlated with the degradation of polyP for both strains. These results suggested that the degradation of polyP participated in the sequestration of Hg. In fact, this mechanism might explain at 72 h the recovery of the polyP level, the efficiency of maximum PSII quantum yield, the low inhibition of growth rate, and the low accumulated Hg in algal biomass. Under the effect of 5 and 7 μM of Hg, the degradation of polyP was complete and could not be recovered, which was caused by a high accumulation and toxicity of Hg already at 24 h. Our results demonstrated that the change of polyP level was correlated with the accumulation and effect of Hg on algal cells during 24–72 h, which can be used as a biomarker of Hg toxicity. Therefore, this study suggested that extracytoplasmic polyP in C. reinhardtii contributed to the cellular tolerance for Hg.

The present experiment was conducted to explicate the genotoxic effects of profenofos, an organophosphate insecticide, on the erythrocytes of silver barb (Barbonymus gonionotus). Silver barb were exposed to a solution of 10% and 50% of lethal concentrations (LC₅₀) of profenofos as sub-lethal concentrations at different days (1, 7, 15, and 30 d), along with a control (0% profenofos). Subsequent recovery patterns were assessed allowing the fish exposed to profenofos free water for the same period that they were exposed to profenofos. Our results revealed that with the progression of time and concentration, fish exposed to profenofos showed significantly (p < .05) higher level of erythrocytic nuclear abnormalities (ENA) such as micronuclei, bi-nuclei, degenerated nuclei, notched nuclei, nuclear bridge and nuclear buds, as well as erythrocytic cellular abnormalities (ECA) such as echinocytic, elongated, fusion, spindle, tear-drop and twin shaped cells. After exposure, the silver barb recovered spontaneously, and the abnormal erythrocytic parameters were normalized with a concentration- and duration-dependent fashion. Therefore, these abnormalities and their recovery can be used to assess the toxic levels of pesticides on aquatic organisms. There is great potential to use this technique as in vivo to predict susceptibility of aquatic animals to environmental pollution.

Antifouling biocides in surface sediments and gastropod tissues were assessed for the first time along coastal areas of Panama under the influence of maritime activities, including one of the world's busiest shipping zones: the Panama Canal. Imposex incidence was also evaluated in five muricid species distributed along six coastal areas of Panama. This TBT-related biological alteration was detected in three species, including the first report in Purpura panama. Levels of organotins (TBT, DBT, and MBT) in gastropod tissues and surficial sediments ranged from <5 to 104 ng Sn g⁻¹ and <1–149 ng Sn g⁻¹, respectively. In addition, fresh TBT inputs were observed in areas considered as moderate to highly contaminated mainly by inputs from fishing and leisure boats. Regarding booster biocides, TCMTB and dichlofluanid were not detected in any sample, while irgarol 1051, diuron and DCOIT levels ranged from <0.08 to 2.8 ng g⁻¹, <0.75–14.1 ng g⁻¹, and <0.38–81.6 ng g⁻¹, respectively. The highest level of TBT (149 ng Sn g⁻¹) and irgarol 1051 (2.8 ng g⁻¹), as well as relevant level of DCOIT (5.7 ng g⁻¹), were detected in a marina used by recreational boats. Additionally, relatively high diuron values (14.1 ng g⁻¹) were also detected in the Panama Canal associate to a commercial port. DCOIT concentrations were associated with the presence of antifouling paint particles in sediments obtained nearby shipyard or boat maintenance sites. The highest levels of TBT, irgarol 1051, and diuron exceeded international sediment quality guidelines indicating that toxic effects could be expected in coastal areas of Panama. Thus, the simultaneous impacts produced by new and old generations of antifouling paints highlight a serious environmental issue in Panamanian coastal areas.

Understanding of the interaction of graphene with natural polysaccharides (e.g., alginate) is crucial to elucidate its environmental fate. We investigated the impact of alginate on the agglomeration and stability of ¹⁴C-labeled few-layer graphene (FLG) in varying concentrations of monovalent (NaCl) and divalent (CaCl₂) electrolytes. Enhanced agglomeration occurred at high CaCl₂ concentrations (≥5 mM) due to the alginate gel networks formation in the presence of Ca²⁺. FLG enmeshed within extended alginate gel networks was observed under transmission electron microscope and atomic force microscope. However, background Na⁺ competition for binding sites with Ca²⁺ at the alginate surfaces shielded the gelation of alginate. FLG was readily dispersed by alginate under environmentally relevant ionic strength conditions (i.e., <200 mM Na⁺ and <5 mM Ca²⁺). In comparison with the bare FLG, the slow sedimentation of the alginate-stabilized FLG (158 μg/L) caused continuous exposure of this nanomaterial to freshwater snails, which ingested 1.9 times more FLG through filter-feeding within 72 h. Moreover, surface modification of FLG by alginate significantly increased the whole-body and intestinal levels of FLG, but reduced the internalization of FLG to the intestinal epithelial cells. These findings indicate that alginate will act as a stabilizing agent controlling the transport of FLG in aqueous systems. This study also provides the first evidence that interaction of graphene with natural polysaccharides affected the uptake of FLG in the snails, which may alter the fate of FLG in aquatic environments.