Bulletin of Environmental Contamination and Toxicology最新文献

This study focuses on the determination of dioxins and related compounds (DRCs) in sediment and soil samples gathered from craft villages and industrial zones in Bac Ninh province, northern Vietnam. The PCDD/Fs and DL-PCBs levels in sediment samples ranged from 8.34 to 1302 pg/g and 34.5 to 3186 pg/g, respectively, and total equivalent toxicity (TEQ) of DRCs ranged from 0.596 to 88.1 pgTEQ/g. The total mass concentration of DRCs in the soil samples varied from 14.2 to 4857 pg/g, with corresponding total TEQ values ranging from 0.387 to 2.61 pgTEQ/g. Risk assessment based on sediment quality guideline indicators shows that DRCs at paper recycling village had moderate adverse biological effect. Some soil samples collected in industrial clusters have total carcinogenic risk (CR) values close to the threshold (1.0 × 10^-6). Based on the results, it is necessary to continue monitoring and evaluating DRC compounds in craft village and industrial cluster environments and have remediation solutions to reduce these contaminated compounds.

Irgarol 1051 and Diuron are used as boosters in copper-based anti-fouling paints, as well as in agriculture and home gardening. We monitored the coral reefs and adjacent waters of northern Okinawa Island three times, i.e., in August 2015, June 2016 and December 2016. The mean concentrations were 1.44 ng/L for Irgarol and 1.07 ng/L for Diuron. Although the range of these concentrations was lower than those previously recorded in southern Japan, Irgarol and Diuron were significantly higher in December 2016 than in June 2016. Several estimations of Predicted No Effect Concentrations (PNECs) have recently been published. In December 2016, compared to the lowest PNEC concentration of each substances, the concentrations of Irgarol and Diuron exceeded the PNEC at nine sites and three sites, respectively. These results suggest that the effects of low concentrations of Irgarol and Diuron, close to the PNEC, on hermatypic corals need to be investigated. The regulation of anti-fouling paints in Japan is self-regulated through industry cooperation. Irgarol and Diuron have not been registered as anti-fouling paints for fishing nets by the fishing cooperatives. The significant increase of these substances suggests that the activity of vessels with paints containing Irgarol has increased in December 2016. This study highlights the need for continuous monitoring of these herbicides in coral reefs and adjacent waters.

While microplastics from lake, beach and ocean environment has become a growing global concern, tidal variations of microplastics in beach sediments are not well documented. Here, sediments were sampled over one monthly lunar tidal cycle during low tidal period in Shajing Beach along the Maowei Bay, China. The shape and abundance of microplastics were measured in sediments to determine their periodic variations by wavelet analysis method. The results showed that microplastics are generally granule, fiber and film shapes on Shajing Beach. The dominant type was fiber, followed by the granule. Meanwhile, the microplastic abundances showed a periodic change about 15 days. The granule and fiber but not film also followed such periodic variations. Tourism and human activities along the bay are the most likely causes for microplastics in Shajing Beach, while half-mouth of tidal cycle is responsible for the periodic variation of microplastic abundances and types.

Ciprofloxacin (CIP) and oxytetracycline (OTC) are commonly detected antibiotic species in breeding wastewater, and microalgae-based antibiotic treatment technology is an environmentally friendly and cost-effective method for its removal. This study evaluated the effects of CIP and OTC on Scenedesmus sp. in the breeding wastewater tailwater and the removal mechanisms of antibiotics. The results showed that Scenedesmus sp could increase antibiotic tolerance by enhancing antioxidant system activity. Compared to CIP, Scenedesmus sp showed better performance for OTC removal, the removal efficiencies were 100%, 96.87%, 95.75%, 90.18% and 83.91% at 0.1, 0.5, 1, 5, and 10 mg L^- 1 OTC, respectively. The removal routes indicated that CIP was mainly removed by biodegradation (38.88%) and photolysis (14.30%) whereas OTC was mainly removed by hydrolysis (43.47%) and biodegradation (33.45%). Product toxicity predictions showed that most of the degradation products of CIP and OTC were less toxic than their parent compounds, confirming the feasibility of microalgae biotreatment for antibiotic removal.

The widespread application of swine-farming wastewater to soil and water is increasingly contributing to heavy metal contamination, posing significant environmental risks. This study investigated the concentrations of eight heavy metals in swine-farming wastewater following different treatment processes, and assessed their ecological risks in Sichuan Province, China. The findings revealed that zinc, copper and nickel exhibited the highest concentrations, potentially causing heavy or strong contamination levels and leading to heavy or slight ecological risks. Advanced treatment processes employing physical-chemical, biochemical and ecological technologies, significantly reduced heavy metal concentrations compared to anaerobic fermentation, mitigating the widespread and severe ecological risks in Sichuan. However, the utilization of biogas slurry poses a high potential for severe ecological risks associated with heavy metals, particularly in the Panxi and Northwest regions. To control the ecological risks of heavy metals, advanced treatment processes should be strongly recommended alongside diverse resourceful utilization strategies tailored to large-scale swine farms in different regions of Sichuan Province.

Heavy metals were analyzed in rhizosphere soils and rice grains collected from typical black shale areas. The concentrations of As, Cd, Cu, and Zn in the rhizosphere soil exceeded the current soil environmental quality standards. Cd exhibited the highest bioaccumulation capacity, with 45% of rice grains exceeding food safety limit. Structural equation modeling (SEM) revealed that soil organic matter indicated that 34.79% of rice Cd accumulation and approximately 10%-25% of other metals were inhibited. Multiple regression modelling showed that in areas with high geological background of black shales, the screening and intervention values for soil Cd were adjusted to 0.24 mg kg^-1 and 0.42 mg kg^-1 for pH ≤ 5.5 and 0.27 mg kg^-1 and 1.66 mg kg^-1 for pH 5.5 - 6.5 respectively. Primary exposure pathways for non-carcinogenic risks were identified as food ingestion and skin contact. This study provides fundamental information for land use application and development in region with high geological background.

The pollutants after were discharged into the water can gradually degrade through the self-purification. The oxygen consumption and pollutant degradation rates characterize the self-purification of small and medium-sized streams, while the dynamics of the two characteristics for large rivers has not been reported yet. The in-situ investigation for 297 sites in the 1700 km stream of the Yangtze River was conducted. The oxygen consumption rate was 0.003d^- 1, and the degradation rate of organic pollutants was greater than that of inorganics. The degradation of anion surfactant was the fastest, while the degradation of TN was the slowest, with rates of 0.043 and 0.001 d^- 1, respectively. The oxygen consumption rate was negatively correlated with the degradation rate of COD, anion surfactant, and TP, indicating the synchronicity between reaeration and degradation during the self-purification. This study highlighted the role of synchronicity in modelling of water quality and estimation of environmental capacity for large rivers.

The adverse effect of chemical additives leaching from microplastics (MPs) on Daphnia magna populations is not fully understood. In this study, D. magna populations were exposed to polyethylene (PE) MP fragments (5.0 mg/L), PE MP fragments containing the ultraviolet stabilizer benzophenone-3 (MP/BP-3 fragments, 5.0 mg/L), and BP-3 leachate (79 ± 10 µg/L) from PE MP/BP-3 fragments. The test duration was 42 days to observe the population dynamics of D. magna. BP-3 leachate delayed the development and somatic growth of D. magna, resulting in a significantly lower (p < 0.05) population size (number of organisms) compared with the control group. For instance, the population size was 7.7 ± 8.1 and 115 ± 3.5 (n = 3), respectively, at 18 d. However, both MP and MP/BP-3 fragments did not significantly decrease (p > 0.05) the population size of D. magna until day 18. These findings suggest that chemical additive leachates from MPs may have a distinct adverse effect on aquatic organisms, requiring further comprehensive investigation.

Ionic liquids (ILs) are widely used "green solvent" as they have a low vapor pressure and can replace volatile solvents in industry. However, ILs are difficult to biodegrade and are potentially harmful to the environment. This study, herein, investigated the toxicity of three imidazole ILs ([C₈MIM]Cl, [C₈MIM]Br, and [C₈DMIM]Br) towards soil microorganisms. The results showed that the ILs inhibited the growth of soil culturable microorganisms and affected the activity of soil enzyme. In addition, microbial communities' species and abundance in soil were altered. Finally, functional prediction analysis revealed that ILs mainly affected the carbohydrate metabolism and amino acid metabolic processes of the microorganisms. ILs with single methyl substituent had a more pronounced effect than those with double methyl substituents. The study indicates that the use of ILs with double methyl substituents is more environmentally safe, and that the toxicity of ILs should be taken into account in industrial production for the design and production of more environmentally safe types, such as ILs with double methyl substituents.

The widespread concern over nanoplastics (NPs) has prompted extensive research into their environmental impact. Concurrently, the study examined the combined toxicity of PS NPs and cadmium (Cd) on wheat. As indicated by the results of in situ Micro-ATR/FTIR, the aging process of PS NPs (50 nm) led to an increase in carbonyl and hydroxyl groups on their surface, enhancing hydrophilicity and consequently, the adsorption capacity for Cd. The toxicity assessment, measured by the impact on wheat leaf and root biomass after 7 d culture, revealed that pristine PS NPs with concentrations of 0-5000 mg·kg⁻¹ had a negligible effect on Cd toxicity to wheat leaves. However, aged PS NPs significantly intensified the inhibitory effect on wheat root growth, particularly at low Cd concentrations (≤ 5.0 mg·kg⁻¹). This synergistic toxicity between aged PS NPs and Cd is suspected to stem from the increased bioaccumulation of Cd in wheat, likely facilitated by the aged NPs. Thus, the study shed light on the aging behavior of soil surface NPs and its implications for environmental risk assessment.