ECOLOGICAL INDICATORS
·
2022
·
IF 6.263
Qunpo Jia,Yanpeng Cai,Xiao Yuan,Xiaodong Zhang,Bowen Li,Bo Li
Neonicotinoid insecticides (NEOs) are widely used in many urban regions. Studies on NEOs residues in urban tidal streams and the associated ecological risks are limited. In this study, the occurrence, spatiotemporal distribution, and ecological risks of seven selected NEOs in the Wuchong Stream in Guangzhou, China were investigated. Moreover, the correlation between typical urban factors and the ecological risk of NEOs was discussed. In the Wuchong Stream, the concentrations of NEOs in the water samples ranged from 0.97 to 175.92 ng. L -1 in the dry season and 3.15 to 312.92 ng. L -1 in the wet season.The most commonly used neonicotionoids were acetamiprid and imidacloprid in the Wuchong Sream basin. The concentrations of NEOs in the midstream were higher than that in the downstream and upstream. The results of the ecological risk indicated that NEOs were likely to biologically impair the urban stream ecosystem, especially in the dry season. For three typical aquatic organisms, the current concentrations of NEOs posed a significant threat to aquatic insects. Compared to other urban factors, residentidal district and farmland area were the main socioeconomic factors affecting the ecological risk of NEOs in the Wuchong Stream basin. Therefore, the correct and reasonable application of NEOs and continuous improvement of the applicant methods can reduce the environmental risks of urban streams.
研究领域:
环境科学
·
生态学
✓ 已验证
产品关联
DOI
高影响因子
Toxics
·
2023
·Vol. 11
·期 3
·203
·
IF 4.6
Qunpo Jia,Yanpeng Cai,Xiao Yuan,Bowen Li,Bo Li
Neonicotinoid insecticides (NEOs) are commonly used to prevent unwanted insects in urban fields. Degradation processes have been one of the important environmental behaviors of NEOs in an aquatic environment. In this research, hydrolysis, biodegradation, and photolysis processes of four typical NEOs (i.e., thiacloprid (THA), clothianidin (CLO), acetamiprid (ACE), and imidacloprid (IMI)) were examined through the adoption of response surface methodology–central composite design (RSM-CCD) for an urban tidal stream in South China. The influences of multiple environmental parameters and concentration levels on the three degradation processes of these NEOs were then evaluated. The results indicated that the three degradation processes of the typical NEOs followed a pseudo-first-order reaction kinetics model. The primary degradation process of the NEOs were hydrolysis and photolysis processes in the urban stream. The hydrolysis degradation rate of THA was the highest (1.97 × 10−5s−1), and that of CLO was the lowest (1.28 × 10−5s−1). The temperature of water samples was the main environmental factor influencing the degradation processes of these NEOs in the urban tidal stream. Salinity and humic acids could inhibit the degradation processes of the NEOs. Under the influence of extreme climate events, the biodegradation processes of these typical NEOs could be suppressed, and other degradation processes could be further accelerated. In addition, extreme climate events could pose severe challenges to the migration and degradation process simulation of NEOs.Keywords:neonicotinoid insecticides (NEOs);degradation kinetics;urban tidal stream;mathematical modeling;central composite design (CCD)
研究领域:
环境科学
·
生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jingjing Du,Wenrui Qv,Yulong Niu,Mingxiang Qv,Kai Jin,Jinyou Xie,Zehong Li
Many studies have proved the impacts of nanoplastic pollution in freshwaters on aquatic organisms and ecosystems. To explore toxic mechanisms of nanoplastics on stream functioning, we conducted a microcosm experiment to investigate the effects of polystyrene nanoparticles (PS NPs, 1–100 μg L −1 ) on the process of leaf litter decomposition mediated by the microbial community . The chronic exposure to PS NPs at 1 and 100 μg L −1 caused significant decreases in leaf litter decomposition and nutrient (carbon and nitrogen) releases. During the ecological process, some extracellular enzymes (i.e., β-glucosidase, glycine-aminopeptidase, and phenol oxidase) rather than fungal biomass were suppressed. Besides, decreases in the relative abundance of Anguillospora and Setophaeosphaeria weakened their functions in leaf litter decomposition. Thus, the microcosm experiment showed that PS NPs inhibited stream leaf decomposition by modulating the microbial metabolic activity and fungal community structure. Overall, the results of this study provide evidence for the consequences of nanoplastic pollution on freshwater microbial community and stream ecosystem functioning, which is conducive to evaluate the potential risks of nanoplastics in aquatic environments.
研究领域:
环境科学
·
微生物学
·
生态学
✓ 已验证
DOI
PubMed
高影响因子
Environmental Science-Nano
·
2019
·Vol. 6
·期 6
·1728-1739
·
IF 7.704
Gaozhong Pu,Danjuan Zeng,Ling Mo,Wen He,Longwu Zhou,Kechao Huang,Jianxiong Liao,Shuo Qiu,Shengfeng Chai
The toxic effects of silver nanoparticles (AgNP) to aquatic species and ecosystem processes have been the focus of increasing research in ecology, but their effects under different environmental stressors, such as the ongoing anthropogenic artificial light at night (ALAN) which can cause a series of ecological effects and will potentially interact with other stressors, remain poorly understood. Here, we aimed to assess the combined effects of AgNP and ALAN on the activities and community structure of fungi and bacteria associated to plant litter in a stream. The results showed that ALAN not only led to changes in the average hydrodynamic diameter, ζ-potential and dissolved concentration of AgNP but also inhibited the enzyme activities of leucine-aminopeptidase (LAP), polyphenol oxidase (PPO) and peroxidase (PER) associated with microbes involved in litter decomposition. The negative effect of AgNP on the decomposition of Pterocarya stenoptera leaf litter was alleviated by ALAN owing to the reduction of the Ag+ concentration in the microcosm and of the lignin content of the leaf litter in the A-AgNP treatments, the enhancement of β-glucosidase (β-G) activities and the increase in microbial biomass. The effect of ALAN alone or combined with AgNP or AgNO3 on the taxonomic composition of fungi was much greater than that on bacteria. Linear discriminant analysis effect size (LEfSe) demonstrated that each treatment had its own fungal and bacterial indicator taxa, from the phylum to genus levels, indicating that the microbial communities associated with litter decomposition can change their constituent taxa to cope with different stressors. These results reveal that ALAN can decrease the toxicity of AgNP and highlight the importance of considering ALAN during the assessment of the risk posed by nanoparticles to freshwater biota and ecosystem processes.
研究领域:
生态学
·
环境科学
·
微生物学
·
水生科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Jingjing Du,Xilin Wang,Tianying Tao,Xueting Zhang,Baodan Jin,Jianguo Zhao,Yangyang Lv,Qian Zhang,Keying Hu,Wenrui Qv,Yuanqian Xu,Xia Cao
The particle size of plastic is one of the most important factors influencing its ecotoxicity, but we are unclear about the effect of polystyrene (PS) particle size on microbial decomposers and consequent nutrient cycling in streams. Here, using microcosm experiments, we assessed how three PS sizes (50 nm, 1 μm, and 20 μm) influenced the process and consequences of leaf litter decomposition. Under acute exposure to 1 μm and 20 μm PS, fungal biomass significantly decreased, but microbial biomass significantly increased, indicating compensations may work between fungi and other microbial decomposers. After chronic exposure to 50 nm and 1 μm PS, the leaf decomposition rate decreased by 19.27 % and 15.22 %, respectively, due to the reduced microbial enzyme activity , fungal diversity, and dominance of Anguillospora . As a result, the regeneration of nutrients, especially phosphorus, was significantly depressed, which might influence the primary productivity of streams. Therefore, our results suggest that nanoscale PS has a greater impact on microbial activity , thus affecting their functioning in leaf litter decomposition and consequent nutrient cycling. The findings provide a data support for the risk assessment of plastic pollution in freshwater systems.
研究领域:
生态毒理学
·
微生物学
·
环境科学
·
水生生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）