The farmland ecosystem, with its numerous material cycles and energy flows, is an important part of the carbon cycle in terrestrial ecosystems. Focusing on the carbon neutrality of farmland is meaningful for mitigating global warming and serving national low-carbon strategies. This study enriches the carbon accounting items of farmland and establishes a new research framework to check the carbon neutrality of farmland from the aspect of regional interactions and, subsequently, the inequality among China's provinces. The results revealed that there is still a great gap in the capability of China's farmland to reach carbon neutrality, with a gap value of up to 10,503 × 104 t C. All of the provinces presented net carbon emissions, and the per unit area carbon neutrality gaps showed spatial regularity decreasing from the coastal regions to the inland areas. Anthropogenic carbon emissions on farmland played a dominant role compared with soil organic carbon. Five provinces had reduced interior-regional carbon emissions through grain trade, and the amounts were especially high for developed regions, such as Guangdong, Zhejiang, Beijing, Shanghai and Jiangsu. Sixteen provinces gained external carbon emissions through trade; these were the less developed regions located mainly in the north, such as Inner Mongolia, Hebei, Jilin, Heilongjiang and Xinjiang. Under regional inequality, 15 provinces added to the net amount of the carbon emissions generated in external regions, with China's megacities adding the highest percentage, especially Beijing, with 389.95 % compared with its original emissions. Inequality showed that most provinces had a moderate status. Sichuan and Hunan experienced weak advantages, and six provinces had disadvantages. Therefore, constructing compensation and trade-based rights and responsibilities traceability mechanisms is important.
{"title":"Re-identifying farmland carbon neutrality gap under a new carbon counting and the framework of regional interactions in China.","authors":"Jiqun Wen, Xiaowei Chuai, Ai Xiang, Yonghua Liu, Tong Wang, Yuting Luo, Lijuan Miao, Libao Zhang, Jianbao Li, Rongqin Zhao","doi":"10.1016/j.scitotenv.2024.175996","DOIUrl":"10.1016/j.scitotenv.2024.175996","url":null,"abstract":"<p><p>The farmland ecosystem, with its numerous material cycles and energy flows, is an important part of the carbon cycle in terrestrial ecosystems. Focusing on the carbon neutrality of farmland is meaningful for mitigating global warming and serving national low-carbon strategies. This study enriches the carbon accounting items of farmland and establishes a new research framework to check the carbon neutrality of farmland from the aspect of regional interactions and, subsequently, the inequality among China's provinces. The results revealed that there is still a great gap in the capability of China<sup>'</sup>s farmland to reach carbon neutrality, with a gap value of up to 10,503 × 10<sup>4</sup> t C. All of the provinces presented net carbon emissions, and the per unit area carbon neutrality gaps showed spatial regularity decreasing from the coastal regions to the inland areas. Anthropogenic carbon emissions on farmland played a dominant role compared with soil organic carbon. Five provinces had reduced interior-regional carbon emissions through grain trade, and the amounts were especially high for developed regions, such as Guangdong, Zhejiang, Beijing, Shanghai and Jiangsu. Sixteen provinces gained external carbon emissions through trade; these were the less developed regions located mainly in the north, such as Inner Mongolia, Hebei, Jilin, Heilongjiang and Xinjiang. Under regional inequality, 15 provinces added to the net amount of the carbon emissions generated in external regions, with China's megacities adding the highest percentage, especially Beijing, with 389.95 % compared with its original emissions. Inequality showed that most provinces had a moderate status. Sichuan and Hunan experienced weak advantages, and six provinces had disadvantages. Therefore, constructing compensation and trade-based rights and responsibilities traceability mechanisms is important.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20Epub Date: 2024-09-01DOI: 10.1016/j.scitotenv.2024.175929
Xuan Shi, Jin Zhang, Qize Wang, Kai Wang, Jianshuang Han, Yilian Hui, Xin Jin, Pengkang Jin
The scouring and migration of sediments in sewer systems are the key contributors to overflow pollution. Both physical and biological factors affect the erosion and migration of layered sediments. However, the functional characteristics of these factors and their quantification process still need to be further explored. In this study, the physical form and biological metabolism of the sediment are coupled, and the suspension mechanism under the dual action is proposed systematically and deeply. The influence coefficient of scour initiation was redefined as A^/prime, where the physical factors were particle size and mass, and the biological factors were bio-viscosity and internal cavitation. The bio-viscosity of layered sediment particles is provided by Extracellular Polymeric Substances (EPS). The slope value of |ΔD/-Δf| (ΔD: Dissipation; Δf: frequency) of surface EPS decreased from 0.489 to 0.315 when Quartz Crystal Microbalance with Dissipation (QCM-D) was used to analyse EPS viscosity, indicating that biological activities formed a dense biofilm on the sediment surface and enhanced the bond between particles. Meanwhile, by monitoring the accumulation density of sediments at different depths, it was found that the packing density of the bottom layer decreased from 1.50 to 1.45 g/cm3, which was mainly due to the internal cavitation caused by microorganism consuming organic matrix and releasing H2S and CH4. The delamination difference of EPS results in the uneven change of adhesion between different layers. This, combined with the internal erosion characteristics triggered by microbial stratified metabolism, collectively constitutes the biological effects on the sediment structure. Finally, the coupling mechanism of particle distribution and bio-viscous-cavitation erosion was formed, and the correctness of the formula was verified by repeated experiments, which proved the agreement between the theory and the practice and provided a scientific method for systematically analysing the erosion and migration law of sediment in the sewer system.
{"title":"A new perspective of sediment layering scour and migration under the coupled effects of particle distribution and bio-viscosity-cavitation erosion.","authors":"Xuan Shi, Jin Zhang, Qize Wang, Kai Wang, Jianshuang Han, Yilian Hui, Xin Jin, Pengkang Jin","doi":"10.1016/j.scitotenv.2024.175929","DOIUrl":"10.1016/j.scitotenv.2024.175929","url":null,"abstract":"<p><p>The scouring and migration of sediments in sewer systems are the key contributors to overflow pollution. Both physical and biological factors affect the erosion and migration of layered sediments. However, the functional characteristics of these factors and their quantification process still need to be further explored. In this study, the physical form and biological metabolism of the sediment are coupled, and the suspension mechanism under the dual action is proposed systematically and deeply. The influence coefficient of scour initiation was redefined as A^/prime, where the physical factors were particle size and mass, and the biological factors were bio-viscosity and internal cavitation. The bio-viscosity of layered sediment particles is provided by Extracellular Polymeric Substances (EPS). The slope value of |ΔD/-Δf| (ΔD: Dissipation; Δf: frequency) of surface EPS decreased from 0.489 to 0.315 when Quartz Crystal Microbalance with Dissipation (QCM-D) was used to analyse EPS viscosity, indicating that biological activities formed a dense biofilm on the sediment surface and enhanced the bond between particles. Meanwhile, by monitoring the accumulation density of sediments at different depths, it was found that the packing density of the bottom layer decreased from 1.50 to 1.45 g/cm<sup>3</sup>, which was mainly due to the internal cavitation caused by microorganism consuming organic matrix and releasing H2S and CH4. The delamination difference of EPS results in the uneven change of adhesion between different layers. This, combined with the internal erosion characteristics triggered by microbial stratified metabolism, collectively constitutes the biological effects on the sediment structure. Finally, the coupling mechanism of particle distribution and bio-viscous-cavitation erosion was formed, and the correctness of the formula was verified by repeated experiments, which proved the agreement between the theory and the practice and provided a scientific method for systematically analysing the erosion and migration law of sediment in the sewer system.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142124427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20Epub Date: 2024-09-02DOI: 10.1016/j.scitotenv.2024.176010
L Luque-García, S Bataineh, J Al-Bakri, F A Abdulla, W K Al-Delaimy
Background: The Middle East is one of the most vulnerable regions to the impacts of climate change, yet evidence of the heat-related mortality remains limited in this area. Our present study investigated the heat-mortality association in Jordan and the potential modifying effect of greenness, population density and urbanization level on the association.
Methods: For each of the 42 included districts, daily meteorological and mortality data from 2000 to 2020 were obtained for the warmest months (May to September). First, a distributed lag non-linear model was applied to estimate the district level heat-mortality association, then the district specific estimates were pooled using multivariate meta-regression models to obtain an overall estimate. Last, the modifying effect of district level greenness, population density and urbanization level was examined through subgroup analysis.
Results: When compared to the minimum mortality temperature (MMT, percentile 0th, 22.20 °C), the 99th temperature percentile exhibited a relative risk (RR) of 1.34 (95 % CI 1.23, 1.45). Districts with low greenness had a higher heat-mortality risk (RR 1.39, 95 % CI 1.22, 1.58) when compared to the high greenness (RR 1.28, 95 % CI 1.13, 1.45). While heat-mortality risk did not significantly differ between population density subgroups, highly urbanized districts had a greater heat-mortality risk (RR 1.41, 95 % CI 1.23, 1.62) as compared to ones with low levels of urbanization (RR 1.32, 95 % CI 1.13, 1.55). Districts with high urbanization level had the highest heat-mortality risk if they were further categorized as having low greenness (RR 1.63, 95 % CI 1.30, 2.04).
Conclusion: Exposure to heat was associated with increased mortality risk in Jordan. This risk was higher in districts with low greenness and high urbanization level. As climate change-related heat mortality will be on the rise, early warning systems in highly vulnerable communities in Jordan are required and greening initiatives should be pursued.
背景:中东是最易受气候变化影响的地区之一,但该地区与高温相关的死亡率证据仍然有限。本研究调查了约旦高温与死亡率的关系,以及绿化、人口密度和城市化水平对这种关系的潜在调节作用:方法:我们获取了约旦 42 个地区从 2000 年至 2020 年最热月份(5 月至 9 月)的每日气象数据和死亡率数据。首先,应用分布式滞后非线性模型估算地区层面的高温与死亡率的关联,然后使用多元元回归模型将地区的具体估算值汇总,得出总体估算值。最后,通过分组分析研究了地区绿化程度、人口密度和城市化水平的调节作用:与最低死亡温度(MMT,百分位数第 0 位,22.20 °C)相比,温度百分位数第 99 位的相对风险(RR)为 1.34(95 % CI 1.23,1.45)。与高绿化率地区相比,低绿化率地区的高温致死风险更高(RR 1.39,95 % CI 1.22,1.58)(RR 1.28,95 % CI 1.13,1.45)。虽然不同人口密度分组的高温致死风险没有显著差异,但高度城市化地区的高温致死风险(RR 1.41,95 % CI 1.23,1.62)高于低度城市化地区(RR 1.32,95 % CI 1.13,1.55)。如果将城市化水平高的地区进一步归类为绿化程度低的地区,则这些地区的高温致死风险最高(RR 1.63,95 % CI 1.30,2.04):在约旦,暴露于高温与死亡风险增加有关。这一风险在绿化程度低和城市化水平高的地区更高。由于与气候变化相关的高温死亡率将呈上升趋势,因此需要在约旦高度脆弱的社区建立早期预警系统,并采取绿化措施。
{"title":"The heat-mortality association in Jordan: Effect modification by greenness, population density and urbanization level.","authors":"L Luque-García, S Bataineh, J Al-Bakri, F A Abdulla, W K Al-Delaimy","doi":"10.1016/j.scitotenv.2024.176010","DOIUrl":"10.1016/j.scitotenv.2024.176010","url":null,"abstract":"<p><strong>Background: </strong>The Middle East is one of the most vulnerable regions to the impacts of climate change, yet evidence of the heat-related mortality remains limited in this area. Our present study investigated the heat-mortality association in Jordan and the potential modifying effect of greenness, population density and urbanization level on the association.</p><p><strong>Methods: </strong>For each of the 42 included districts, daily meteorological and mortality data from 2000 to 2020 were obtained for the warmest months (May to September). First, a distributed lag non-linear model was applied to estimate the district level heat-mortality association, then the district specific estimates were pooled using multivariate meta-regression models to obtain an overall estimate. Last, the modifying effect of district level greenness, population density and urbanization level was examined through subgroup analysis.</p><p><strong>Results: </strong>When compared to the minimum mortality temperature (MMT, percentile 0th, 22.20 °C), the 99th temperature percentile exhibited a relative risk (RR) of 1.34 (95 % CI 1.23, 1.45). Districts with low greenness had a higher heat-mortality risk (RR 1.39, 95 % CI 1.22, 1.58) when compared to the high greenness (RR 1.28, 95 % CI 1.13, 1.45). While heat-mortality risk did not significantly differ between population density subgroups, highly urbanized districts had a greater heat-mortality risk (RR 1.41, 95 % CI 1.23, 1.62) as compared to ones with low levels of urbanization (RR 1.32, 95 % CI 1.13, 1.55). Districts with high urbanization level had the highest heat-mortality risk if they were further categorized as having low greenness (RR 1.63, 95 % CI 1.30, 2.04).</p><p><strong>Conclusion: </strong>Exposure to heat was associated with increased mortality risk in Jordan. This risk was higher in districts with low greenness and high urbanization level. As climate change-related heat mortality will be on the rise, early warning systems in highly vulnerable communities in Jordan are required and greening initiatives should be pursued.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20Epub Date: 2024-08-21DOI: 10.1016/j.scitotenv.2024.175529
Gawsia Wahidunnessa Chowdhury, Heather J Koldewey, Md Nazmul Hasan Niloy, Mohammad Mizanur Rahman Khan, Nabanita Das, Surshti Patel, Bushra Nishat, Zoie T Diana, Nina Tsydenova, Subrata Sarker
Discarded fishing nets, a major source of marine litter, significantly threaten the marine environment and contribute to plastic pollution due to the synthetic polymers they contain. Though Bangladesh is a maritime country with 0.5 million of fishers dependent on coastal and marine fishing, there have been no studies to date on the plastic pollution impact of fishing nets. This study demonstrates the fishing nets associated with marine litter in two coastal locations of Bangladesh, Charfesson and Cox's Bazar. Fishing net samples were collected from local net shops and semi-structured interviews were taken of the shop owners to gather information about available fishing nets. This was complemented by photo-quadrat surveys to document waste fishing net materials on the shore in both locations. Among the 17 net samples, there were 12 types of gill nets, which showed a wide range of variation in price, material types, and longevity. Through the FTIR analysis, we identified the presence of Nylon 6, Polyethylene, Polyvinyl chloride, Polypropylene and Polyethylene terephthalate in the collected fishing net samples. Photoquadrat surveys found that fishing nets are related to plastic pollution in coastal areas. This study addressed the knowledge gap regarding the diversity and chemical characteristics of fishing nets and the resulting litter in Bangladesh.
{"title":"Discarded fishing net pollution in coastal areas of Bangladesh.","authors":"Gawsia Wahidunnessa Chowdhury, Heather J Koldewey, Md Nazmul Hasan Niloy, Mohammad Mizanur Rahman Khan, Nabanita Das, Surshti Patel, Bushra Nishat, Zoie T Diana, Nina Tsydenova, Subrata Sarker","doi":"10.1016/j.scitotenv.2024.175529","DOIUrl":"10.1016/j.scitotenv.2024.175529","url":null,"abstract":"<p><p>Discarded fishing nets, a major source of marine litter, significantly threaten the marine environment and contribute to plastic pollution due to the synthetic polymers they contain. Though Bangladesh is a maritime country with 0.5 million of fishers dependent on coastal and marine fishing, there have been no studies to date on the plastic pollution impact of fishing nets. This study demonstrates the fishing nets associated with marine litter in two coastal locations of Bangladesh, Charfesson and Cox's Bazar. Fishing net samples were collected from local net shops and semi-structured interviews were taken of the shop owners to gather information about available fishing nets. This was complemented by photo-quadrat surveys to document waste fishing net materials on the shore in both locations. Among the 17 net samples, there were 12 types of gill nets, which showed a wide range of variation in price, material types, and longevity. Through the FTIR analysis, we identified the presence of Nylon 6, Polyethylene, Polyvinyl chloride, Polypropylene and Polyethylene terephthalate in the collected fishing net samples. Photoquadrat surveys found that fishing nets are related to plastic pollution in coastal areas. This study addressed the knowledge gap regarding the diversity and chemical characteristics of fishing nets and the resulting litter in Bangladesh.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20Epub Date: 2024-08-22DOI: 10.1016/j.scitotenv.2024.175692
Zilin Yang, Yushan Chen, Jiawei Dong, Nian Hong, Qian Tan
Nitrogen (N) is one of the most important pollutants on urban road surfaces. Understanding the N deposition forms, load characteristics, and influential factors can help to provide management and control strategies for road stormwater runoff pollution. This study focuses on a highly urbanized area in Guangzhou, China, and presents the characteristics of both dissolved and particulate N deposition forms as well as their correlations with land-use types and traffic factors. In addition, an artificial neural network (ANN) based classification model is utilized to estimate N pollution hotspot area and total nitrogen (TN) flux from road to receiving water bodies. The results showed that N on urban road surfaces mainly existed in the form of particulate organic nitrogen. Land use types dominated by residential area (RA) and urban village (UV) have higher TN build-up loads. Geodetector analysis indicated that land use has a greater impact on nitrogen build-up loads than traffic factors. Through classification and estimation using the ANN model, RA, and UV were classified as hotspot areas, and the TN flux from roads in the study area was calculated to be 3.35 × 105 g. Furthermore, it was estimated that the annual TN flux from roads in Guangzhou accounts for 19 % of the city's total urban domestic discharge. These findings are expected to contribute to the pollution control of stormwater runoff from urban road surfaces and provide valuable guidance for enhancing the ecological health of urban water environments.
氮(N)是城市道路表面最重要的污染物之一。了解氮的沉积形式、负荷特征和影响因素,有助于为道路雨水径流污染提供管理和控制策略。本研究以中国广州的一个高度城市化地区为研究对象,介绍了溶解氮和颗粒氮沉积形式的特征及其与土地利用类型和交通因素的相关性。此外,还利用基于人工神经网络(ANN)的分类模型估算了氮污染热点区域以及从道路到受纳水体的总氮(TN)通量。结果表明,城市道路路面上的氮主要以颗粒有机氮的形式存在。以住宅区(RA)和城中村(UV)为主的土地利用类型具有较高的 TN 累积负荷。地质探测器分析表明,土地利用对氮累积负荷的影响大于交通因素。通过使用 ANN 模型进行分类和估算,将 RA 和 UV 划分为热点区域,并计算出研究区域内来自道路的 TN 通量为 3.35 × 105 g。此外,据估计,广州市每年来自道路的 TN 通量占全市城市生活污水排放总量的 19%。这些研究结果有望为城市道路路面雨水径流的污染控制作出贡献,并为提高城市水环境的生态健康水平提供有价值的指导。
{"title":"Characterizing nitrogen deposited on urban road surfaces: Implication for stormwater runoff pollution control.","authors":"Zilin Yang, Yushan Chen, Jiawei Dong, Nian Hong, Qian Tan","doi":"10.1016/j.scitotenv.2024.175692","DOIUrl":"10.1016/j.scitotenv.2024.175692","url":null,"abstract":"<p><p>Nitrogen (N) is one of the most important pollutants on urban road surfaces. Understanding the N deposition forms, load characteristics, and influential factors can help to provide management and control strategies for road stormwater runoff pollution. This study focuses on a highly urbanized area in Guangzhou, China, and presents the characteristics of both dissolved and particulate N deposition forms as well as their correlations with land-use types and traffic factors. In addition, an artificial neural network (ANN) based classification model is utilized to estimate N pollution hotspot area and total nitrogen (TN) flux from road to receiving water bodies. The results showed that N on urban road surfaces mainly existed in the form of particulate organic nitrogen. Land use types dominated by residential area (RA) and urban village (UV) have higher TN build-up loads. Geodetector analysis indicated that land use has a greater impact on nitrogen build-up loads than traffic factors. Through classification and estimation using the ANN model, RA, and UV were classified as hotspot areas, and the TN flux from roads in the study area was calculated to be 3.35 × 10<sup>5</sup> g. Furthermore, it was estimated that the annual TN flux from roads in Guangzhou accounts for 19 % of the city's total urban domestic discharge. These findings are expected to contribute to the pollution control of stormwater runoff from urban road surfaces and provide valuable guidance for enhancing the ecological health of urban water environments.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20Epub Date: 2024-09-02DOI: 10.1016/j.scitotenv.2024.175909
Raza Ullah, Julia Farias, Biruk A Feyissa, Martin Tsz-Ki Tsui, Alex Chow, Clinton Williams, Tanju Karanfil, Ayalew Ligaba-Osena
The use of reclaimed water from wastewater treatment plants for irrigation has a risk of introducing micropollutants such as microplastics (MPs) and antimicrobials (AMs) into the agroecosystem. This study was conducted to investigate the effects of single and combined treatment of 0.1 % polyamide (PA ∼15 μm), and varying sulfamethoxazole (SMX) levels 0, 10, 50, and 150 mg/L on rice seedlings (Oryza sativa L.) for 12 days. The study aimed to assess the impact of these contaminants on the morphological, physiological, and biochemical parameters of the rice plants. The findings revealed that rice seedlings were not sensitive to PA alone. However, SMX alone or in combination with PA, significantly inhibited shoot and root growth, total biomass, and affected photosynthetic pigments. Higher concentrations of SMX increased antioxidant enzyme activity, indicating oxidative stress. The roots had a higher SMX content than the shoots, and the concentration of minerals such as iron, copper, and magnesium were reduced in roots treated with SMX. RNA-seq analysis showed changes in the expression of genes related to stress, metabolism, and transport in response to the micropollutants. Overall, this study provides valuable insights on the combined impacts of MPs and AMs on food crops, the environment, and human health in future risk assessments and management strategies in using reclaimed water.
{"title":"Combined effects of polyamide microplastic and sulfamethoxazole in modulating the growth and transcriptome profile of hydroponically grown rice (Oryza sativa L.).","authors":"Raza Ullah, Julia Farias, Biruk A Feyissa, Martin Tsz-Ki Tsui, Alex Chow, Clinton Williams, Tanju Karanfil, Ayalew Ligaba-Osena","doi":"10.1016/j.scitotenv.2024.175909","DOIUrl":"10.1016/j.scitotenv.2024.175909","url":null,"abstract":"<p><p>The use of reclaimed water from wastewater treatment plants for irrigation has a risk of introducing micropollutants such as microplastics (MPs) and antimicrobials (AMs) into the agroecosystem. This study was conducted to investigate the effects of single and combined treatment of 0.1 % polyamide (PA ∼15 μm), and varying sulfamethoxazole (SMX) levels 0, 10, 50, and 150 mg/L on rice seedlings (Oryza sativa L.) for 12 days. The study aimed to assess the impact of these contaminants on the morphological, physiological, and biochemical parameters of the rice plants. The findings revealed that rice seedlings were not sensitive to PA alone. However, SMX alone or in combination with PA, significantly inhibited shoot and root growth, total biomass, and affected photosynthetic pigments. Higher concentrations of SMX increased antioxidant enzyme activity, indicating oxidative stress. The roots had a higher SMX content than the shoots, and the concentration of minerals such as iron, copper, and magnesium were reduced in roots treated with SMX. RNA-seq analysis showed changes in the expression of genes related to stress, metabolism, and transport in response to the micropollutants. Overall, this study provides valuable insights on the combined impacts of MPs and AMs on food crops, the environment, and human health in future risk assessments and management strategies in using reclaimed water.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142131513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Human activities led to elevation in carbon dioxide (CO2) concentrations in atmosphere. While such increase per se may be beneficial for the growth of some crops, it comes with a caveat of affecting crop nutritional status. Here, we present a comprehensive analysis of changes in concentration of essential (Cu, Fe, Mn, Zn, Mo, Ni) and non-essential (Ba, Cd, Cr, Hg, Pb, and Sr) heavy metals in response to elevated CO2, drawing on a meta-analysis of 1216 paired observations. The major findings are as follows: (1) Elevated CO2 leads to reduced concentrations of Cu, Fe, Mn, and Zn in crops; (2) the extent of above reduction varies among plants species and is most pronounced in cereals and then in legumes and vegetables; (3) reduction in accumulation of non-essential (toxic) metals is less pronounced, potentially leading to an unfavorable essential/non-essential metal ratio in plants; (4) the above effects will come with significant implication to human health, exacerbating effects of the "hidden hunger" caused by the lack of Fe and Zn in the human diets. The paper also analyses the mechanistic basis of nutrient acquisition (both at physiological and molecular levels) and calls for the changes in the governmental policies to increase efforts of plant breeders to create genotypes with improved nutrient use efficiency for essential micronutrients while uncoupling their transport from non-essential (toxic) heavy metals.
{"title":"Assessing impact of elevated CO<sub>2</sub> on heavy metal accumulation in crops: meta-analysis and implications for food security.","authors":"Xunzhe Yang, Ping Yun, Xiaoxiang Zhao, Zhe Zhang, Chen Chen, Yonghong Zhou, Yinglong Chen, Haiqin Zhang, Sergey Shabala","doi":"10.1016/j.scitotenv.2024.175949","DOIUrl":"10.1016/j.scitotenv.2024.175949","url":null,"abstract":"<p><p>Human activities led to elevation in carbon dioxide (CO<sub>2</sub>) concentrations in atmosphere. While such increase per se may be beneficial for the growth of some crops, it comes with a caveat of affecting crop nutritional status. Here, we present a comprehensive analysis of changes in concentration of essential (Cu, Fe, Mn, Zn, Mo, Ni) and non-essential (Ba, Cd, Cr, Hg, Pb, and Sr) heavy metals in response to elevated CO<sub>2</sub>, drawing on a meta-analysis of 1216 paired observations. The major findings are as follows: (1) Elevated CO<sub>2</sub> leads to reduced concentrations of Cu, Fe, Mn, and Zn in crops; (2) the extent of above reduction varies among plants species and is most pronounced in cereals and then in legumes and vegetables; (3) reduction in accumulation of non-essential (toxic) metals is less pronounced, potentially leading to an unfavorable essential/non-essential metal ratio in plants; (4) the above effects will come with significant implication to human health, exacerbating effects of the \"hidden hunger\" caused by the lack of Fe and Zn in the human diets. The paper also analyses the mechanistic basis of nutrient acquisition (both at physiological and molecular levels) and calls for the changes in the governmental policies to increase efforts of plant breeders to create genotypes with improved nutrient use efficiency for essential micronutrients while uncoupling their transport from non-essential (toxic) heavy metals.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142124430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20Epub Date: 2024-09-01DOI: 10.1016/j.scitotenv.2024.175790
Shahram Nakhaei, Mojgan Salavati, Ali Moghimi Kandelus
The Sefid-rud River is a significant river on the southern coast of the Caspian Sea in Iran. In this study, we collected 28 samples of surface sediments and water to assess the level of metal contamination. Chemical analysis revealed that the average concentrations of heavy metals in both sediments and water increase from upstream to downstream. There is no clear significant relationship observed between changes in the values of investigated elements in sediments and water. The levels of these elements in the sediments, exceed toxic response thresholds. In the water samples, As, Ni and V concentrations exceed the WHO standard values. According to the Igeo, EF and PLI indices, the sediments at most stations are not contaminated by any of the elements. The CF and Dc indices suggest low contamination levels at all stations. The NIPI and ecological risk indices (Er and RI) indicate non-polluted conditions at all stations except SF22, SF20, SF11, and SF6. The MI and HEI indices indicate pollution in all water samples of the Sefid-rud, but critical values are only observed at SF5 and SF15. The other stations show no contamination. The Cf index indicates high pollution levels for all elements except Cu, Zn, and Pb. The upstream area poses a relatively high and considerable ecological risk according to the PERI index. In conclusion, the sediments of the Sefid-rud River have a higher potential for the exchange of toxic substances compared to the aquatic environment.
Sefid-rud 河是伊朗里海南岸的一条重要河流。在这项研究中,我们采集了 28 份表层沉积物和水样,以评估金属污染程度。化学分析显示,沉积物和水中重金属的平均浓度从上游到下游都在增加。在沉积物和水中的调查元素值的变化之间没有观察到明显的重要关系。这些元素在沉积物中的含量超过了毒性反应阈值。在水样中,砷、镍和钒的浓度超过了世界卫生组织的标准值。根据 Igeo、EF 和 PLI 指数,大多数站点的沉积物没有受到任何元素的污染。CF 和 Dc 指数表明,所有站点的污染程度都较低。NIPI 和生态风险指数(Er 和 RI)表明,除 SF22、SF20、SF11 和 SF6 站外,所有站点均未受到污染。MI和 HEI 指数显示,Sefid-rud 的所有水样都受到了污染,但只有 SF5 和 SF15 出现了临界值。其他站点未发现污染。Cf 指数表明,除铜、锌和铅外,所有元素的污染程度都很高。根据 PERI 指数,上游地区具有相对较高的生态风险。总之,与水生环境相比,Sefid-rud 河的沉积物具有更高的有毒物质交换潜力。
{"title":"Contamination of toxic elements in the sediments, water, and igneous rocks of the Sefid-rud River in Northern Iran using contamination indicators, with a specific focus on Ti-rich coastal sediments.","authors":"Shahram Nakhaei, Mojgan Salavati, Ali Moghimi Kandelus","doi":"10.1016/j.scitotenv.2024.175790","DOIUrl":"10.1016/j.scitotenv.2024.175790","url":null,"abstract":"<p><p>The Sefid-rud River is a significant river on the southern coast of the Caspian Sea in Iran. In this study, we collected 28 samples of surface sediments and water to assess the level of metal contamination. Chemical analysis revealed that the average concentrations of heavy metals in both sediments and water increase from upstream to downstream. There is no clear significant relationship observed between changes in the values of investigated elements in sediments and water. The levels of these elements in the sediments, exceed toxic response thresholds. In the water samples, As, Ni and V concentrations exceed the WHO standard values. According to the Igeo, EF and PLI indices, the sediments at most stations are not contaminated by any of the elements. The CF and Dc indices suggest low contamination levels at all stations. The NIPI and ecological risk indices (Er and RI) indicate non-polluted conditions at all stations except SF22, SF20, SF11, and SF6. The MI and HEI indices indicate pollution in all water samples of the Sefid-rud, but critical values are only observed at SF5 and SF15. The other stations show no contamination. The Cf index indicates high pollution levels for all elements except Cu, Zn, and Pb. The upstream area poses a relatively high and considerable ecological risk according to the PERI index. In conclusion, the sediments of the Sefid-rud River have a higher potential for the exchange of toxic substances compared to the aquatic environment.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142124433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20Epub Date: 2024-09-04DOI: 10.1016/j.scitotenv.2024.175976
Nuria Perujo, Lola Neuert, Patrick Fink, Markus Weitere
Microbial consortia in riverbed substrates and their extracellular matrix (biofilms) play a key role in phosphorus (P) entrapment. When P entrapment saturates, the benthic compartment changes from a P sink to a P source thus increasing eutrophication risk. P entrapment saturation is expected to differ between intracellular and extracellular P entrapment and between different magnitudes and durations of P inputs. We studied biofilm P-entrapment following short (48 h) and long (14 days) P loading events in stream bypass flumes supplied with a gradient of dissolved P concentrations. This allowed us to link local biofilm processes in sediments to potential effects on river self-purification, via quantifying the P removal efficiency in the flumes. We found that in short-term events, biofilms develop intracellular mechanisms to cope with P inputs, while long-term events and high P inputs suppress the intracellular uptake mechanisms and increase the prevalence of extracellular entrapment. Specifically, long-term events lowered the threshold for intracellular P entrapment saturation, and decreased the ratio between intracellular and extracellular entrapment resulting in lower removal efficiency for dissolved phosphorus. Our results highlight the risk that aquatic ecosystems may face as the ratio of intracellular to extracellular P entrapment decreases, which may reduce their ability to deal with P inputs, thereby increasing risks of eutrophication.
河床基质中的微生物群落及其胞外基质(生物膜)在磷(P)吸附中起着关键作用。当磷(P)吸附饱和时,底栖区块就会从磷汇变成磷源,从而增加富营养化的风险。细胞内和细胞外磷(P)的截留饱和度预计会有所不同,输入磷(P)的量级和持续时间也会不同。我们在溶解 P 浓度梯度的溪流旁路水槽中研究了短时间(48 小时)和长时间(14 天)P 负荷事件后的生物膜 P 诱导饱和度。这使我们能够通过量化水槽中的磷去除效率,将沉积物中的局部生物膜过程与对河流自净的潜在影响联系起来。我们发现,在短期事件中,生物膜发展出细胞内机制来应对 P 输入,而长期事件和高 P 输入则抑制了细胞内吸收机制,增加了细胞外截留的普遍性。具体而言,长期事件降低了细胞内磷捕获饱和的阈值,降低了细胞内和细胞外捕获的比例,从而降低了对溶解磷的去除效率。我们的研究结果突显了水生生态系统可能面临的风险,即随着细胞内与细胞外磷捕集比的降低,水生生态系统处理磷输入的能力可能会降低,从而增加富营养化的风险。
{"title":"Saturation of intracellular phosphorus uptake and prevalence of extracellular phosphorus entrapment in fluvial biofilms after long-term P pulses: Implications for river self-purification.","authors":"Nuria Perujo, Lola Neuert, Patrick Fink, Markus Weitere","doi":"10.1016/j.scitotenv.2024.175976","DOIUrl":"10.1016/j.scitotenv.2024.175976","url":null,"abstract":"<p><p>Microbial consortia in riverbed substrates and their extracellular matrix (biofilms) play a key role in phosphorus (P) entrapment. When P entrapment saturates, the benthic compartment changes from a P sink to a P source thus increasing eutrophication risk. P entrapment saturation is expected to differ between intracellular and extracellular P entrapment and between different magnitudes and durations of P inputs. We studied biofilm P-entrapment following short (48 h) and long (14 days) P loading events in stream bypass flumes supplied with a gradient of dissolved P concentrations. This allowed us to link local biofilm processes in sediments to potential effects on river self-purification, via quantifying the P removal efficiency in the flumes. We found that in short-term events, biofilms develop intracellular mechanisms to cope with P inputs, while long-term events and high P inputs suppress the intracellular uptake mechanisms and increase the prevalence of extracellular entrapment. Specifically, long-term events lowered the threshold for intracellular P entrapment saturation, and decreased the ratio between intracellular and extracellular entrapment resulting in lower removal efficiency for dissolved phosphorus. Our results highlight the risk that aquatic ecosystems may face as the ratio of intracellular to extracellular P entrapment decreases, which may reduce their ability to deal with P inputs, thereby increasing risks of eutrophication.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20Epub Date: 2024-09-01DOI: 10.1016/j.scitotenv.2024.175910
Javier Pinochet, Martin Thiel, Mauricio Urbina
Estimates suggest that the amount of plastic litter discarded in the ocean is several times greater than what remains floating at the sea surface, raising questions about the fate of this marine debris. Fouling-induced sinking of plastic litter is one of the proposed mechanisms responsible for this mass difference. While some of this 'missing' plastic mass may be explained by the effects of fouling, it has also been hypothesized that sinking litter may return to the surface after benthic organisms consume the biofouling. However, this hypothesis has never been tested. The present study evaluated the structure and biomass of the fouling community in response to benthic predation in both summer and winter seasons. Floating PVC plates were installed during winter and summer in central Chile (36°S) until the growing biofouling community caused them to sink. Plates were then moved to the seabed, where they were exposed to benthic predation, while control plates were maintained in a mesh cage impeding predator access. In summer, all plates recovered their buoyancy, while in the winter only 60 % recovered buoyancy. All caged control samples remained on the bottom in both seasons. The community structure differed both in the treatments and across the seasons, with plates that recovered buoyancy initially being dominated by Ulva sp. and Ciona robusta. Conversely, plates that did not refloat were mainly covered by species resistant to predation such as Pyura chilensis, Austromegabalanus psittacus, and Balanus laevis. Thus, fouling community structure influences how predation facilitates buoyancy recovery, because not all epibionts can be consumed by predators. While previous studies had shown how fouling organisms cause sinking of floating litter, this is the first study to provide experimental evidence that predation can reverse this process and allow litter to resurface and become again available as dispersal vectors for native and invasive species.
{"title":"How plastic litter sunk by biofouling recovers buoyancy - The role of benthic predation.","authors":"Javier Pinochet, Martin Thiel, Mauricio Urbina","doi":"10.1016/j.scitotenv.2024.175910","DOIUrl":"10.1016/j.scitotenv.2024.175910","url":null,"abstract":"<p><p>Estimates suggest that the amount of plastic litter discarded in the ocean is several times greater than what remains floating at the sea surface, raising questions about the fate of this marine debris. Fouling-induced sinking of plastic litter is one of the proposed mechanisms responsible for this mass difference. While some of this 'missing' plastic mass may be explained by the effects of fouling, it has also been hypothesized that sinking litter may return to the surface after benthic organisms consume the biofouling. However, this hypothesis has never been tested. The present study evaluated the structure and biomass of the fouling community in response to benthic predation in both summer and winter seasons. Floating PVC plates were installed during winter and summer in central Chile (36°S) until the growing biofouling community caused them to sink. Plates were then moved to the seabed, where they were exposed to benthic predation, while control plates were maintained in a mesh cage impeding predator access. In summer, all plates recovered their buoyancy, while in the winter only 60 % recovered buoyancy. All caged control samples remained on the bottom in both seasons. The community structure differed both in the treatments and across the seasons, with plates that recovered buoyancy initially being dominated by Ulva sp. and Ciona robusta. Conversely, plates that did not refloat were mainly covered by species resistant to predation such as Pyura chilensis, Austromegabalanus psittacus, and Balanus laevis. Thus, fouling community structure influences how predation facilitates buoyancy recovery, because not all epibionts can be consumed by predators. While previous studies had shown how fouling organisms cause sinking of floating litter, this is the first study to provide experimental evidence that predation can reverse this process and allow litter to resurface and become again available as dispersal vectors for native and invasive species.</p>","PeriodicalId":422,"journal":{"name":"Science of the Total Environment","volume":null,"pages":null},"PeriodicalIF":8.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142124438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}