Human welfare and biodiversity are at risk due to the deterioration of water and sediment quality. Particularly, in last few decades, global water and sediment quality degraded due to the rapid industrialization and urbanization. This study aimed to determine the concentration of nine heavy metals and metalloid (Pb, Cr, Cd, Hg, As, Mn, Ni, Cu, and Zn) and assess the ecological risks using different pollution indices (e.g., heavy metal pollution index [HPI], Nemerow pollution index [NI], geo-accumulation index [Igeo], contamination factor [CF], degree of contamination [CD] and pollution load index [PLI], ecological risk index [ERI]) in water and sediment of the Shitalakshya River, an industrially affected urban river of Bangladesh. For the first time, 20 water and sediment samples were collected across a wider geographical area of the Shitalakshya River during both monsoon and dry seasons and analyzed using the atomic absorption spectrometer. Average concentrations of heavy metals and metalloid in water were within the Bangladesh standard except for Cr (51.69 ppb) and Mn (228.20 ppb) during monsoon season, portraying potential ecological and human health risks. Besides, average concentration of Mn (549.75 and 370.93 ppb), Ni (549.75 and 370.93 ppb), and Cu (45.34 and 36.09 ppb) in sediment during both seasons were above international standard, implying risk to aquatic sediment biota. The average HPI values indicated moderate to high contamination, whereas the NI values implied polluted water in monsoon season with severe pollution in port area of the river. Similarly, Igeo, CF, CD, and PLI elucidated different levels of contamination in the sediment, particularly during dry season. The ERI values also referred moderate ecological risk in the sediment during dry season. Overall, our findings highlight the alarming level of heavy metal pollution in the Shitalakshya River, necessitating immediate action to protect the aquatic environment, sediment biota, and human health. PRACTITIONER POINTS: This study determined the concentration of heavy metals and metalloid in water and sediment of the Shitalakshya River, Bangladesh. The study revealed that the average concentration of Cr and Mn in water exceeded national standard, whereas Mn, Ni, and Cu in sediment exceeded international limit. Potential ecological risk of heavy metals was also assessed using different pollution indices. Calculated pollution indices indicated different degree of pollution, implying critical ecological condition due to heavy metal pollution in aquatic environment and sediment biota.

Microplastic (MP) pollution has gained considerable attention in various ecosystems; however, it has received relatively less attention in freshwater-riverine environments than in other ecosystems. The Ganges River Delta, one of the world\'s most densely populated areas, is a potential source of MP pollution in the freshwater ecosystem. MPs were identified throughout the year in the lower Ganges River water. Seasonally, the highest abundance was observed during the monsoon (14.66 ± 2.06 MPs/L), followed by the pre-monsoon (13.46 ± 1.75 MPs/L) and post-monsoon (11.50 ± 0.40 MPs/L). Throughout the year, MP discharge was estimated at 4.12 × 1012 to 2.17 × 1013 MPs/year. Fourier transformed infrared spectroscopy identified plastic polymers in the water, like ethylene vinyl acetate, polystyrene, polypropylene, polyethylene, and nylon. Moderate contamination by MPs was assessed throughout the year. Significant correlations between MP abundance and both rainfall and discharge were observed. It is essential to implement preventative measures in the Ganges River Basin to mitigate MP pollution before the situation worsens. PRACTITIONER POINTS: Throughout the year, MP concentration ranged from 10.67 to 20.33 MPs/L The highest MP occurrence was observed in the monsoon season (14.66 ± 2.06 MPs/L) The lowest abundance was detected in the post-monsoon period (11.50 ± 0.40 MPs/L) There was a moderate level of MP contamination in the lower Ganges River water It was shown that discharge and rainfall were correlated with MP abundance.

Oil spills from pipeline accidents can result in long-lasting health effect in the people living in a ‎polluted region‎. In this study, the level of the 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs‎) and heavy metals (HMs) have been ‎analyzed in environmental matrices of a region with frequent oil ‎pipeline accidents in Iran‎.‎ The results showed that the mean ‎concentration of ΣPAHs and ΣHMs decreased from the upstream to the downstream and also the levels were ‎higher in the wet season than those in the dry season. The average concentration of HMs in sediments was higher than that in other ‎environments. The 3-ring and 4-ring PAHs were dominant in all of the studied matrices with the average values of 32.61 % and 45.85 %, respectively. The ecological risks of PAHs and HMs were medium and high in all matrices, respectively. In wet season, the total cancer risk (TCR) related to PAHs in agricultural soil was greater than 10-4, whereas it\'s very close to the threshold for HMs in water. This study offers a reference for assessing the long-term impact of oil spills in contaminated environmental matrices. The results are crucial for developing effective strategies to mitigate oil pollution ‎impacts and protect environmental and public health.

Aggravated accumulation of emerging micropollutants (EMs) in aquatic environments, especially after COVID-19, raised significant attention throughout the world for safety concerns. This article reviews the sources and occurrence of 25 anti-COVID-19 related EMs in wastewater. It should be pointed out that the concentration of anti-COVID-19 related EMs, such as antivirals, plasticizers, antimicrobials, and psychotropic drugs in wastewater increased notably after the pandemic. Furthermore, the ecotoxicity, ecological, and health risks of typical EMs before and after COVID-19 were emphatically compared and analyzed. Based on the environmental health prioritization index method, the priority control sequence of typical EMs related to anti-COVID-19 was identified. Lopinavir (LPV), venlafaxine (VLX), di(2-ethylhexyl) phthalate (DEHP), benzalkonium chloride (BAC), triclocarban (TCC), di-n-butyl phthalate (DBP), citalopram (CIT), diisobutyl phthalate (DIBP), and triclosan (TCS) were identified as the top-priority control EMs in the post-pandemic period. Besides, some insights into the toxicity and risk assessment of EMs were also provided. This review provides direction for proper understanding and controlling the EMs pollution after COVID-19, and is of significance to evaluate objectively the environmental and health impacts induced by COVID-19.

The water diversion project is an effective engineering approach to overcome water scarcity as a water source for the area. However, the complex environmental conditions of long-distance water diversion bring many uncertainties for water security. In this study, we assessed the pollution condition and risk levels of emerging contaminants and traditional contaminants in the water and soil along a water diversion project in Tianjin. Then, we assessed the influence of eco-economic characteristics on environmental conditions and established a comprehensive assessment framework of water source sustainability by analytic hierarchy process (AHP). The results showed that excessive nutrient elements and heavy metal pollution mainly contributed to environmental problems in the water source area. Contrary to pollution assessment, the soil ecosystem was more subject to environmental pressure due to atmospheric deposition. The health risk assessment indicated that all contaminants had negligible non-carcinogenic risks for adults, with arsenic being considered a priority pollutant. The statistical analysis results indicated land use allocation was the most important factor in the environmental management of the water source area. According to the result of the integrated environmental assessment, the main characteristics of pressure zones were high pollution levels and human activity intensity. It is urgent to control agricultural pollution and allocate land use rationally for water source pressure zones. By considering the risks of traditional and emerging contaminants in water and soil, this study could support urban water source management and the sustainable development of the water diversion project.

Riverine sediments are important reservoirs of heavy metals, representing both historical and contemporary anthropogenic activity within the watershed. This review has been conducted to examine the distribution of heavy metals in the surface sediment of 52 riverine systems from various Asian and European countries, as well as to determine their sources and environmental risks. The results revealed significant variability in heavy metal contamination in the world\'s riverine systems, with certain hotspots exhibiting concentrations that exceeded the permissible limits set by environmental quality standards. Among the studied countries, India has the highest levels of chromium (Cr), cobalt (Co), manganese (Mn), nickel (Ni), zinc (Zn), cadmium (Cd), copper (Cu), and lead (Pb) contamination in its riverine systems, followed by Iran > Turkey > Spain > Vietnam > Pakistan > Malaysia > Taiwan > China > Nigeria > Bangladesh > Japan. Heavy metal pollution in the world\'s riverine systems was quantified using pollution evaluation indices. The Contamination Factor (CF) revealed moderate contamination (1 ≤ CF < 3) throughout the geological units, with the exception of Pb, Cd, and Cu. The Contamination Degree (CD) classifies the contamination level into different categories: Low degree of contamination (CD < 6), moderate degree of contamination (6 ≤ CD < 12), considerable degree of contamination (12 ≤ CD < 24), and a very high degree of contamination (CD ≥ 24), while the Pollution Load Index (PLI) estimate the total amount of heavy metal pollution in riverine sediments, with Turkey having the highest PLI value of 6.512, followed by Spain, Vietnam, Taiwan, Pakistan, Bangladesh, China, India, Japan, Malaysia, Iran, and Nigeria. In applied multivariate statistics, correlation analysis determined the fate and distribution of heavy metals in riverine systems, while Principal Component Analysis (PCA) elucidated the potential sources, including industrial, agrochemical, mining, and domestic wastewater discharges, lubricant leakages, multiple geogenic inputs, erosion of mafic and ultramafic rocks, and minimal atmospheric deposition. As per Potential Ecological Risk Index (PERI) perspectives, Vietnam, Spain, and Turkey have the highest ecological risk, followed by Nigeria > Pakistan > Bangladesh > China > Taiwan > Japan and Iron, while the potential risks of ∑non-carcinogenic Pb, Cr, Ni, Cu, Cd, Co, Zn, and Mn for exposed human children and adults through ingestion and dermal contact were significantly influenced between acceptable to high risk, necessitating special attention from pollution control agencies.

Thailand ranks as the sixth largest contributor to global microplastic pollution, which is exacerbated by extensive plastic use. Despite rising concerns, no comprehensive review is available on microplastic contamination and its potential risk in Thailand. This review synthesised data on microplastic abundance and characteristics within the country from 118 peer-reviewed publications (2017-2024). We found predominant microplastic presence in crustaceans (1.69-160.15 items/g), followed by Mollusca (0.03-9.5 items/g) and fishes (0.01-28.17 items/g), with higher abundances in wastewater (4 × 102 to 6.09 × 105 items/m3) compared to that in freshwater (1.44-2.92 × 106 items/m3) and seawater (2.70 × 10-1 to 6.25 × 104 items/m3). Marine sediments (48.3-2.13 × 104 items/kg) also showed significantly higher microplastic concentrations than terrestrial sediments (3-2.92 × 103 items/kg). Predominant microplastics were identified as fibers (59.36% and 35.05% for biological and environmental samples, respectively) and fragments (24.14%, 30.68%) in blue (25.95%, 18.64%), and colourless/transparent (20.01%, 14.47%), primarily composed of polyethylene terephthalate (19.46%, 9.19%), nylon (3.23%, 9.99%), polypropylene (19.78%, 24.23%), and polyethylene (14.81%, 11.66%). The potential ecological risk was low in all ecosystems except for wastewater. Shrimp and fish were more susceptible to microplastics compared to other studies in the region. Additionally, the sources, transport, and pathways of microplastic pollution in Thailand\'s aquatic territories and the current measures and policies implemented by the government to address plastic pollution are discussed. This review has compiled up-to-date insights into the prevalence, distribution, and risks associated with microplastics, which is instrumental in formulating effective strategies for contaminant control and ultimately reducing plastic pollution.

Benzotriazoles are a class of ultraviolet absorbents which absorb UV ranging from 280 to 400 nm and are widely used in personal care products and industrial production. Their residues in environmental matrices have received great concern in recent years, but most studies have focused on pollution in water and few have examined BUVs in marine sediments. In this study, we investigated the occurrence, potential sources, and ecological risk of 15 types of BUVs in the sediments of Bohai Sea in China for the first time. The total concentrations of the 15 BUVs ranged from 0.139 to 4.125 ng/g dw with a median concentration of 0.340 ng/g. UV-327 and UV-360 were predominant among the BUV congeners, accounting for 22.6% and 17.7% of the total concentration of Σ15BUVs, respectively. The detection frequencies of the BUV congeners generally exceeded 95%, reflecting the wide use and persistence of these chemicals. The concentrations of the BUV congeners in this study were one order of magnitude lower than those in other areas. Moreover, the distributions of BUVs presented a decreasing gradient from nearshore to offshore, indicating that coastal input was the main influencing factor. Two potential primary sources, plastic manufacturing and domestic wastewater, were identified via principle component analysis. The ecological risks of BUVs to aquatic organisms in the sediments were evaluated using the risk quotient (RQ) method. Generally, the risk to aquatic organisms from exposure to BUVs in Bohai Sea could be considered low at the measured concentrations. While our study provides important new insight into the ecological risks of BUVs in the estuary, further research on the pollution levels and toxicity risks of BUVs in Bohai Sea should be conducted to better understand the ecological effect of these pollutants.

Neonicotinoids (NEOs) and fipronil are widely used in pest control, but their spatiotemporal distribution and risk levels in the \"river-estuary-bay\" system remain unclear. Between 2018 and 2021, 148 water samples from rivers to inshore and offshore seawater in Laizhou Bay, China were collected to investigate the presence of eight NEOs and fipronil and its metabolites (FIPs). Significant seasonal variations in NEOs were observed under the influence of different cultivation practices and climatic conditions, with higher levels in the summer than in the spring. The average concentrations of total neonicotinoids (ΣNEOs) and ∑FIPs decreased from rivers (63.64 ng/L, 2.41 ng/L) to inshore (22.62 ng/L, 0.14 ng/L) and offshore (4.48 ng/L, 0.10 ng/L) seawater of Laizhou Bay. The average concentrations of ΣNEOs decreased by 85.3 % from 2018 to 2021. The predominant insecticides in the study area were acetamiprid, thiamethoxam, imidacloprid, and fipronil sulfone, with a gradual shift toward low-toxicity and environmentally friendly species over time. Influenced by agricultural intensity, ∑NEOs were mostly distributed in the Yellow River, Xiaoqing River, and their estuaries, where they pose chronic ecological risks. However, FIP exhibited high risk in certain rivers and sewage treatment plants owing to the use of animal repellents or landscape gardening insecticides. This study provides evidence of the transfer of NEOs and FIPs from rivers to the ocean and also clarifies their transition dynamics and changes in risk levels from rivers to oceans. Additionally, the study offers data support for identifying critical pesticide control areas.

Microplastics (MPs) and antibiotic resistance genes (ARGs) are gaining increasing attention as they pose a threat to the ecological environment and human health as emerging contaminants. MPs has been proved to be a hot spot in ARGs, and although it has been extensively studied in water environment, the results of bibliometrics statistical analysis in this paper showed that relevant studies in soil ecological environment are currently in the initial stage. In view of this, the paper provides a systematic review of the sources, interactions, influencing factors, and ecological risks associated with MPs and ARGs in soil environments. Additionally, the mechanism and influencing factors of plastisphere formation and resistance are elaborated in detail. The MPs properties, soil physicochemical properties, soil environmental factors and agricultural activities are the primarily factors affecting the interaction between MPs and ARGs in soil. Challenges and development directions of related research in the future are also prospected. It is hoped that the review could assist in a deeper comprehension and exploration of the interaction mechanism between MPs and ARGs in soil as well as the function of MPs in the transmission process of ARGs among diverse environmental media and organisms, and provide theory basis and reference for the MPs and ARGs pollution control and remediation in soil.