Regional accumulation and ecological risks of typical plastic additives in agricultural soils in China.

Organonitrogen pesticides in Beibu gulf seawater: spatiotemporal distribution, key influencing factors, sources, and ecological risks.

Organonitrogen pesticides (ONPs) are widely used in agriculture and can enter the ocean via surface runoff, posing potential threats to marine ecosystems. This study systematically investigated the occurrence and spatiotemporal distribution of 49 ONPs in seawater of the Beibu gulf, China, examined their key influencing factors, and conducted source apportionment and ecological risk assessment using multiple statistical models. The results showed that target ONPs were ubiquitously detected, with total concentrations (Σ49ONPs) ranging from 14.3 to 38.0 ng/L (mean: 20.2 ng/L). Spatially, higher concentrations were observed in the northern and central gulf, and lower in the southern area. Seasonally, the Σ49ONPs in summer 2022 (10.7-37.2 ng/L) were significantly higher than in winter (6.36-14.2 ng/L, p < 0.01), but comparable to summer 2021 (14.3-38.0 ng/L), with this seasonal pattern primarily linked to variations in riverine discharge. Correlation and random forest analyses identified terrestrial inputs and their interactions with suspended particulate matter (SPM) as critical drivers of ONP distribution and fate. Seawater Si:P ratios and Chl a concentrations serve as effective indicators of ONPs levels, while SPM acts as both a carrier and a sink. These findings underscore the necessity of integrating runoff management with pesticide application controls in coastal pollution mitigation. Multi-model source apportionment indicated that ONPs mainly originated from local agricultural applications and rubber industrial processing activities, with additional modulation by ocean currents and water exchange rates. Ecological risk assessment revealed that total ONPs concentrations posed moderate-to-high risks to marine organisms across trophic levels at most sampling sites, deserving particular attention.

Integrated Assessment of Organochlorine Pesticide Residues in Soil and Pepper: Ecological and Human Health Risks

This study investigated organochlorine pesticide (OCP) residues in agricultural soils and pepper samples to assess their ecological and human health risks. Eighty soil samples (pre‐[40] and post‐[40] pesticide application) and 40 pepper samples were analysed using gas chromatography–mass spectrometry. Bioaccumulation factors (BAFs), health and ecological risk assessments were carried out. Before pesticide application, soils already contained detectable OCP residues, particularly α‐BHC (5.0–5.3 µg/kg) and γ‐HCH (7.7–9.3 µg/kg), indicating background contamination. Following pesticide application, residue levels increased significantly ( p < 0.05), with endosulfan sulfate (1789.88 µg/kg) and endrin (161.33 µg/kg) reaching the highest concentrations at contamination hotspots resulting in ecological risk quotients that exceeded guideline thresholds. Pepper samples showed substantial bioaccumulation of OCPs, confirming their transfer from soil into edible crops. The highest BAFs were recorded for 4,4′‐DDE (11,168.62), dieldrin (5180.07), 4,4′‐DDT (5164.89), and endosulfan I (1645.27). Health risk assessment indicated that most non‐carcinogenic risks for adults were within acceptable limits, although dieldrin exceeded the safety threshold (HQ = 1.35). Children were more vulnerable, with hazard quotient values exceeding 1.0 for several pesticides, including dieldrin (13.46), 4,4′‐DDE (5.36), aldrin (2.71), endrin aldehyde (2.47), and heptachlor epoxide (1.27). Cancer risks ranged from 2.21 × 10 − 6 to 5.27 × 10 − 4 for adults and 4.51 × 10 − 5 to 1.08 × 10 − 2 for children, with dieldrin and aldrin posing the greatest concern. These findings revealed persistent OCP contamination, pronounced spatial variability, and high BAF values in peppers, highlighting elevated ecological risks and greater health risks for children.

Concentration of potentially toxic elements in soils of an intensively agricultural and industrial watershed

Soil contamination by potentially toxic elements (PTEs) can alter the structure and functioning of ecosystems and pose risks to public health. In this context, micro.watersheds are important units of analysis, as they integrate natural and anthropogenic processes that influence the distribution of these elements in the environment. In general, environmental agencies establish soil quality guidelines valid for large territorial areas, such as states or countries.However, studies at smaller scales are still limited, especially in micro–watersheds. Our objectives were to quantify the concentrations of arsenic, cadmium, cobalt, copper, chromium, lead, nickel, and zinc in the soils of the Guamium river watershed, located in a Brazilian region with metalwork, boiler making and foundry industries, steel mills, sugarcane and ethanol plants, and the automotive sector; to compare these concentrations with the guidelines established by the Environmental Company of the State of São Paulo; and to establish quality reference values for PTEs in the micro–watershed. Arsenic and cooper presented the highest concentrations, with values equal to or greater than the prevention value established by the environmental agency. The study contributes to the understanding of the natural and anthropogenic variability of PTEs in tropical soils and provides support for environmental monitoring, risk assessment, and the definition of more representative reference values on a regional scale.

Integrated Assessment of Heavy Metal Accumulation in Urban Trees and Soils and Associated Non-carcinogenic Health Risks in Sabzevar, Iran

Distribution, sources, and ecological risks of phthalate esters (PAEs) in sediments from Xincun and Li'an Lagoons, Lingshui, South China.

Tropical lagoons are vulnerable coastal ecosystems where intensive aquaculture and plastic-related activities may promote the accumulation of phthalate esters (PAEs) in sediments. However, the distribution patterns, potential sources, and ecological risks of PAEs in tropical lagoon systems remain insufficiently understood. This study investigated 15 PAE compounds in surface sediments from Xincun and Li'an Lagoons, southern Hainan, China. All target PAEs were detected, with ΣPAEs concentrations ranging from 365 to 1438 ng/g dw. DBP, DiBP, and DEHP were the dominant compounds, accounting for 80.7% of total PAEs. PAE concentrations were generally higher in lagoon interiors than at outlets, reflecting the combined effects of semi-enclosed hydrodynamic conditions, anthropogenic inputs, and tidal dilution. Principal component analysis suggested that PAE contamination was mainly associated with plastic-related materials, aquaculture activities, domestic wastewater, and waste-related inputs, although these source interpretations remain qualitative. HQ-based ecological risk assessment revealed clear species-specific differences. DBP was identified as the primary risk contributor, posing high risks to algae (HQ ≥ 1) at all sampling sites, while DiBP showed medium risks to fish at 10.0% of sites. These findings highlight the need to prioritize DBP and DiBP in future monitoring programs. Effective management should focus on reducing plastic waste and aquaculture-related inputs, improving domestic wastewater treatment, and strengthening pollution control in highly impacted lagoon areas. This study provides baseline information for understanding PAE contamination and supporting sustainable management of tropical lagoon ecosystems.

Pollution Levels, Ecological Risks, and Potential Sources of Toxic Elements in Farmland Soils of the Ibinur Lake Basin, China

Potentially toxic elements (PTEs) are one of the most concerning pollutant types in the surface environment. In this study, a total of 115 farmland soils from the 0–20 cm layer were collected from the Ibinur Lake Basin (ILB) in northwest China to investigate the concentration characteristics, pollution status, potential ecological risks, and possible sources of seven PTEs (As, Cd, Cu, Ni, Pb, Hg, and Zn). The pollution load index (PLI) method was applied to quantify soil pollution status, while the potential ecological risk index (RI) was adopted to evaluate PTE-induced ecological risks. Multivariate statistical approaches were further implemented to trace the potential sources of these PTEs. The obtained results revealed that the average concentrations of As, Cd, Ni, Pb, and Zn present in farmland soil surpass the corresponding background values by factors of 2.41, 1.99, 1.15, 1.18, and 5.60, respectively. Single-factor pollution assessment indicated heavy Zn pollution, moderate As pollution, low-level Cd, Pb, and Ni pollution, and slight Cu pollution across farmland soils in the ILB, whereas no Hg pollution was detected. PTEs in farmland soil show a low pollution level, with an average PLI value of 1.31. Obvious spatial heterogeneity was observed in the distribution of all seven PTEs. The comprehensive potential ecological risk of PTEs remained low, with an average RI of 23.87; among all target PTEs, As and Cd contributed the largest share of ecological risks. Source apportionment demonstrated that Cd, Cu, Ni, Pb, and Zn were potentially derived from combined natural and anthropogenic inputs, Hg was likely associated with lithogenic natural sources, and As was potentially derived from agricultural anthropogenic activities. Collectively, As and Cd were identified as the priority pollutants posing pollution and ecological risks in this basin. This study improves the systematic understanding of PTE pollution risks in arid agricultural soils and the results suggest that regular long-term monitoring should be implemented for local soils.