Spatiotemporal variations, surface inventory, and cross regional impact of current-use organoamine pesticides in Chinese Marginal Seas

Comprehensive ecological risk assessment method for multi-pesticide pollution in the Bohai Sea and Yellow Sea, China

Pesticide residues and their accumulation in marine environments pose potential threats to the ecosystem balance and human health. Assessment of pesticide residue levels and ecological risks in marine waters is insufficient. Therefore, we conducted a quantitative analysis of four different categories of pesticides in the surface waters of the Bohai Sea and Yellow Sea in China. A comprehensive ecological risk assessment framework was constructed based on the importance of ecosystem services, utilizing the risk quotient (RQ) and entropy weighting methods to evaluate the multi-pesticide ecological risks in the study area. Thirteen pesticides were detected in the surface waters, with total concentration levels ranging from 8.18 to 80.60 ng/L, and the herbicide Atrazine and insecticide Imidacloprid were found at the highest levels. Concentration levels were higher in the Bohai Sea than in the Yellow Sea, and the highest area was mainly located on the coast of Shandong Province, China. The ecological risk of multi-pesticide pollution was the highest in the coastal regions of Shandong and was associated with Atrazine and Acetamiprid. Source analysis suggested that triazine herbicide and neonicotinoid insecticides are predominantly land-sourced, whereas sulfonylurea herbicides are primarily atmospheric. This study provides valuable support for formulating relevant environmental protection policies and measures.

Spatiotemporal distribution and fate of typical pesticides in the Bohai Sea and surrounding rivers, China

Pesticide leakage has lasting and profound effects on the stability and health of marine ecosystems. To explore the occurrence, distribution, and fate of typical pesticides in marine environments, three sampling campaigns were conducted in the Bohai Sea and surrounding rivers. Atrazine was the most pronounced pesticide, with a high concentration and detection frequency in both seawater and sediment. The presence of typical organophosphorus pesticides (OPs) was significantly lower than historical levels. Pesticide concentrations decreased from inshore to offshore. Furthermore, the spatiotemporal distribution characteristics of the pesticides highlighted the agricultural patterns and differences in pesticide use. Environmental factors and physicochemical properties jointly determined the behaviors and fates of pesticides in the marine environment. Sediment served as both a sink for widely used atrazine and a source of restricted OPs. Although some pesticides have been restricted or banned, such as dimethoate and chlorpyrifos, the risks caused by their long-term use and environmental accumulation cannot be ignored and the normalized monitoring of typical pesticides is necessary in the marine environment.

Summer profiles: Tracing currently used organophosphorus pollutants in the surface seawater of the Arctic Ocean

We investigate the spatial distribution and potential ecological impact of Currently Used Organophosphorus Pollutants (CUOPPs) in the Arctic Ocean, focusing on the East Siberian Sea, Laptev Sea, and high Arctic regions. Analyzing surface water samples collected during a scientific expedition aboard the "Xuelong 2" in August and September 2021, we detected 38 out of 83 targeted CUOPPs, including Phorate, Paraoxon, and Azinphos-ethyl, with concentrations exhibiting significant geographical variance. The results reveal a pronounced increase in CUOPP concentrations towards the Arctic poles, diverging markedly from the patterns observed in the East China Sea, thereby highlighting distinct regional pollution profiles and environmental interactions. Our findings suggest various potential sources and transport mechanisms for CUOPPs, indicating complex pollutant dynamics. Furthermore, the study delves into the influence of Arctic sea ice dynamics on the distribution patterns of CUOPPs, underscoring the pivotal role of environmental factors such as surface currents. Ecological risk assessments conducted for essential Arctic species pose a high ecological risk in the Arctic Ocean, with a "Summer Alert" effect. This investigation elucidates the intricate relationship between CUOPPs dispersal in the Arctic and the broader implications of climate change, offering critical insights into the emerging environmental challenges in polar ecosystems.

Global geographical redistribution and source dynamics of selected semi-volatile organic compounds in the marine air boundary layer

The semi-volatile organic compounds (SVOCs), various priority pollutants of the marine air boundary layer (MABL), continue to elude full comprehension, creating substantial uncertainties about their global transport dynamics. We investigated 39 individual SVOCs during 3 large-scale Arctic and Antarctic expedition cruises. Our findings illuminate a discernable global gradient in their concentrations, with low molecular weight polycyclic aromatic hydrocarbons (PAHs) dominating. Interestingly, currently used pesticides (CUPs) have surpassed legacy organochlorine pesticides (OCPs) as primary pollutants. Despite international efforts to reduce emissions, SVOC mass inventories in polar regions have risen and are now identified as a significant source. The Westerlies disrupt SVOCs' global transport pathways, resulting in the "Westerly Wind Wall Block" effect, substantially influencing their redistribution in the Southern Hemisphere (SH). Our analysis ultimately underscores the pivotal roles of air-seawater exchange mechanisms and oceanic currents in the global transport dynamics of SVOCs within the MABL.

Monitoring of current-use pesticides along a Europe-Arctic transect using ships of opportunity

Understanding the occurrence and fate of current-use pesticides (CUPs) in coastal and open marine waters is essential for conducting exposure and risk assessments to ensure the protection of marine ecosystems from chemical pollution. While CUPs have been frequently studied in freshwater systems, knowledge of their behavior in marine environments remains fragmentary. This study investigated 28 CUPs across 50 sites along a transect from the Baltic outflow to pristine Arctic waters using ships of opportunity with installed FerryBox system. Overall, 14 CUPs were detected at least at one site at concentrations ranging from sub-ng/L to ng/L. CUP concentrations were higher in the Baltic outflow and decreased along the transect. Atrazine, simazine, tebuconazole, and propiconazole were detected in > 40 % of samples, including remote open sea regions, suggesting their potential for long-range marine transport. This Baltic Sea was identified as a major source of CUPs to connected marine systems. Additional CUPs were detected in the Baltic outflow, encompassing diuron, isoproturon, metazachlor, metolachlor, pyrazon, terbuthylazine, and chlortoluron. Ecotoxicological assessment indicated a moderate risk posed by metolachlor to algae. The use of the described infrastructure holds great promise for advancing our understanding of the occurrence and fate of CUPs in marine environments.

Distribution, sources, and eco-risk of Current-Use Pesticides (CUPs) in the coastal waters of the northern Shandong Peninsula, China

This study investigated the spatial distributions and seasonal variations of 19 CUPs in the coastal areas of the Shandong Peninsula and its surrounding rivers and assessed their ecological risk. In freshwater and seawater, insecticides (chlorpyrifos, methoxychlor, and pyridaben), as well as fungicides (fenarimol) and herbicides (dichlobenil) were the main pollutants (Detection Frequency: 100 %). Spatially, during winter, the regional pollution levels of Σ19CUPs in seawater showed a trend of Laizhou Bay (LZB, mean:4.13 ng L-1) > Yellow River Estuary (YRE, mean:2.57 ngL-1) > Bohai Bay (BHB, mean:2.21 ng L-1) > Yanwei Area (YWA, mean:1.94 ng L-1). The similarities of major substances between rivers and the marine environment suggest that river discharge is the main source of CUPs pollution in coastal areas. In summer, CUPs in rivers posed a high risk. In winter, the risk significantly decreased, indicating a moderate overall risk. Seawater exhibited a low risk in winter.

Occurrence, multiphase partition and risk assessment of organic amine pesticides in drinking water source of Xiang River, China

The extensive use of organic amine pesticides (OAPs) in agricultural practices has resulted in the contamination of water environments, posing threats to ecosystems and human health. This study focused on the Xiang River (XR), a representative drinking water source, as the research area to investigate the occurrence characteristics of 34 OAPs. Diphenylamine emerged as the most prevalent OAP in surface water due to industrial and agricultural activities, while cycloate dominated in sediments due to cumulative effects. Generally, the concentration of OAPs in a mixed tap water sample was lower than those in surface water samples, indicating OAPs can be removed by water plants to a certain extent. The water-sediment distribution coefficients (kd) of ΣOAPs were much less than 1 L/g, the majority of OAPs maintained relatively high concentrations in water samples instead of accumulating in sediments. Furthermore, risk assessment revealed that carbofuran showed a moderate risk to the aquatic environment, with a risk quotient of 0.23, while other OAPs presented minor risks. This study provided crucial insights for regional pesticide management and control in the XR basin, emphasizing the importance of implementing strategies to minimize the release of OAPs into the environment and protect human health.

Spatial distribution and risk assessment of pyrethroid insecticides in surface waters of East China Sea estuaries

Pyrethroid insecticides are the most commonly used household insecticides and pose substantial risks to marine aquatic organisms. many studies have detected pyrethroid insecticides in the waters and estuaries of the western United States, but their distributions within western Pacific estuaries have not been reported. Accordingly, we used high-throughput organic analyses combined with high volume solid-phase extraction to comprehensively assess 13 pyrethroid insecticides in East China Sea estuaries and the Huangpu River. The results demonstrated the presence of various ∑13pyrethroid insecticides in East China Sea estuaries (mean and median values of 8.45 ± 5.57 and 7.78 ng L-1, respectively), among which cypermethrin was the primary contaminant. The concentrations of ∑12pyrethroid insecticide detected in the surface waters at the Huangpu River (mean 6.7 ng L-1, outlet 16.4 ng L-1) were higher than those in the Shanghai estuary (4.7 ng L-1), suggesting that runoff from inland areas is a notable source of insecticides. Wetlands reduced the amount of runoff containing pyrethroid insecticides that reached the ocean. Several factors influenced pesticide distributions in East China Sea estuaries, and higher proportions were derived from agricultural sources than from urban sources, with a higher proportion of agricultural sources than urban sources, influenced by anthropogenic use in the region. Permethrin and cypermethrin were the main compounds contributing to the high ecological risk in the estuaries. Consequently, to prevent risks to marine aquatic life, policymakers should aim to reduce insecticide contaminants derived from urban and agricultural sources.

Ocean current redistributed the currently using Organoamine Pesticides in Arctic summer water

In a comprehensive study on the presence and distribution of Currently Using Organoamine Pesticides (CUOAPs) in the Arctic Ocean, this study collected and analyzed 36 surface seawater samples during the summer of 2021. The study detected 36 CUOAPs, 17 of these compounds at levels exceeding the Method Detection Limits (MDLs). Concentrations of CUOAPs ranged from 0.11 to 2.94 ng/L, exhibiting an average of 1.83 ± 0.83 ng/L. Spatial distribution analysis revealed lower CUOAP concentrations in the central Arctic Ocean, with Cycloate constituting the most abundant component (23.66 %). The investigation identified terrestrial inputs and long-range atmospheric transport as potential sources of CUOAPs in the Arctic Ocean region. The origins of individual CUOAPs appeared to be associated with application procedures and their propensity for co-occurrence at low latitudes. The study also examined the role of ocean currents in the transport and redistribution of CUOAPs in surface seawater across different regions. While ocean currents played a significant role, the influence of sea ice cover on CUOAP distribution was minimal. An ecological risk assessment analysis underscored the need for regional attention to the presence of CUOAPs in the Arctic Ocean.