Occurrence, fate, seasonal variability, and risk assessment of twelve triazine herbicides and eight related derivatives in source, treated, and tap water of Wuhan, Central China

Involving degradation products provides a new perspective of diffuse pollution assessment of atrazine with a modified mass balance approach

Atrazine (ATR) is an endocrine disruptor known for its persistence and mobility. While the diffuse characteristics and potential risks of ATR have been extensively studied, its transregional migration and degradation characteristics have received less attention. In this study, a modified mass balance approach considering the diffuse source (DS), tributaries, water resource usage, degradation, adsorption, and evaporation was developed based on the traditional mass balance framework and field sampling to estimate the DS fluxes of ATR in a large river basin. Field sampling revealed that the ATR concentration in the surface water increased downstream, whereas the ATR levels in suspended particulate matter decreased. The ATR degradation ratio also decreased downstream, suggesting increased input along the river. The modified mass balance approach identified DS as the primary ATR source in the river, followed by tributaries. Together, the DS input and tributary inflow accounted for 95.6 % ± 2.1 % of the total ATR flux, with DS alone contributing 73.8 % ± 10.2 %. Finally, the ATR parent and its hazardous materials (ATR, desethylatrazine, and desisopropylatrazine) accounted for 6 % and 27 %, respectively, of the total ATR content that reached the estuary. This integrated consideration of ATR and its degradation products offer a new perspective on their transregional migration and degradation patterns resulting from diffuse pollution.

Unraveling the Composition Profile and Ecological Risk of Triazine Herbicides and Their Transformation Products in Urban Sewage Discharge

Triazine herbicides (THs) are used globally to control weeds in urban environments, but their transformation products (TPs) are rarely considered due to the lack of reference standards. In this study, a total of 41 TPs were found in wastewater influents and effluents of 28 municipal wastewater treatment plants (MWWTPs) from six cities in China by integrating suspect screening (36 TPs), molecular networking (9 TPs), and diagnostic fragment searching (12 TPs). Among these, 36 TPs were detected for the first time in urban aquatic environments, and 28 TPs were first reported in aquatic environments. Polar THs and their TPs were only partially removed from the aqueous phase in the wastewater treatment process. Concentrations of THs and their TPs present in wastewater effluents ranged from 107 to 435 ng/L. Thus, THs and their TPs discharged from wastewater effluents pose a medium risk to freshwater algae in the receiving waters. Moreover, 4 THs (ametryne, atrazine, terbutryn, and prometryne) and 3 TPs (atrazine-desisopropyl, TP247, and TP258) pose significant risks in several effluents. Considering the persistent and mobile properties and ecological risk of THs and their TPs, these contaminants should be specifically considered in further environmental monitoring and included in the regulation.

Unveiling the toxicological effects and risks of prometryn on red swamp crayfish (Procambarus clarkii): Health assessments, ecological, and molecular insights

Prometryn is commonly used in agricultural and non-agricultural settings. However, possible harm to aquatic organisms remains a persistent concern. Prometryn was also the only one of the 26 triazine herbicides detected in this study. Numerous studies have assessed the harmful effects of prometryn in teleost fish and shrimp. There is a lack of information regarding the ecological and human health risks, as well as the toxic mechanisms affecting crayfish. In this study, human health risk assessment (THQ) and ecological risk assessment (RQ) were conducted on P. clarkii in the rice-crayfish co-culture (IRCC) farming model. The 96 h of exposure to 0.286 mg/L and 1.43 mg/L prometryn was conducted to investigate the potential effects and molecular mechanisms of hepatopancreatic resistance to prometryn in P. clarkii. The original sample analysis revealed that the THQ calculated from the prometryn levels in the muscle and hepatopancreas was below 0.1, suggesting no threat to human health. However, the calculated RQ values were >0.1, indicating a risk to P. clarkii. Histological analysis and biochemical index detection of the experimental samples revealed that the hepatopancreatic injury and oxidative damage in P. clarkii were caused by prometryn. Moreover, transcriptome analysis identified 2512 differentially expressed genes (DEGs) after 96 h of prometryn exposure. Prometryn exposure caused significant changes in metabolic pathways, including oxoacid metabolic processes and cytochrome P450-associated drug metabolism. Further hub gene analysis via PPI indicated that exposure to prometryn may inhibit lipid synthesis, storage, and amino acid transport and affect glucose metabolic pathways and hormone synthesis. Additionally, we hypothesized that prometryn-triggered cell death could be linked to the PI3K-Akt signaling cascade. This study's findings have significant meaning for the efficient and logical application of herbicides in IRCC, ultimately aiding in advancing a highly productive agricultural system.

Spatiotemporal variations and priority ranking of emerging contaminants in nanwan reservoir: A case study from the agricultural region in huaihe river basin in China

The presence of emerging contaminants (ECs) in drinking water sources is an increasing concern, yet limited data exists on their occurrence and risk in the upper Huaihe River Basin, an important agricultural region in Central China. This study investigated 70 ECs, including pesticide and antibiotics in surface water from drinking water source areas in Nanwan Reservoir along the upper reaches of the Huaihe River Basin to prioritize the ECs based on ecological risk and health risk assessment. A total of 66 ECs were detected in the surface water at least once at the selected 38 sampling sites, with concentrations ranging from 0.04 to 2508 ng/L. Ecological risk assessment using the risk quotient (RQ) method revealed high risks (RQ > 1) from 7 ECs in the dry season and 15 ECs in the wet season, with triazine pesticides as the main contributors. Non-carcinogenic risks were below negligible levels, but carcinogenic risks from neonicotinoid and carbamate pesticides and macrolide antibiotics were concerning for teenagers. Ciprofloxacin exhibited a high level of resistance risk during the wet season. A multi-indicator prioritization approach integrating occurrence, risk, and chemical property data ranked 6 pesticides and 3 antibiotics as priority pollutants. The results highlight EC contamination of drinking water sources in this agriculturally-intensive region and the need for targeted monitoring and management to protect water quality.

Occurrence of marine plastic litter and plasticizers from touristic beaches of Arauco Gulf in Central Chile

Marine plastic litter (MPL) was collected from beaches (n = 3) of the Arauco Gulf in central Chile in spring 2021 and summer 2022. MPL was analyzed for physical and chemical characteristics, and plasticizers were also screened using FTIR-ATR. Three hundred seventeen plastic items with an accumulated weight of 226.8 g were found. MPL densities ranged from 0.4 to 17.1 items m-2. Significant differences (p < 0.05) between seasons were observed for Arauco and Maule beaches, being ∼ten times higher in summer compared to spring. Solid pieces were the predominant shape, macroplastics were the most abundant (>2.5 cm), and white and blue colors were dominant. Polypropylene (52 %) and polyethylene (31 %) were the predominant polymers. Plasticizers (n = 3) were detected in the MPL in the study area (dioctyl phthalate, polybutene, and alpha-methylstyrene) for the first time. This study contributes new information related to MPL in coastal areas of central Chile and their chemical composition.

Research progress on the generation of NDMA by typical PPCPs in disinfection treatment of water environment in China: A review

The drugs and personal care products in water sources are potential threats to the ecological environment and drinking water quality. In recent years, the presence of PPCPs has been detected in multiple drinking water sources in China. PPCPs are usually stable and resistant to degradation in aquatic environments. During chlorination, chloramination, and ozonation disinfection processes, PPCPs can act as precursor substances to generate N-nitrosodimethylamine (NDMA) which is the most widely detected nitrosamine byproduct in drinking water. This review provides a comprehensive overview of the impact of PPCPs in China's water environment on the generation of NDMA during disinfection processes to better understand the correlation between PPCPs and NDMA generation. Chloramine is the most likely to form NDMA with different disinfection methods, so chloramine disinfection may be the main pathway for NDMA generation. Activated carbon adsorption and UV photolysis are widely used in the removal of NDMA and its precursor PPCPs, and biological treatment is found to be a low-cost and high removal rate method for controlling the generation of NDMA. However, there are still certain regional limitations in the investigation and research on PPCPs, and other nitrosamine by-products such as NMEA, NDEA and NDBA should also be studied to investigate the formation mechanism and removal methods.

Swellable microneedle-coupled light-addressable photoelectrochemical sensor for in-situ tracking of multiple pesticides pollution in vivo

In vivo monitoring of multiple pesticide contamination is of great significance for evaluating the health risks of different pesticides, agricultural production safety, and ecological and environmental assessment. Here, we report a hydrogel microneedle array coupled light-addressable photoelectrochemical sensor for tracking multiple pesticide uptake and elimination in living animals and plants, holding three prominent merits: i) enables in-situ detection of in vivo pesticides, avoiding cumbersome and complex sample transportation and handling processes; ii) allows repeated in vivo sampling of the same organism, improving tracking test controllability and accuracy; iii) avoids lethal sampling, providing a better understanding of the pesticides fate in living organisms. The coupled sensor is mechanically robust for withstanding more than 0.35 N per needle and highly swellable (800 %) for timely extraction of sufficient in vivo solution for analysis. For proof-of-concept, it achieves in-situ detection of atrazine, acetamiprid, and carbendazim efficiently and quantitatively in artificial agarose skin models, mouse skin interstitial fluids, and plant leaves with little inflammatory reaction. This simple, highly integrated, minimally invasive, and high-throughput in vivo monitoring method is ideal for future field environmental monitoring and plant and animal disease diagnosis.

Distribution Characteristics and Risk Assessment of 57 Pesticides in Farmland Soil and the Surrounding Water

To investigate the effect of pesticide use on surface water, the concentration and distribution characteristics of 57 pesticides and 3 degradation products were analyzed in the farmland soil and surface water in the Xingkai Lake area, including water from paddy fields, drainages and the Xingkai Lake, in Heilongjiang Province, China. Forty-three pesticides and three degradation products were detected in farmland soil. In dry field (corn and soybean field) soil, the main detected pesticides were atrazine and acetochlor with mean concentrations of 26.09 ng·g-1 and 49.08 ng·g-1, respectively. In paddy field soil, oxadiazon, mefenacet and chlorpyrifos were the main detected pesticides with mean concentrations of 14.32 ng·g-1, 78.60 ng·g-1 and 20.03 ng·g-1, respectively. In the surrounding water, including water from paddy fields, drainages and Xingkai Lake, the total concentrations of contaminants detected in the water samples ranged from 71.19 ng·L-1 to 10,145.76 ng·L-1. Of the three sampling periods, the mean concentration of contaminants in the water exhibited its peak during the vegetative period. In the analysis of the drainage water, the primary pesticides detected were atrazine, acetochlor and buprofezin with mean concentrations of 354.83 ng·L-1, 109.09 ng·L-1 and 254.56 ng·L-1, respectively. Atrazine, simetryn, buprofezin and isoprothiolane were the main pesticides detected in Xingkai Lake water, with the mean concentrations of 222.35 ng·L-1, 112.76 ng·L-1, 301.87 ng·L-1 and 138.02 ng·L-1, respectively. The concentrations of contaminants could be correlated with drainage, Da Xingkai Lake and Xiao Xingkai Lake water (ρ > 0.8) suggested that the source of these contaminants in drainage and Xingkai Lake water could be the same. The maximum potentially affected fraction (PAF) values of atrazine, chlorpyrifos and prometryn were higher than 5% in Xingkai Lake water, resulting in high ecological risks.