Occurrence, Distribution, and Risk Assessment of Organophosphorus Pesticides in the Aquatic Environment of the Sele River Estuary, Southern Italy

The concentration of selected organophosphorus pesticides associated with PM10 in agricultural ambient air in Iran: Health risk assessment using Monte Carlo simulation

Organophosphate pesticides, widely utilized for pest management globally, are associated with various adverse health effects upon exposure. This study aimed to investigate the presence of organophosphate pesticides in particulate matter (PM10) and evaluate the potential risks to human health using both deterministic and probabilistic approaches in urban and suburban areas of Yasuj City, Iran. A total of 32 air samples were collected during the study period. Active sampling was conducted using a SKC pump with a selective air inlet, and the samples were analyzed via liquid chromatography-mass spectrometry. The results indicated that Diazinon exhibited the highest average concentration among PM10-bound organophosphate pesticides, measuring 4.23 ng/m³ in suburban areas and 2.51 ng/m³ in urban environments. Although no significant overall difference was observed in organophosphate pesticide levels in PM10 between urban and suburban areas, suburban regions generally exhibited higher concentrations, with the exceptions of Parathion and Butachlor. The hazard index (HI) percentiles for children exposed to these pesticides in Yasuj's air were calculated as 0.0047 (5th percentile), 0.0141 (50th percentile), and 0.0291 (95th percentile). For adults, the corresponding values were 0.0016, 0.0050, and 0.0101, respectively. The median carcinogenic risk (CR) values were estimated at 1.40E-9 for children and 2.49E-9 for adults. Notably, the concentration of Diazinon and its interaction with inhalation rates were critical determinants of HI, while Malathion concentration and its interaction with inhalation rates significantly impacted CR for both demographic groups. Our findings suggest that pesticide levels in urban and suburban air are relatively low and pose minimal health risks. However, the study underscores the necessity for ongoing monitoring and increased public awareness regarding pesticide exposure.

Pollution of organophosphorus pesticides in the Dongting Lake, China and its relationship with dissolved organic matter: Occurrence, source identification and risk assessment

The escalating global demand for food and industrialization has placed significant pressure on the integrity and management of inland lake ecosystems. Herein, the organophosphorus pesticides (OPPs) pollution status and their relationship with dissolved organic matter (DOM) in Dongting Lake were investigated to identify the ecological risks and potential sources of OPPs. The total concentrations of 18 detected OPPs were in the range of 13.49-375.24 ng/L, with higher concentration observed in east and west lake regions. Among these, fenthion was the dominant contributor, accounting for 64% of total OPPs, posing significant ecological risk to aquatic organisms. Nearly all of sites showed high combined risk of total OPPs. Parallel factor analysis (PARAFAC) and fluorescence regional integration (FRI) technique showed that DOM was mainly composed of terrestrial humic-like and tryptophan-like substances. Moreover, correlation analysis revealed a close association between DOM optical parameters and OPP concentrations. Specifically, OPPs exhibited a significantly positive correlation with tyrosine-like substances, while displaying a negative correlation with fulvic acid-like substances. These results indicated that OPP concentrations may decrease with increasing humification levels and declining tyrosine-like substance contents. This study underscores the critical role of DOM in assessing the occurrence and sources of OPPs in aquatic environments, providing valuable insights for effective environmental management strategies.

Enhanced retention of hydrophobic pesticides in subsurface soils using organic amendments

The rapid global population growth since the early 2000s has significantly increased the demand for agricultural products, leading to widespread pesticide use, particularly organophosphorus pesticides (OPPs). This extensive application poses severe environmental risks by contaminating air, soil, and water resources. To protect groundwater quality, it is crucial to understand the transport and fate of these pesticides in soil and sediment. This study investigates the effects of hydrochars and biochars derived from sugar beet shreds (SBS) and Miscanthus×giganteus (MIS) on the retardation and biodegradation of OPPs in alluvial Danube sandy soil. The research is novel in its approach, isolating native OPP-degrading bacteria from natural alluvial sandy soil, inoculating them onto chars, and reapplying these bioaugmented chars to the same soil to enhance biodegradation and reduce pesticide leaching. The amendment of chars with immobilized Bacillus megaterium BD5 significantly increased bacterial abundance and activity. Metabarcoding of the 16S rRNA gene revealed a dominance of Proteobacteria (48.0-84.8 %) and Firmicutes (8.3-35.6 %). Transport modeling showed retardation coefficients (Rd) for OPPs ranging from 10 to 350, with biodegradation rates varying between 0.05 % and 75 %, indicating a positive correlation between retardation and biodegradation. The detection of biodegradation byproducts, including derivatives of phosphin, pyridine, and pyrazole, in the column leachate confirmed that biodegradation had occurred. Additionally, principal component analysis (PCA) revealed positive correlations among retardation, biodegradation, specific surface area (SSA), aldehyde/ketone groups, and bacterial count. These findings demonstrate the potential of biochar and hydrochar amendments to enhance OPP immobilization in contaminated soils, thereby reducing their leaching into groundwater. This study offers a comprehensive approach to the remediation of pesticide-contaminated soils, advancing both our fundamental understanding and the practical applications of environmental remediation techniques.

Evaluation of phosphate insecticides and common herbicides: monitoring and risk assessment in water treatment plant, distribution networks, and underground water wells

Despite the negative effects that the use of pesticides (such as herbicides and insecticides) have on human health and water resources, a significant portion of the world's agricultural production depends on them. The purpose of this study was to determine selected residual concentrations of pesticides (diazinon, ethion, malathion, alachlor, methyl-parathion, trifluralin, atrazine, chlorpyrifos, and azinphos-methyl) in samples from Shiraz potable water sources. For this purpose, water treatment plant, groundwater wells, treated surface water, and a mixture of groundwater and treated surface water were taken. In addition, statistical and risk analyses (carcinogenic and non-carcinogenic) were used. According to the results, chlorpyrifos with 84.4% had the highest removal efficiency and methyl-parathion with 10% had the lowest removal rate in the Shiraz water treatment plant process. The highest mean concentration was related to azinphos-methyl (1.5 μg/L) and chlorpyrifos (0.59 μg/L) in the groundwater samples. All measured compounds in water source samples were below standard levels, except for chlorpyrifos and azinphos-methyl, which were reported in groundwater above the limit recommended by the Environmental Protection Agency (EPA). The results showed that while the selected pesticides measured had a low non-carcinogenic risk for both adults and children, malathion and trifluralin posed a high carcinogenic risk for adults.

Ecotoxicological risk assessments and components of persistent organic pollutants and metals in the historical settlement area (Iznik (Nicea) lake) large water resource sediments

The main objectives of this study are to measure permanent organic and inorganic pollutants in detail in an area that hosts historical structures underneath and feeds the huge ecosystem with water, to reveal risk values. Total PAH concentrations in the samples ranged from 43.41 to 202.7 ng/g. Total OCP concentration ranged from 5.15 to 17.98 ng/g, while total PCB concentration ranged from 0.179 to 0.921 ng/g. PCB 28/31, 138, and 153 are the highest detected PCBs. It was found that the lake sediment reached toxic equivalent quotient (TEQ) values of 29.21 for total PAHs and 28.90 for carcinogenic PAHs. Negligible concentration risk quotient had a low to moderate ecological and toxicological risk between 12.91 and 64.42. Highest pollution index value was found 3.81 and the risk index value reached 417.4. It has been revealed that toxicologically risky components accumulate over many years even in the best-protected water resources.

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.

Trace metals and pesticides in water-sediment and associated pollution load indicators of Netravathi-Gurupur estuary, India: Implications on coastal pollution

Various environmental indicators were used to evaluate the water and sediment quality of the Netravathi-Gurupur estuary, India, for trace metals and pesticide pollution. The descended order of studied metal concentrations (μg/L) in the water was Fe (592.71) > Mn (98.35) > Zn (54.69) > Cu (6.64) > Cd (3.24) > Pb (2.38) > Cr (0.82) and in sediment (mg/kg) was Fe (11,396.53) > Mn (100.61) > Cr (75.41) > Zn (20.04) > Cu (12.77) > Pb (3.46) > Cd (0.02). However, pesticide residues were not detected in this estuarine environment. The various metal indexes categorised the water as uncontaminated, whereas contamination factor, enrichment factor, geo-accumulation index, degree of contamination and pollution load index indicated low to moderate sediment contamination. Multivariate statistics showed that the dominance of natural sources of trace metals with little anthropogenic impact. Improvement in water/sediment quality during the study period might be due to COVID-19 imposed lockdown.

Assessing Heavy Metals in the Sele River Estuary: An Overview of Pollution Indices in Southern Italy

Rapid industrialization, coupled with a historical lack of understanding in toxicology, has led in an increase in estuary pollution, frequently resulting in unexpected environmental situations. Therefore, the occurrence of heavy metals (HMs) constitutes a major environmental issue, posing a serious risk both to aquatic ecosystems and public health. This study aimed to evaluate the levels of eight HMs (As, Hg, Cd, Cr, Cu, Ni, Pb, and Zn) in water, suspended particles, and sediment near the Sele River estuary (Italy) in order to assess their environmental impacts on the sea and health risks for humans. The results revealed an increasing order of HM concentration according to the scheme suspended particulate matter (SPM) > sediment (SED) > dissolved phase (DP) and a moderate contamination status in sediment. The health risk assessment indicated that the non-carcinogenic risk was negligible. Carcinogenic risk, expressed as the incremental lifetime cancer risk (ILCR), was negligible for Cd and Ni and within tolerable limits for As, Pb, and Cr. The findings suggested that, even if there are currently no specific limits for chemical parameters in the transitional waters of Italy, monitoring systems should be implemented to determine pollution levels and implement effective steps to improve river water quality and reduce human health risks.

Network Toxicology and Molecular Docking to Investigate the Non-AChE Mechanisms of Organophosphate-Induced Neurodevelopmental Toxicity

Organophosphate pesticides (OPs) are toxic substances that contaminate aquatic environments, interfere with the development of the nervous system, and induce Neurodevelopmental Toxicity (NDT) in animals and humans. The canonical mechanism of OP neurotoxicity involves the inhibition of acetylcholinesterase (AChE), but other mechanisms non-AChE are also involved and not fully understood. We used network toxicology and molecular docking to identify molecular targets and toxicity mechanisms common to OPs. Targets related to diazinon-oxon, chlorpyrifos oxon, and paraoxon OPs were predicted using the Swiss Target Prediction and PharmMapper databases. Targets related to NDT were compiled from GeneCards and OMIM databases. In order to construct the protein-protein interaction (PPI) network, the common targets between OPs and NDT were imported into the STRING. Network topological analyses identified EGFR, MET, HSP90AA1, and SRC as hub nodes common to the three OPs. Using the Reactome pathway and gene ontology, we found that signal transduction, axon guidance, cellular responses to stress, and glutamatergic signaling activation play key roles in OP-induced NDT.

Ecotoxicological Risk Assessment of Actellic 50 EC Insecticide on Non-Target Organisms in Parallel with the Application of Standardized Tests

This paper contributes to the ecotoxicological risk assessment of the Actellic 50 EC insecticide (with 50% pirimiphos-methyl as the active substance) tested on non-target organisms. The insecticide concentrations tested were the same for all organisms (0.1, 0.01, and 0.001 mg L-1 of Actellic 50 EC), with an exposure of 3-5-21 days for plants and 4-5-14 days for animals. The non-target organisms tested were both plants (wheat and two ferns) and animals (the Prussian carp and marsh frog tadpoles). The tested insecticide significantly inhibited the growth of roots in wheat, a result that was also confirmed by a microbiotest application (62% root growth inhibition in sorghum and 100% germination inhibition in white mustard and garden cress). In ferns, even for the lowest concentration, the percentage of germinated spores was inhibited by 40% for Asplenium scolopendrium. The recorded toxicological effects of Actellic 50 EC upon the Prussian carp included a decrease in the respiratory rate and oxygen consumption, an increase in the number of erythrocytes and leukocytes, and an increase in blood glucose levels. The highest concentration (0.1 mg L-1 of Actellic 50 EC) caused a 50% decrease in the survival rate of marsh frog tadpoles after 5 days of exposure, negatively affecting body volume and length. Given the high degree of toxicity of the insecticide Actellic 50 EC, we recommend continuing investigations on non-target species, including both plants and animals, as the sub-chronic effects are quite little known in the scientific literature.