Occurrences, Potential Sources and Health Impacts of Organochlorine Pesticides in Soil from Wuhan, Central China

Herbicide contamination of Batak plain agricultural soils and risk assessment

Herbicide residue levels were analyzed in agricultural soils of Batak plain and health risk assessments were made for relevant pesticides. Herbicide contamination levels were analyzed with the use of Quick-Easy-Cheap-Efficient-Rugged-Safe (QuEChERS)-liquid chromatography/tandem mass spectrometry (LC-MS/MS) procedure. Herbicide-free soil samples were spiked at two different levels. Overall recovery of the method was 87.32%. Present findings were parallel to SANTE recovery limits. About 50% of collected samples from the study sites contained herbicides at different concentrations. Totally, eight herbicides were detected, and herbicide concentrations ranged between 1.085 and 1724.23 μg kg-1. Metolachlor had the highest concentration (1724.23 μg kg-1) in a sample taken close to the pesticide waste disposal area. Six herbicides were detected at different concentrations in the same sample. Persistent herbicides (terbuthylazine and pendimethalin) were detected in 35 samples. Risk assessments revealed that hazard index (HI) and hazard quotient (HQ) were less than 1. The greatest HQ values were identified for terbuthylazine as 2772.48 × 10-7 and 20793.61 × 10-7 for adults and children, respectively. The HI for all herbicides were 3916.05 × 10-7 for adult and 29370.39 × 10-7 for children.

Connotation, status, and governance of land ecological security in China's new urbanization: recent advances and future prospects

The rapid development of China's new urbanization has created favorable conditions for economic growth and social development. Urbanization includes population urbanization and land urbanization, among which land urbanization leads to land ecological security problems. At present, there is a lack of comprehensive understanding of land ecological security in China's new urbanization construction. This paper aims to fill the gap by systematically combing relevant literature on the connotation, status, and governance of land ecological security in China's new urbanization. Literature review shows that China's land ecological security is still at a low level, and the new urbanization construction has significant impacts on land ecological security. Land contamination is the most critical factor threatening land ecological security, and there are differences in the levels of land contamination and types of pollutants in different new urbanization construction forms. According to an example of land ecological security governance with enterprises as the main body and multiple subjects cooperating, the governance of land ecological security needs to integrate a variety of different subjects to coordinate governance. Future research directions should focus on the construction of land ecological security assessment index system, development of land contamination multi-level control technology, and construction of multi-subject collaborative governance model with "government-enterprise-social organization-residents."

Investigation of organochlorine pesticides in the Wang Lake Wetland, China: Implications for environmental processes and risks

Wang Lake Wetland is an important habitat for many fish and migratory birds. To explore the effect of periodic hydrological changes on the transfer and ecological risk of OCPs in the multimedia system of the wetland, eight sampling sites were selected for collecting soil (SS), sediment (SD) and water, to acquire dissolved phase (DP) and suspended particulate matter (SPM) samples during low- and high-flow periods. The results indicated that OCPs are pervasive in the various media of Wang Lake Wetland, and there was a significant temporal variability in concentration of ∑23OCPs in the SPM samples. Several OCPs exist certain ecological risks to aquatic organisms, but higher level of OCPs do not always equal to higher ecological risk. The residues of OCPs are largely attributed to their historical use, but recent inputs of some of them are still non-ignorable. The relatively higher values of organic carbon normalized partition coefficient (KOC) for SPM-W (KOC(SPM-W)) were obtained, which reflected the more frequent exchange of OCPs in the SPM samples. The sediment of the Wang Lake Wetland is likely to be a sink for several OCPs with high n-octanol/water partition coefficient (KOW) (e.g., DDTs and its metabolites), and high-temperature and rainfall-driven changes may promote the migration of OCPs with low KOW to the DP.

Review of scientific literature on available methods of assessing organochlorine pesticides in the environment

Organochlorine pesticides (OCPs) are persistent organic pollutants (POPs) widely used in agriculture and industry, causing serious health and ecological consequences upon exposure. This review offers a thorough overview of OCPs analysis emphasizing the necessity of ongoing work to enhance the identification and monitoring of these POPs in environmental and human samples. The benefits and drawbacks of the various OCPs analysis techniques including gas chromatography-mass spectrometry (GC-MS), gas chromatography-electron capture detector (GC-ECD), and liquid chromatography-mass spectrometry (LC-MS) are discussed. Challenges associated with validation and optimization criteria, including accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ), must be met for a method to be regarded as accurate and reliable. Suitable quality control measures, such as method blanks and procedural blanks, are emphasized. The LOD and LOQ are critical quality control measure for efficient quantification of these compounds, and researchers have explored various techniques for their calculation. Matrix interference, solubility, volatility, and partition coefficient influence OCPs occurrences and are discussed in this review. Validation experiments, as stated by European Commission in document SANTE/11813/2017, showed that the acceptance criteria for method validation of OCP analytes include ≤20 % for high precision, and 70-120 % for recovery. This may ultimately be vital for determining the human health risk effects of exposure to OCP and for formulating sensible environmental and public health regulations.

The status of organochlorine pesticide contamination in Greek agricultural soils: the ghost of traditional agricultural history

Inadequate information regarding pesticide contamination in Greek agricultural soils is currently available, while national soil monitoring programs have not been initiated yet. The aim of the present study was to assess the levels, compositions, and distribution of thirty three organochlorine pesticides (OCPs) in Greek agricultural soils, due to the environmental threat posed by these compounds, even after decades from their abrogation from the market. Determination of the organochlorine pesticides was achieved using gas-chromatography-mass spectrometry, following a QuEChERS sample preparation method. A total of 60 soil samples, from two soil horizons (up to 60 cm), were obtained from agricultural lands in Greece throughout 2019-2020. The major findings presented DDTs, γ-HCH, alachlor, and 4,4- DCBP in the examined soil samples, with DDTs being the major compounds with their maximum cumulative concentration (ΣDDTs) reaching 1273.4 μg kg-1 d.w. Compositional profile and diagnostic ratios suggested that the occurrence of DDT residues was due to historical inputs. Most of the samples did not exceed the target values set by the Netherlands and Canadian guidelines for DDTs in soil; however, there was one exception in the case of Aegina Island. Finally, based on the environmental exposure assessment conducted, the vast majority of the analytes presented lower concentrations compared to the predicted environmental concentrations, with an exemption for DDE metabolite where the measured and predicted concentrations were almost equal.

Determination of fungicide residues in soil using QuEChERS coupled with LC-MS/MS, and environmental risk assessment

Fungicide residues of soil samples taken from Batak Plain of Çanakkale province of Türkiye were assessed. Fungicide residue analyses were performed with the use of QuEChERS method and LC-MS/MS device. Blank samples were spiked at two different limit of quantification (LOQ) levels for method verification. Overall recovery was identified as 85.69% with an RSD of 12.36% (n=360; SD=10.59). A total of 110 soil samples were taken in November 2020. Present analyses revealed that 59.09% of samples contained fungicide residues at different concentrations. Propiconazole had the highest concentration (1736.06 μg/kg) in one sample, taken from the edge of the field where pesticide wastes were found and 26 fungicides were found at different concentrations in the same sample. Azoxystrobin was encountered in majority of the samples (29 samples). The most frequent fungicides were ordered as; boscalid and tebuconazole (22 samples) > metalaxyl (17 samples) > fluopyram (15 samples). Thirteen triazole fungicides were found in soil samples, mostly at moderately hazardous level (Class II). Risk assessments revealed that hazard levels of fungicides for adults and children were low with a hazard quotient (HQ) and hazard index (HI) of <1. Despite the safe nature of fungicides in soil samples, the greatest HQ values were identified for propiconazole (326.52E-08 for adults and 2449.00E-08 for children). The sum of hazard quotients for all fungicides was 86.31E-08 8 for adult and 647.35E-08 for children. In terms of soil pollution, it is important for farmers to apply fungicides with low HQ levels.

Miniaturized kapok fiber-supported liquid extraction for convenient extraction of pesticide residues in vegetable oils: Determination of organochlorine pesticides as a proof-of-concept study

In this paper, a miniaturized kapok fiber-supported liquid extraction (mini-KF-SLE) method was proposed for selective extraction of pesticide residues in vegetable oils. The natural kapok fiber was used as an inert oil support material based on its hydrophobic and lipophilic properties, and the extraction device was conveniently constructed by loading 15 mg of kapok fiber at the lower middle part of a 1-mL pipette tip. The vegetable oil sample (150 mg) without any pretreatment was directly loaded, followed by the addition of 150 μL of acetonitrile (ACN) as the extractant. After static extraction for 30 min, the extractant was pipetted out with a pipettor. As the proof of concept, it was applied for extracting eight organochlorine pesticides (OCPs) from vegetable oils and the eluate was analyzed by gas chromatography-electron capture detector (GC-ECD). Under optimized conditions, the extraction recoveries of OCPs were calculated to be in ranges of 35.8-79.5%. The satisfied quantitation ability was verified by the established method with coefficients of determination (R²) being greater than 0.99. The limits of detection (LODs) were in ranges of 2.0-50.0 ng/g. The relative recoveries were in ranges of 78.3-117.0% with the inter-/intra-day relative standard deviation (RSD) both being less than 13.3%. The potential of mini-KF-SLE to extract other kinds of pesticides was further verified by the successful extracting three triazole pesticides in vegetable oils with good extraction recoveries (>41.4%). The proposed mini-KF-SLE in combination with instrument detection techniques has the great potential in the low-cost and high-throughput determination of various pesticide residues in vegetable oils.