Fate Of Organochlorine Pesticides Research Articles

Organochlorine pesticide residues persist throughout the sugar production process

Thailand, one of the world’s largest sugarcane producers, has historically used organochlorine pesticides (OCPs) extensively in its plantations. Therefore, OCP residues are anticipated in plantation soil. However, the persistence of these compounds during sugar production is ambiguous. Thus, this study investigated the OCP residues in sugarcane at the different processing stages. Five product samples, i.e., sugarcane juice, bagasse, raw sugar, granulated white sugar, and molasses were obtained from different regions in Thailand. High concentrations of p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT), γ-hexachlorocyclohexane (γ-HCH or lindane), and cyclodiene derivatives such as aldrin, dieldrin, heptachlor and its epoxide were found in the samples. This is surprising because the OCP use in sugarcane plantations has been long banned in Thailand. Bagasse and raw sugar had the highest total OCP concentrations of 1.0393 ± 0.7555 mg/kg and 0.9658 ± 0.8209 mg/kg, followed by white sugar (0.1616 ± 0.1311 mg/kg), molasses (0.0813 ± 0.1195 mg/kg), and sugarcane juice (0.0173 ± 0.0112 mg/kg). This study offers comprehensive information on the fate of OCPs during the entire sugarcane processing stage, from the cane to the final granulated sugar. The findings also suggest persistent OCP presence in plantation soil, possibly due to illegal use.

Dissolved legacy and emerging organochlorine pesticides in the Antarctic marginal seas: Occurrence, sources and transport

Polar regions are recognized as final sinks of the persistent contaminants, however, environmental investigations in the Antarctica are greatly limited by harsh field conditions. In this study, seawater samples were collected in the Antarctic marginal seas during the austral summer of 2021 to investigate the environmental behavior and fate of organochlorine pesticides (OCPs). The concentrations and source markers of representative legacy hexachlorocyclohexane (HCH), hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethanes (DDTs) indicated the coexistent sources of historical residues and fresh inputs. While the emerging OCPs, including quintozene, pentachloroaniline and dichlobenil, showed relatively lower detection frequency. Due to the differences in temperature and sea ice coverage, dissolved OCPs generally displayed higher concentrations in the eastern Antarctic than those in the western Antarctic. The ‘surface depleted and depth enrichment’ vertical profile of representative OCPs in the continental shelf of Prydz Bay was jointly controlled by biological pump and water mass structure.

The biological pump effects of phytoplankton on the occurrence and benthic bioaccumulation of hydrophobic organic contaminants (HOCs) in a hypereutrophic lake

The distribution of hydrophobic organic contaminants (HOCs) in eutrophic ecosystems has been widely studied, but how phytoplankton blooms affect their occurrence and benthic bioaccumulation is poorly understood. To fill this knowledge gap, the biological pump effects of phytoplankton on the fate of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in sediments and benthos (Corbicula fluminea) from Lake Taihu, a hypereutrophic lake in China, were identified. The spatial-temporal distribution of HOCs suggests that higher phytoplankton biomass, coupled with sediment organic matter (SOM) content, greatly increased the concentration of HOCs in sediments in both winter and summer seasons. This could be attributed to the biological pump effects sequestering more HOCs from water to sediments with settling phytoplankton, especially during the summer. The biological pump effects further promoted the uptake of sediment-bound HOCs by benthos. The significant positive relationships between concentrations of HOCs in sediments and benthos were observed during the winter dormancy phase of benthos. Furthermore, the benthic bioaccumulation of HOCs could be strengthened by phytoplankton, due to their contribution to SOM and the following increased bioavailability of HOCs in sediments. Further research is needed to elucidate the phytoplankton biological pump effects on the fate of HOCs in benthic food chain, especially for hypereutrophic waters.

Spatio-temporal distribution of organochlorine pesticide residues in water and sediments of tropical reservoirs: a case study of Bui Reservoir, Ghana

This study investigated the spatio-temporal distribution of organochlorine pesticides (OCPs) in water and sediments of the Bui Reservoir from June 2017 to May 2018, to provide baseline data for monitoring contamination in the Reservoir. Samples were collected during four seasons reflecting levels of rainfall and from five sites around the Reservoir. Water and sediment samples were subjected to liquid-liquid separation and ultrasonic extraction, respectively. GC-ECD was used to identify and quantify the pesticide residues. Eight OCPs each for water and sediment were detected and their concentrations in water and sediment range from 0.1–4.6 µg l−1 and 1.38–104.86 ng g−1 dry weight, respectively. α-Hexachlorocyclohexane and trans-chlordane dominated with mean concentrations of 3.2 ± 0.08 µg l−1 and 70.91 ± 3.47 ng g−1 dry weight in water and sediment, respectively. There were non-significant differences (p > 0.05) in the spatial distribution of OCPs in water and sediments, but significant differences (p < 0.001) in the temporal distribution of the contaminants in water and sediments, with the wet season samples accounting for the highest concentrations. This indicated that the distribution, behaviour and fate of OCPs the the reservoir have close links with meteorological properties beyond their chemical composition.

Organochlorine pesticides and dissolved organic matter within a system of urban exorheic lakes.

Urban lakes represent the most extensive water bodies in cities and provide blue ecosystem services, by retaining pollutants, offering cultural services, and mitigating climate change. Human activities threaten to decrease the supply of ecosystem services associated with urban lakes. Exorheic lakes play an essential role in reducing and changing the characteristics of pollutants and organic matter along the environmental continuum. This study aims to gain further understanding on the distribution and fate of organochlorine pesticides (OCPs) in relation to fluorescent dissolved organic matter (DOM) within an exorheic lake system, located along Colentina river, Bucharest. Results indicated a historical usage of HCHs, which were present in lake water and sediment samples, in concentrations exceeding the regulatory limits, with potential eco-toxicity on aquatic biota. Decades of intense applications along the river, before OCPs ban, led to their accumulation in sediments and their re-mobilization, each year, after the lakes were drained, dredged, and refilled. Fluorescence measurements revealed that DOM accumulated in certain lakes due to wastewater discharges, and surface runoff, but decreased towards the end of the exorheic lakes through dilution, sedimentation, and biodegradation. The results also showed that fluorescent DOM may have a substantial impact on OCPs cycle in urban lakes and may help to determine the conditions and effectiveness of removing OCPs from water and sediments. These issues contribute to the decrease of ecosystem services supply associated with urban lakes, having multiple hidden consequences on the urban environment.

The effects of different types of crop straw on the transformation of pentachlorophenol in flooded paddy soil.

The incorporation of various types of crop straw to agricultural soils has long been practiced to improve soil fertility. However, the effects of crop straw on the fate of organo-chlorine pesticides in flooded paddy soils are not well understood. The dechlorination of pentachlorophenol (PCP) in four vertical profiles (0-10, 10-20, 20-30, 30-50mm depth) of two flooded paddy soils, a Plinthudult (Soil 1) and a Tropudult (Soil 2) was investigated following the application of four crop straws (rice, wheat, rape and Chinese milk vetch) to them. In all treatments, PCP dechlorination decreased with increasing soil depth. In the crop straw treatments, PCP was almost completely dechlorinated within 60 days, and rapidly transformed to 2,3,4,5-tetrachlorophenol, and further to 3,4,5-trichlorophenol. Further dechlorination of 3,4,5-trichlorophenol also occurred in all treatments except for the rape straw. It is possible that the NH4+ and NO3- derived from the straw are responsible for the inhibition of the 3,4,5-trichlorophenol dechlorination. The reduction of Fe (III) and SO42- increased following application of the crop straws. The RDA analysis indicated that the Fe (III) reducing bacteria might be involved in the ortho-dechlorination, while SO42- reducing bacteria were involved in para- and meta-dechlorination of PCP. The complete detoxification of PCP depended upon both the crop straw type and soil properties.

The Fate of Organochlorine Pesticides in Water from Chaohu Lake, China

Forty samples of surface water and bottom water were collected from Chaohu Lake, China. The organochlorine pesticides (OCPs) in the samples were extracted by a solid-phase extraction (SPE) system and detected by Soxhlet extraction followed by gas chromatography (GC) using a mass-selective detector. The fate of OCPs in the water from Chaohu Lake was studied. The concentrations of total OCPs in the surface water and the bottom water varied from 0.17 to 2.89 ng L-1 and from 0.01 to 3.49 ng L-1, respectively, which were lower than total OCP concentrations detected in other lakes around the world. Sixteen types of OCPs were detected, with a concentration sequence of hexachlorocyclohexanes (HCHs) > dichlorodiphenyltrichloroethanes (DDTs)> hexachlorobezene (HCB) > chlordanes > endosulfans. The levels of all HCH and DDT isomers in the bottom water were higher than those in the surface water. Results suggested that the presence of DDTs could be attributed to residue from technical DDTs and the recent use of dicofol, as well as antifouling paints for ships, while HCHs were most likely primarily derived from aged technical-grade HCH and lindane.

Distribution of organochlorine pesticides in atmospheric air of Tamilnadu, southern India

Passive air sampling was performed for urban, suburban, coastal, and agriculture air during April 2009–January 2010 in Tamilnadu, southern India, to know the distribution and fate of organochlorine pesticides (OCPs) residues. Exposed polyurethane foam samples (30 ± 2 days) were soxhlet extracted, and the extracts were analyzed using gas chromatography–mass spectrometric method. The total concentrations of 13 OCPs were in the range of not detected (ND)–41,400 pg/m3. Dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethylene, heptachlor, and mirex were found predominant during monsoon season. The elevated α/γ isomer ratio of hexachlorocyclohexane (HCH) (5.03) during summer revealed fresh/recent usage of HCH in coastal area. Dichlorodiphenyltrichloroethane ratio shows its fresh application in all the locations during monsoon season, which probably used to contain the diseases causing vectors. Detection of banned pesticides, such as aldrin, dieldrin, and heptachlor in air, indicating their illegal usage/or from old source. Furthermore, mirex, an unregistered pesticide in India, is being reported for the first time in air. More importantly, the obtained information will be used as a valuable baseline data for the management of atmospheric OCPs in future.

Assessment and Investigation on the Fate of Organochlorine Pesticides in Water and Sediments of International Amir-kalaye Wetland in North of Iran

A total of 48 water samples and 24 sediment samples were collected at four sampling stations along the wetland during four seasons from 2009 to 2010 and analyzed by gas chromatograph-electron capture detector (GC-ECD). In water the total concentration of OCPs was 0.33, 0.01, 0.1 and 0.07 mg/L in summer, autumn, winter and spring, respectively. The most frequent OCP compounds detected were endrin and chlordane (0.08 and 0.07 mg/L), heaxachlorobenzene and chlordane (0.06, 0.02 mg/L), and chlordane (0.07 mg/L) in summer, winter and spring, respectively. The maximum concentration of ΣOCPs was found in samples collected from station 1 in summer (0.26 mg/L). In sediments the total concentrations of OCPs were 15.84 and 2.62 mg/g-dry weight (dw) in summer and winter, respectively. Chlordane was the most frequently found OCP compound, followed by lindane, 9.92 and 2.47 mg/g-dry weight (dw), respectively, in summer. While, lindane (2.52 mg/g-dw) and endosulfan I (0.1 mg/g-dw) were the highest OCP compounds detected in winter. The results obtained in this study show that there still exist a variety of organochlorine pesticide residues in the water and sediments from the Amir-kalaye wetland in Iran.

The role of shelf mud depositional process and large river inputs on the fate of organochlorine pesticides in sediments of the Yellow and East China seas

[1] The distribution and fate of dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) in sediments from the East China Sea (ECS) and the Yellow Sea (YS) were compared and studied in this work. The ECS has directly large river-dominated inputs of sediment-associated pollutants while the YS does not. The results indicated that these mud deposits of the YS and ECS were the sinks of land-originated DDTs and HCHs. The consistence of these OCP species and total organic carbon (TOC) and the sediment grain size in the YS indicated that the shelf mud depositional process was the dominant factor in controlling the distribution and fate of these organic compounds under the more homogeneous and hydrodynamic-based sedimentary conditions of the YS. The distribution of these chemicals in the coastal ECS, however, showed a much different pattern where the concentrations of DDTs and HCHs decreased with distance from the coast, and the correlations between DDTs and HCHs with TOC were very poor. This indicates that the continuous transferring of organochlorine pesticides (OCPs) into the coastal ECS by the direct riverine inputs and surface runoffs play a key role on the occurrence and fate of OCPs within this more heterogeneous environmental system.

Organochlorine pesticides and polybrominated diphenyl ethers in irrigated soils of Beijing, China: Levels, inventory and fate

Limited information on the levels, inventory and fate of Organochlorine pesticides (OCPs) and Polybrominated diphenyl ethers (PBDEs) in the soils irrigated by sewage or wastewater is available. In this study, variation in concentrations, profiles and fate of OCPs and PBDEs were investigated using soil samples collected from a region irrigated by sewage, mixed water and clean water in the east of Beijing, China. No significant variation was observed among groups, except for penta-BDEs. The measured ΣOCPs and ΣPBDEs residues ranged from 6.4 to 171.2 ng g −1 (dw) and 501.9 to 3310.7 pg g −1 (dw), respectively. ΣDDTs and BDE-209 were the most abundant congeners accounting for about 76% of ΣOCPs and 93% of ΣPBDEs. Concentrations of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDTs) and its major degradation products, and hexachlorobenzene (HCB) ranged from 1.2 to 11.4 ng g −1 (dw), 4.0 to 155.6 ng g −1 (dw) and 0.3 to 3.4 ng g −1 (dw), respectively. The major DDT degradation products were p, p′-DDT and p, p′-DDE. The major hexachlorocyclohexane (HCH) isomer in irrigated soils is β-HCH, reflecting its higher affinity to solids and resistance to degradation than other isomers. Both α-HCH/β-HCH and p, p′-DDT/ p, p′-DDE ratios were log-normally distributed and negatively correlated to log(ΣHCHs) and log(ΣDDTs), respectively, suggesting no significant recent application of OCPs. Individual BDE congeners, ΣPBDEs and ΣOCPs were significantly correlated with total organic carbon (TOC). Moreover, a good correlationship between ΣPBDEs and black carbon (BC) was obtained but not between ΣOCPs and BC. Sewage irrigation did not have obvious effect on their contaminant levels and inventory of OCPs and PBDEs.

Altitudinal and Chiral Signature of Persistent Organochlorine Pesticides in Air, Soil, and Spruce Needles (Picea abies) of the Alps

The present study investigated the distribution, transportation, and biodegradation of the selected chiral persistent organochlorine pesticides (OCP) in the Alps. In the complex environment, we found the movement and fate of OCP could be defined by many factors. Taking HCE as an example, below the timberline its accumulation from air into SPMD increased with altitude and seasonally changed, but the trends reversed above the timberline. In soil, the tendency of HCE concentrations vs organic materials followed a sigmoid curve, and HCE concentration-altitude correlations are positive in central Alps but negative in southern Alps. The HCE enantiomeric ratios (ERs) in soil correlated to HCE isomers concentrations, the humus pH values, and the sampling site altitudes. HCE shift from humus to mineral soil can also be traced by ERs. The altitudinal and longitudinal trends in needles suggested that alpha-HCH has a more complex movementthan HCE in Alps. In conclusion, altitude conducted condensation, plant canopies, organic material in soil, and geographic specific precipitations may affect OCP distributions and transportation, whereas altitude conducted temperature and soil pH could dictate their fate in the environment.

Concentrations, enantiomeric compositions, and sources of HCH, DDT and chlordane in soils from the Pearl River Delta, South China

Concentrations, and enantiomeric compositions of HCH, DDT and chlordane in 74 soils of the Pearl River Delta, South China were investigated. The mean concentrations of HCHs and DDTs descended in the order: crop soils>paddy soils>natural soils. The concentrations (ng/g dw) of p,p'-DDE, p,p'-DDT, p,p'-DDD and o,p'-DDT in crop soils were 0.14-231, 0.07-315, <DL-96.7 and 0.06-73.8, respectively, while those of chlordane were generally below 0.78 for trans-chlordane (TC) and 0.75 for cis-chlordane (CC). Enantiomeric factors (EF value) were determined for o,p'-DDT, alpha-HCH, TC and CC. Both preferential depletions of (-) enantiomer and (+) enantiomer were observed for o,p'-DDT and alpha-HCH, indicated by EF values either <0.5 or >0.5. An EF value >0.5 generally suggested a preferential degradation of the (-) enantiomers of both TC and CC. The racemic alpha-HCH observed in the soils with higher HCH concentrations indicated that the transformation from gamma-HCH (e.g. lindane) to alpha-HCH may be an important process in the soils. The isomer ratios of p,p'-DDT/(DDE+DDD), o,p'-DDT/p,p'-DDT and enantiomeric compositions of o,p'-DDT suggested that both illegal use of technical DDT and the DDT impurity in dicofol may be responsible for the freshly DDT input in the region. The sources of DDTs were drawn by principal component analysis-multiple linear regression (PCA-MLR). The relative contributions of dicofol-type DDT, residues, and fresh technical DDT were estimated to be 55%, 21% and 17%, respectively. In addition, CC was found to degraded faster than TC in soils from the Pearl River Delta. The study demonstrated that the combination of isomer ratios and enantiomeric composition analysis may provide critical information on the potential sources and fate of organochlorine pesticides in soil.

Air−Soil Exchange of Organochlorine Pesticides in Agricultural Soils. 1. Field Measurements Using a Novel in Situ Sampling Device

Initial results are presented for in situ measurements of soil−air partitioning for a range of organochlorine (OC) pesticides in two contaminated agricultural soils. A soil survey was conducted and used to identify high levels of several OC pesticides in two regions of southern Ontario that are known for their intensive agriculture, the Tobacco Belt and the Holland Marsh. Experiments were conducted at one field in each region by sampling air very close to the soil surface using a disc-shaped sampler. The equilibrium status of the sampled air was tested by comparing the chiral signature of the soil with the signature in air sampled by the device and ambient air. Although results showed that 104% of trans-chlordane (TC) and 96% of cis-chlordane (CC) in the air under the sampler originated from the soil, the propagated errors in these results (34% SD for TC and 26% SD for CC) are too large to provide conclusive evidence for equilibrium. Therefore, a soil−air quotient (QSA) is reported here instead of the soil−air partition coefficient (KSA). This value is an approximation of the “true” KSA. Results show a linear relationship between log QSA and log KOA and fit in with the relationship KSA = 0.411ρφOCKOA where ρ is the soil density (kg L-1). Using this relationship, fugacities were calculated in air and soil. Results of this calculation identify a strong disparity that favors soil-to-air transfer. This gradient is confirmed by measurements at different heights over one of the fields. Soil−air exchange is a key process in the overall fate of OC pesticides. The results from this study will improve our ability to model this process and account for differences between soils.

Transport and fate of organochlorine pesticides in the River Wuchuan, Southeast China

Persistent organic pollutants (POPs) such as chlorinated pesticides are of global concern due to their widespread occurrence, persistence, bioaccumulation and toxicity to animals and human. This paper summarises recent research on 18 chlorinated pesticides in an important catchment in China, by determining their concentrations and behaviour in water, sediment, soil and plants. The concentrations of the total pesticides were in the ranges 187-893 ng l(-1) in river water, 8.53-210 ng g(-1) dry weight in soil, 2.66-13.45 ng g(-1) dry weight in river sediment, and 651-2823 ng g(-1) dry weight in plants. The predominance of beta-HCH as the major isomer of HCHs in all water, soil, sediment and plant samples was clearly observed, due to beta-HCH's resistance to biodegradation. On average beta-HCH accounted for 44%, 53%, 50%, and 46% of the total HCH concentration in water, soil, sediment and plant, respectively. Of the DDTs, DDE accounted for 48%, 43%, 53%, 55% of the total DDT, which suggested that DDT had been transformed to its metabolites, DDE and DDD, of which DDE was the more stable. The chlorinated pesticide levels in the River Wuchuan were generally below the guideline values in China, but some sites displayed levels in excess of EC Environmental Quality Standards for HCHs and DDTs. The results therefore provide important information on the current contamination status of a key agricultural watershed in China, and point to the need for urgent actions to evaluate the long-term fate and toxicity of such persistent compounds and an appropriate remediation strategy.

Fate of organochlorine pesticides in soils and terrestrial biota of “Los Padres” pond watershed, Argentina

Concentrations of organochlorine pesticides (OCPs) in soils and associated biota around “Los Padres” pond watershed were determined by gas chromatography with electron capture detector (GC–ECD). Pesticides were analyzed in different horizons (upper 0–15, middle 15–30, lower 45–55 cm) of natural and horticultural soils, developed in highlands and lowlands. Physical and chemical characteristics (organic matter content, pH, moisture, texture, etc.) were determined. Higher concentrations of total OCPs were found in highlands, because of the high content of clay material and organic matter. Lindane, heptachlor, aldrin, DDT and metabolites were found in soils. Depending on physical and chemical characteristics of pesticides and soils, different behaviours were found. Lindane could leach down to lower horizons, rich in clays, while hydrophobic pesticides remain in the upper horizons, retained by organic matter. Vegetables (carrots and potatoes) accumulated lindane with important contributions of DDTs and heptachlor. OCPs were taken up, accumulated and metabolized efficiently by terrestrial invertebrates (earthworms and beetles). The results obtained testify the pollution by OCPs in “Los Padres” pond watershed.

特集 「地球環境および地域環境と化学」 有機塩素系農薬の特定地域での環境中運命予測

特集 「地球環境および地域環境と化学」 有機塩素系農薬の特定地域での環境中運命予測

Fate of Organochlorine Pesticides During Processing of Milk into Dairy Products

Abstract Two lactating dairy cows per group were fed selected pesticides dissolved in organic solvents and mixed into a grain concentrate for a two week period. The reference pesticides used in this study were dieldrin; a mixture of heptachlor, DDT, and lindane; toxaphene; chlordane; endosulfan (Thiodan); and dicofol (Kelthane). The milk from these contaminated cows was collected and processed into the following dairy products: pasteurized whole milk, 30% cream, butter, spray-dried whole milk, condensed whole milk, sterilized condensed whole milk, and Cheddar cheese. The byproducts (skim milk, buttermilk, and Cheddar cheese whey) from manufacturing these products were also saved for subsequent analysis. The residues in these dairy products and byproducts were extracted, cleaned up, and analyzed by electron capture gas chromatography. The 30% cream, condensed milk, and pasteurized milk were analyzed at 0, 7, and 14 days and Cheddar cheese, spray-dried milk, butter, and sterilized condensed milk after storage for 0, 3, and 6 months. The results indicated that, in general, the pesticides used were very stable for ordinary dairy processing operations and remained essentially unchanged even after storage at refrigeration and room tempera-tures for 6 months. However, dieldrin, lindane, and chlordane showed a 27, 34, and 11% decrease, respectively, for spray-dried products and the concentration of dicofol showed a slight decrease in the sterilized condensed whole milk products, whereas the concentration of DDE extracted from the products stored 3 and 6 months was generally less than the amount extracted initially. In manufacturing Cheddar cheese, most of the pesticides showed some bacteriostatic or bactericidal action against starter microorganisms. Generally the pesticide residues were found in greater concentration (on a fat basis) in the skim milk, buttermilk, and whey than in products from which these were derived. This might be attributable to the affinity of the residues for the lipoprotein portion of the products. Concentrations of dieldrin and toxaphene increased slightly during storage of the milk and milk products, suggesting that a reorientation occurred.