Organochlorine Pesticide Residues Research Articles

First report on the exposure and health risk assessment of organochlorine pesticide residues in Caulerpa racemosa, and their potential impact on household culinary processes

Seaweeds are widely consumed as natural seafood in various Asian countries. Chemical contaminants, such as pesticide residues (PRs), can contaminate it due to its high bio-accumulation nature. Limited research exists on the presence of PRs in edible seaweeds, their decrease in levels during cooking processes, and the evaluation of hazard indices and associated health risks to humans. This study investigated the effects of different cooking methods on the levels of organochlorine pesticides in Caulerpa racemosa seaweed. It also assessed the potential health risks associated with consuming seaweed by estimating daily intake, hazard quotient, and hazard index. The PRs were reduced after different cooking methods. The impact of thermal cooking on PRs in C. racemosa was found to be notably beneficial. The PRs decreased following MWC, boiling, and steam cooking. Several PRs were analyzed, and endrin, DDT, endosulfan, and cypermethrin were found to be the most prevalent. The HQ and HI values for raw and cooked seaweeds were found to be below one, suggesting that the PRs in C. racemosa pose no risk to consumers of seaweed. In summary, thermal cooking proves to be an efficient method for minimizing PRs, while the cooking of seaweeds ensures a high level of safety during consumption.

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.

Assessment of Organochlorines Pesticides Residues in Water, Fish and Sediment Samples from Wurbo Lake, Bali, Taraba State, Nigeria

Organochlorines pesticides (OCPs) have been used worldwide, particularly in many African countries as in Nigeria for the control of pests. OCPs are characterized by their bioaccumulation in the environment, especially in the food chain, where they find their way into the human body. The research was aim to estimate the residual concentrations of different OCPs in water, fish and sediment from Kundi Lake to find out the extent of pesticide contamination and accumulation. The water sample was subjected to liquid-liquid extraction method while the fish and the sediment samples were subjected to soxhlet extraction. The extracts were later analysed for organochlorines pesticide residues using Gas-Chromatography coupled with mass spectrometer (GC-MS). The average length, average weight and condition factor of the studied fish species were measured. The Mormyrus rume had the highest average length of 17.12±0.05 cm, and average weight of 195.36±0.05 g follow by Clarias gariepinus which had the average length of 16.83±0.01 cm, and average weight of 189.43±0.03 g. Tilapia zilli was the least species of fish sample with a length of 12.75±0.03 cm and average weight of 102.21±0.02 g. Also, all the fish species sampled in this present study had condition factors>1. Based on the results obtained from all samples, it was found that the levels of organochlorine pesticides residues in water were generally below MRL as compared with FAO/WHO (0.5ppm). In fish samples, highest concentration of pesticide residues in Mormyrus rume follow by Clarias gariepinus, while the Tilapia zilli recorded low concentration of the pesticide residues. The Endosulfan II recorded high concentration of 4.68 ppm in Mormyrus rume follow by Endrin which recorded the concentration of 2.75 ppm, Aldrin 1.78 ppm and Atrazine 1.72 ppm all in Mormyrus rume. In Clarias gariepinus, Simazine 1.56 ppm follows by Endosulfan I 1.28 ppm while In Tilapia zilli, Endosulfan II 1.16 ppm follows by Atrazine 0.91 ppm and Beta Lindane 0.81 ppm. The results indicate that the area is contaminated with high levels of these pesticides in fish and sediment which may pose a great danger to the environment. Regular monitoring is therefore required to control the levels of pesticide residues in the water bodies.

Physisorption Behaviors of Organochlorine Pesticides on the InP3 Monolayer from Theoretical Insight.

Dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (BHC), aldrin, and chlordimeform are ubiquitous organochlorine pesticide (OCP) residues in the environment, which pose a great threat to human health and ecosystems due to their high toxicity and easy accumulation. Based on the density functional theory (DFT) calculations, a two-dimensional InP3 monolayer was selected as a sensing material to study the sensitivity detection and adsorption behaviors toward BHC, aldrin, chlordimeform, and DDT. The calculation results show that four pesticide molecules are adsorbed on the InP3 surface by physical interaction. The identified response values (69.1, -43.1%) for DDT and chlordimeform reveal the potential of the InP3 monolayer as a sensing material for the detection of these two pesticides, accompanied by the achievement of cyclic utilization by heating to 498 K. The most satisfactory result is the adsorption of BHC, owing to the admirable sensing response (62.7%) and short recovery time (1.8 s) at room temperature, which makes InP3 a promising pesticide sensor for BHC. However, the InP3 surface is unsuitable for aldrin sensing due to poor response (-1.9%). Our work gives theoretical insight into the good sensitivity and recycling of the InP3 monolayer as a new pesticide sensor to detect DDT, BHC, and chlordimeform, which further broadens the application prospect of the InP3 nanosheet into the sensitive detection of organochlorine pesticides in the ecological environment.

Levels of organochlorine contaminants in natural bovine milk marketed in Mojuí dos Campos and Belterra, Brazil

Analyzing the organochlorine pesticide (OCP) content in milk is relevantbecause it helps evaluate the quality of milk that reaches the consumer's table and also helps identify the geographical areas where there is a high possibility of contamination. Accordingly,thispilot project was aimed at determining the extent of contamination by OCP residues and their metabolites in fresh cow's milk in Mojuí dos Campos and Belterra, Pará, using solid-phase extraction (SPE) and gas chromatography coupled with electron capture detection (GC-ECD). The OCPs evaluated in this study weredichlorodiphenyltrichloroethane (DDT) and its metabolites (dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)), hexachlorocyclohexane (HCH) (α, β, γ, and δ), endosulfanα and β, andendosulfansulfate. None of the thirty bovine milk samples analyzedshowed any contamination with OCPs.TheOCP content was within the limit of quantification of the method. The results of this study add to the existing knowledge on the quality ofbovine milk produced in these locations. However, further researchon other environmental matricesis required to confirm the results obtained in this study.

Impact of thermal cooking processes on organochlorine pesticide residues (OCPs) in the edible green seaweed, Ulva lactuca, and associated human health risk assessment

Seaweeds are emerging natural food items in different countries. However, they are known to be potentially contaminated by chemical residues. This study examined the impact of domestic cooking methods such as boiling, steaming, and microwave cooking on reduction of organochlorine pesticide (OCP) level in edible green seaweed Ulva lactuca. Thermal cooking processes significantly influences the OCP residues in U. lactuca. The OCP residue concentration decreased after boiling, steaming, and microwave cooking compared to raw seaweed. The total OCP residue concentration in raw seaweed was 0.707 mg/kg, which reduced to 0.168, 0.178, and 0.241 mg/kg after boiling, microwaving, and steam cooking, respectively. Aldrin, endrin, DDT, and endosulfan were predominant OCPs in raw and processed seaweeds. Health risk due to OCP residues was evaluated using food consumption data, acceptable daily intake, and safety indices such as hazard quotient (HQ) and hazard index (HI). The HQ and HI values did not exceed the unit value (HQ, HI < 1), indicating that the level of OCP residues in U. lactuca does not pose any appreciable risk to the consumers. Therefore, the research finding establishes that different thermal cooking processes reduce the OCP residue concentration in U. lactuca.

Multi residue analysis of persistent organochlorine pesticides in fish from Baro River, Gambella, Southwest Ethiopia

In this study, the concentrations of organochlorine pesticides in thirty (30) randomly collected Tilapia Zilli fish samples from the Baro River, Ethiopia were determined. The pesticide residues were extracted by soxhlet extraction technique using a mixture of n-hexane and acetone. The extracts were cleaned with silica gel and analyzed using a GC-MS. Concentrations of organochlorine pesticides were calculated from linear calibration curves of nine mixtures of standards with a concentration range of 5-200 μg/kg in the fish sample and had correlation coefficients of 0.999 for all concentrations. The ranges of the limit of detections (LODs) and limit of quantifications ( LOQs) were 0.008–0.017 μg/kg and 0.025–0.052 μg/kg respectively. Recovery was determined from spiked samples at concentrations of 5 μg/kg, 60 μg/kg, and 200 μg/kg. Recoveries of 90.87–102.6% were obtained and the method precision calculated from relative standard deviation (RSD) was found to be 1.00–8.62%. Of the thirteen studied organochlorine pesticides five of them were detected in collected fish samples with concentrations of 67.08 μg/kg, 15.35 μg/kg, 16.6 μg/kg, 3.87 μg/kg, and 17.1 μg/kg for Endosulfan II, Endrin, Endosulfan I, 4,4’-DDD, and Chlordane, respectively. The occurrence of organochlorine pesticide residues in fish samples shows that these compounds have been used in the study areas. The levels of chlordane and Endosulfan II detected in fish samples were above the maximum residual limits (MRLs) set by the Codex Alimentarius Commission. Therefore public awareness of pesticide use and management needs to be worked on by concerned bodies.

Urbanization-driven soil degradation; ecological risks and human health implications.

Urban soils contaminated with heavy metals and pesticide residues are of great concern because of their adverse impact on human health. A total of 66 agricultural topsoil samples (15cm) were collected to represent the study area and determine how anthropogenic activities adversely affect soil quality and human health. Sampling was conducted in the summer, when it was dry and hot, and in the winter, after atmospheric deposition. Seventeen potentially hazardous metals/metalloids (Ag, As, Al, B, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Mo, Pb, Se, Zn, and V) were measured in the soils. The mean concentrations of metals ranged between 0.05 and 8080mg/kg, and their distribution was site-specific, with high pollution at the sampling sites owing to proximity to human activities. In agricultural areas, the greatest arsenic concentration was recorded at 48mg/kg. The potential ecological risk index (PERI) and health hazard index (HI) were calculated, as well as metal contamination indices including contamination factor (Cf), geo-accumulation index (Igeo), and pollution load index (PLI). The mean PLI was calculated to be 4.89, indicating that the area is highly polluted. The potential ecological risk index showed remarkably high risks for As, Cd, and Hg, and moderate risks for Ni and Pb. The arsenic hazard index (HI) was greater than one (2.41) in children, indicating a risk of exposure through ingestion. Pesticide residue analyses were performed in areas where the metal intensity was high. Banned or restricted organochlorine pesticide (OCPs) residues, including, dieldrin, endrin ketone, endosulfan I, II, heptachlor, heptachlor epoxide, lindane (γ-HCH), PP-DDD, and methoxychlor, were detected between 0.002 and 1.45mg/kg in the soil samples.

Oxidative stress, hematological, biochemical, and hormonal alterations induced by exposure tilapia fish of Edko Lake, Egypt, to organochlorine pesticide residues in Edko Lake water.

Background: Organochlorine (OCl) pesticide residues, including gamma-HCH, beta-HCH, heptachlor epoxide, p, p DDE, Dieldrin, endrin aldehyde, endosulfan sulfate, and endrin ketone, were found in the water of Egypt's Edko Lake in the Beheira Governorate. Therefore, the present study evaluated the effect of these OCl pesticide residues on some hematological, biochemical, and hormonal indices of lake tilapia fish. Results: The impact on hematological parameters indicated that these OCl residues cause a significant increase in WBC counts, hematocrit (HCT) values in male and female fish and a considerable rise in HGB and lymphocytes (LYM) in male fish. Liver function biomarkers, such as aspartate amino transaminase (AST) and alanine amino transaminase (ALT), increased significantly because of these OCl residues. In contrast, alkaline phosphatase (ALP) went down a lot. In addition, they decreased the level of glucose compared to the control. Levels of biomarkers related to kidney functions, i.e., uric acid and creatinine, increased significantly. Also, antioxidant enzymes like catalase, glutathione peroxidase (GPx), and glutathione reductase (GR) increased. However, the activity of GST decreased a lot in both male and female fish, and the level of superoxide dismutase (SOD) was reduced in male fish. Results revealed an alteration in thyroid hormone levels (thyroxine (T4) and triiodothyronine (T3)) in fish plasma compared with the control. Also, a significant decrease in folic stimulation hormone (FSH) in female fish and a substantial reduction in progesterone and testosterone hormones in male fish. Conclusions: The OCl pesticide residues found in Edko Lake water directly induced significant adverse effects on hematological components and biomarkers of liver and kidney functions and may have caused hormonal disturbances that harm fish health.

Levels of organochlorine pesticide residues in fresh tomatoes from selected farming communities in Navrongo, Ghana

The levels of organochlorine pesticide (OCP) residues in tomatoes sourced from three agricultural communities in Navrongo (Bonia, Korania, and Nangalkenia) were analyzed using gas chromatography. A comprehensive analysis revealed the presence of nineteen (19) distinct organochlorine pesticides, with a minimum of five different residues detected in each tomato sample. The OCPs were detected within a range of 0.04 to 15.90 μg/kg. Remarkably, beta-hexachlorocylohexane (β-HCH) exhibited the highest concentration (15.90 μg/kg), while both cis-chlordane and trans-heptachlor epoxide displayed the lowest concentration (0.04 μg/kg) in Korania. In the Nangalkenia community, gamma-hexachlorocylohexane (δ-HCH) demonstrated the highest concentration (10.21 μg/kg), while trans-chlordane and o,p'‑Dichlorodiphenyltrichloroethane (o, p-DDT) exhibited the lowest concentration (0.04 μg/kg). Furthermore, within the Bonia community, p, p-Dichlorodiphenyltrichloroethane (p, p-DDT) displayed the highest concentration (8.25 μg/kg), whereas o, p-DDT and trans-heptachlor epoxide exhibited the lowest concentration (0.13 μg/kg). Notably, the analysis indicated that two (2) of the organochlorine pesticides, specifically β-HCH and δ-HCH, surpassed the Maximum Residue Limits (MRLs) established by the United Kingdom/European Commission (UK/EC). The results of the questionnaire survey unveiled a substantial proportion of illiterate farmers (54%), which potentially plays a significant role in the farmers' misuse or indiscriminate use of pesticides. Additionally, both the questionnaire responses and field visits provided insight into the specific types of pesticides employed by the farmers. These include karate, lambda, carbofuran, mancozeb, ridomil, sunpyrifos, kocide, cypermethrin, and dimethoate.

Risk assessment of polycyclic aromatic hydrocarbons and organochlorine pesticides in olive oil in Jordan

Many organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) pose risks to human health; so, their levels in foods should be constantly monitored. In the present work, the potential health risks of 21 OCPs residues and 16 carcinogenic PAHs in Jordanian olive oil were evaluated. A total of 27 olive oil samples were obtained from nine olive mills in Jordan. The levels of PAHs and OCPs were evaluated by gas chromatography coupled with mass spectrometry detector. Among the studied pesticides, only 4,4-Dichlorodiphenyldichloroethylen (4,4-DDE) was found in the tested samples. The estimated average dietary intake (EADI) and hazard risk index (HRI) were then assessed for the 4,4-DDE. The estimated HRI value of 4,4-DDE was less than 1, thus indicating no health risk to consumers. Regarding PAHs, the average concentration of 16 PAHs in the tested olive oil was 36.5 µg/kg. Health risks due to PAH contamination were estimated by determining the dietary daily intake (DDI) and toxic equivalent quotient (TEQ). The values ranged from 0.139 × 10-2 to 7.70 × 10-2 and 0.01 to 0.57 µg/kg for DDI and TEQ, respectively. Light PAHs were predominant in the samples, while no heavy PAHs were detected. The incremental lifetime cancer risk (ILCR) was estimated, and the values ranged from 0.1 × 10-7 to 5.62 × 10-7, and none of the olive oil samples exceeded the limit value of 10-6, thus indicating insignificant potential risk.

Spatial distribution and temporal trend of organochlorine pesticides in Chinese surface soil.

Although organochlorine pesticides (OCPs) in the Stockholm Convention List were banned for a period of time, the residue of OCPs in environment was still detected recently. Therefore, the continuous environmental monitoring was necessary and important for the deep understanding on the temporal trend of environmental fate of OCPs. In this study, the national scale surface soil samples in 26 provinces of China in 2012 were collected, and 28 OCPs were analyzed. The mean concentrations (ng/g dw) of Σhexachlorocyclohexanes (HCHs), Σdichlorodiphenyltrichloroethane (DDTs), hexachlorobenzene (HCB), and hexachlorobutadiene (HCBD) were 2.47 ± 5.4, 4.29 ± 8.28, 3.33 ± 7.68, and 0.041 ± 0.097, respectively. The correlations between OCPs concentrations with temperature, latitude, and longitude were conducted for the deep study of the spatial distribution pattern of OCPs. It was found that HCHs, HCB, and HCBD are positively correlated with latitude and longitude; however, the correlations were not significant. HCHs followed the secondary distribution pattern, and DDTs followed both the primary and/or secondary distribution patterns. Except for HCB, other OCPs showed a gradual downward trend from 2005 to 2012, indicating the effectiveness of the phase-out of OCPs. In summary, the results of the study provided new insight into the related studies, which will help us to better understand the long-term environmental fate of OCPs on large scales.

Determination of levels of organochlorine pesticide residues in some common grown and consumed vegetables purchased from Ho Municipal markets, Ghana

Determination of levels of organochlorine pesticide residues in some common grown and consumed vegetables purchased from Ho Municipal markets, Ghana

Determination of organochlorine pesticides residues in water, fish and sediment samples from River Tella, Gassol, Taraba State, Nigeria

The study was aimed at determining the levels of organochlorine pesticides residues in water, sediment and fish species at River Tella to find out the extent of pesticide contamination and accumulation in the river. Total of fourteen (14) organochlorine pesticide residues were analyzed which include Delta lindane, Alpha Lindane, Beta Lindane, Gamma Lindane, Heptachlor, Aldrin, Heptachlor Epoxide, Endosulfan I, Endosulfan II, P’P-DDE, P’P-DDD, P’P-DDT and Methoxychlor. The water sample was subjected to liquid-liquid extraction method while the fish and the sediment samples were subjected to soxhlet extraction. The extracts were later analyzed for organochlorine pesticide residues using Gas-Chromatography coupled with mass spectrometer (GC-MS). The study has revealed that the level of pesticides residues in water was less than that of fish and sediment which was also below the WHO/FAO values. It was also observed that high concentrations recorded were recorded in high in Gamma Lindane (24.71), follow by Alpha Lindane (23.70) and Beta Lindane (4.50). Mormyrus rume follow by Claria gariepinus while the Tilapia zilli recorded low concentration of the pesticide residues. The Aldrin recorded high concentration of 5.11 ppm in Mormyrus rume follow by Endosulfon II which recorded the concentration of 25.03 ppm also in Mormyrus rume. Endrin also recorded the concentration of 4.88 ppm in Clarias. gariepinus. The lowest pesticide residues was recorded in p,p'-DDD (0.01 ppm), p,p'-DDT (0.03 ppm), Methoxychlor (0.01 ppm). The Heptachlor epoxide and P’P-DDE were not detected in water sample. The presence of high concentration in fish may pose a great danger when these fish are being consumed over time. Regular monitoring is therefore required to control the levels of pesticide residues in the water bodies. The measurement of the fish showed that Clarias gariepinus had the average length of 15.89 cm, and average weight of 179.87 g. Mormyrus rume had the average length of 15. 18 cm, and average weight of 210. 54g. Tilapia zilli was the least species of fish sample with a length of 12.96 cm and average weight of 96.88 g. The water quality parameters of the river were also studied, which recorded the temperature of 28.89 oC was recorded, pH value of 9.01, Conductivity value of 40.11, DO value of 6.14 and TDS of 2.35.

Correlation Between Toxic Elements and Pesticide Residues in Medicinal Herbs Available in Pharmaceutical Market.

The use of medicinal plants for self-medication of minor health conditions has become a widespread practice in contemporary society. Few consumes, however, question the contamination of these products with toxic factors resulting from the planet's increasingly polluted environment. This paper presents the levels of five toxic elements (As, Cr, Pb, Cd, and Hg) and nine organochlorine pesticides (hexachlorobenzene (HCB), lindane, heptachor, aldrin, dieldrin, endrin, p,p'DDE, p,p'DDD, and p,p'DDT) in 14 brands of regularly consumed medicinal products in Romania. The toxic elements content was determined using energy-dispersive X-ray fluorescence (EDXRF) technique, and organochlorine pesticide residues (OPCs) were quantified using gas-chromatographic method, equipped with electron capture detector (GC-ECD). The results show that in the case of Cr, Cd, and Hg, the concentrations exceeded the limit values established by World Health Organisation (WHO) for raw herbal material. The higher level of OPCs (such as p,p'DDD, p,p'DDT, aldrin, and dieldrin) was found in the samples of Hypericum perforatum-St. John's wort, Crataegus monogyna-hawthorn, and Epilobium parviflorum-hoary willowherb. The correlations between the content of toxic elements and pesticides were determined by statistical analysis. Hierarchical clustering technique was used to detect natural grouping between the toxic elements and pesticides. For herb samples, four clusters were identified, the strongest correlated cluster consisting of Pb, HCB, Cr, and Hg. A further analysis within this cluster suggested that Cr levels are statistically different from the rest of the elements.

Trace Elements and Persistent Organic Pollutants in Unhatched Loggerhead Turtle Eggs from an Emerging Nesting Site along the Southwestern Coasts of Italy, Western Mediterranean Sea

Marine pollution is one of the major threats affecting loggerhead turtles, which due to their long life span, highly migratory behavior, and carnivorous diet, may be exposed to elevated levels of toxic elements throughout their life. The transfer of chemicals from mothers to their offspring is of particular conservation concern because it may affect embryonic development and hatching success. In this study, the concentrations of 16 toxic and potentially toxic trace elements, 6 indicator polychlorinated biphenyls (PCBs), and organochlorine pesticide residues (OCPs) were determined in 138 eggs from 46 loggerhead turtle nests laid during the 2021 nesting season in Campania, Italy, western Mediterranean Sea. The possible impact of pollutant levels on hatching success and early embryonic death was also investigated. Trace element analysis was performed using an ICP-MS, except for mercury, which was determined using a Direct Mercury Analyzer® (DMA). PCBs and OCPs were analyzed with high-resolution gas chromatography coupled with high-resolution mass spectrometry (HRGC-HRMS) and gas chromatography tandem quadrupole mass spectrometry GC-MS /MS, respectively. The concentrations of essential elements in the eggs were higher than those of non-essential elements. In addition, the highly chlorinated PCBs (153, 138, and 180) contributed the most to the total PCBs, while OCPs were not detected. No correlations were found between contaminant concentrations and reproductive parameters (hatching success and no obvious embryos). The results obtained suggest that the levels of contaminants found in the eggs do not affect the reproductive success of the species in the study area.

Pollution Characteristics of Organochlorine Pesticides in Water and Sediments of Huixian Karst Wetland in Guilin

Karst wetland plays an important role in the ecological environment; however, due to the existence of karst pipeline, pollutants can threaten the underground environment through the highly developed karst pipeline. Therefore, understanding the pollution characteristics of the karst surface environment is the premise of pollution ecological risk assessment and prevention. In this study, 24 organochlorine pesticides (OCPs) were analyzed to study the concentration, composition, source, and risk of OCPs in water and surface sediments in the Huixian Wetland of Guilin. The results showed that:the concentration of OCPs in water ranged from 3.17 ng·L-1 to 92.50 ng·L-1, and the concentration of OCPs in sediment ranged from 1.16 ng·g-1 to 219.52 ng·g-1, showing the main pollution characteristics of HCHs and DDTs. The concentration of OCPs in water was higher in the wet season than that in the dry season. The concentration of OCPs in sediments was higher in the dry season than that in the wet season. The isomer ratios revealed that OCPs in the study area were mainly derived from long-term degradation residues, and some sites had new input of lindane. Based on Monte Carlo simulation, the human health risk assessment of the study area showed that the 95% quantile carcinogenic risk of OCPs in water was greater than 1×10-6, with potential but acceptable health risk. The non-carcinogenic risk was lower than 1, which indicated that the level of OCPs residues in the water in the study area was not enough to cause non-carcinogenic risk to the human body.

Concentration levels and risk assessment of organochlorine and organophosphate pesticide residue in selected cereals and legumes sold in Anambra State, south-eastern Nigeria

Abstract The levels of organochlorine and organophosphate pesticide residues in selected cereal crops (beans, cowpea, millet, maize, sorghum, and rice) purchased from major markets in Anambra, south-eastern Nigeria, were assessed and compared with established MRLs. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used for extraction and clean-up of pesticide residues. Thereafter detection and quantification were done using GC/MS. The result reveals that the analysed grain samples contained some organochlorine pesticides and organophosphates. The organochlorine was most dominant followed by the organophosphates. Organochlorine pesticide residues varied from 0.048 to 0.298 mg/kg in beans, BDL to 0.398 mg/kg in cowpea, 0.018–0.337 mg/kg in maize, 0.023–0.375 mg/kg in millet, 0.058–0.415 mg/kg in sorghum and 0.045–0.442 mg/kg in rice while organophosphate pesticide residue varied from BDL to 0.315 mg/kg in beans, BDL to 0.113 mg/kg in cowpea, BDL to 0.228 mg/kg in maize, BDL to 0.253 mg/kg in millet, BDL to 0.218 mg/kg in sorghum and BDL to 2.1 35 mg/kg in rice. Highest concentration of endosulphan II (0.442 mg/kg) was detected in rice, followed by aldrin (0.415 mg kg−1) in sorghum and endosulphan II (0.40 mg/kg) in sorghum. The pesticide toxicity index (PTI) was above one (1), whereas health index (HI) was less than one (1) and cancer risk were within USEPA reference guideline for crops indicating children will have greater health effect than adults. Hence, strict monitoring and control of pesticide residues in agricultural products is advocated.

Concentration evaluation and risk assessment of pesticide residues in selected vegetables sold in major markets of Port Harcourt South-South Nigeria

Abstract Concentration levels and health risk assessment of residues of organochlorine and organophosphate pesticides in four commonly vegetables (Cucumber, carrot, cabbage, and eggplant) collected from major markets of Port Harcourt city, South-south Nigeria were assessed. The collected samples were analysed using QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction method by gas chromatography coupled with Electron Capture Detector (ECD). Pesticide concentrations were compared with UK/EU maximum residual limits (MRLs). Health risk estimates were analysed using estimated daily intake (EDI), hazard quotient (HQ), and hazard ratio (HR) for children (16.7 kg) and adults (60 kg) weight groups. The results of this study showed that 80% of the vegetable samples contained detectable pesticide residues, of which 70% had residues that exceeded MRLs while 20% had residues below detectable levels. The highest concentrations of HCH residues are present in cabbage with a concentration of 0.25 ± 0.15 mg/kg for α-HCH while the least are present in eggplant with concentration of 0.038 ± 0.025 mg/kg in lindane. Pirimophos-methyl was detected in cucumber at 0.017 mg/kg while parathion and isofenfos was detected only in eggplants at concentration of 0.042 mg/kg and 0.022 mg/kg respectively. Concentrations of parathion, chlorpyrifos, and pirimophos-methyl residues were lower than MRLs in all the detected vegetable samples analysed. Non-carcinogenic health risk estimates for the children consumer groups showed that mevinfos, p, pʹ DDD, aldrin, and heptachlor epoxide detected in eggplant, carrot, and cabbage had HQ &gt; 1. While for adults, only p, pʹ DDD and heptachlor epoxide revealed non-carcinogenic effect in cabbage. Risk was highest for child consumers. However, most of the pesticide residues were less than 1 for the HQs value which is indicative of insignificant health risk. Human risk estimations for the carcinogenic health effect for the studied vegetables showed that lindane and delta HCH could pose carcinogenic health risks to adult, while aldrin, dieldrin, heptachlor, α HCH, β HCH, delta HCH, and heptachlor epoxide could pose carcinogenic health risks to children. The HRI values in some of the detected residues indicate that the cancer benchmark concentrations exceeded the EDI for the respective organochlorine pesticide in the vegetable samples, thus raising serious concerns of possible carcinogenicity. Non carcinogenic and carcinogenic risk assessment of organochlorine pesticide residues in the studied vegetable indicates health threat. Hence, strict monitoring and control of pesticide residues in agricultural products is being suggested, to protect consumers, especially the children who are vulnerable to the adverse effects of pesticides.

Detection of organochlorine pesticides in estuarine sediments of protected wetlands in Taiwan using high‐resolution gas chromatography/high‐resolution mass spectrometry and gas chromatography‐electron capture detector

AbstractTrace residues of organochlorine pesticides (OCPs) in estuarine surface sediments were investigated at three protected wetlands in southern Taiwan using high‐resolution gas chromatography/high‐resolution mass spectrometry (HRGC/HRMS) and gas chromatography‐electron capture detector (GC‐ECD). This study facilitates the development of new strategies for investigating OCPs, particularly at background levels. Linear relationships were obtained between total OCP concentrations (∑OCP), as analyzed by HRGC/HRMS, and the sediment's total organic carbon (TOC) and water content. It contrasted with the results acquired by GC‐ECD, where no significant relationship was found. GC‐ECD is a rugged option for daily routine practice, particularly in cases of patterns yielded by GC‐ECD is clear; the HRGC/HRMS method provides more reliable qualitative and quantitative capabilities and is highly recommended for studying the fate of OCPs and carrying out risk assessments. The average ∑OCP of these three wetlands by HRGC/HRMS was found in a range of 0.214 to 1.049 ng/g dry weight. The highest OCP level might be attributed to associated irrigation systems receiving massive discharges of domestic sewage from an urban area upstream of the wetland. The ratio of dichlorodiphenyltrichloroethane (DDT) to its metabolites indicated that the DDT residue in these areas was from aged input. According to sediment quality guidelines, adverse ecotoxicological effects of OCPs upon sediments were not expected in these protected wetlands.