Organochlorine Pesticide Residues Research Articles

Ecological and Health Risk Assessment of Heavy Metals and Organochlorine Pesticides in Water and Sediments from Otamiri River in Imo State, Nigeria

Ecological and health risk of selected heavy metals and Organochlorine pesticide residues (OCPs) were assessed in Water and Sediments from Otamiri River in Imo state, Nigeria. Water and sediment samples were collected during rainy and dry periods from three different points and mixed together to form a composite sample. Pesticide residues and heavy metals were analysed using gas chromatography-mass spectrometry and atomic absorption spectrophotometer respectively. The concentration of heavy metal during rainy and dry season ranged from ND to 1.56 mg/l and ND to 3.61 mg/l for water samples, 0.005 to 1.8 mg/kg, and 0.008 to 1.0 mg/kg for sediments respectively. The geo-accumulation index Igeo(x) of heavy metals on sediment ranged from 0 to 0.7 while the values of pollution index were greater than one, signifying heavy metal pollution status of the river. The ecological risk index showed that Nickel and Cadmium had moderate to considerable ecological risk ranging from 129.9-348. The OCP residues concentration ranged from ND to 6.35 mg/l and ND to 4.55 mg/l for water samples, ND to 3.22 mg/kg and ND to 3.5 mg/kg for sediments during rainy and dry season respectively, with predominance of BHCs, DDTs and heptachlor epoxide in water and sediment matrixes. The pesticide residues found in the present study were generally below the maximum residues limit (MRL) set by FAO/WHO bodies. Ecological risk using the Risk quotient was found to be (RQ ≥1) during both seasons and shows higher risks for β-HCH, endosulphan sulfate and p,p′-DDT. The non-carcinogenic risk hazard index (HI) values of both exposure routes were less than one. Conversely, the estimated carcinogenic risk by OCPs through ingestion exposure ranged from 8.142E−9 to 1.20E−7 and 6.36E-7 to 6.44E-4 while dermal range from 3.4E-11 to 2.14E-8 and 7.14E-7 to 8.6E-4 for adults and children respectively, showing considerable carcinogenic risk associated to p,p′-DDT, heptachlor epoxide, α- HCH and aldrin. There is need for regular monitoring of the river to ensure water quality sustainability due to environmental and health risk of the levels of heavy metals and OCPs.

The Lingering Menace: How Legacy Organochlorine Pesticides Still Threaten Our Rivers and Food Chains

The bioaccumulation of organochlorine pesticides (OCPs) in aquatic organisms has been extensively explored in recent years due to associated ecological risks and potential threats to human health through food. This study aims to assess the bioaccumulation of organochlorine pesticides (OCPs) in 18 freshwater fish species from the Pearl River Delta, China. The observed OCP concentrations ranged from 0.69 to 43.15ng/g wet weight, indicating low to moderate pollution levels. A linear mixed-effects model revealed the contribution of the feeding habits and geographic distributions at 58.67 and 0.67% of OCP accumulation, respectively. Bottom-dwelling carnivorous fish species exhibited greater OCP residue levels than those in the upper layers of the freshwater. Estuarine organisms showed higher Dichlorodiphenyltrichloroethane (DDT) residue levels than those inland species. On the other hand, although there were no direct carcinogenic or exposure risks associated with OCPs in the study area, potential related hazards were observed. Consumers are, therefore, advised to select fish species from the middle and upper delta rather than bottom fish, shellfish, and shrimp. The current research provides valuable guidance for aquatic food consumption.

Assessment of organochlorine pesticide residues in agricultural soils of southern Nigeria and analysis of potential health risks

The use of pesticides in commercial farms can lead to exposure among various vulnerable groups. This study assessed the distribution, human health risks, and origins of 13 targeted organochlorine pesticides (OCPs) in soil samples from commercial farms in Southern Nigeria. Following a questionnaire survey on pesticide usage, soil samples were subjected to Soxhlet extraction and analyzed using gas chromatography-mass spectrometry. Results indicated that 31.6% of farmers did not use personal protective equipment, and only 37.6% had received training on safe pesticide application. While pyrethroids and organophosphates were commonly used, organochlorines were rarely applied. The detected levels of OCPs in the agricultural zones ranged from below detection limit (BDL) to 18.35 ± 13.83µg/kg and were generally within the minimum risk level (MRL), except for α-HCH and β-HCH in Oron and Etinan zones. The estimated non-carcinogenic risk s from detected OCPs were insignificant at the time of the study, as the calculated Hazard Indexes (HIs) and Hazard Quotients (HQs) for ingestion, dermal absorption, and inhalation were all less than 1, indicating generally low risks. The carcinogenic risk assessment showed that the Incremental Lifetime Cancer Risk (ILCR) values ranged from 10-10 to 10-4, indicating a very low to low risk level according to the classification by the United States Agency for Toxic Substances and Disease Registry (US ATSDR). Source apportionment suggested that most OCP congeners were of historical origin, with only a few indicating recent use. In conclusion, organochlorine pesticide residues in the studied farms posed minimal health risks, with most originating from historical rather than recent use.

Polyaromatic hydrocarbon and chlorinated pesticides pollution in Iacob Lake of Romania: radionuclide-dated sediments and chromatographic analysis

This study aims to assess the persistent organic pollutant (POP) pollution history of Iacob Lake, Danube Delta, Romania. For this purpose, 16 polycyclic aromatic hydrocarbons (PAHs) and 20 organochlorine pesticides (OCPs) were determined by gas chromatography coupled with specific detectors in the lake sediment core collected in 2014. Before POP analysis, the sediment layers were dated using the 210Pb dating method. The target compounds were isolated from the sediment by ultrasound-assisted extraction, followed by extract clean-up by open-column chromatography. The obtained results showed that between 1940 and 2012, the concentrations of PAHs and OCPs in the dry-weight sediment layers ranged from 73.81 to 214.54 ng g−1 and from 71.78 to 192.69 ng g−1, respectively. Different PAH and OCP diagnostic ratios were used to identify and assess pollution sources. Our results show that the main sources of PAHs in Iacob Lake are mixed petroleum spills, biomass, coal, and petroleum combustion, while OCP residues come from legacy uses. Referring to the Sediment Quality Guidelines, the mean effect range-median quotient, and the toxic equivalent factor, it was found that the highest ecological risks occurred for the pesticide DDT, while the ecological risk for PAHs was considerably low.

Pesticide residues in tropical agricultural soils: Distribution, seasonality, and earthworm ecological risk

Soil contamination by pesticide residues is associated with agricultural intensification in tropical regions and endangers human health and the environment. A mixture of pesticide residues and their degradation products persist in agricultural soils and represent a risk to soil organisms. In this study, we aimed to investigate the concentration and distribution of organochlorine (OC) and organophosphate (OP) pesticide residues in agricultural soils where the industrial cultivation of maize and soybeans is intensively carried out, at three depths (0–5, 5–15, and 15–30 cm) and during two seasons (rainy and dry). Likewise, we performed the ecological risk assessment of those found pesticide residues on two earthworm species, Eisena fetida, and Aporrectoda calagionsa. We calculated the Toxicity-Exposure Ratio (TER) using Predicted no Effect Concentrations (PNEC) and measured concentrations in soils, for identifying the risk of pesticide residues separately. The Risk Quotient (RQ) method was used to evaluate the ecological risk of pesticide residue mixtures in soils from each cropping system. Endrin ketone and dieldrin were the pesticide residues with the highest frequency of detection. The highest concentration in the study was found in a soil sample from maize crops in the dry season at 15–30 cm depth (2917 ng/g). The pesticide mixture from soil samples belonging to maize (0–5 cm) and soybean (5–15 cm) crops in dry season posed the highest ecological risk for A. caliginosa with 100 %, and a maximum RQ of 82.2. Endrin ketone is the OC that contributed most to the overall toxicity of the pesticide mixture in soil samples from maize crop and dieldrin in soil samples from soybean crop. Among OP, disulfoton contributed most to RQsite in soybean crop and methyl parathion in maize crop. Results pointed out the need to apply alternatives to remediate obsolete pesticide residues and restrict the use of methyl parathion and disulfoton in maize and soybean crops, to reduce the ecological risk that represent for earthworms.

Determination of organochlorine pesticide residues in food by polystyrene coated silica magnetic microspheres combined with gas chromatography-mass spectrometry

In this work, a sample pre-treatment technology, based on magnetite-silica-polystyrene (Fe3O4@SiO2@PS) composite as the adsorbent, combined with Gas Chromatography-Mass Spectrometry (GC–MS) has been developed and used for the trace analysis of organochlorine pesticide residues in food. SEM, TEM, FI-IR, VSM, XPS, BET, TGA and XRD techniques were used to characterize the synthetic adsorbent material, the adsorbent had excellent magnetic separation properties (saturation magnetization values with 32.7 emu g−1) and adsorption properties (adsorption capacity with 16.67 mg g−1 to 20.53 mg g−1), and the adsorption performance of Fe3O4@SiO2@PS aligned with the pseudo-second-order kinetics. Under the optimal conditions, the developed method showed satisfactory performance within a range of 0.01 to 4 mg L−1 (R2 ≥ 0.9971), the low detection limits (LOD) were from 0.05 to 0.20 μg kg−1, and the quantification limits (LOQ) were from 0.16 to 0.67 μg kg−1, respectively. The spiked recovery rates ranged from 74.7 % and 93.7 %, with relative standard deviations (RSD) from 2.09 % to 6.43 %. Thus, the developed adsorbent and method offer an efficient alternative to the commonly used SPE-based approach.

Determination of pesticide residues in beans using QuEChERS technique coupled to gas chromatography-mass spectrometry: Multivariate optimization of CEN and AOAC methods

The use of pesticides has led to environmental pollution and posed a global health risk, since they remain as residues on foods. Beans one of the most widely cultivated crop in Africa, and susceptible to attack by insects both on field and during storage, leading to the application of pesticides to control pests' infestation. However, misuse of these chemicals by farmers on beans has resulted in the rejection of beans exported to European countries, due to the presence of pesticide residues at concentrations higher than the maximum residues levels (MRLs). In this study, the effectiveness of the Association Official Analytical Chemists (AOAC) Official Method and the European Committee of Standardization (CEN) Standard Method, were determined using multivariate approach for the analysis of organochlorine pesticide residues in 6 varieties of beans samples. The significance of factors (mass of sample, volume of acetonitrile, mass of magnesium sulphate, sample pH, centrifugation time and speed) affecting the efficiency of extraction was estimated using Plackett-Burman design, while central composite design was used to optimize the significant factors. The following optimum factors were subsequently used for method validation, recovery tests, and real sample analysis: 4 g of sample sludge (1:1 v/v), 10 mL of acetonitrile, 4.45 g of MgSO4, and 5 min of centrifugation at 5000 rpm. The figure of merit of analytical methodology estimated using matrix-matched internal standard calibration method gave linearity ranging from 0.25 to 500 μg/kg, with correlation coefficient (R2) greater than 0.99, the recovery ranged from 75.55 to 110.41 (RSD = 0.70–16.65), with LOD and LOQ of 0.23–1.77 μg/kg and 0.76–5.88 μg/kg, respectively.

Comparison of chemical components and quality evaluation of Panax ginseng and its processed products from different habitats in Northeastern China

Ginseng (Panax ginseng C.A. Meyer) is a widely used dietary supplement in Traditional Chinese Medicine due to its numerous health-promoting properties. However, limited research is available on the distinctions in the chemical composition between different ginsengs. Hence, this study explores the chemical composition of different ginsengs obtained from different habitats in Northeastern China. The fresh, red, and white ginsengs were collected from different places in the Jilin province, China. Ginsenoside and non-ginsenoside contents in the ginseng extracts were analyzed by an Ultra-high performance liquid chromatography system & VION® ion mobility hybrid Quadrupole Time-of-Flight. The results show a notable difference in the ginsenoside content among the samples. The qualification ratio of ginsenoside Re, Rg1, and Rb was 46.2%, with Re being the most abundant, followed by Rg1 and Rb1 in all the ginseng analyzed. Furthermore, the study revealed that white and red ginseng had higher total ginsenosides (8.18 ± 0.04 mg/kg) and total polysaccharides (17.4%) content, respectively. The fresh ginseng samples exhibited higher protein content (20.02 ± 0.2 g/100g) and lower fat content (2.0 g/100g) than others. Further, the ginseng samples analyzed in this study met the requirements specified in the Chinese Pharmacopoeia for total ash, heavy metals, and organochlorine pesticide residues. This study offers a comprehensive comparative analysis of the chemical composition of P. ginseng sourced from various habitats in Northeastern China. It underscores the significance of making informed choices when selecting ginseng types for scientific evaluation.

Mapping pesticide residues in soil for China: Characteristics and risks

The widespread application of pesticides in China has led to the accumulation of residues in soil. However, few regional studies have fully elucidated the characteristics of pesticide residues in soil (PRS) and the associated risks to the ecosystem and human health on a national level. Therefore, this study aims to compile a dataset on PRS in China from 2006 to 2020 and analyze the interactions and impacts between PRS and the environment. The average concentration of PRS in China was 243.96 μg/kg which was lower than the levels reported in Euro-Americans and other nations. This study revealed PRS in China predominantly originates from organochlorine pesticide residues, with DDTs and HCHs being significant contributors. Despite the high intensity of pesticide application in the Southeast China, PRS concentrations were comparable to those in the Northeast, due to environmental factors that favor pesticide degradation in the Southeast. Both legacy and in-use pesticides were transported by surface runoff or air current, resulting in their accumulation in soil of the lower Yangtze River basin or the piedmont soil of Qinling Mountains, respectively. The average soil environment carrying capacity of PRS in China was −69.5 kg. The ecological risk contributed by PRS in China was mainly at a negligible level. Carcinogenic risks of PRS to adults (4.6 ×10−4) and children (6 ×10−4) exceeded the tolerable thresholds (10−5) by a small margin.

Validation of an Analytical Method for Organochlorine Pesticide Residues in Beef Products by GC-MS Using Sampling with Increment Reduction

We developed a simultaneous determination method for the environmentally persistent organochlorine pesticides aldrin/dieldrin, γ-BHC, DDT, endrin, and heptachlor in beef products. In the method, we adopted incremental reduction for sample collection in order to improve the uniformity of the samples. In incremental reduction, a sample was ground and spread to an even thickness, divided into sections, and collected in an equal amount from each section. After extraction with an acetonitrile/ethanol mixture (1 : 1 v/v), sample clean-up was performed by refrigerated centrifu-gation and solid-phase extraction. This process was easy and did not require gel permeation chromatography. The sample was analyzed by GC-MS. A validation study of the development method showed that the tested pesticides met the target values indicated in the validity evaluation guideline.

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) distribution, origins, and risk evaluation in the Egyptian Mediterranean coast sediments.

A study was conducted on 31 surface sediments located in different sectors of the Egyptian Mediterranean coast. The sediments were analyzed for their pollution levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The sediments were collected from various depths in harbors, coastal lakes, bays, and lagoons, covering the southeastern Mediterranean of the Nile Delta region. The study aimed at determining the distribution, origin, and potential ecological impact of OCP and PCB pollutants. The researchers used the SRM method of GC-MS/MS to measure the concentration of 18 PCBs and 16 OCPs residues. The study found that the total concentration of OCPs in the samples ranged from 3.091 to 20.512 ng/g, with a mean of 8.749 ±3.677 ng/g. The total concentration of PCB residues ranged from 2.926 to 20.77 ng/g, with a mean of 5.68 ±3.282 ng/g. The concentration of DDTs exceeded the effect range low (ERL) (1.00) and threshold effect level (TEL) (1.19) in several stations, but it was still below the effect range median (ERM) (7.00) and the probable effect level (PEL) (4.77). This indicates a low ecological risk. The principal component analysis (PCA) was also conducted to determine the sources of all pollutants in the sediment. The PCA showed significant correlations between the concentrations of Gama-HCH and Beta-HCH (0.741), suggesting similar sources. PRACTITIONER POINTS: OCPs and PCBs residues were analyzed in the sediment of the southeastern Mediterranean. The concentration, existence, and causes of OCPs and PCBs were investigated. OCPs and PCBs ecological risk and ecotoxicological calculation were investigated in detail. Cluster analysis, PCA, and correlation coefficient were also investigated.

Levels of organochlorine pesticides in onion and tomato samples from selected towns of Jimma Zone, Ethiopia

This study aimed to determine residues of organochlorine pesticides (OCPs) in tomato and onion samples collected from selected markets in the Jimma zone. A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was used for sample preparation followed by gas chromatography-mass spectrometry (GC-MS) for OCPs analysis. The method used showed wide linear ranges from 5-50 μg/L for all eight pesticides, with R2 values ≥ 0.992. The LOD values for the pesticides tested ranged from 0.14 μg/kg for p,p'-DDE to 2.40 μg/kg for p,p-DDT. LOQ values ranged from 0.46 μg/kg for p,p-DDE to 8.32 μg/kg for p,p'-DDT. The recoveries ranged from 74.84 – 109.45 % except for β-BHC (67.82 %). While most of the OCPs in the onion and tomato samples met European Union (EU) and Codex standards, some exceeded the limits. Methoxychlor and p,p'-DDT in onions, and methoxychlor, p,p'-DDT, α-BHC, and δ-BHC in some tomatoes, were detected above the permitted levels. Specific OCPs were not detected in some samples including aldrin in Meki Tomato (Mek-T), γ-chlordane in Agaro Tomato (Ag-T), and p,p'-DDE in Gera Tomato (Ger-T). The residual concentrations of OCPs varied among the samples. Among tomatoes, Gera had the highest percentage of detected OCPs contaminants (37 %), followed by Agaro (34.34 %) and Meki (28.55 %). Similarly, Sire onion (SrO) had the highest percentage of detected OCPs (28 %) compared to Minjer (25.16 %), Shewa Robit (25.10 %), and Sudan onion (22.25 %). In conclusion, most tomato and onion samples analyzed in this study contained OCP residues highlighting the importance of conducting a consumer health risk assessment.

Organochlorine pesticide residues and urinary arsenic and fluoride levels in mothers and their newborns who are residents of rural areas in Durango State, Mexico

ABSTRACT Maternal and prenatal exposure to organochlorine pesticides (OCP), arsenic (As), and fluoride (F−) is a critical public health concern. The present study assessed serum OCP residues and urinary As and F− levels in mother and newborn pairs who are residents of rural areas of Durango State, Mexico, from August 2018 to February 2019. Levels of OCP, As, and F− were measured in serum and urine samples by Gas chromatography – Tandem mass spectrometry (GC – MS/MS), Hydride generation – Atomic fluorescent spectrometry (HG-AFS, and ion-selective electron analysis (ISE), respectively, in 60 binomial mothers – newborns. Dieldrin, endrin aldehyde, and endosulfan-II were significantly higher in newborns than in mothers (p ˂0.05). Meanwhile, no significant differences were observed for As and F− concentrations between mother – newborn pairs. Differences were observed in ∑Dienes and ∑DDTs comparing newborns with normal and low birth weights and a positive relationship in ƩDienes, ƩChlordanes, and ƩDDTs between mother and newborn pairs (p ˂ 0.05). These findings highlight the importance of extensive research regarding the influence of pollution.

Agricultural-Derived organochlorine pesticide residues impact on macroinvertebrate community in an Afrotropical Stream

This study evaluated the impact of pesticide application through agricultural activities in Chanchaga River, Nigeria, using macroinvertebrate data sets obtained for six months (September 2021–February 2022). Four (4) stations, characterized by various agricultural activities, were sampled along the river. Analysis of the water samples for organochlorine pesticide residues (OCP) using Gas Chromatography-Mass Spectrometry (GC/MS) at the peak of the two seasons revealed a high concentration of eleven isomers of organochlorine, which ranged from 0.01 to 0.81 μg/L, and a mean concentration that was above international drinking water standards set by the World Health Organization, the Federal Environmental Protection Agency, and the European Union. The mean concentration of detected OCP was recorded as DDT (0.72 μg/L), Dieldrin (0.59 μg/L), Paraquat (0.54 μg/L), Aldrin (0.49 μg/L), Metribuzin (0.48 μg/L), Butachlor (0.47 μg/L), Alachlor (0.28 μg/L), Atrazine (0.23 μg/L), Phenol (0.10 μg/L), Endrin (0.09 μg/L), and Benzene (0.08 μg/L). Atrazine, alachlor, metribuzin, aldrin, phenol, and endrin showed significant differences across the two seasons (p < 0.05), while dieldrin, butachlor, paraquat, benzene, and DDT showed no significant differences across the two seasons (p > 0.05). A total of 622 macroinvertebrate individuals from 19 species in 18 families from 8 orders were collected. More individuals were collected during the dry season (58.17 %) and the wet season (41.83 %). Canonical Correspondence Analysis (CCA) ordination revealed a strong relationship between species abundance and some organochlorine pesticide residues such as DDT, endrin, metribuzin, atrazine, benzene, and dieldrin. The response of macroinvertebrates to OCP indicates that Chanchaga River is a disturbed river, and the indicator organisms (Lestes sp., Coenagrion sp., Zyxomma sp., Appasus sp., Chironomus sp., Lymnaea natalensis, and Caridina nililotica) can also be used for further biomonitoring.

Incorporation of Cu-TATAB metal-organic framework within polyurethane nanocomposite for enhanced thin film microextraction of some chlorinated pesticides

In this research, electrospun nanofibers based on copper-based metal organic framework (MOF)/polyurethane (PU) were prepared in order to achieve an applicable and superior extractive phase. The incorporation of MOF, in the synthesized nanocomposite contributed to the enhanced sorption efficiency. The prepared sorbent was implemented for the thin film microextraction (TFME) of target compounds with subsequent quantification using gas chromatography-mass spectrometry (GC–MS). To obtain the maximum efficiency of the synthesized sorbent, the influential parameters on extraction and desorption steps, including the MOF percentage in nanocomposite, desorption solvent type and its volume, desorption time, solution ionic strength and extraction time were optimized. After method development, the linear dynamic range (0.02–700 μg L−1), limits of detection (LODs) (0.005–0.1 μg L−1) and limits of quantification (LOQs))0.02–0.33 μg L−1(were calculated. The relative standard deviations values for intra-day and inter-day analysis were found to be in the range of 4.3–5.3 % and 6.2–8.1 %, respectively. The developed method was validated for the TFME of model organochlorine (OC) pesticide residues in fish, soil and water samples. the recovery values for the spiked samples at two concentration levels of 5 and 100 µg l-1 were found in the range of 72–110 %.

Occurrence and health risk estimate of organochlorine pesticides in fruits and vegetables matrices.

Occurrence of 20 organochlorine pesticides (OCPs) in 60 organic and non-organic fruits and vegetables matrices was undertaken using QuEChERS Method EN 15662 for sample preparation analyzed by gas chromatography-mass spectrometry (GC-MS/MS). The procedural method was validated by spiking the OCP standard solutions at three fortified levels at 10, 50, and 100 µg/kg wet weight (ww) to the real matrix of fruit and vegetable with good recovery ranging from 75 to 108% with relative standard deviation (RSD) ≤ 11%, and the limits of detection and quantification (LODs and LOQs) were 0.002-0.02μg/kg and 0.004-0.1μg/kg ww, respectively. The assessment of health risks associated with pesticide residues through consumption of vegetables and fruits and the effect of washing and peeling on concentration of various pesticides were also studied. The results showed that the concentration levels of 60% of samples were lower than the LOQs, while the rest was contaminated by OCP residues. Organic fruits and vegetables showed the absence of OCPs, while several of the studied compounds were detected from conventional agriculture. Skin removal (peeling) was the most effective strategy to eliminate or decrease pesticide residues, and should be one of the solutions to reduce the health impact of pesticides in fruits and vegetables. The analysis of health risk assessment was based on the use of the estimated average daily intake (EDI), hazard index (HI), and hazard ratio (HR) for individuals in two weight categories: children (weighing 16.7kg) and adults (weighing 60kg). The HI values were less than 1 suggesting that there was no probable non-carcinogenic health effect, except for heptachlor for children (HI of 1.285). However, the values of HR revealed that children were more susceptible to the carcinogenic health effect associated with consuming contaminated vegetables.

Assessment of Organochlorine Pesticide Residue Levels in Fruits and Vegetables Sold in Federal Capital Territory (FCT), Nigeria

The study evaluated the organochlorine pesticide residue levels in fruits and vegetables sold in Federal Capital Territory, Abuja. Six samples were bought from eleven major markets across the six Area Councils of FCT, Abuja. The samples were mixed to form composite groups of the fruits and vegetables, and prepared using QuEChERS method. It was analysed using Agilent 7890 Gas Chromatography equipped with a micro-cell Electron Capture Detector (μECD). The analysis revealed that the hazard index (HI) for all the fruits and vegetables studied were well below the levels of adverse health effect for chronic exposure except for Onion in children which was 1.2287. The HI for the various fruits and vegetables in children were higher than those for the adult. For example, the HI for Tomato, Green Amaranth Leaves and Pepper all in children were 0.4485, 0.4411 and 0.3981 respectively while the HI for Tomato, Green Amaranth Leaves and Pepper all in adult were 0.1121, 0.1103 and 0.0995 respectively. The calculated cancer risk associated with the consumption of these fruits and vegetable showed values well below the upper bound of 1.0x10-6 except for Aldrin, Dieldrin, Heptachlor, Heptachlor Epoxide. a-BHC, b-BHC, and d-BHC especially in children. From the hazard index and cancer risk analysis, Aldrin and Dieldrin have been implicated as the pesticides of concern since they were present in reasonable concentrations for almost all the samples and age groups studied. The highest potential of cancer risk was found in Onions for children. Also, the total cancer risk implicated Onions (with a value of 1.2x10-4 for adult and 4.7x10-4 for children) and Pepper (with a value of 5.5x10-5 for adult and 2.2x10-4 for children) as the most contaminated foodstuffs with pesticide residues in the studied area. The order of the total cancer risk from the study was Onions &gt; Pepper &gt; Tomato &gt; Green Amaranth Leaves &gt; Fluted Pumpkin Leaves &gt; Okra for both adult and children. In conclusion it was observed that pesticide residues of Endrin, o,p'-DDE and Heptachlor in Onions, Green Amaranth Leaves and Pepper were above the Codex maximum residue level (MRL). Endrin in Onions had 858.0%, o, p'-DDE in Onions had 276.0%, o, p'-DDE in Green Amaranth Leaves had 100.8%, Heptachlor in Pepper had 168.4% and Heptachlor in Onions had 119.2%. Also, the hazard index of chronic exposure and cancer risk of children for Onions requires urgent attention as their values were well above the acceptable limit. Therefore, periodic monitoring of pesticides residues in these fruits and vegetables cannot be over emphasized, but will go a long way to prevent, control and reduce environmental pollution and health risks. Also, taking precautionary measures like proper cooking before consumption of these foodstuffs is advised.

Seasonal dynamics and ecological risks of organochlorine pesticides in Kafrelsheikh-Egypt: Implications for aquatic ecosystems and public health

Kafrelsheikh, situated in the middle of the Nile Delta, significantly contributes to Egypt's aquaculture and agriculture sectors. However, the local use of organochlorine pesticides (OCPs) in agriculture is often a source of OCP residues in associated drainage waters, which may threaten aquatic ecosystems. These pesticides persist in local water bodies, jeopardizing aquatic ecosystems and potentially impacting human health. This comprehensive study assessed the seasonal variations of 17 OCPs in both water sources and Nile tilapia across eight fish farming locations in Kafrelsheikh. Using gas chromatography coupled with mass spectrometry (GC-MS), we detected OCP concentrations in water that varied seasonally where winter recorded the highest levels at 22.5 ng/mL and, summer showed the lowest levels at 6.2 ng/mL. Despite water samples occasionally showing risk quotients (RQs) greater than 1, indicating a potential threat to aquatic life, the OCP levels in Nile tilapia were sufficiently low, with target hazard quotients (THQ) below 1, suggesting no significant risk for human consumption. The research highlights a pressing need for regular environmental monitoring and stricter regulatory control over pesticide use to protect aquatic life and ensure the safety of aquaculture products. These findings provide a critical basis for policy-making, aimed at balancing agricultural productivity with environmental sustainability in regions heavily dependent on both.

Assessment of Pesticide Residues in some Selected Plants in Billliri and Kaltungo Local Government Area, Gombe State, Nigeria

The study aimed to assess pesticide residues in selected plants in the Billiri and Kaltungo local government areas of Gombe State, Nigeria. Parts of the selected plants, namely Acacia nilotica, Piliostigma reticulatum, and Calotropis procera were randomly collected, including leaves, stem bark, and roots. These plant parts were washed with tap water and de-ionized water to remove air pollutants, then oven-dried at 105°C to eliminate moisture. The dried samples were pulverized using an agate pestle and mortar and sieved through a 0.5 mm mesh to obtain a uniform particle size. Pesticide residues were determined using gas chromatography (GC). Fourteen organochlorine pesticide residues were detected, including Delta-Lindane, Alpha-Lindane, Gamma-Lindane, Heptachlor, Aldrin, Heptachlor Epoxide, Endosulfan I, P,P-DDE, Endrin, Endosulfan II, P,P-DDD, P,P-DDT, and Methoxychlor.Based on the results from all locations, the lowest concentrations were below the maximum residue limit as per FAO/WHO guidelines, which range from 0.001 to 0.5 ppm. The highest concentrations of organochlorine pesticide residues reported in this study may be attributed to environmental pollution and pesticide use, consistent with the mean values reported in soils from Numan LGA in Adamawa State, Nigeria. In the intricate tapestry of modern agriculture, the assessment of organochlorine pesticide residues in the distinct agroecological locales of Billiri and Kaltungo Local Government Areas unravels a compelling narrative of historical legacies, environmental intricacies, and imperatives for change. Keywords: Pesticide residues, Organochlorine pesticides, Acacia nilotica, Piliostigma reticulatum, Calotropis procera, Environmental pollution and Gas chromatography (GC)

Determination of Concentrations of Pesticide Residues in Chevon obtained from Abattoir of Jimeta, Adamawa State, Nigeria

The current work was aimed at determining levels of Organochlorine (OCP) and Organophosphorus pesticide (OPP) residues in goats obtained from the study area. This was to enable the public aware of the presence of hazardous pesticides residues in the food chain. Forty samples were collected from; Chevon, intestines, kidneys and livers of ten sampled goats. The sampled goats were represented by G1 = first goat, G2 = second goat, G3 = third goat, G4 = fourth goat, G5 = fifth goat, G6 = sixth goat, G7 = seventh goat, G8 = eighth goat, G9 = ninth goat and G10 = tenth goat. Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) was used in preparing the samples. Analysis was done with Gas chromatography – Mass spectrometer (GC/MS) Acqmethod pesticide. Results showed that OCP residues were not detected in all the samples. Anthracene, dichlorpyrifos, diazinon, dimethoate, primifos-methyl, and malathion were detected below the threshold value of 0.001 mg/Kg. Likewise, all pesticide residues in G7 and G9 samples were below the threshold limit (0.001) mg/Kg. Dichlorvos wasdetected in chevon of G1, G3 and G4 with range from 0.043 mg/Kg in G4 – 0.113 mg/Kg in G1. Chlorpyrifos was detected in intestine of G1, G2, G3, G4, G6, G8 and G10. The highest was 0.051 mg/Kg in G4 and lowest was 0.013 mg/Kg in G10. Kidney samples of GI, G2, G3 and G4 contained chlorpyrifos ranging from 0.011 mg/Kg in G8 – 0053 mg/Kg in G4. dichlovos was detected in kidney samples of G1, G2, G3, G4 and G8. Highest concentration of dichlovos in the kidney was; 0.069 00014 mg/Kg in G1 while the lowest was in G8 (0.011mg/Kg). Liver samples of G2, G4, G6 and G10 contained chlopyrifos ranging from 0,007 mg/Kg in G10 – 0.050 mg/Kg in G4. dichlovos was present in livers of G2, G4 and G6. Highest was in G4 (0.037 mg/Kg) and lowest value was in G6 (0.021 mg/Kg). Apart from in Kidney of G8, concentrations of chlorpyrifos in all the samples were above the maximum residue level (MRL) values of 0.01 mg/Kg. Consumption of which may pose health problem. Concentration of dichlorvos detected in the samples were below the MRL of 1.00mg/Kg, this may not pose immediate health issues but continuous intake may bring about accumulative health risk issues. Keywords: Chevon, chlorpyrifos, dimethoate, organophosphorus, malathion, dichlorvos, health, risk