Dieldrin Residues Research Articles

HEALTH RISK ASSESSMENT OF ORGANOCHLORINE PESTICIDE RESIDUE IN CRUDE PALM OILS IN SELECTED PALM PLANTATIONS IN CROSS RIVER STATE, NIGERIA

Crude palm oil (CPO) is thought to be the most produced and consumed vegetable oil globally. However, when oil palm is grown using pesticides, it may contain OCP residues, which could be hazardous to humans due to their bioaccumulation in the body. For this reason, this study was conducted. Over the course of six months, the processed CPO (n = 18) was gathered once a month from the oil palm plantations owned by JP, Calaro, and Mrs. P. (control). The samples underwent analysis using gas chromatography mass spectrometry (GC-MS/MS) to detect the presence of organochlorinated pesticides (OCPs). Dieldrin and endosulphan II residues were found in the CPO from oil palm plantations (Calaro and JP) that were sprayed with pesticides. The CPO from the Calaro plantation had the highest total OCPs (0.23 ng/mL), followed by the CPO from the JP oil palm plantation (0.14 ng/mL). Dieldrin residues from Calaro and JP oil palm plantations were found in CPO, which is unsafe for ingestion by humans, because they exceeded FAO/WHO acceptable limits for pesticides in food. Since dieldrin was the main source of non-carcinogenic contamination for consumers, it had the highest EDI values in CPO from Calaro (1.23 x 10-4 ng/kg/day) and JP oil palm (7.03 x 10-5 ng/kg/day). This indicates that dieldrin has the highest potential to cause serious health problems. Dieldrin’s EDI values in CPO from Calaro and JP oil palm plantations were higher than the RfD value of 0.00005, suggesting a possible risk to health. CPO from Calaro had the highest HR after ingesting dieldrin, suggesting a higher risk of developing cancerous conditions. The government must therefore educate farmers on the best practices for applying pesticides and create laws and policies to regulate the proper use of pesticides on agricultural land in light of the possibility that CPO processed from oil palm that is cultivated with pesticides may be contaminated and that there may be health risks involved.

Optimization of Dieldrin Selection for the Genetic Sexing of Aedes albopictus.

The mass production of mosquitoes at an industrial scale requires efficient sex separation, which can be achieved through mechanical, genetic or artificial intelligence means. Compared with other methods, the genetic sexing approach offers the advantage of limiting costs and space by removing females at the larval stage. We recently developed a Genetic Sexing Strain (GSS) in Aedes albopictus based on the sex linkage of the rdlR allele, conferring resistance to dieldrin, to the male (M) locus. It has been previously reported that dieldrin ingested by larvae can be detected in adults and bioaccumulated in predators, raising the question of its use at a large scale. In this context, we performed several experiments aiming at optimizing dieldrin selection by decreasing both dieldrin concentration and exposure time while maintaining a stable percentage of contaminating females averaging 1%. We showed that the previously used dieldrin exposure induced an important toxicity as it killed 60% of resistant males at the larval stage. We lowered this toxicity by reducing the dose and/or the exposure time to recover nearly all resistant males. We then quantified the residues of dieldrin in resistant male adults and showed that dieldrin toxicity in larvae was positively correlated with dieldrin concentrations detected in adults. Interestingly, we showed that the use of reduced dieldrin exposure led to a dieldrin quantification in adult males that was below the quantity threshold of the Gas Chromatography-Mass Spectrometry detection method. Presented data show that dieldrin exposure can be adjusted to suppress toxicity in males while achieving efficient sexing and lowering the levels of dieldrin residues in adults to barely quantifiable levels.

Health risk assessment of organochlorine pesticide residues in edible tissue of seafood.

Fish is one of the most valuable foods with high-quality animal protein. However, aquaculture, or ingesting contaminated food, allows organochlorine pesticides (OCPs) to enter the fish's body, and therefore, it negatively impacted public health. One-hundred and twenty random samples of Clupea harengus (C. harengus), Mugil cephalus (M. cephalus), Sardinella aurita (S. aurita), Oreochromis niloticus (O. niloticus), Neptunus pelagicus (N. pelagicus) and Sepia savigngi (S. savigngi) (n = 20 each) were collected from local markets in Mansoura city, Egypt. Samples were checked to see whether any residues of OCPs with the application of risk assessment due to their consumption by Mansoura citizens. The findings indicated that summation hexachlorocyclohexane (∑HCH) in examined seafood samples ranged from 0.27 ± 0.13 in N. pelagicus to 61.61 ± 52.03 μg.kg-1 in S. aurita. Also, the γ-HCH isomer was considered the more prominent among isomers. Hexachlorobenzene (HCB) was found in five different species, with mean values of 2.03 ± 1.85, 1.5.7 ± 1.17, 0.94 ± 0.87, 0.35 ± 0.06, and 0.18 ± 0.06 μg.kg-1 in C. harengus, S. aurita, M. cephlaus, O. niloticus, and S. savigngi. Moreover, summation of Heptachlors (∑HPTs) was 10.19 ± 7.63, 1.27 ± 0.26, 2.58 ± 0.11, 0.95 ± 0.12, 0.21 ± 0.11 and 0.32 ± 0.03 μg.kg-1 of wet weight in examined C. harengus, M. cephlaus, S. aurita, O. niloticus, N. pelagicus, and S. savigngi. Aldrin and dieldrin residues were 3.75 ± 1.31 and 4.86 ± 1.33 μg.kg-1 in C. harengu, meanwhile they were 1.61 ± 0.77 and 0.78 ± 0.04 μg.kg-1in M. cephalus. Dichlorodiphenyldichloroethylene (pp-DDE) was dominant in all examined species within different concentrations 5.08 ± 4.12, 0.98 ± 0.10, 3.07 ± 0.91, 0.93 ± 0.27, 0.08 ± 0.01 and 0.35 ± 0.02 μg.kg-1 in C. harengus, M. cephlaus, S. aurita, O. niloticus, N. pelagicus and S. savigngi, respectively. We concluded that all examined seafood samples were lower than the recommended maximum residue limit. Also, the estimated daily intake was less than the permitted daily intake. Non-carcinogenic indices of target hazard quotient and hazard index for OCPs in all examined species were less than 1.

Determination of the Most Efficient Household Technique for the Reduction of Pesticide Residues from Raw Fish Muscles.

Substantial quantities of pesticides are routinely applied to enhance agricultural crop production. Pesticides used in this way continuously accumulate in the environment and in foods. Harvested crops contain pesticide residues at various concentrations, with potential harmful impacts on human health. Hence, it is of value to identify techniques for the effective decontamination of tainted foods. However, cleaning with water or household agents, e.g., acetic acid and sodium bicarbonate, are recognized treatments for the efficient degradation of pesticides from vegetables and fruits. There is an apparent void of information about the decontamination treatments for raw fishes using household agents that are affordable for all classes of consumers. Hence, the present study was performed to determine the most efficient household technique for reducing pesticide residue levels from precooked raw fish to ensure the utmost food safety. Fish muscles of four species of fishes, viz., Clarias gariepinus, Channa striatus, Anabas testudineus and Trichogaster trichopterus, were treated with six treatments: washing with running tap water (T1), dipping in normal water (T2), dipping in 2% salt solution (T3), dipping in 2% vinegar (T4), dipping in 0.1% sodium bicarbonate solution (T5) as well as dipping in 0.1% sodium bicarbonate solution + 2% vinegar + 2% salt solution + lemon juice (T6), as fish muscle is the major consumable portion of fish. The current study demonstrated that the removal percentage of lindane, heptachlor, aldrin, endosulfan, dieldrin, endrin, DDT, methoxychlor and cypermethrin residues against the treated household treatments, in downward order, were soaking in 0.1% sodium bicarbonate solution + 2% vinegar + 2% salt solution + lemon juice solution (T6) > soaking in 2% vinegar (T4) solution > soaking in 0.1% sodium bicarbonate (T5) solution > soaking in 2% salt (T3) solution > washing with running tap water (T1) > soaking in stable normal water (T2). The treatment of raw fish muscle samples by soaking them in 0.1% sodium bicarbonate solution + 2% vinegar + 2% salt solution + lemon juice was found to be the most efficient household treatment, performing significant reductions (%) in pesticide concentration: 72–80% (p < 0.05) in Channa striata, 71–79% (p < 0.05) in Clarias gariepinus, 74–80% (p < 0.05) in Anabas testudineus as well as 78–81% (p < 0.05) in Trichogaster trichopterus before cooking.

Biochar reduced extractable dieldrin concentrations and promoted oligotrophic growth including microbial degraders of chlorinated pollutants

The role of organic amendments for natural degradation of aged persistent organic pollutants (POPs) in agricultural soils remains controversial. We hypothesised that organic amendments enhance bacterial activity and function at the community level, facilitating the degradation of aged POPs. An incubation study was conducted in a closed chamber over 12 months to assess the effects of selected organic amendments on extractable residues of aged dieldrin. The role of bacterial diversity and changes in community function was explored through sequenced marker genes. Linear mixed effect models indicated that, independent of amendment type, cumulative CO2 release was negatively associated with decreases in dieldrin concentration, by up to 7% per µmol CO2–C respired by microorganisms. The addition of poultry litter led to the highest daily carbon mineralisation, which was associated with low dieldrin dissipation after 9 months. In comparison, biochar resulted in significant decreases in extractable dieldrin residues over time, which coincided with shifts towards aerobic, oligotrophic, gram-negative bacteria, some with dehalogenation metabolism, and with increased potentials for biosynthesis of membrane components such as fatty acids and high redox quinones. The results supported an alternative theory that labile carbon promoted blooms of copiotrophic growth, which suppressed the required community-level traits and oligotrophic diversity to degrade chlorinated pollutants.

Investigation of Residual Concentration of Organochlorine, Organophosphorus, and Carbamate Pesticides in Urban Drinking Water Networks of Hamadan Province, Iran

Pollution of water resources with pesticides is one of the environmental problems and a serious threat to the communities’ health. This study aimed to determine the residual concentration of pesticides in urban drinking water networks of Hamadan province in 2019. In order for investigating the residual concentration of organochlorine (aldrin, dieldrin, lindane, methoxychlor and permethrin), organophosphorus (chlorpyrifos, diazinon and malathion), and carbamate (atrazine and alachlor) pesticides in urban drinking water distribution networks of the province, a total of 46 samples were taken. The samples were analyzed by GC-ECD and the results were analyzed using Excel software (a descriptive cross-sectional study). The residues of aldrin, dieldrin, lindane, diazinon, malathion, atrazine, and alachlor were found in none of the samples. The maximum concentrations of chlorpyrifos and permethrin were 2.20 and 8.03 μg/L, respectively. The methoxychlor residue was observed only in one sample (C=0.35 μg/L) and all other samples were free of methoxychlor. Residues of studied pesticides in all samples are much less than the maximum allowable in the national standard and the World Health Organization (WHO) and Environmental Protection Agency (EPA) guidelines. Therefore, it can be concluded that the studied networks water quality as well as the urban drinking water resources in Hamadan province are at a very desirable level in terms of the pesticide residues. If the consumption of pesticides is not controlled, there is a possibility of increasing the concentration of these pollutants in water resources, which in turn may threaten the human health in the future.

Shrimp/prawn farming status in south-west region of Bangladesh in context of quality control and food safety issues

To determine hazardous antibiotics/chemicals and pesticides residues in Good Aquaculture Practice(GAP) and non-GAP farms and exploring the post-harvest management techniques of shrimp/ prawn forensuring its food safety issues, a study was conducted from July 2016 to June 2019 in three upazilas viz.Bagerhat Sadar, Rampal and Kachua of Bagerhat district. A total of 550 shrimp/prawn farms were randomlysurveyed considering GAP criteria. The farms were categorized as Category A- the farms which comply 90-100% GAP criteria; Category B- farms which comply 70-&lt; 90% GAP criteria and Category C- farms whichcomply 50-&lt;70% GAP criteria. From the study it was found that only 1.67±0.58 % farms were underCategory-A, 37.67±6.81 % farms were under Category-B and 53±6.08 % farms were under Category-C. Atotal of 108 shrimp/prawn samples were collected in which 30% samples were from GAP farms and 70%samples were from non-GAP farms. Collected samples were analyzed for hazardous antibiotics/chemicals andpesticides residues (Heptachlor, Endrin, Dieldrin and DDT) using LC-MS and GC-MS machine. Nohazardous Nitrofuran and Chloramphenicol metabolites were found from the collected samples and noresidual concentrations of Heptachlor, Endrin, Dieldrin and DDT were found from GAP samples. In non-GAP samples, 14.8% samples contained some residues of Heptachlor, Endrin and Dieldrin in which 10.2%samples residues were lower than the Maximum Residual Limit (MRL) which is not harmful for humanhealth. Only 4.6% samples had residues which were slightly higher than the MRL. Exploration of postharvestmanagement techniques of shrimp and prawn were done by observing the icing system quality andtransportation system from farms to market/depot. It was found that 5.67±2.08% farmer used proper icingand transportation system as well, 16.33±3.21% farmers used moderate icing and transportation system and78±2% farmers used poor icing and transportation system. It was also observed that pathogenic bacterialload was higher in poor icing and transportation system as well than the proper icing and transportationsystem. From the study it can be concluded that, if farmers follow at least 50% of the GAP criteria then thefoods (shrimp/prawn) will be safer for human consumption.

Assessment of Organochlorine Pesticides Residues in Tilapia fish (Oreochromis niloticus)

The current study aimed to determine organochlorine pesticides (OCPs) residues in muscle tissues of Tilapia (Oreochromis niloticus) with different weights collected randomly from different localities at Cairo and Giza markets by Gas Chromatoghraphy. The total mean values of DDT, DDD, DDE, Endrin, Dieldrin, Endosulfan, γ-chlordane, δ-BHC, Hepatochlor epoxide, Methoxychlor and Hepatochlor residues in the examined samples of tilapia were 16.82 ± 4.7, 44.80 ± 4.65, 8.34 ± 1.42, 26.54 ± 3.13, 10.91 ± 2.72, 6.20 ± 1.17, 21.32 ± 3.44, 16.17 ± 3.07, 5.33 ± 10.67 , 1.24 ± 0.31 and 1.28 ± 0.31 ng/g, respectively. Accumulation of organochlorine pesticides in fish tissues was related to rate of pollution, lipid content, feeding behavior, rate, size and age. There were significant differences between organochlorine pesticides residues and different weights of tilapia. Most of the examined samples were within the maximum permissible limits of pesticides residues according to US-FDA (2008) and Codex Alimentarius Commission (1996) and should not pose a health risk to consumers. The public health hazards of organochlorine pesticides residues were discussed.

Occurrence of Organochlorine Pesticide (OCP) Residues in Chicken Skin, Liver and Muscle in Egypt

This study was conducted for determination of organochlorine (OCPs) pesticide residues in muscle, skin and liver of chickens (laying hens). The examined samples were collected from three laying hen farms (white Hy- Line breed) in El- Dakahlia, El-Sharkia and El-Giza Governorates, Egypt. Five samples of each tissue were collected at 3 stages; start, peak and end, of egg production from the three farms with the total of 45 samples for each tissue type. The examined samples were extracted and prepared to organochlorine pesticide detection by gas Chromatography system equipped with electron capture detector (ECD). Exactly 14 of organochlorine pesticide residues were analyzed. The obtained results revealed that the Methoxychlor, PP-DDE, Dieldrin, Aldrin, Heptachlor epoxide and α-BHC residues were not detected in all the examined samples. Meanwhile, PP-DDT, PP-DDD, Endrin, Endosulfan, Heptachlor, Δ-BHC, ɤ-BHC (lindane) and ɤ-chlordane were detected in the examined samples in different concentrations. No considerable difference in organochlorine residues could be noticed either between the different Governorates or between the different stages of egg production. The results exhibited relatively higher levels of these residues in skin and liver samples comparing with those in the muscle samples.

Composition of soil organic matter drives total loss of dieldrin and dichlorodiphenyltrichloroethane in high-value pastures over thirty years.

The residues of dieldrin and dichlorodiphenyltrichloroethane (DDT), internationally-banned agricultural insecticides, continue to exceed government guidelines in some surface soils 30 years after use. Little is known regarding the soil factors and microbial community dynamics associated with the in-situ biodegradation of these organochlorine chemicals. We hypothesised that soil organic matter, a key factor affecting microbial biomass and diversity, affects the biodegradation and total loss of the pollutants 30 years after use. We sampled 12 contaminated paddocks with residue concentrations monitoring data since 1988 that represent two different agricultural surface-soils. The total loss and current concentrations of the residues was correlated with soil physicochemical properties, microbial biomass carbon, microbial community diversity indices and microbial community abundance. Current dieldrin and DDT residue concentrations were positively correlated with soil organic matter and clay contents. However, key indicators for loss of residues after 23-30 years were low carbon-to‑nitrogen ratios, high microbial-C-to-total-C ratios and high fungal community evenness. The results support the composition of soil organic matter as an important factor affecting degradation of organochlorines and that co-metabolism of dieldrin and DDT could be enhanced by manipulating the composition of soil organic matter to cater for a broad diversity of microbial function.

Persistent Organochlorine Compounds Levels in Selected Fish Species from Lake Victoria and Associated Human Health Risks

Nile perch (<i>L. niloticus </i>) and Nile tilapia (<i>O. niloticus</i>) are the major commercial fish species in Lake Victoria region of Tanzania. This study was conducted to assess the levels of persistent organochlorine compounds, namely PCBs and OCPs in these two fish species and the probable human health risks associated with the consumption of these two fish species from Lake Victoria. Fish samples were collected between May and August 2016 and the necessary anthropometric measurements such as length and weight were taken. The extraction was done using a modified QuEChERS method and the identification and quantification of the chemicals were done using GC/ECDs. The results of this study revealed that fish species sampled were undersize, which was an indication of overfishing and abuse of bylaws. Among the 19 OCPs which were considered, only four (β- HCH, HCB, Aldrin and Dieldrin) were detected at measurable quantities. β- HCH ranged from <0.24 to 1.19µg/kg. The mean concentrations were 0.77±0.43µg/kg and 0.56±0.16µg/kg for <i>L. niloticus</i> and <i>O. niloticus</i> respectively. HCB levels ranged from <0.18 to 0.59µg/kg in <i>L. niloticus</i> and <0.18µg/kg in <i>O. niloticus</i>. Aldrin ranged from <0.14 to 0.34µg/kg in <i>L. niloticus</i> whereas it was not detected in <i>O. niloticus</i>. Moreover, Dieldrin residues ranged from <0.17 to 1.06µg/kg in <i>O. niloticus</i> but were not detected in <i>L. niloticus</i>. Generally, there were slightly higher levels of the detected OCPs in <i>L. niloticus</i> than the corresponding levels in <i>O. niloticus</i> mainly due to their differences in trophic levels and feeding habits. The indicator PCBs were not detected in all the investigated fish samples. The levels of all the detected organochlorines were far below the MRL set for fish and fishery products suggesting that the fresh fish from Lake Victoria are safe for human consumption. Low levels of the detected residues and non- detection of many organochlorines considered indicate that contamination in Lake Victoria has not reached alarming levels. The human health risk assessment of the detected organochlorines showed cancer risk from 8.6E-06 to 3.2E-05 for children and from 7.8E-06 to 1.3E-05 for adults indicating that there is a low cancer risk for both age groups. The non- cancer risks (HI) on the other hand, were 5.7E-02 for children and 4.7E-02 for adults, which is an indication of an insignificant risk.

Evaluating organochlorine pesticide residues in the aquatic environment of the Lake Naivasha River basin using passive sampling techniques

Passive sampling techniques can improve the discovery of low concentrations by continuous collecting the contaminants, which usually go undetected with classic and once-off time-point grab sampling. The aim of this study was to evaluate organochlorine pesticide (OCP) residues in the aquatic environment of the Lake Naivasha river basin (Kenya) using passive sampling techniques. Silicone rubber sheet and Speedisk samplers were used to detect residues of α-HCH, β-HCH, γ-HCH, δ-HCH, heptachlor, aldrin, heptachlor epoxide, pp-DDE, endrin, dieldrin, α-endosulfan, β-endosulfan, pp-DDD, endrin aldehyde, pp-DDT, endosulfan sulfate, and methoxychlor in the Malewa River and Lake Naivasha. After solvent extraction from the sampling media, the residues were analyzed using gas chromatography electron capture detection (GC-ECD) for the OCPs and gas chromatography-mass spectrometry (GC-MS) for the PCB reference compounds. Measuring the OCP residues using the silicone rubber samplers revealed the highest concentration of residues (∑OCPs of 81 (± 18.9 SD) μg/L) to be at the Lake site, being the ultimate accumulation environment for surficial hydrological, chemical, and sediment transport through the river basin. The total OCP residue sums changed to 71.5 (± 11.3 SD) μg/L for the Middle Malewa and 59 (± 12.5 SD) μg/L for the Upper Malewa River sampling sites. The concentration sums of OCPs detected using the Speedisk samplers at the Upper Malewa, Middle Malewa, and the Lake Naivasha sites were 28.2 (± 4.2 SD), 31.3 (± 1.8 SD), and 34.2 (± 6.4 SD) μg/L, respectively. An evaluation of the different pesticide compound variations identified at the three sites revealed that endosulfan sulfate, α-HCH, methoxychlor, and endrin aldehyde residues were still found at all sampling sites. However, the statistical analysis of one-way ANOVA for testing the differences of ∑OCPs between the sampling sites for both the silicone rubber sheet and Speedisk samplers showed that there was no significant difference from the Upper Malewa to the Lake site (P < 0.05). Finally, the finding of this study indicated that continued monitoring of pesticides residues in the catchment remains highly recommended.

Quantification of Pesticide Residues in Drinking Water in Different Areas of District Charsadda, Pakistan

Pesticides residues were determined quantitatively in drinking water samples collected fromdistrict Charsadda of the province Khyber Pakhtunkhwa, Pakistan employing GC-MS technique. Thesurvey was conducted soon after the flood in 2010. Aldicarb (0.003 mg/L) was found only in C7, whileresidues of acetachlor (0.001 mg/L) was found in C8. Among the pesticides quantified Chlorpyrifosdelivered highest amount of residues in C8, C9, C10, C11 and C12. Residues of o, p'-DDT were foundhigher in C1 to C6 than the permitted value (0.002 mg/L), while higher concentration of Pyridaben thanthe allowed value (0.0001 mg/L) was resulted in C1, C5, C6 and C14. Residues of Carbofuran, Atrazine,a-Endosulfan and Dieldrin, b-Endosulfan, Difenoconazole-1 and Difenoconazole-2 were not detectedin any of the collected water samples. Concentrations of rest of the pesticides residues detected in watersamples were within the permissible limits. The study revealed that water samples collected from districtCharsadda are highly contaminated with pesticides, which is a health risk factor for the inhabitant ofthis areas.

Identification and level of organochlorine insecticide contamination in groundwater and iridology analysis for people in Upper Citarum cascade

Organochlorines are the main pollutants in the class of persistent organic pollutants which are types of pollutants that are being questioned worldwide due to chronic persistence, toxicity and bioaccumulation. Human around the Citarum River are still using groundwater as a drinking source. It is very risky for people health that consume groundwater because in 2009 the application of organochlorine still found in the Upper Citarum watershed rice field and had potential to contaminate groundwater. Groundwater was analyzed with nine species belonging to the organochlorine pollutants Organic Peristent types. 7 types of organochlorinesAldrin was detected with an average concentration of 0.09 ppb, dieldrin with an average concentration of 24 ppb, heptaklor with an average concentration of 0.51 ppb, with concentrations of endosulfan on average 0.73 ppb, DDT with average concentration of 0.13 ppb, Lindan with an average concentration of 1.2 ppb, endrin with an average concentration of 0.03 ppb. Types with the highest concentration of organochlorine a lindan and endosulfan. Residues of aldrin, dieldrin and heptaklor in groundwater already exceeds the quality standards for drinking water Permenkes 492/2010. Based on the iridology analysis obtained several systems are expected to nervous, immune and reproductive system disorders and toxin deposits under the skin.

Evaluation of pesticide residue analysis of dieldrin in soil using a high resolution gas chromatograph/mass spectrometer (HR-GC/MS)

The objective of this study was to evaluate the effectiveness of using HR-GC/MS for the rapid screening of dieldrin residues in soils. Persistent organic pollutants (POPs) of organochlorine pesticides such as dieldrin, were analyzed in sedimentary rock and granite rock collected from greenhouses, Niigata, Japan. Dieldrin remains in Japanese farming soils, more than 40 years after their use as insecticides was prohibited. The averages in soil moisture ranged from 2.79% to 7.20% in soils derived from sedimentary rock and from 25.59% to 31.40% in soils derived from granite rock. Mean concentrations of dieldrin residues in sedimentary rock and granite rock were 39.7 ng g-1 and 40.51 ng g -1 , respectively. Dieldrin residue was detected at a slightly higher concentration in granite rock than sedimentary rock samples. There was no consistency between the two soils or between surface and subsurface soils. The coefficients of variation of the two soils were 10.6% and 8.7%, respectively. These results suggest that our high-resolution mass spectrometry detector (HR-GC/MS) is effective at analyzing residual organochlorine pesticides in soil. In order to increase the precision and sensitivity for chemical analysis of POPs, high-resolution gas chromatography coupled with a HR-GC/MS is highly recommended.

Organic amendments for risk mitigation of organochlorine pesticide residues in old orchard soils

Performance of compost and biochar amendments for in situ risk mitigation of aged DDT, DDE and dieldrin residues in an old orchard soil was examined. The change in bioavailability of pesticide residues to Lumbricus terrestris L. relative to the unamended control soil was assessed using 4-L soil microcosms with and without plant cover in a 48-day experiment. The use of aged dairy manure compost and biosolids compost was found to be effective, especially in the planted treatments, at lowering the bioavailability factor (BAF) by 18–39%; however, BAF results for DDT in the unplanted soil treatments were unaffected or increased. The pine chip biochar utilized in this experiment was ineffective at lower the BAF of pesticides in the soil. The US EPA Soil Screening Level approach was used with our measured values. Addition of 10% of the aged dairy manure compost reduced the average hazard quotient values to below 1.0 for DDT + DDE and dieldrin. Results indicate this sustainable approach is appropriate to minimize risks to wildlife in areas of marginal organochlorine pesticide contamination. Application of this remediation approach has potential for use internationally in areas where historical pesticide contamination of soils remains a threat to wildlife populations.

Organochlorine and organophosphorus pesticide residues in raw buffalo milk from agroindustrial areas in Assiut, Egypt

Raw buffalo milk samples from the agroindustrial zone in upper Egypt were analyzed for the presence of organochlorine and organophosphorus pesticides using gas chromatography–mass spectroscopy. Five organochlorine pesticides namely, alachlor, dieldrin, hexachlorobenzene, lindane and methoxychlor and three organophosphorus pesticides chlorpyrifos, malathion, and parathion-methyl were detected in the milk samples. In 44% of the samples, the concentrations of lindane and malathion residues exceeded tolerance levels set by the European Commission (EC) in 2008. In addition, the concentrations of chlorpyrifos, methoxychlor, and hexachlorobenzene residues exceeded the 2008 EC maximum residual limits (MRLs) by 33, 66, and 88% of the examined samples, respectively. However, the levels of alachlor, dieldrin, and parathion-methyl residues were below EC MRLs. The results of this study confirm the risks of pesticide residues exposure that threaten consumer health in Egypt. Thus, we recommend that pesticide residue monitoring programs be instituted in all the developing countries.

Residual Characteristics of Organochlorine Pesticides in Vegetable Soils from the Middle of Yuanmou

The aim of this paper is to analyze the characteristics of organochlorine pesticides (OCPs) residues in vegetable soils from the middle of Yuanmou. 12 surface soil (0~20 cm) samples of vegetable fields soil were collected and 18 types of OCPs in soil were analyzed by gas chromatography Results show that excepting for α-endosulfan, endrin, aldrin, o,p’-DDT and p,p’-DDT, other 13 types of OCPs was found with different degree in all the samples. The detection rate of 18 types of OCPs was nd~100%, the residue level was nd~11.76 μg•kg-1, OCPs residues were main chlorthiepin sulfate, HCHs and dieldrin. Residues of endosulfan, HCHs and dieldrin in the soils might come from the old usage and residues of heptachlor might come from the recent usage. Contamination of OCPs in soils from the middle of Yuanmou were relative lower than most areas in south of China.

Anopheles arabiensis egg treatment with dieldrin for sex separation leaves residues in male adult mosquitoes that can bioaccumulate in goldfish (Carassius auratus auratus).

The sterile insect technique (SIT) is a biological control tactic that is used as a component of area-wide integrated pest management (AW-IPM) programs. The SIT can only be applied against disease-transmitting mosquitoes when only sterile male mosquitoes are released, and the blood-sucking and potentially disease-transmitting females are eliminated from the production line. For Anopheles arabiensis, a potent vector of malaria, a genetic sexing strain was developed whereby females can be eliminated by treating the eggs or larvae with the insecticide dieldrin. To evaluate the presence of dieldrin residues in male mosquitoes designated for SIT releases, a simple, sensitive, and accurate gas chromatography–electron capture detector (GC–ECD) method was developed. In addition, bioaccumulation and food chain transfer of these residues to fish after feeding with treated mosquitoes was demonstrated. The overall recovery from method validation studies was 77.3 ± 2.2% (mean ± relative standard deviation [RSD]) for the mosquitoes, and 99.1 ± 4.4% (mean ± RSD) for the fish. The average dieldrin concentration found in adult male An. arabiensis was 28.1 ± 2.9 µg/kg (mean ± standard deviation [SD]). A range of 23.9 ± 1.1 µg/kg to 73.9 ± 5.2 µg/kg (mean ± SD) of dieldrin was found in the fish samples. These findings indicate the need to reassess the environmental and health implications of control operations with a SIT component against An. arabiensis that involves using persistent organochlorines in the sexing process.

Health risk assessment of pesticides residue in maize and cowpea from Ejura, Ghana

Low productivity in agriculture due to damage cause by pests has led to the application of pesticides to control pest infestation. Residues of pesticides applied on crops are often found in the food which can cause chronic effect on the health of humans who consume such products. The aim of this study is to measure pesticides residues in maize and cowpea and compare the values with stablished safety limits. A total of 37 pesticides comprising 15 organochlorines, 13 organophosphorus and 9 pyrethroids pesticides were identified in maize and cowpea samples obtained from farms in Ejura. Analytical methods included solvent extraction of the pesticide residues and their subsequent quantification using gas chromatograph equipped with Electron Capture Detector and Pulse Flame Photometric Detector after clean-up on alumina/activated charcoal column. The results showed that the mean concentration of pesticides in maize ranged from 0.001 to 0.103mgkg−1 for organochlorine pesticides, 0.002–0.019mgkg−1 for organophosphorus pesticides and 0.002–0.028mgkg−1 for pyrethroids pesticides. In cowpea the mean concentration ranged from 0.001 to 0.108mgkg−1 for organochlorine pesticides, 0.002–0.015mgkg−1 for organophosphorus pesticides and 0.001–0.039mgkg−1 for pyrethroids pesticides. Maximum Residue Limits for β-HCH, β-endosulfan, p,p′-DDE and p,p′-DDD were exceeded in both maize and cowpea samples. Health risk estimation revealed that residues of heptachlor, dieldrin, endrin, β-endosulfna, γ-chlordane and chlorfenvinphos found in maize exceeded the Acceptable Daily Intake. Similarly the levels of heptachlor and p,p′-DDD found in cowpea also exceeded the Acceptable Daily Intake. This suggests a great potential for chronic toxicity to consumers of these food items.