Low Levels Of Pesticides Research Articles

Cross-Sectional Examination of Thyroid Hormones and Environmental Exposure to Multiclass Pesticides in Women of Reproductive Age in China.

Some pesticides have been shown to interfere with thyroid functions through changes in thyroid hormone (TH) levels. However, few human studies have explored associations between TH levels and environmental exposure to currently used pesticides, including neonicotinoids, phenylpyrazoles, phenoxy acids, and azoles. Moreover, such studies often measure biomarkers of exposure in urine or blood, and thus reveal only recent exposure. In contrast, hair has been demonstrated to be a suitable matrix for assessing chronic exposure to both persistent and nonpersistent organic pollutants. We investigated 54 biomarkers of pollutant exposure in relation to tetraiodothyronine (T4), 3,3',5-triiodothyronine (T3), 3,3',5'-triiodothyronine (rT3), and 3,3'-diiodothyronine (T2). In a cross-sectional study of 196 healthy Chinese women of reproductive age (25-45 years of age), concentrations of both pollutants and THs were analyzed in the first (starting from the scalp) of the hair matrix, collected in 2016. Associations between pollutants and TH levels were explored using stability-enhanced least absolute shrinkage and selection operator (lasso) by regressing all exposures against each outcome of interest, adjusted for age, body mass index, and city. Each TH was associated with the mixture of at least eight of the examined pesticides. We found associations of -HCH, PCP, DMP, DETP, 3Me4NP, carbofuran, , imidacloprid, 2,4-D, metolachlor, difenoconazole, and tebuconazole with THs. For example, a 2-standard deviation (SD) increase in -transformed hair DMP concentration was associated with lower hair T4 concentration [ (95% CI: , )] and higher hair T3 concentration [8.16% (95% CI: 1.73, 15.0%)] in the adjusted unpenalized regression models. We also found associations of some pesticides with T3/T4, rT3/T4, and rT3/T3 molar ratios, including PCP, DMP, 2,4-D, metolachlor, difenoconazole, and tebuconazole. Our results suggest that exposure to the low levels of pesticides examined here may disrupt thyroid homeostasis in humans. Further studies are needed to confirm our results and to evaluate the long-term consequences of these subtle interferences. https://doi.org/10.1289/EHP14378.

Integration of Payload Sensors to Enhance UAV-Based Spraying

This work focuses on the use of load sensors to help with spraying tasks using unmanned aerial vehicles (UAVs). The study details the construction of a prototype for load measurement to validate the proof of concept. To simulate the application of agricultural pesticides, the UAV follows a predefined route and an image processing system detects the presence of diseased plants. After detection, the UAV pauses its route momentarily and activates the spraying device. The payload sensor monitors the fertilizer application process, which determines whether the amount of pesticide has been fully applied. If the storage tank is empty or the remaining quantity is insufficient for another operation, the system will command the UAV to return to the base station for refueling. Experimental validations were carried out in an indoor controlled environment to verify the proposal and the functionality of the in-flight payload monitoring system. Additionally, the UAV’s flight controller demonstrated robust performance, maintaining stability despite the challenges posed by liquid-load oscillations and varying payloads during the spraying process. In summary, our main contribution is a real-time payload monitoring system that monitors weight during flight to avoid over- or under-spraying. In addition, this system supports automatic refueling, detecting low levels of pesticides and directing the UAV to return to base when necessary.

Residue levels, processing factors and risk assessment of pesticides in ginger from market to table

Ginger is consumed as a spice and medicine globally. However, pesticide residues in ginger and their residue changes during processing remain poorly understood. Our results demonstrate that clothianidin, carbendazim and imidacloprid were the top detected pesticides in 152 ginger samples with detection rates of 17.11–27.63%, and these pesticides had higher average residues of 44.07–97.63 μg/kg. Although most samples contained low levels of pesticides, 66.45% of the samples were detected with pesticides, and 38.82% were contaminated with 2–5 pesticides. Peeling, washing, boiling and pickling removed different amounts of pesticides from ginger (processing factor range: 0.06–1.56, most <1). By contrast, pesticide residues were concentrated by stir-frying and drying (0.50–6.45, most >1). Pesticide residues were influenced by pesticide physico-chemical parameters involving molecular weight, melting point, degradation point and octanol–water partition coefficient by different ginger processing methods. Chronic and acute dietary risk assessments suggest that dietary exposure to pesticides from ginger consumption was within acceptable levels for the general population. This study sheds light on pesticide residues in ginger from market to processing and is of theoretical and practical value for ensuring ginger quality and safety.

The Impact of Farm and Industrial Feed Waste on the Safety Parameters of Tenebrio molitor Larvae

The rising global demand for animal-based food has an increasingly detrimental ecological impact, exacerbated by significant food waste (approximately one-third of all food). This research aimed to analyze the possibility of changing the usually balanced feed with sustainable alternatives that remain as a by-product of the production of farms, grain processing, and breweries, thus promoting the sustainability of agriculture. The mealworm larvae were reared on different substrates: (1) agar-agar gels, wheat bran, and brewer’s yeast, (2) carrots, wheat bran, and brewer’s yeast, (3) sprouted potatoes, wheat bran, and brewer’s yeast, and (4) carrots, brewers’ spent grain and brewer’s yeast. For analysis, the frozen larvae were lyophilized and tested for chemical safety in three accredited laboratories. The results have shown that all tested samples had lower levels of pesticides than the detection limit. In scientific literature, we didn’t find studies on polycyclic aromatic hydrocarbons (PAH). In our study, we found PAH in the substrate and these toxins, as our study shows, can also enter the larvae, but no significant accumulation was observed (sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene was 0.0007 mg/kg). Furthermore, the total content of PAH, benzo(a)pyrene and histamine did not exceed recommended levels. We have noticed that the highest concentration of heavy metals (e.g., chromium—1.45 ± 0.02) was found in the sample with the brewer’s by-products. While numerous studies utilize plant-derived by-products, the accumulation of glycoalkaloids has not been explored. Among the all glycoalkaloids (tomatidin, tomatine, α-solanine, α-chaconine and solanidin), amounts of α-solanine and α-chaconine were the highest, detected in the sample with sprouted potatoes (175.12 ± 0.21 and 139.32 ± 0.32 mg/kg, respectively). The amount of total putrescine, tyramine, spermine, and spermidine in mealworm larvae was statistically higher compared to the amount detected in the substrate, and histamine level-on the contrary, was statistically significantly lower compared to the amount detected in the substrate. Considering the amount of toxic substances found in the substrate from the by-products, we can assume that mealworms did not accumulate high levels of toxins, which would violate regulations.

Validation and Simultaneous Monitoring of 311 Pesticide Residues in Loamy Sand Agricultural Soils by LC-MS/MS and GC-MS/MS, Combined with QuEChERS-Based Extraction.

Soil can be contaminated by pesticide residues through agricultural practices, by direct application or through spray-drift in cultivations. The dissipation of those chemicals in the soil may pose risks to the environment and human health. A simple and sensitive multi-residue analytical method was optimized and validated for the simultaneous determination of 311 active substances of pesticides in agricultural soils. The method involves sample preparation with QuEChERS-based extraction, and determination of the analytes with a combination of GC-MS/MS and LC-MS/MS techniques. Calibration plots were linear for both detectors over the range of five concentration levels, using matrix-matched calibration standards. The obtained recoveries from fortified-soil samples ranged from 70 to 119% and from 72.6 to 119% for GC-MS/MS and LC-MS/MS, respectively, while precision values were <20% in all cases. As regards the matrix effect (ME), signal suppression was observed in the liquid chromatography (LC)-amenable compounds, which was further estimated to be negligible. The gas chromatography (GC)-amenable compounds showed enhancement in the chromatographic response estimated as medium or strong ME. The calibrated limit of quantification (LOQ) value was 0.01 μg g-1 dry weight for most of the analytes, while the corresponding calculated limit of determination (LOD) value was 0.003 μg g-1 d.w. The proposed method was subsequently applied to agricultural soils from Greece, and positive determinations were obtained, among which were non-authorized compounds. The results indicate that the developed multi-residue method is fit for the purpose of analyzing low levels of pesticides in soil, according to EU requirements.

Au nanogap SERS substrate for the carbaryl pesticide determination in juice and milk using chemomterics

Conventional spectroscopic methods like IR, and Raman are not very effective at detecting low levels of pesticides or harmful chemicals in food matrices. A quick, highly accurate approach that can identify pesticides present in different food products at lower levels must be developed in order to address this problem and ensure food safety. In this study, a highly sensitive and uniform wafer-scale Au nanogap surface-enhanced Raman spectroscopy (SERS) substrate was used for the quantitative analysis of carbaryl pesticide levels in standard solution, mango juice, and milk samples using chemometrics. Carbaryl was detected up to 3 ppb concentration levels for all three group of samples. However, due to the higher sensitivity, uniformity, and enhancement factors of the SERS substrate used in this investigation, the limit of detection (LOD) values for the standard solution, mango juice, and milk were 0.37 ppb, 0.57 ppb, and 0.15 ppb at 1380 cm−1, 1380 cm−1, and 1364 cm−1 wavenumber ranges. In order to predict different carbaryl concentrations (1, 2, 3, 4, and 5 ppb), the variable importance in projection (VIP) method combined with partial least squares regression (PLSR) and attained the coefficient of determination (R2) values of 0.994, 0.989, and 0.978 along with minimum root mean square error (RMSE) values of 0.112, 0.190, and 0.278 ppb for the prediction datasets. Furthermore, PLS-DA was able to distinguish between pure and adulterated samples with the highest classification accuracy of 100 % for a standard solution, and mango juice and 94.4 % for milk samples. Considering this, we can conclude that the SERS Au Nanogap substrate can rapidly and effectively detect carbaryl pesticides quantitatively and qualitatively in mango juice and milk.

Wild bees are exposed to low levels of pesticides in urban grasslands and community gardens

Globally documented wild bee declines threaten sustainable food production and natural ecosystem functioning. Urban environments are often florally abundant, and consequently can contain high levels of pollinator diversity compared with agricultural environments. This has led to the suggestion that urban environments are an increasingly important habitat for pollinators. However, pesticides, such as commercial bug sprays, have a range of lethal and sub-lethal impacts on bees and are widely available for public use, with past work indicating that managed bees (honeybees and bumblebees) are exposed to a range of pesticides in urban environments. Despite this, we still have a poor understanding of (i) whether wild bees foraging in urban environments are exposed to pesticides and (ii) if exposure differs between genera. Here we assessed pesticide exposure in 8 bee genera foraging across multiple urban landscapes. We detected 13 different pesticides, some at concentrations known to have sub-lethal impacts on pollinators. Both the likelihood of pesticides being detected, and the concentrations observed, were higher for larger bees, likely due to their greater foraging ranges. Our results suggest that restricting agrochemical use in urban environments, where the economic benefits are limited, is a simple way to reduce anthropogenic stress on wild bees.

Biosensor Based on Covalent Organic Framework Immobilized Acetylcholinesterase for Ratiometric Detection of Carbaryl.

A ratiometric electrochemical biosensor based on a covalent organic framework (COFThi-TFPB) loaded with acetylcholinesterase (AChE) was developed. First, an electroactive COFThi-TFPB with a two-dimensional sheet structure, positive charge and a pair of inert redox peaks was synthesized via a dehydration condensation reaction between positively charged thionine (Thi) and 1,3,5-triformylphenylbenzene (TFPB). The immobilization of AChE on the positively charged electrode surface was beneficial for maintaining its bioactivity and achieving the best catalytic effect; therefore, the positively charged COFThi-TFPB was an appropriate support material for AChE. Furthermore, the COFThi-TFPB provided a stable internal reference signal for the constructed AChE inhibition-based electrochemical biosensor to eliminate various effects which were unrelated to the detection of carbaryl. The sensor had a linear range of 2.2–60 μM with a detection limit of 0.22 μM, and exhibited satisfactory reproducibility, stability and anti-interference ability for the detection of carbaryl. This work offers a possibility for the application of COF-based materials in the detection of low-level pesticide residues.

Site-specific target-modification mutations exclusively induced by the coexposure to low levels of pesticides and streptomycin caused strong streptomycin resistance in clinically relevant Escherichia coli

Environmentally relevant levels of pesticides may promote the emergence of stronger streptomycin-resistant mutants in an Escherichia coli K-12 strain in the presence of sublethal levels of streptomycin. However, it is not clear whether this synergistic effect exists in other strains within and outside the Escherichia genus. Here, we investigated the long-term evolution toward stronger antibiotic resistance under the pesticides and streptomycin coexposure in bacterial strains of three different genera, including pathogenic E. coli strains O157:H7 and O103:H2, one Pseudomonas strain, and one Staphylococcus strain. Consistently, the coexposure induced significantly stronger streptomycin-resistant mutants in the two E. coli strains. However, it did not promote any evolution toward stronger streptomycin resistance in the Pseudomonas and Staphylococcus strains. Site-specific mutations of genes, such as rpsL(Lys88Arg), which encode streptomycin target proteins were exclusively evolved in the coexposed E. coli strains and conferred 80-fold increase in streptomycin resistance. These findings imply that a higher risk of strong and inheritable streptomycin resistance of E. coli strains, including the pathogenic ones, may exist in certain environments where pesticides and antibiotics cooccur.

Farmers’ Livelihood Differentiation and Pesticide Application: Empirical Evidence from a Causal Mediation Analysis

As agriculture is becoming a less reliable source of income, many farmers are turning to other industries to supplement their lackluster profits from farming in a process known as farmers’ livelihood differentiation. Despite the existence of a voluminous literature on farmers’ livelihood differentiation, little is known about its effect on agricultural production behavior. To fill this knowledge gap, this study uses rice planting data from 537 Chinese farm households to analyze how farmers’ livelihood differentiation affects pesticide application among rural farmers in China. This study not only examines the effects of farmers’ livelihood differentiation on farmers’ pesticide application, but also underscores the potential pathways behind the effects of farmers’ livelihood differentiation according to land resource endowment via a causal mediation analysis. The results showed that (1) farmers’ livelihood differentiation had a direct effect on the amount of pesticide use. Compared to the full-time agricultural households, regular part-time farmers and ir-regular part-time farmers generally tend to use lower levels of pesticides. (2) The mediating effect of farmers’ livelihood differentiation on pesticide use was through land resource endowment. Compared to the full-time agricultural households, ir-regular part-time farmers reduce their pesticide use through maintaining better land resource endowment, while regular part-time farmers increase their pesticide application by maintaining poor land resource endowment. These results may provide important implications for policymakers to improve cultivated land protection policies and encourage the use of soil testing technology to determine the formulation of the fertilizer used in the agricultural ecological environment.

Differences in the levels of sulphites and pesticide residues in soils and wines and under organic and conventional production methods

The surface and output of organic agriculture is growing steadily in recent years, being generally seen as a healthier, safer and more sustainable alternative to conventional agriculture. Comparisons between organic and conventional products are nonetheless scarce in the literature, especially in the case of wine. The aim of this study was to compare sulphite content and pesticide residues in both soils and wines under organic and conventional production. Fourteen samples of organic and conventional wines and vineyard soils were collected in pairs for each of the seven wine-producing islands of the Canary Islands. A QuEChERS-based method was employed to detect 218 pesticides and 49 POPs. Sulphites were measured by potentiometric titration with a double electrode. On average, higher levels of sulphites were found in conventional wines. Similarly, conventional wines presented higher numbers and concentrations of pesticide residues both in soils and wines than their organic counterparts. The overall pesticide concentrations in our sample was 4.2 µg/kg. Conventional wines presented a considerably higher average concentration than organic wines (8.2 against 0.25 µg/kg). In turn, concentrations in conventional soils averaged 8.7 against 2.8 µg/kg in organic soils, a 68.19 % lower residue concentration. The analytes most commonly found were PCB 28, p,p′-DDE, tebuconazole and the metabolite 4,4′-dichlorobenzophenone in soils and mefenoxam, tebuconazole, fluopyram and boscalid in wines. No single wine exceeded the 10 % of the MRLs established by the European Union for wine grapes. However, the presence of low levels of pesticides in organic wines should be monitored.

Impacts of a novel controlled-release TiO2-coated (nano-) formulation of carbendazim and its constituents on freshwater macroinvertebrate communities

Recently, the delivery of pesticides through novel controlled-release (nano-)formulations has been proposed intending to reduce (incidental) pesticide translocation to non-target sites. Concerns have however been raised with regards to the potentially enhanced toxicity of controlled-release (nano-)formulations to non-target organisms and ecosystems. We evaluated long-term (i.e. 1 and 3 month-) impacts of a novel controlled-release pesticide formulation (nano-TiO2-coated carbendazim) and its individual and combined constituents (i.e. nano-sized TiO2 and carbendazim) on naturally established freshwater macroinvertebrate communities. In doing so, we simultaneously assessed impacts of nano-sized TiO2 (nTiO2), currently one of the most used and emitted engineered nanomaterials world-wide. We determined ecological impacts on diversity (i.e. β-diversity), structure (i.e. rank abundance parameters), and functional composition (i.e. feeding guilds & trophic groups) of communities and underlying effects at lower organizational levels (i.e. population dynamics of individual taxa). Freshwater macroinvertebrate communities were negligibly impacted by nTiO2 at environmentally realistic concentrations. The controlled-release (nano-)formulation significantly delayed release of carbendazim to the water column. Nevertheless, conventional- (i.e. un-coated-) and nTiO2-coated carbendazim induced a similar set of adverse impacts at all investigated levels of ecological organization and time points. Our findings show fundamental restructuring of the taxonomic- and functional composition of macroinvertebrate communities as a result of low-level pesticide exposure, and thereby highlight the need for mitigating measures to reduce pesticide-induced stress on freshwater ecosystems.

Bacillus subtilis Bs10 as an efficient inoculant for growth promotion in soybean plants

Currently, food with low levels of pesticides, sustainable agricultural practices and increased crop productivity have gained prominence worldwide. Rhizobacterial inoculants are an alternative to manage large crops that favors sustainable plant growth. Thereby, this study aimed to assess the effect of increasing doses of inoculant based on the rhizobacterium Bacillus subtilis Bs10 compared to the commercial product based on B. subtilis on the development of soybean culture. Two experiments were carried out with two soybean cultivars, M8210 IPRO and M8615 IPRO, assessed at the vegetative and reproductive stages. Doses of B. subtilis Bs10 with 0, 100, 200, 300, 400 mL per 50 kg seeds were inoculated in each experiment, as well as an additional treatment with commercial product based on B. subtilis. Biomass, nodulation, plant height, internodes, number of pods and number of grains of soybean cultivars were assessed. The inoculation of B. subtilis Bs10 significantly (p &lt; 0.05) improved the agronomic characteristics of both soybean cultivars with an increase in shoot and root biomass, nodulation, phosphorus content, and accumulation of nitrogen in the aerial part. The doses of B. subtilis Bs10 between 200 and 350 mL had significant prominence in increasing the variables studied herein.

Chronic sublethal pesticide exposure affects brood production, morphology and endosymbionts, but not immunity in the ant, Cardiocondyla obscurior

Abstract Insect diversity and biomass have been declining around the world. This might have severe consequences on the environment since insects provide many crucial ecosystem services. One major driver behind the decline is continuous pesticide use which also affects nontarget organisms. Even at low doses, chronic exposure to pesticides may have negative long‐term effects. Ants have not received much attention in this context, despite their importance in terrestrial ecosystems. A full factorial experimental design was used to test how ingestion of two widely used pesticides influence colonies of the ant Cardiocondyla obscurior. Colonies were exposed for 12 weeks to the herbicide glyphosate and the neonicotinoid insecticide thiacloprid, separately and in combination. Brood production and the size of new workers and queens produced in these colonies were measured. In addition, the relative densities of two endosymbionts were quantified and immunocompetence tested by measuring survival after fungal infection. The two pesticides in combination decreased brood production, which was measured as the number of produced eggs and pupae. Workers and queens produced in pesticide‐exposed colonies differed in body size from individuals produced in control colonies. Furthermore, endosymbiont densities decreased after glyphosate exposure. Neither pesticide influenced survival after fungal infection. The results show that chronic exposure to two widely used pesticides causes apparent trade‐offs in reproduction and other physiological traits of ants, potentially decreasing fitness. Even low levels of pesticides in the environment may therefore have negative effects on ant colonies, contributing to the worldwide insect decline.

Effect of Oral Administration of Paraquat Pesticide on the Hippocampus and Substantia Nigra in Wistar Rats' Brains

هدفت هذه الدراسة إلى تحديد التأثيرات النسيجية العصبية من خلال التعرض المزمن للمستويات المنخفضة من المبيد العشبي(الباراكوات) في الحصين والمادة السوداء في أدمغة جرذان الويستر، نُشرت بشكل جيد التأثيرات السمية العصبية للمستويات الحادة والذي يدل على إمكانية التأثير المنخفض على أمراض مختلفة. أظهرت الدراسة الحالية تشريحياً ونسيجياً للأدمغة المتأثرة التغيرات الخلوية المميزة للمبيدات العشبية، تضمنت تناقص معنوي في حجم الدماغ مع اختفاء معظم ملامحه الخارجية، بالإضافة إلى تحديد الفضوات حول الخلايا التي تراجعت لعدة أسباب كالموت الخلوي المبرمج والتنخر، وظهور التشابكات الليفية العصبية داخل الخلايا في عدة مناطق مثل الحصين والمادة السوداء. بالإضافة إلى تحديد الصفيحات الأميلوئيدية خارج الخلايا على شكل ألياف، كما لوحظ التراجع العصبي في مناطق قرن آمون 1،2و3 (الطبقة الجزيئية، الطبقة متعددة الشكل، والطبقة الهرمية) بوساطة تصبغ العصبونات المتراجعة باستخدام نيترات الفضة مع ملاحظة ازدياد عدد الخلايا الدبقية النجمية.

Association between Pesticides in House Dust and Residential Proximity to Farmland in a Rural Region of Taiwan.

Pesticide drift was reported in many international studies, but rarely studied in Taiwan. We conducted a study in a rural region of Taiwan to examine the associations between pesticides in house dust and nearby agricultural areas using geographic information system (GIS). A questionnaire regarding home characteristics and pesticide use, and indoor and outdoor dust samples were collected from 47 rural homes. Dust samples were analyzed for six pesticides, and agricultural land data for GIS analysis were retrieved from a national website. All but prallethrin were frequently detected from indoor dust samples (>50%), and the maximum concentrations were all below 1000 ng/g. Detection frequencies and concentrations of pesticides in outdoor dust samples were even lower than that in indoor dust samples. Only “work involving pesticides” in the questionnaire was significantly associated with four pesticides in house dust (p < 0.05). Carbofuran and tetramethrin in house dust were significantly correlated with rice cultivation area at certain buffer distances (ρ > 0.33, p < 0.05), and chlorpyrifos was found to be associated with abandoned cultivation area, suggesting the occurrence of pesticide drift. Despite the low levels of pesticides in house dust, residents in the rural region should be cautious of pesticide drift from nearby active or abandoned farmlands.

Pilot-scale direct UV-C photodegradation of pesticides in groundwater and recycled wastewater for agricultural use

Pesticides widely used for intensive agriculture may leach to groundwater and pose problems to drinking water and irrigation. UV-C disinfection systems (UV-DS) for water disinfection can be used also for the abatement of organic micropollutants. A pilot-scale continuous flow-through UV-DS system was evaluated for its degradation efficiency of atrazine (ATR), malathion (MAL) and glyphosate (GLY) from 40 L water. Groundwater used to irrigate potato fields and recycled wastewater used to wash potatoes were treated without catalysts to avoid any toxicity effect on potatoes. Chromatographic methods were used to quantify very low pesticide levels before and after UV-C treatments (<10 µg L−1), while a specific method was adapted to analyse traces of GLY (0.0008–10 µg L−1) in recycled wastewater containing suspended particulate matter (SPM). ATR was completely eliminated from groundwater after 15 min photodegradation while 80% was removed from the turbid wastewater after 25 min. For MAL, 70–80% was removed in 25 min from the groundwater. For wastewater, the initial concentration was important for the performance of the photolytic process. An amount of 75% of GLY was eliminated after 10 min irradiation at concentrations higher than those found in natural groundwater. In wastewater, the UV-C treatment was less efficient because GLY was mainly adsorbed to SPM which obstruct the photodegradation process. Therefore, the pilot-scale UV-DS using a turbulent flow and a multiple-lamp system was performed to remove quantitatively traces of pesticides from large volumes of water, by direct photolytic oxidation, when the turbidity of the treated water was limited.

Adverse Health Effects in Women Farmers Indirectly Exposed to Pesticides.

Farmers are among the most vulnerable populations because of the exposure to low levels of pesticides. Acetylcholinesterase and butyrylcholinesterase activities are considered as biomarkers of pesticides poisoning. However, biomarkers of oxidative stress are also playing an important role in toxicity of these contaminants. Further, increased activities of gamma-glutamyltransferase, alanine aminotransferase, urea and creatinine have been linked with hepatic and nephrotoxic cell damage, respectively. The aim of this study was to ascertain if the indirect exposure to pesticides leads to some biochemical parameter changes. Thus, cholinesterase activities, oxidative stress status (lipid and protein oxidation), hepatic function (AST and ALT levels), hormonal function (TSH, T4, FSH, LH and AMH), renal function (serum creatinine and urea), as well as possible subclinical kidney damage (urinary proteins and biomarkers of early kidney damage) were evaluated in farmer women who collect fruits and vegetables comparing with a group of women non-occupational exposed to pesticides but living in the same rural environment. Samples were taken periodically along one year to relate the observed effects to a chronic exposure. Our main results showed for the first time a subclinical kidney damage in a rural setting with indirect chronic exposure to pesticides.

Pyrethroid exposure among children residing in green versus non-green multi-family, low-income housing.

Background:There is growing concern about children’s chronic low-level pesticide exposure and its impact on health. Green building practices (e.g. reducing leakage of the thermal and pressure barrier that surrounds the structure, integrated pest management, improved ventilation) have the potential to reduce pesticide exposure. However, the potential impact of living in green housing on children’s pesticide exposure is unknown.Objective:To address this question, a longitudinal study of pyrethroid metabolites (3-phenoxybenzoic acid [3-PBA], 4-fluoro-3-phenoxybenzoic acid [4-F-3-PBA], trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid [trans-DCCA]) in first morning void urine, collected from 68 children from New Orleans, Louisiana residing in green and non-green housing was conducted.Methods:Children were followed for one year with three repeated measures of pesticide exposure. Generalized Estimating Equations examined associations between housing type (green v non-green) and urinary pyrethroid metabolite concentrations adjusting for demographic and household factors over the year.Results:Ninety-five percent of samples had detectable concentrations of 3-PBA (limit of detection [LOD]: 0.1 μg/L); 8% of 4-F-3-PBA (LOD: 0.1 μg/L), and 12% of trans-DCCA (LOD: 0.6 μg/L). In adjusted models, green housing was not associated with statistically significant differences in children’s 3-PBA urinary concentrations compared to non-green housing.Significance:In this study, green building practices had no impact on children’s pyrethroid urinary concentrations. Further studies with larger sample sizes are needed to confirm these findings.

Quantification of Neonicotinoid Pesticides in Six Cultivable Fish Species from the River Owena in Nigeria and a Template for Food Safety Assessment

The Owena River Basin in Nigeria is an area of agricultural importance for the production of cocoa. To optimise crop yield, the cocoa trees require spraying with neonicotinoid insecticides (Imidacloprid, Thiacloprid Acetamiprid and Thiamethoxam). It is proposed that rainwater runoff from the treated area may pollute the Owena River and that these pesticides may thereby enter the human food chain via six species of fish (Clariasgariepinus, Clariasanguillaris, Sarotherodongalilaeus, Parachannaobscura, Oreochromisniloticus and Gymnarchusniloticus) which are cultured in the river mostly for local consumption. This work aims to establish a working method to quantify the likely levels of the insecticides in the six species of fish, firstly by undertaking a laboratory-based study employing the QuEChERS method to extract the four neonicotinoids from fish purchased in marketplace in the UK, spiked with known quantities of the pesticide and using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) as the detection method; secondly, by using these samples to optimise the detection method for very low levels of pesticides, then applying the optimised techniques to the analysis of three of each six species of fish taken from the Owena River. A significant benefit of this combined technique is that only small samples of fish are required. Success with this part of the study showed that very low concentrations of the insecticides could be detected in fish muscle. The third aim is to apply a simple quantitative risk assessment model using the data sets obtained, together with information about daily diet, human body weight and recommended safety limits of pesticides in food to illustrate how human health may be affected by the consumption of these fish. The multiple determinations of neonicotinoids in edible fishes in Nigeria are pioneer research and fill a gap in addressing the relationship between waterborne pesticides and food quality in the country. Fundamentally, this work is an exercise to demonstrate the applicability of the aforementioned instrumental method of analysis to fish muscle, which requires only a small sample size of fish; a large number of fish is not required for a proof of concept, in this case. Although not a monitoring programme for the whole Owena River Basin ecosystem per se, this work successfully demonstrates the technical feasibility of a system of chemical analysis and establishes the foundation for ecological surveys in the immediate future. Parameters involving exposures to xenobiotics in ecotoxicological modelling can now be expressed in terms of both mass and molar concentrations of a chemical in animal tissues if so desired.