Kumasi, Sekondi-Takoradi, and Accra are the major recipients of agricultural commodities or productions in Ghana, primarily due to their population and ready markets. To ensure food security, meet food demands, and mitigate the threats posed by pests and diseases, pesticides are used when cultivating vegetables and fruits in Ghana. The present study has been conducted to assess the concentration of various pesticide residues in tomatoes, obtained from three market centers (namely Bantama, Central, and Ayigya Markets) in Kumasi, dealing with potential health risks for the consumers. Analyzed samples have revealed high percentage of organophosphorous pesticide residues (45%) in Ayigya market with Bantama market recording high percentage of organochlorines and pyrethroid. Laboratory analysis of tomato samples for various pesticides residues has indicated that all the pesticide residues pose no threat to human’s health with all estimated hazard indices being below 1; however, heptachlor (HI=0.85) and dieldrin (HI=0.74) have shown the highest risk levels in children. The study reveals that there is some need for strict monitoring of heptachlor and dieldrin in tomato, especially in case of children.

International audience | Numerous toxicological studies have shown that ingestion of pesticides can induce physiological stress in breeding birds, with adverse consequences on egg laying parameters and offspring quality through parental effects. However, previous studies do not mimic current levels of pesticide residues in typical landscapes, and they do not consider potential cocktail effects of pesticides as they occur in the wild. Herein, we explored whether realistic pesticide exposure affected reproduction parameters and offspring condition through parental effects in Grey partridge. We fed 24 breeding pairs with either seeds from conventional agriculture crops treated with various pesticides during cropping, or organic grains without pesticide residues as controls. The conventional and organic grain diets mimicked food options potentially encountered by wild birds in the field. The results showed that ingesting low pesticide doses over a long period had consequences on reproduction and offspring quality without altering mortality in parents or chicks. Compared with organic pairs, conventional pairs yielded smaller chicks at hatching that had a lower body mass index at 24 days old. Additionally, these chicks displayed lower haematocrit when body mass index was higher. Therefore, ingestion of conventional grains by parents resulted in chronic exposure to pesticide residues, even at low doses, and this had detrimental consequences on offspring. These results demonstrate a sublethal effect of pesticide residues through parental effects. The consequences of parental exposure on chicks might partly explain the decline in wild Grey partridge populations, which raises questions for avian conservation and demography if current agrosystem approaches are continued

International audience | It is essential to monitor pesticides in soils as their presence at trace levels and their bioavailability can induce adverse effects on soil's ecosystems, animals, and human health. In this study, we developed an analytical method for the quantification of traces of multi-class pesticides in soil using liquid chromatography-tandem mass spectrometry. In this way, 31 pesticides were selected, including 12 herbicides, 9 insecticides, and 10 fungicides. Two extraction techniques were first evaluated namely: the pressurized liquid extraction and the QuEChERS procedure. The latest one was finally selected and optimized, allowing extraction recoveries of 55 to 118 %. The addition of the chelating agent EDTA, which binds preferentially to soil cations that complex some pesticides, facilitates their extraction. Coupled with liquid chromatography-tandem mass spectrometry, the procedure displayed very high sensitivity, with limits of quantification (LOQ) in the range 0.01-5.5 ng/g. A good linearity (R² >0.992) was observed over two orders of magnitude (LOQ-100×LOQ) with good accuracy (80%-120 %) for all compounds except the two pyrethroids lambda-cyhalothrin and tau-fluvalinate (accuracy comprised between 50 and 175%) and the cyclohexanedione cycloxydim (accuracy<35%). Good repeatability and reproducibility were also achieved. The method was finally successfully applied to 12 soil samples collected from 3 land-use types. Among the 31-targeted pesticides, 24 were detected at least once, with concentration levels varying from LOQ to 722 ng/g. Many values were below 0.5 ng/g, indicating that the developed method could provide new knowledge on the extremely low residual contents of some pesticides.

Chlorpyrifos is one of the most heavily used pesticides in domestic and agricultural insect prevention globally. Given the potential neurotoxicity of chlorpyrifos and its high detection rates in food and drinking water, health risks attributable to chlorpyrifos residue in Chinese drinking water and food in both China and Denmark were assessed in this study. Mixed left-censored handling models were used to deal with the non-detected values in chlorpyrifos concentrations. Results show that chronic exposure imputed to chlorpyrifos residue is much lower than the reference dose, and will thus not pose appreciable health risk to the consumer. Compared to the total exposure from chlorpyrifos in drinking water and food sources, chronic exposure from drinking water sources in China accounts for 0–4.4%. Health risk owing to chlorpyrifos in food within China is 6-7-fold higher than in Denmark, and this coincides with the fact that all application of chlorpyrifos is banned in Denmark, in contrast to China. However, the Danish consumers are still exposed from imported food items. The main health risk contributors in China are the food groups of Grains and grain-based products and Vegetable and vegetable products, while the main chronic health risk contributor in Denmark is the food group of imported fruit and fruit products.

Production of chrysanthemum (Dendranthema grandiflora) in greenhouses often requires intensive pesticide use, which raises serious concerns over food safety and human health. This study investigated uptake, translocation and residue dissipation of typical fungicides (metalaxyl-M and fludioxonil) and insecticides (cyantraniliprole and thiamethoxam) in greenhouse chrysanthemum when applied in soils. Chrysanthemum plants could absorb these pesticides from soils via roots to various degrees, and bioconcentration factors (BCFLS) were positively correlated with lipophilicity (log Kₒw) of pesticides. Highly lipophilic fludioxonil (log Kₒw = 4.12) had the greatest BCFLS (2.96 ± 0.41 g g⁻¹), whereas hydrophilic thiamethoxam (log Kₒw = −0.13) had the lowest (0.09 ± 0.03 g g⁻¹). Translocation factors (TF) from roots to shoots followed the order of TFₗₑₐf > TFₛₜₑₘ > TFfₗₒwₑᵣ. Metalaxyl-M and cyantraniliprole with medium lipophilicity (log Kₒw of 1.71 and 2.02, respectively) and hydrophilic thiamethoxam showed relatively strong translocation potentials with TF values in the range of 0.29–0.81, 0.36–2.74 and 0.30–1.03, respectively. Dissipation kinetics in chrysanthemum flowers followed the first-order with a half-life of 21.7, 5.5, 10.0 or 8.2 days for metalaxyl-M, fludioxonil, cyantraniliprole and thiamethoxam, respectively. Final residues of these four pesticides, including clothianidin (a primary toxic metabolite of thiamethoxam), in all chrysanthemum flower samples were below the maximum residue limit (MRL) values 21 days after two soil applications each at the recommended dose (i.e., 3.2, 2.1, 4.3 and 4.3 kg ha⁻¹, respectively). However, when doubling the recommended dose, the metabolite clothianidin remained at concentrations greater than the MRL, despite that thiamethoxam concentration was lower than the MRL value. This study provided valuable insights on the uptake and residues of metalaxyl-M, fludioxonil, cyantraniliprole and thiamethoxam (including its metabolite clothianidin) in greenhouse chrysanthemum production, and could help better assess food safety risks of chrysanthemum contamination by parent pesticides and their metabolites.

In recent years, the impact of Plant Protection Products (PPPs) on insect pollinator decline has stimulated significant amounts of research, as well as political and public interest. PPP residues have been found in various bee-related matrices, resulting in governmental bodies worldwide releasing guidance documents on methods for the assessment of the overall risk of PPPs to different bee species. An essential part of these risk assessments are PPP residues found in pollen and nectar, as they represent a key route of exposure. However, PPP residue values in these matrices exhibit large variations and are not available for many PPPs and crop species combinations, which results in inaccurate estimations and uncertainties in risk evaluation. Additionally, residue studies on pollen and nectar are expensive and practically challenging. An extrapolation between different cropping scenarios and PPPs is not yet justified, as the behaviour of PPPs in pollen and nectar is poorly understood. Therefore, this review aims to contribute to a better knowledge and understanding of the fate of PPP residues in pollen and nectar and to outline knowledge gaps and future research needs. The literature suggests that four primary factors, the crop type, the application method, the physicochemical properties of a compound and the environmental conditions have the greatest influence on PPP residues in pollen and nectar. However, these factors consist of many sub-factors and initial effects may be disguised by different sampling methodologies, impeding their exact characterisation. Moreover, knowledge about these factors is ambiguous and restricted to a few compounds and plant species. We propose that future research should concentrate on identifying relationships and common features amongst various PPP applications and crops, as well as an overall quantification of the described parameters; in order to enable a reliable estimation of PPP residues in pollen, nectar and other bee matrices.

In order to study the distribution of pesticide residues in beekeeping matrices, samples of live in-hive worker honey bees (Apis mellifera), fresh stored pollen and beeswax were collected during 2016–2017 from 45 apiaries located in different landscape contexts in Spain. A total of 133 samples were screened for 63 pesticides or their degradation products to estimate the pesticide exposure to honey bee health through the calculation of the hazard quotient (HQ). The influence of the surrounding environment on the content of pesticides in pollen was assessed by comparing the concentrations of pesticide residues found in apiaries from intensive farming landscapes to those found in apiaries located in mountainous, grassland and urban contexts. Beeswax revealed high levels of miticides used in beekeeping such as coumaphos, chlorfenvinphos, fluvalinate and acrinathrin, which were detected in more than 75% of samples. Pollen was predominantly contaminated by miticides but also by insecticides used in agriculture such as chlorpyrifos and acetamiprid, which showed concentrations significantly higher in apiaries located in intensive farming contexts. Pesticides residues were less frequent and at lower concentrations in live honey bees. Beeswax showed the highest average hazard scores (HQ > 5000) to honey bees. Pollen samples contained the largest number of pesticide residues and relevant hazard (HQ > 50) to bees. Acrinathrin was the most important contributor to the hazard quotient scores in wax and pollen samples. The contributions of the pesticides dimethoate and chlorpyrifos to HQ were considered relevant in samples.

The effects of wastewater irrigation and sewage sludge on the dissipation behavior of the fungicide benalaxyl and its primary metabolite benalaxyl acid in soil were studied on an enantiomeric level during a 148-day exposure experiment. Chiral separation and analysis of the two pairs of enantiomers were achieved using HPLC-MS/MS with a chiralpak IC chiral column. Benalaxyl decreased with half-life of 16.1 days in soil under tap water irrigation with preferential residue of S-benalaxyl. Benalaxyl acid was formed with great preference of R-enantiomer before 21 days while enriched in S-enantiomer afterwards. The degradation of benalaxyl was restrained by both wastewater and treated wastewater irrigation, but the enantioselectivity in S-benalaxyl residue was enhanced. Benalaxyl acid was also formed with similar enantioselectivity as in tap water irrigation. Sewage sludge could accelerate benalaxyl degradation with shorter half-life. Surprisingly, the enantioselectivity with preference degradation of S-enantiomer in sewage sludge was opposite to that in soil. More benalaxyl acid was generated with EF values always lower than 0.5 and remained longer in sewage sludge than in soil. A sterilization experiment indicated that the conversion of benalaxyl to benalaxyl acid and the enantioselectivity were determined by the microorganisms in soil or sewage sludge. Farming practices like wastewater irrigation and sewage sludge application might not only influence the fate of pesticide, but also the enantioselectivity of chiral pesticide enantiomers and thus the risks of pesticide residues posed to the environment.

Although enantioselective sorption to soil particles has been proposed as a mechanism that can potentially influence the availability of individual chiral pesticide enantiomers in the environment, environmental fate studies generally overlook this possibility and assume that only biotic processes can be enantioselective, whereas abiotic processes, such as sorption, are non-enantioselective. In this work, we present direct evidence for the effect of the enantioselective sorption of a chiral pesticide in a natural soil on the availability of the single pesticide enantiomers for transport. Batch sorption experiments, with direct determination of the sorbed amounts, combined with column leaching tests confirmed previous observations that from non-racemic aqueous solutions the sorption of the chiral fungicide metalaxyl on the soil appeared to be enantioselective, and further demonstrated that the enantiomer that was sorbed to a greater extent (R-metalaxyl, Kd = 1.73 L/kg) exhibited retarded leaching compared to its optical isomer (S-metalaxyl, Kd = 1.15 L/kg). Interconversion and degradation of the pesticide enantiomers, which are potential experimental artifacts that can lead to erroneous estimates of sorption and its enantioselectivity, were discarded as possible causes of the observed enantioselective behavior. The results presented here may have very important implications for a correct assessment of the environmental fate of chiral pesticides that are incorporated into the environment as non-racemic mixtures, and also of aged chiral pesticide residues that have been transformed from racemic to non-racemic by biologically-mediated processes.

This study provides information on the current status of contamination by DDT in agricultural soils in south-western Spain. A recent use of technical DDT in at least 17% of the soils was found based on the values (<1) of the ratio [Formula: see text] . According to the ratio [Formula: see text] , a dicofol type contamination was detected in about 27% of the soils. A wide range of concentrations was observed (0.08–11.1 ng/g d.w.) regardless of the type of crop soil. Enantiomeric fractions (EFs), based on the chiral analysis of o,p′-DDT residues differed from the racemic value (0.500) in most soils but they were not correlated with the study variables [DDTs], SOM, [Formula: see text] and [Formula: see text] . Given the health risks posed by DDT, our findings support how the environmental control of legacy pollutants such as DDT cannot be neglected.