Effect of home food processing on chlordecone (organochlorine) content in vegetables

Uncovering potential mangrove microbial bioindicators to assess urban and agricultural pressures on Martinique island in the eastern Caribbean Sea

Martinique's mangroves, which cover 1.85 ha of the island (<0.1 % of the total area), are considerably vulnerable to local urban, agricultural, and industrial pollutants. Unlike for temperate ecosystems, there are limited indicators that can be used to assess the anthropogenic pressures on mangroves. This study investigated four stations on Martinique Island, with each being subject to varying anthropogenic pressures. An analysis of mangrove sediment cores approximately 18 cm in depth revealed two primary types of pressures on Martinique mangroves: (i) an enrichment in organic matter in the two stations within the highly urbanized bay of Fort-de-France and (ii) agricultural pressure observed in the four studied mangrove stations. This pressure was characterized by contamination, exceeding the regulatory thresholds, with dieldrin, total DDT, and metals (As, Cu and Ni) found in phytosanitary products. The mangroves of Martinique are subjected to varying degrees of anthropogenic pressure, but all are subjected to contamination by organochlorine pesticides. Mangroves within the bay of Fort-de-France experience notably higher pressures compared to those in the island's northern and southern regions. In these contexts, the microbial communities exhibited distinct responses. The microbial biomass and the abundance of bacteria and archaea were higher in the two less-impacted stations, while in the mangrove of Fort-de-France, various phyla typically associated with polluted environments were more prevalent. These differences in the microbiota composition led to the identification of 65 taxa, including Acanthopleuribacteraceae, Spirochaetaceae, and Pirellulaceae, that could potentially serve as indicators of an anthropogenic influence on the mangrove sediments of Martinique Island.

Fate of chlordecone during home cooking processes - Transfer into the liquid and aerial phases by conventional thermal processes

This study focuses on the fate of chlordecone (CLD) during cooking processes. Neat CLD was subjected to thermogravimetric analysis, which revealed that the vast majority of the compound (79 %) was vaporised at temperatures between 55 and 245 °C. In order to monitor the behaviour of CLD during cooking processes, a QuEChERS extraction protocol was optimised for vegetable cooking oil and a heating kinetics experiment was conducted at 195 °C on CLD-spiked cooking oil. The results showed a strong decrease in CLD over time and, for the first time to our knowledge, transformation of CLD into chlordecol. Finally, a comparison was conducted between the cooking of uncured pork with and without vegetable oil. The use of vegetable oil led to a significant decrease in CLD content, but revealed that a fraction of the CLD transferred into the cooking oil. This study provides data that shed light on the fate of CLD during cooking.

Boiling, Blanching, and Stir-Frying Markedly Reduce Pesticide Residues in Vegetables

Nowadays, a lot of produce (fruits and vegetables) sold in many countries are contaminated with pesticide residues, which cause severe effects on consumer health, such as cancer and neurological disorders. Therefore, this study aims to determine whether cooking processes can reduce the pesticide residues in commonly consumed vegetables (Chinese kale and yard long beans) in Thailand. For cooking experiments, the two vegetables were cooked using three different processes: boiling, blanching, and stir-frying. After the treatments, all cooked and control samples were subjected to extraction and GC-MS/MS analysis for 88 pesticides. The results demonstrated that pesticide residues were reduced by 18–71% after boiling, 36–100% after blanching, and 25–60% after stir-frying for Chinese kale. For yard long beans, pesticide residues were reduced by 38–100% after boiling, 27–28% after blanching, and 35–63% after stir-frying. Therefore, cooking vegetables are proven to protect consumers from ingesting pesticide residues.

Correlation between endemic chlordecone concentrations in three bovine tissues determined by isotopic dilution liquid chromatography-tandem mass spectrometry

Chlordecone (CLD) is an organochlorine pesticide widely used from the 1970s to the 1990s in the French West Indies that induced long-term pollution of the ecosystem. Due to involuntary soil ingestion, some species bred in open-air areas can be contaminated. As CLD is distributed in various tissues depending on the breeding species, this study focuses on the distribution of CLD in bovines. For this purpose, three tissues, i.e. fat, muscle, and liver, from 200 bovines originating from Martinique and Guadeloupe were sampled in 2016 to determine their endemic contamination levels. Analyses were performed with the official method for veterinary controls, isotopic dilution liquid chromatography-tandem mass spectrometry, which has been fully validated and which reaches a limit of quantification of 3 μg.kg^-1 fresh weight (fw). Irrespective of the matrices, CLD was detected in 68% of samples (404 samples above the LOD) and quantified in 59% of samples (332 samples above the LOQ). Regarding contamination levels, the liver had a broader range of concentrations (LOQ up to 420.6 μg.kg^-1 fw) than fat (LOQ up to 124.6 μg.kg^-1 fw) and muscle (LOQ up to 67.6 μg.kg^-1 fw). This confirms the atypical behaviour of CLD compared to other persistent organochlorine pollutants. Statistical processing demonstrated a correlation between CLD concentrations among the three studied tissues. The CLD concentration ratios were 0.54 for muscle/fat, 3.75 for liver/fat, and 0.14 for muscle/liver.

Effect of home cooking processes on chlordecone content in beef and investigation of its by-products and metabolites by HPLC-HRMS/MS

Chlordecone (CLD) is a toxic organochlorine pesticide frequently used in the French West Indies until 1993, resulting in a contamination of soil and food. This study assessed the behaviour of CLD residues and CLD processing factors (PFs) during four home cooking processes: cooking in a conventional oven ("oven"), frying ("pan"), cooking in a microwave oven ("microwave") and grilling ("grill"). These four processes were applied to six types of naturally contaminated beef (kidney, liver, rib, chuck, top-sirloin and sirloin). Targeted analyses with isotopic dilution were carried out by ID-HPLC-MS/MS to determine CLD concentrations before and after each cooking process and the corresponding processing factors. HPLC-HRMS/MS was used to find potential organochlorine degradation by-products and/or CLD metabolites present in samples by target, suspect and non-target screening. Cooking processes and especially microwave cooking led to a significant decrease in the CLD contained in beef (2% < PF < 17%). Traces of 5b-hydro-CLD and of another mono-hydro-CLD were found in the uncooked liver but no CLD degradation by-product was observed in the cooked liver.

Control of poultry contamination in chlordecone-contaminated areas of the French West Indies

The consumption of private hold poultry foodstuffs, escaping of official maximum residue limit (MRL) controls in the commercial foodstuff, is an important exposure way for the local populations to chlordecone on the French West Indies. Therefore, chlordecone contamination of different tissues in 42 birds from 32 private holders was determined depending on the contamination of the soil of the outside plot but also surveying the rearing practices of these holders of both islands. Chlordecone contents in tissues increased rapidly with this of the topsoil of the site. The most sensitive tissues to chlordecone presence were egg yolk and liver, followed by abdominal fat and finally leg tissue. The rearing practices varied between the surveyed private holders of both islands. Nevertheless, practices for the distribution of feed and water as well as covering of soil were hardly protective, what would increase the exposure risk of these birds to this potentially present soil-bound contaminant. Although depuration of birds seems possible, the ongoing modelization of the necessary time to meet MRL thresholds indicates that such time lapse seems hardly compatible with acceptable delays for private holders. Therefore, very protective rearing practices are the main way to obtain poultry foodstuffs compliant to MRL, what seems possible if the topsoil is contaminated at less than 0.1 mg kg-1 and perhaps up to 0.5 mg kg-1 if protective practices vis-a-vis of soil exposure are very strict. Nevertheless, a higher contamination of the topsoil seems not compatible with compliant poultry foodstuffs.

Growing food in polluted soils: A review of risks and opportunities associated with combined phytoremediation and food production (CPFP)

Innumerable private households and small-scale producers currently operate on polluted soils. Phytoremediation is one of the most cost-effective remediation options but as a stand-alone technology, it is often not lucrative enough to make it appealing for farmers, especially in economically vulnerable regions. Economic incentives are crucial for remediation projects to materialise and synergies can be obtained by integrating phytoremediation with other profitable activities including food production. This review aims to synthesise state-of-the-art scientific data to provide a general understanding of opportunities and risks for sustainable remediation of agricultural soil by the use of combined phytoremediation and food production (CPFP). The results show that strategies based on CPFP may be appropriate options for most pollutants in virtually all climatic or socioeconomic contexts but a number of challenges need to be surpassed. The challenges include remediation-technological issues such as undeveloped post-harvest technology and inadequate soil governance. The need for remediation solutions for polluted fields is increasingly urgent since many farmers currently operate on polluted land and the scarcity of soil resources as the human population continuously increases will inevitably force more farmers to cultivate in contaminated areas. We conclude that, although large scale CPFP has not yet reached technological maturity, appropriate combinations of soil types, plant species/cultivars, and agronomic practices together with thorough monitoring of the pollutants' pathways can potentially allow for safe food production on polluted soil that restricts the transfer of a number of pollutants to the food chain while the soil pool of pollutants is gradually reduced.

Soil thresholds and a decision tool to manage food safety of crops grown in chlordecone polluted soil in the French West Indies

Due to the persistent pollution of soils by an organochlorine, chlordecone (CLD also known as Kepone ^©) in the French West Indies, some crops may be contaminated beyond the European regulatory threshold, the maximum residue limit (MRL). Farmers need to be able to foresee the risk of not complying with the regulatory threshold in each field and for each crop, if not, farmers whose fields are contaminated would have to stop cultivating certain crops in the fields concerned. To help farmers make the right choices, we studied the relationship between contamination of the soil and contamination of crops. We showed that contamination of a crop by CLD depended on the crop concerned, the soil CLD content and the type of soil. We grouped crop products in three categories: (i) non-uptakers and low-uptakers, (ii) medium-uptakers, and (iii) high-uptakers, according to their level of contamination and the resulting risk of exceeding MRL. Using a simulation model, we computed the soil threshold required to ensure the risk of not complying with MRL was sufficiently low for each crop product and soil type. Threshold values ranged from 0.02 μgkg^-1 for dasheen grown in nitisol to 1.7 μgkg^-1 for yam grown in andosol in the high-uptake category, and from 1 μgkg^-1 for lettuce grown in nitisol to 45 μgkg^-1 for the leaves of spring onions grown in andosol in the medium-uptake category. Contamination of non-uptakers and low-uptakers did not depend on soil contamination. With these results, we built an easy-to-use decision support tool based on two soil thresholds (0.1 and 1 μgkg^-1) to enable growers to adapt their cropping system and hence to be able to continue farming.

Natural transformation of chlordecone into 5b-hydrochlordecone in French West Indies soils: statistical evidence for investigating long-term persistence of organic pollutants

Chlordecone (CLD) was an organochlorine insecticide whose previous use resulted in an extensive pollution of the environment with severe health effects and social consequences. A closely related compound, 5b-hydrochlordecone (5b-hydroCLD), has been searched for and often detected in environmental matrices from the geographical area where CLD was applied. The current consensus considered that its presence was not the result of a biotic or abiotic dechlorination of CLD in these matrices but rather the consequence of its presence as impurity (synthesis by-product) in the CLD released into the environment. The aim of the present study was to determine if and to what extent degradation of CLD into 5b-hydroCLD occurred in the field. To test this hypothesis, the ratios of 5b-hydroCLD and CLD concentrations in a dataset of 810 soils collected between 2006 and 2012 in Martinique were compared to the ratios measured in 3 samples of the CLD dust commercial formulations applied in the banana fields of French West Indies (FWI) and 1 sample of the technical-grade CLD corresponding to the active ingredient used in such formulations. Soil data were processed with a hierarchical Bayesian model to account for random measurement errors and data censoring. Any pathway of CLD transformation into 5b-hydroCLD occurring over the long term in FWI soils would indeed change the ratio of 5b-hydroCLD/CLD compared to what it was in the initially applied formulations. Results showed a significant increase of the 5b-hydroCLD/CLD ratio in the soils-25 times greater in soil than in commercial formulations-which suggested that natural CLD transformation into 5b-hydroCLD over the long term occurred in these soils. Results from this study may impact future decisions for the remediation of the polluted areas.

Food safety in Thailand 2: Pesticide residues found in Chinese kale (Brassica oleracea), a commonly consumed vegetable in Asian countries

There is increasing public concern over human health risks associated with extensive use of pesticides in agriculture. Regulation of pesticide maximum residue limits (MRLs) in food commodities is established in many developed countries. For Thailand, this regulation exists in law but is not fully enforced. Therefore, pesticide residues in vegetables and fruits have not been well monitored. This study investigated the pesticide residues in Chinese kale, a commonly eaten vegetable among Asians. The Chinese kale samples (N = 117) were purchased from markets in Nakhon Pathom Province, Thailand, and analyzed for the content of 28 pesticides. Analysis was performed by the multiresidual extraction followed by GC-MS/MS. Of pesticides investigated, 12 pesticides were detected in 85% of the Chinese kale samples. Although carbaryl, deltamethrin, diazinon, fenvalerate and malathion were found in some samples, their levels were lower than their MRLs. However, in 34 samples tested, either carbofuran, chlorpyrifos, chlorothalonil, cypermethrin, dimethoate, metalaxyl or profenofos was detected exceeding their MRLs. This represents a 29% rate of pesticide detection above the MRL; a rate much higher than in developed countries. Washing vegetables under running water significantly reduced (p < 0.05) profenofos residues by 55%. The running water method did not significantly decrease cypermethrin residues in the samples but washing with vinegar did. Our research suggests that routine monitoring of pesticide residues is necessary to reduce the public health risks associated with eating contaminated vegetables. Washing vegetables before consumption is advisable as this helps to reduce the level of pesticide residues in our daily intake.

Human health risk assessment of pesticide residues in market-sold vegetables and fish in a northern metropolis of China

With growing concerns about food safety and stricter national standards in China, attention has focused on vegetables and fish as they are an important part of the Chinese daily diet, and pesticide residues can accumulate in these foodstuffs. The local consumption habits of vegetables and fish were determined using questionnaires distributed in the major regions of the northern metropolis. Then, the samples of fruit-like vegetables, leafy and root vegetables, and five species of fish (freshwater and marine) were collected from supermarkets and traditional farmers' markets in the city. The concentrations and profiles of pesticide residues (hexachlorocyclohexane (HCH), dichlorodiphenyl trichloroethane (DDT), and endosulfan) in the samples were determined and compared. For the vegetables, the concentration ranges of ΣDDT, ΣHCH, and Σendosulfan were not detectable (ND) to 10.4 ng/g fresh weight (f.w.), ND to 58.8 ng/g f.w., and ND to 63.9 ng/g f.w., respectively. For the fish samples, the corresponding values were 0.77-25.0 ng/g f.w., 0.02-1.42 ng/g f.w., and 1.22-22.1 ng/g f.w., respectively. Only one celery sample exceeded the maximum residue limits (MRLs) of HCH residues set by Chinese regulations (GB2763-2014). The estimated daily intakes (EDIs) and hazard ratios (HRs) were calculated using data from the recently published Exposure Factors Handbook for the Chinese Population. The EDIs and HRs showed that the levels of organochlorine pesticide (OCP) residues in vegetables and fish in this area are safe.

Food safety in Thailand 1: it is safe to eat watermelon and durian in Thailand

OBJECTIVES

The wide use of pesticides raises serious concerns regarding food safety and environmental impacts. There is increasing public concern about the potential health risks linked with exposure to pesticides. Regulation of maximum residue limits (MRL) of pesticide residues in food commodities has been established in many developed countries. For developing countries, like Thailand, this regulation often exists in law, but is not completely enforced in practice. Thus, pesticide residue levels in vegetables and fruits have not been thoroughly monitored. The present study aimed to examine potential health risks associated with pesticide exposure by determining the pesticide residues in two commonly consumed fruits, watermelon and durian.

METHODS

The fruit samples were purchased from markets in central provinces of Thailand and assayed for the content of 28 pesticides. Analysis of pesticides was performed by multiresidue extraction and followed by GC-MS/MS detection.

RESULTS

Of 28 pesticides investigated, 5 were detected in 90.7% of the watermelon samples (n = 75) and 3 in 90% of durian samples (n = 30). Carbofuran, chlorpyrifos, diazinon, dimethoate and metalaxyl were found in watermelons, whereas dichlorvos, dimethoate and metalaxyl were detected in durians. However, their levels were much lower than the recommended MRL values.

CONCLUSIONS

These pesticide levels detected in the fruits are unlikely to harm the consumers; therefore it is safe to eat watermelon and durian in Thailand. While our results found negligible risk associated with pesticide exposure from consuming these common tropical fruits, special precautions should be considered to decrease total exposure to these harmful pesticides from various foods.

Organochlorine (chlordecone) uptake by root vegetables

Chlordecone, an organochlorine insecticide, continues to pollute soils in the French West Indies. The main source of human exposure to this pollutant is food. Root vegetables, which are staple foods in tropical regions, can be highly contaminated and are thus a very effective lever for action to reduce consumer exposure. We analyzed chlordecone contamination in three root vegetables, yam, dasheen and sweet potato, which are among the main sources of chlordecone exposure in food in the French West Indies. All soil types do not have the same potential for the contamination of root vegetables, allophanic andosols being two to ten times less contaminating than non-allophanic nitisols and ferralsols. This difference was only partially explained by the higher OC content in allophanic soils. Dasheen corms were shown to accumulate more chlordecone than yam and sweet potato tubers. The physiological nature of the root vegetable may explain this difference. Our results are in good agreement with the hypothesis that chlordecone uptake by root vegetables is based on passive and diffusive processes and limited by transport and dilution during growth.