Monitoring Pesticide Residues in Fruits and Vegetables at Two of the Biggest Fresh Produce Markets in Africa

Determination of pesticide residue content in fruits and vegetables from Lagos, Nigeria

Developing countries like Nigeria are increasingly employing pesticides to boost the productivity of their agriculture and food supply, despite the fact that doing so poses a health risk to the general populace. The purpose of this study was to assess pesticide residue levels in Lagos, Nigeria. A total of 18 samples from three neighbourhood markets were collected, and they were then examined for the presence of organochlorine (Endosulfan I, Pentachlorophenol, Heptachlor epoxide, and Endosulfan II) and organophosphate (Dichlorvos, Dimethoate, Phorate, and methyl parathion) residues. During the pre-treatment, the multi-residue Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS citrate) method with the addition of acetonitrile was used, and then samples were analysed using GC-MS. All of the samples contained dichlorvos, but the orange sample's concentration was below the limit of quantification, making quantification impossible. Dimethoate concentrations were below MRLs except waterleaf sample. With a concentration of 0.043 μg/mL, Waterleaf had the highest quantity of dimethoate in the sample. The findings of this study indicate that in order to safeguard the health of consumers, it is necessary to closely monitor organochlorine and organophosphate use nationwide, along with other related pesticides, and to test for pesticide residues in food products.

Consumer risk perception towards pesticide-stained tomatoes in Uganda

BACKGROUND

Tomatoes are consumed daily. Unfortunately, abuse of pesticide application by vegetable growers in Uganda increases risks of pesticide residue exposure among consumers, as they may be above Maximum Residue Limits (European Union Maximum Residue Limits used as a standard in Uganda). This study aimed to determine consumer attitudes and risk perceptions towards pesticide-stained tomatoes in Uganda to support interventions that could be used to reduce pesticide residue exposures in food.

METHODS

A mixed methods cross-sectional study sampled 468 household consumers in four regions of Uganda, selecting one district (interventional project area) per region. In each district, about 60 household members were randomly selected from a total of three Sub Counties and interviewed. In addition, 9 tomato handlers (three tomato farmers, three tomato retailers, and three tomato wholesalers) participated in Focus Group Discussions (FGDs) per district. Collected data were entered into MS-Excel 13 and exported into Stata version 14.0 for cleaning and analysis at a 5% level of significance and 95% Confidence Intervals (CI). The proportion of risk perceptions and attitudes were computed and presented as percentages, while factors associated with risk perception were determined using Fisher exact test. Qualitative data collected under a traditional theory were analyzed using thematic content analysis.

RESULTS

More than half, 54.2% (253/468), of the respondents were females, mean age was 37 years (SD = 13.13, ranging from 18 to 88 years). Half of the respondents, 50.9% (238/467), were farmers by occupation, and 40.3% (188/468) had completed upper primary education. Only 5.0% (20/396) of consumers reported a high-risk perception towards tomatoes stained with pesticide residues, the rest, 95.0% (376/396), were buying pesticide-stained tomatoes despite their awareness of the possible health effects. The main reason for buying the pesticide-stained tomatoes was that a majority, 59.0% (230/390), lacked an alternative to stained tomatoes like organically grown tomatoes. However, consumers generally had a negative attitude towards pesticide-stained tomatoes, with 67.0% (313/468) of the consumers disagreeing with the statement that tomatoes sold on the market are safe. Consumer risk perception was significantly associated with their awareness about residues in the tomatoes; where the proportion of consumers who were aware of the risk of pesticide-stained tomatoes was 42.8 times more likely not to buy stained tomatoes compared to the proportion of those who were not aware. OR, 42.8 (95% CI: 10.76-170.28). However, after Fisher-Exact tests analysis, level of education P(0.975), gender P(0.581), and age group P(0.680) were not associated with consumer risk perception (95% CI and 5% level of significance).

CONCLUSION

Although the consumers had a negative attitude towards the pesticide-stained tomatoes, their risk perception towards them ranked low, with most consumers buying tomatoes stained with pesticide residues due to a lack of an alternative. Ministry of Agriculture extension service efforts should promote and emphasize community to start household-based organic kitchen gardens as the efforts for the establishment of a national pesticide residue monitoring center awaits.

Determination, Quality, and Health Assessment of Pesticide Residues in Kumquat in China

Pesticide residues in kumquat fruits from China, and the quality and chronic/acute intake risks in Chinese consumers, were assessed using the QuEChERS procedure and UHPLC-MS/MS and GC-MS/MS methods. Our 5-year monitoring and survey showed 90% of the 573 samples of kumquat fruits collected from two main production areas contained one or multiple residual pesticides. Overall, 30 pesticides were detected, including 16 insecticides, 7 fungicides, 5 acaricides, and 2 plant growth modulators, of which 2 pesticides were already banned. Two or more residual pesticides were discovered in 81% of the samples, and pesticide residues in 9.4% of the samples surpassed the MRLs, such as profenofos, bifenthrin, triazophos, avermectin, spirodiclofen, difenoconazole, and methidathion. The major risk factors on the safety of kumquat fruits before 2019 were profenofos, bifenthrin, and triazophos, but their over-standard frequencies significantly declined after 2019, which was credited to the stricter supervision and management policies by local governments. Despite the high detection rates and multi-residue occurrence of pesticides in kumquat fruits, about 81% of the samples were assessed as qualified. Moreover, the accumulative chronic diet risk determined from ADI is very low. To better protect the health of customers, we shall formulate stricter organic phosphorus pesticide control measures and stricter use guidelines, especially for methidathion, triazophos, chlorpyrifos, and profenofos. This study provides potential data for the design of kumquat fruit quality and safety control guidelines and for the reduction in health risks to humans.

Cumulative health risk assessment of pesticide residues in apple products in the Northwest of Iran using Monte Carlo simulation

Pesticide residues in fruits and vegetables cause serious health issues, especially among children. This research was carried out to monitor and evaluate the risks of organophosphate pesticide residues in Maragheh County apple products from 2020. The Monte Carlo Simulation approach (MCS) was used to evaluate the non-cancerous effects of exposure to pesticide residues in adults and children. Apple samples were taken every two weeks at the Maragheh central market during the summer and fall months. In this study, seventeen pesticide residues in 30 apple samples were estimated using a modified QuECheRS extraction technique coupled with GC/MS. Of the seventeen organophosphate pesticides, thirteen were identified as pesticide residues (76.47%). The highest concentration found in the apple samples was associated with chlorpyrifos pesticide at 1.05 mg/kg. Pesticide residues exceeding the maximum residue limits (MRLs) were found in 100% of apple specimens, and more than 75% of the samples contained ten or more pesticide residues. Approximately 45%-80% of pesticide residues on apple samples were removed after washing and peeling. Chlorpyrifos pesticide had the highest health quotient (HQ) for men, women, and children with values of 0.046, 0.054, and 0.23, respectively. Cumulative risk assessment (CRA) of non-carcinogenic effects indicates that there is no significant health risk in the adult age group from apple consumption (HI < 1). Nevertheless, children are at high non-cancer risk from eating unwashed apples (HI = 1.3). This finding shows that high levels of pesticide residues in apple samples, especially unwashed apples, can be a serious concern for the health of children. To better protect consumer health, continuous and regular monitoring, strict regulations, training, and awareness of farmers, especially control pre-harvest interval (PHI) is recommended.

Monitoring of pesticide residues in peppers from Çanakkale (Turkey) public market using QuEChERS method and LC-MS/MS and GC-MS/MS detection

Residue analyses were conducted for 283 pesticide active ingredients on pepper samples collected from the local markets (between April and November) of Çanakkale province of Turkey by using QuEChERS method and LC-MS/MS and GC-MS/MS devices. In present pepper samples, 35 different pesticide residues were detected. About 25.0% (27 samples) of present samples had single residue and 43.5% (47 samples) had multiple residues. Of the detected pesticides, acetamiprid, triadimenol, imidacloprid, boscalid, pirimiphos-methyl, tebuconazole, and metalaxyl were the most common ones, while carbendazim/benomyl, fenpropathrin, and thiram were the banned ones. Moreover, 24 of the pesticide residues detected were above the MRL values, 19 pesticides were in the "moderately hazardous (II)," and two pesticides were in the "extremely hazardous (Ib)" class (WHO). Present findings revealed that consumer health may be in danger despite all legal measures by the Ministry of Agriculture and Forestry of Turkey, thus greater emphasis should be put on monitoring of pesticide use and residues.

Monitoring of level of mean concentration and toxicity equivalence (TEQ) of polychlorinated biphenyls (PCBs) in selected vegetables, beans and grains in khanewal and multan, Pakistan

Contamination of food chain by Polychlorinated biphenyls through use of pesticides, electric and industrial waste poses human health risk. In previous studies, PCB species were stated as endocrine disrupting pollutants and showed toxic health effects like cancerous and noncancerous in animals. The aim of this study was to investigate the levels of PCBs and its toxicity equivalence in food item from plant source to evaluate the health risk in Khanewal and Multan, Pakistan. Samples were collected and processed for further analysis of PCB species through GC/MS after extraction and clean up. The mean concentrations of PCBs ranged as 2.71–151.67 ng/g in beans and grains and 2.30–97.00 ng/g dry weight in vegetables and were lower than 200–3000 ng/g PCBs recommended by FDA tolerance level for all foods. The mean concentrations of two NDL-PCB species detected in all vegetables, beans and grains except S.indicum and T.aestivum were lower than maximum allowable concentration of non-dioxin like PCBs i.e. 40ngg⁻¹ reported by European Commission. Mean TEQ of sum of 14 PCB species ranged as 1.52–5.91 ng-WHO-TEQg⁻¹ in vegetables and 1.46–10.04 ng-WHO-TEQg⁻¹ in beans and grains. The present study concluded that the mean concentrations and mean TEQs of PCB species in most of the vegetables, beans and grains were found safe but due to higher consumption rate of some vegetables and grains, posed the moderate level of risk for human health. This study emphasizes on an implement of the strict rules regarding the use of restricted chemicals to diminish the effluence in food chains. Current research will be useful in up gradation of effective measures to reduce the poisonous contribution of PCB sources and the sustainability of terrestrial ecosystem in the country.

Modeling farmers' intention for safe pesticide use: the role of risk perception and use of information sources

Intention for safe pesticide use plays a crucial role in the mode of pesticide spraying, but several factors are involved in the formation of intention by farmers. This work focused on the levels of farmers' perception of pesticide risks (i.e., toxicity levels, health, and environmental effects) and utilization of information sources and examined their impact on intention for safe pesticide use in rural Iran. Most farmers (53%) showed low levels of risk perception by pesticide use and reported poor use of the available information sources about pesticides. Pesticide retailers were mentioned as the primary information point of farmers. In addition, almost half of the farmers (49.2%) expressed worryingly negative intention for safe pesticide use. Perception of pesticide risks and utilization of information sources were significantly correlated with age and spraying experience (P < 0.01), while intention for safe pesticide use was significantly correlated with farming experience (P < 0.05) and spraying experience (P < 0.05). Analysis with structural equation modeling showed that perception of pesticide risks and use of information sources together explained 80% of the variability in farmers' intention. Moreover, perception of pesticide risks (P < 0.01) and employment of information sources (P < 0.05) had a positive relationship with intention for safe handling of pesticides, thus showing a predictive link with intention. Therefore, promoting farmers' perception of pesticide risks and providing credible information sources are essential for improving intention for safe pesticide use among farmers.

Pesticide residues in fruits and vegetables from the southern part of Botswana

This study reports a surveillance of multi-pesticide residues of fruits and vegetables sold in the local markets carried out in 2018-2019 in Botswana to access consumer safety. A validated method for analysis of 232 pesticide residues in fruits and vegetables was applied, based on QuEChERS-GC-MS/MS methodology. A total of 83 fruit and vegetable sold in different markets were bought from three different areas of the southern region . Levels of pesticides ranged between 0.0032 ± 0.0009 mg/kg and 70.4 ± 19.4 mg/kg. A total of 78% of the samples contained pesticide residues, whereas only 13% of the samples violated the EU/Codex MRLs. In particular, rape vegetable samples exceeded legislative limits most, followed by cabbage, green pepper and tomato. The most frequently detected compounds were chlopyrifos, chlorfenapyr, tebuconazole, methamidophos and cypermethrin. These results will serve as a foundation for future studies, involving continuous monitoring programmes.

Occurrence, temporal variation, quality and safety assessment of pesticide residues on citrus fruits in China

Citrus is highly consumed in China and considered a major source of pesticide carrier in human diet. In this paper, pesticide residues in mandarins, tangerines and oranges from China were evaluated, as well as the quality and long-term dietary risks for the Chinese consumers. Temporal variations for eight MRL non-compliant pesticides were also investigated. 106 pesticides were analyzed using QuEChERS procedure and UPLC-MS/MS, GC-MS and GC methods. Forty different pesticides were detected in 86% of the 2922 samples from 2013 to 2018. Chlorpyrifos was the most frequently detected pesticide with a detection rate of 40%. Residues of eight pesticides in 3.8% of the total samples exceeded their MRLs. The most severely excessive pesticide was bifenthrin with 283% MRL. The occurrences and exceeding rates of eight pesticides presented clear temporal variations during the six harvesting years. Isocarbophos, carbofuran and triazophos were the main risk factors threatening the citrus safety pre-2015, whereas profenofos and bifenthrin gradually became dominant after 2016, coinciding with government control measures. The index of quality for residues (IqR) levels of 88% of the samples were below 1.0, which indicated a satisfactory quality of citrus fruits in China, although 70% of the samples contained two or more residues. The cumulative chronic dietary risks were acceptable for both the Chinese general population and children and would not pose health risks. However, more strictly enforced control measures for methidathion and isocarbophos, and reduced usage of triazophos, quinalphos, profenofos and bifenthrin should be pursued to further improve the safety of citrus fruits.

Pesticide residue levels in vegetables and surface waters at the Central Rift Valley (CRV) of Ethiopia

Seven pesticides, profenofos, metalaxyl, λ-cyhalothrin, 4,4'-DDT, 4,4'-DDE, and α- and β-endosulfan, were determined in vegetables (tomato, onion) from 20 locations and surface waters from 12 locations in the Central Rift Valley (CRV) of Ethiopia. Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) and solid phase extraction (SPE) methods were used for the vegetables and water, respectively. In 2.5% of the tomato samples, profenofos was detected above European maximum residue limits (MRLs), in 12.5% of the samples metalaxyl, and in 2.5% α- and β-endosulfan. In 5% of the onion samples, profenofos was detected above European MRLs, in 7.5% of the onion samples metalaxyl, and in 5% λ-cyhalothrin. In surface water, profenofos was detected at the highest concentration of 2300 μg/L in the Bulbula River, 890 μg/L near the agricultural land north of Lake Ziway (ANLZ-1), 1700 μg/L in the floriculture effluent (FE-1), and 900 μg/L in tap water at the Batu Drinking Water (BDW) supply. These results show that the levels of pesticides are in several cases substantially elevated, and emphasize the need of regular pesticide monitoring programs for surface waters and vegetables in the Ethiopian CRV.

Measurement of biorational effect of imidacloprid on some aphids spp. as well as on wheat (Triticum aestivum L.) using biochemical parameters and ISSR-PCR

Aphid species are the most common insect pest infesting wheat plants. The LC values of imidacloprid against aphid spp., ISSR-PCR molecular markers and biochemical parameters in wheat plant in the present study were carried out. The LC₅₀ of imidacloprid on Rhopalosiphum maidis, Rhopalosiphum padi, Sitobion avenae, and Schzaphis graminum were 71.626, 85.853, 91.05, and 115.806, respectively. While, the biochemical parameters in treated wheat plants including; total protein, RNA, and DNA contents increased in all experimental groups. Moreover, total carbohydrates and soluble sugar also increased in treated wheat seedlings. Also, the genetic diversity studies revealed that among six ISSR primers produced 36 amplified DNA fragments in a molecular weight range of (480-1545 bp). About 28 fragments were monomorphic, and 8 fragments were polymorphic. It can be concluded that the effectiveness of imidacloprid against sucking insects in treated wheat plants may due to few genetic variations and some metabolic changes in the Triticum. aestivum. PRACTICAL APPLICATIONS: The current study indicated that the potent efficacy of imidacloprid against different aphid spp. which were the most insect pest in wheat plants. As well as the application of imidacloprid as seed dressing insecticide, significantly increase carbohydrate, protein, amino acids, and RNA content in T. aestivum plants. While there was no significant increase in DNA in treated one. The recorded increase in these biochemical parameters may due to the increase in the gene expressions as a result of the application of such pesticides. These results explain the extra mechanism of the effect of imidacloprid against sucking insects. Also, the conducted results explain the effect of imidacloprid as a seed dressing insecticide in wheat crop protection from sucking insects and increasing seed germination, increasing seed wheat and number of seeds/spike.

Assessment of Antimicrobial and Pesticide Residues in Food Products Sourced from Peasant Family Farming in Chile

The presence of antimicrobial and pesticide residues in products sourced from peasant family farms selected from eight regions of Chile was determined. A total of 204 samples were analyzed from family farm products, including honey, lettuce, tomato, strawberry, raspberry, lamb meat, and cow's milk. Pesticide residues were found in 43 of 107 samples tested for them, but only 4 samples had concentrations that exceeded the maximum residue limits (MRLs) set by Chilean regulations. As for animal products, 2 of 15 cow's milk samples tested positive for permethrin residues; however, these concentrations did not exceed Chilean MRLs. No pesticide residues were detected in honey samples. As for antimicrobial drugs, 4 of 14 lamb meat samples and 11 of 79 cow's milk samples tested positive for different classes of antimicrobial residues, such as tetracyclines, macrolides, aminoglycosides, and β-lactams. Among these, only three samples exceeded the MRLs for these matrices. Traces of tetracyclines and sulfonamides were detected in 7 of 29 honey samples. These findings show that these chemical contaminants are present in trace concentrations in foodstuffs produced by peasant family farms in Chile; however, most residues did not exceed the regulatory limits. This study is the first assessment of the presence of residues from antimicrobial drugs and pesticides in food products sourced from peasant family farms in Chile. Data about the current state of drug residues in this segment of food products provide a baseline for efforts to close possible gaps in current surveillance schemes.

Heavy metals content in some non-alcoholic beverages (carbonated drinks, flavored yogurt drinks, and juice drinks) of the Egyptian markets

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The studied samples (juices, flavored yogurts and carbonated drinks) were mostly free of Pb, Cd and Cr.

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Concentrations of Fe, Mn and Ni were above the recommended permissible limits in most of the beverage samples.

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Canned beverages were most contaminated by toxic elements as compared to the plastic bottled beverages.

Heavy metals are elements present in trace quantities in the environment and, in small concentrations, they play important roles for the living organisms yet it can cause toxicity if exceeded the recommended levels. Toxic metals contamination is an important environmental problem that was mainly manifested in the growing industrial cities where the levels in toxic metals exceeded the recommended levels leading to the increase of several health problems (that vary from memory disorder to carcinogenic diseases). The main sources of food contamination by toxic metals are the increase in petroleum fuels exhausts and the addition of fertilizers and metal-based pesticides during farming processes. Nowadays, the non-alcoholic drinks represent one of the highest consumption groups worldwide especially in the Middle East and Islamic countries. The current work aims to investigate the safety of some non-alcoholic beverages (carbonated drinks, flavored yogurt drinks and juice drinks) from toxic metal contamination in the Egyptian market. The study revealed that non-alcoholic beverage samples (juices, flavored yogurts and carbonated drinks) in the Egyptian market are mostly free of lead (Pb), cadmium (Cd) and chromium (Cr) contamination. On the other hand, the results of current beverage samples indicate that iron (Fe), manganese (Mn) and nickel (Ni), except Mn in juices and carbonated drinks, were presented in concentrations above the recommended permissible limits of both the World Health Organization (WHO) and Egyptian Ministry Health (EMH). Meanwhile, Cu was found in concentrations below the recommended permissible limits.