Behaviour of mesotrione in maize and soil system and its influence on soil dehydrogenase activity

Dietary risk assessment of children and adults consuming fruit and vegetables with multiple pesticide residues

Fruit and vegetables are a basic component of the human diet. European pesticide monitoring data indicated recently that in one sample multiple residues were detected which might be a public concern. Thus, the challenge of the present study was to assess the potential dietary exposure of the most critical EU children and adults subpopulations consuming fruit and vegetables. Overall, a total of 1182 samples 333 fruit and 849 vegetable samples from Polish production were monitored for the presence of 550 active substances during 2021-2023. Multiple pesticide occurrence was as follows: 2021-8%; 2022-12%; 2023-10%. In individual sample up to 11 pesticides were simultaneously detected in the range of 0.0052 mg kg-1 (fenpyroximate) - 7.10 mg kg-1 (difenoconazole). The top detected active substance was acetamiprid (neonicotinoid insecticide) and boscalid (carboxamide fungicide). The risk assessment occurring during a single day/meal to 28 detected pesticides was calculated. Acute exposure was low for fruit samples, despite a high frequency of many pesticides, e.g. cherries containing 11 pesticides (i.e. cyantraniliprole 35.5% ARfD for children, lambda-cyhalothrin 73.4% ARfD for adults). In the vegetable group, one dill sample containing not-approved chlorpyrifos could pose a risk to children (120.0% ARfD). Unacceptable risk to children's health (% ARfD>100) was assessed for a lettuce sample with 9 pesticides, including endocrine disruptors pyrethroids i.e. cypermethrin and deltamethrin. The model based on the worst-case scenario provided a margin for consumer safety. The approach showed that fruit and vegetables with multiple residues could not be considered a serious public health problem.

Acute oral toxicity and genotoxicity assessment of the essential oil from Croton pulegiodorus Baill (Euphorbiaceae) leaves in mice

Essential oils obtained from Croton pulegiodorus leaf are renowned for their biological activities; however, data on their toxicity are limited. Therefore, this study aimed to evaluate the acute oral toxicity and genotoxicity of a C. pulegiodorus leaf essential oil (CPLEO). Chemical characterization of CPLEO was conducted by gas chromatography coupled to mass spectrometry (GC-MS). In vitro assay was performed to verify the hemolytic capacity of the oil in mice erythrocytes. Next, an acute oral toxicity study was conducted on female mice at CPLEO doses of 2000, 1000, 500, 250, 100, and 50 mg/kg. Hematological, biochemical, and histopathological markers were assessed in mice from groups were no death occurred. Relative consumption of water and food and the weight of animals and their organs were also recorded. Finally, a genotoxicity analysis was performed using the micronucleus and comet assays. The extraction yield of CPLEO was 1.149% and its major compounds were ascaridole (23.18%), eucalyptol (17.20%), camphor (14.20%), p-cymene (7.91%), α-terpineol (4.69%), and isobornyl acetate (4.57%). CPLEO showed a hemolytic effect only at high concentrations (185.5-1000 mg/mL). It showed acute oral toxicity in mice with a LD50 of 460.42 mg/kg. CPLEO (50-250 mg/kg) caused some significant changes in hematological and biochemical parameters. Histopathological evaluation indicated alterations in liver and kidneys but transaminases, urea and creatinine levels remained like the negative control. CPLEO administration impaired weight gain and reduced water and food consumption. Finally, it was not genotoxic by both comet and micronucleus tests. The results highlight the need for attention when choosing doses to evaluate the bioactivities of CPLEO.

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.

Mehri KO, Pisharath VA, Holley R, Obaid RS. Pesticide residues in fresh fruits imported into the United Arab Emirates

Pesticides are a major public health issue connected with excessive use because they negatively impact health and the environment. Pesticide toxicity has been connected to various human illnesses by means of pesticide exposure in direct or indirect ways. A total of 4513 samples of imported fresh fruits were collected from Dubai ports between 2018 to 2020. Their contamination by pesticides was evaluated using gas chromatography combined with mass spectrometry (GC-MS/MS) and liquid chromatography-mass spectrometry (LC-MS/MS). The display of monitoring results was based on the Maximum Residue Limit (MRL) standard as per the procedures of the European Union. Eighty-one different pesticide residues were detected in the tested fruit samples. In 73.2% of the samples, the pesticide levels were ≥ MRL, while 26.8% were > MRL standards. Chlorpyrifos, carbendazim, cypermethrin, and azoxystrobin were the most frequently detected pesticides in more than 150 samples. Longan (81.4%) and rambutan (66.7%) showed the highest number of imported samples with multiple pesticide residues > MRL. These results highlight the need to continuously monitor pesticide residues in fruits, particularly samples imported into the United Arab Emirates (UAE). Fruit samples with residues > MRL are considered unfit for consumption and prevented from entering commerce in the UAE.

Human health risk assessment of pesticide residues in vegetable and fruit samples in Gujarat State, India

The present study was initiated with the purpose to evaluate possible health risks associated with pesticide residues through consumption of vegetables and fruits by general population of Gujarat, India. A total of 1075 samples comprising of twelve different varieties of commonly consumed food commodities were collected from twenty-five divergent locations in Gujarat. The collected samples were extracted using QuEChERS method and analyzed for the presence of organophosphorus (OPs), organochlorine (OCs) and synthetic pyrethroids (SPs) pesticides using UHPLC-HR/MS, GC-μECD and GC-MS/SIM. The results indicated that 2.3% of vegetable and fruit samples showed the presence of pesticide residues exceeding maximum residue limits (MRLs). The results suggested that, detected residue levels in samples were within safe limits and their consumption will not pose any significant health risk to human. The outcomes present significant information regarding the status of vegetable and fruit contamination and pointed out the prerequisite for further studies with reference to monitoring of pesticides and other toxic contaminants in different samples for assessing cumulative health risk.

Single and joint toxicity assessment of acetamiprid and thiamethoxam neonicotinoids pesticides on biochemical indices and antioxidant enzyme activities of a freshwater fish Catla catla

Neonicotinoids pesticides are extensively used in many countries due to their high insect selectivity. Acetamiprid and thiamethoxam are the neonicotinoids most commonly detected in the aquatic environment. This work examined the single and joint toxicity of acetamiprid and thiamethoxam in a freshwater fish Catla catla. Fish were exposed to acetamiprid (0.5 mg/L and 1 mg/L), thiamethoxam (0.01 mg/L and 0.5 mg/L) and their binary mixtures (0.5 mg/L of acetamiprid and 0.01 mg/L of thiamethoxam) for 96 h. The stress biomarkers such as glucose, protein, electrolytes, Na⁺/K^{+ -}ATPase and oxidative stress were evaluated. Among the biochemical parameters, plasma protein, electrolytes (sodium, potassium and chloride) and gill ATPase activity were decreased in response to individual and binary mixtures treatments. In contrast, blood glucose level showed significant increase in all the treatments. Exposure to various concentrations of acetamiprid and thiamethoxam resulted in significant decrease in superoxide dismutase (SOD) activity in the gill tissue. However, SOD activity was significantly elevated during binary mixtures treatment. Glutathione peroxidase (GPx), catalase (CAT), glutathione-S-transferase (GST) and reduced glutathione (GSH) levels in gills were decreased significantly after individual and binary mixtures treatments. Fish exposed at individual and binary mixtures significantly elevated the level of LPO in gill tissue. Our findings suggest that multi-biomarker approach can be effectively used to assess the effects of joint toxicity of pesticides and to monitor the neonicotinoids pesticides in the aquatic environment.

Photocatalytic Detoxification of Some Insecticides in Aqueous Media Using TiO2 Nanocatalyst

The present study was performed to fabricate a titanium dioxide (TiO2) nanocatalyst with proper characteristics for the removal of some insecticides (dimethoate and methomyl) from aqueous media. A TiO2 catalyst of regular (TiO2-commercial-/H2O2/UV) or nano (TiO2-synthesized-/H2O2/UV) size was employed as an advanced oxidation process by combining it with H2O2 under light. Moreover, the total detoxification of insecticides after treatment with the most effective system (TiO2(s)/H2O2/UV) was also investigated through exploring the biochemical alterations and histopathological changes in the liver and kidneys of the treated rats. Interestingly, the present study reported that degradation rates of the examined insecticides were faster using the TiO2 catalyst of nano size. Complete degradation of the tested insecticides (100%) was achieved under the TiO2(s)/H2O2/UV system after 320 min of irradiation. The half-life values of the tested insecticides under H2O2/TiO2(c)/UV were 43.86 and 36.28 for dimethoate and methomyl, respectively, whereas under the H2O2/TiO2(c)/UV system, the half-life values were 27.72 and 19.52 min for dimethoate and methomyl, respectively. On the other hand, no significant changes were observed in the biochemical and histopathological parameters of rats administrated with water treated with TiO2(s)/H2O2/UV compared to the control, indicating low toxicity of the TiO2 nanocatalyst-. Altogether, the advanced oxidation processes using TiO2 nanocatalyst can be considered as a promising and effective remediation technology for the complete detoxification of methomyl and dimethoate in water. However, further future research is needed to identify the possible breakdown products and to verify the safety of the used nanomaterials.

Determination of inorganic arsenic, heavy metals, pesticides and mycotoxins in Indian rice (Oryza sativa) and a probabilistic dietary risk assessment for the population of Saudi Arabia

In this study, total arsenic (As), inorganic arsenic (iAs), cadmium (Cd), lead (Pb), mercury (Hg), pesticides, and aflatoxins (B1, B2, G1, G2) in Indian rice (Oryza sativa) and their dietary exposure risks for the general Saudi population were evaluated. A total of 483 samples were acquired from various ports and supermarkets throughout the country. Average elemental concentrations were found to be in the following order: As (0.1 ± 0.024)>iAs (0.038 ± 0.015)>Pb (0.023 ± 0.008)>Cd (0.019 ± 0.005)>Hg (0.002 ± 0.0004), and results did not exceed maximum residue limits (MRLs). Out of the 294 analyzed pesticides, 15 were detected in rice, of which six were fungicides, and nine were insecticides with a detection frequency of 22% and 26%, respectively. Eight of the detected pesticides were non-approved by the European Union (EU) commission, but their detection frequencies were low. Surprisingly, rice samples analyzed for aflatoxins were below the limit of quantification (LOQ). Risk assessment coupled with Monte Carlo simulation based on the hazard quotient (HQ) and incremental lifetime cancer risk (ILCR) approaches revealed that exposure to metal(loid)s and pesticides in rice were below levels that might pose a health risk.

Determination and dietary risk assessment of 284 pesticide residues in local fruit cultivars in Shanghai, China

The presence of pesticide residues has become one of the main risk factors affecting the safety and quality of agro-food. In this study, a multi-residue method for the analysis of 284 pesticides in five local fruit cultivars in Shanghai was developed based on ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS). The limits of determination and the limits of quantitation of pesticides were 0.6–10 and 2–30 μg/kg, respectively. A total of 44, 10, 10, 18, and 7 pesticides were detected in strawberries, watermelons, melons, peaches, and grapes, respectively. The pesticide levels in 95.0% of the samples were below the maximum residual limits (MRLs) prescribed by China, and in 66.2% of the samples below the EU MRLs. The dietary risk assessment study showed big differences in the chronic and acute exposure risk values among different Chinese consumer groups. Through fruit consumption, children/females showed higher exposure risks than adults/males. But both the risk values were less than 100%, indicating that potential dietary risk induced by the pesticides was not significant for Chinese consumers. Nevertheless, certain measures are needed for both growers and the government in order to decrease the MRL-exceeding rate of pesticide residues and ensure the quality and safety of fruits for consumers.

Vanadium contamination and associated health risk of farmland soil near smelters throughout China

Whereas there is broad consensus that smelting causes serious soil contamination during vanadium production, little is known about the vanadium content of soil near smelters and the associated health risk at continental scale. This study is the first to map the distribution of vanadium in farmland soil surrounding smelters throughout mainland China, and assess the associated health risk. Analysis of 76 samples indicated that the average vanadium content in such soil was 115.5 mg/kg - far higher than the 82 mg/kg background content in China (p < 0.05). Southwest China (198.0 mg/kg) and North China (158.3 mg/kg) possessed highest vanadium contents. Vanadium content was strongly related to longitude, altitude, and atmospheric temperature. The reducible fraction accounted for the largest percentages in vanadium speciation. The average Pollution Load Index for all samples was 1.51, denoting significant metal enrichment. The Children's hazard index was higher than unity, indicating elevated health risk. The relative contribution of vanadium to the total health risk ranged from 6.02% to 34.5%, while nickel and chromium were the two main contributors in most regions. This work may serve as a model providing an overview of continental vanadium contamination around smelters, and draw attention to their possible health risks.

Assessing dietary exposure risk to neonicotinoid residues among preschool children in regions of Taiwan

Neonicotinoids (NEOs) are a class of pesticides widely used worldwide. This study analyzed post-cooking residues of NEO pesticides and assessed their potential health risks for preschool children (0-6 years old) by conducting a total diet study (TDS). It involved food sampling, preparation, analysis of pesticide residues, estimation of food consumption data, and assessment of food safety risks. Food sampling was conducted between March and June 2015. A total of 128 food samples were obtained from 4 parts of Taiwan. After the food had been prepared, the 128 samples were aggregated into 32 composite food items and the NEO residues analyzed. Acetamiprid had the highest detection rate of the NEO residues (59.4%), and the concentrations ranged from not detected to 80.5 μg/kg. The estimated daily intake (EDI) of NEO residues among preschool children was found to be lower than the adjusted acceptable daily intake (ADI) even for highly exposed groups. The results showed that NEO pesticides were primarily detected in preserved fruits, cherry tomato, rape, bell fruit, and baby bok choy. The main health risk posed by detected NEO residues at high consumption rates for preschool children was attributed to acetamiprid (34.20 %ADI) and imidacloprid (23.69 %ADI), respectively. Therefore, this research implicates that the present level of NEO residues in the diets for preschool children in Taiwan does not exceed 100 %ADI.

Comprehensive toxicological study over 160 processing factors of pesticides in selected fruit and vegetables after water, mechanical and thermal processing treatments and their application to human health risk assessment

The challenge of the present comprehensive toxicological study was to evaluate water, mechanical and thermal processing factors (PFs) of twenty four pesticides (acetamiprid, alpha‑cypermethrin, azoxystrobin, boscalid, bupyrimate, chlorpyrifos, chlorothalonil, cyprodinil, deltamethrin, difenoconazole, fenazaquin, fenhexamid, fludioxonil, folpet, iprodione, lambda‑cyhlothrin, metalaxyl, pirymicarb, propargite, pyraclostrobin, tetraconazole, tiophanate methyl, thiram, trifloxystrobin) in different fruit and vegetables and estimate health risk for adults and children. The water (PF = 0,09-0,94), mechanical (PF = 0,13-0,32) and thermal (PF = 0,02-0,57) technology significantly or completely reduced concentrations of twenty one active substances in broccoli, tomatoes, strawberries and black currants. Pyrethroid insecticides (alpha‑cypermethrin, deltamethrin and lambda‑cyhalothrin) exhibited PF above one in berries influenced by high temperatures. Comprehensive processing factor database technology/pesticide/matrix (over 160 PFs) for 24 pesticides in selected fruit and vegetable species after different processing treatments was created. This paper for the first time compares health risk assessments of acute and chronic of two subpopulations of adults and the most critical group of small children using two mathematical models, without (I) and with including (II) calculated PF values. More realistic estimation of the dietary intakes of the pesticides was achieved using PFs. The hazard quotients (HQs) estimated from chronic and acute dietary exposure (Model l) were above 20% and after intake correction (Model II) were reduced to HQs = 11.5% after water, 3% mechanical and 9.5% thermal treatment.

Estimating acute and chronic exposure of children and adults to chlorpyrifos in fruit and vegetables based on the new, lower toxicology data

This paper presents, for the first time, results for chlorpyrifos (CHLP) in Polish fruits and vegetables over the course of a long period of research, 2007-2016, with toxicological aspects. The challenge of this study was to re-evaluate the impact of chlorpyrifos residues in fruit and vegetables on health risk assessed via acute and chronic exposure based on old and new, lower, established values of: Average Daily Intakes (ADIs)/Acute Reference Doses (ARfDs) and Maximum Residue Levels (MRLs). A total of 3 530 samples were collected, and CHLP in the range of 0.005-1.514 mg/kg was present in 10.2% of all samples. The MRL was exceeded in 0.7% of all samples (MRL established in 2009-2015), and recalculation yielded a much greater number of violations for the new MRL (2016), which exceeded 2.9% of all samples. Acute exposure to CHLP calculated according to the old, higher toxicological data (0.10 mg/kg bw/day), does not exceed 14% of its respective ARfDs for adults and both groups of children, but when calculated for incidental cases according to the current value (ARfD 0.005 mg/kg bw) for infants and toddlers, was above 100% of its respective ARfDs in: white cabbage (263.65% and 108.24%), broccoli (216.80% and 194.72%) and apples (153.20% and 167.70%). The chronic exposure calculated for both newly established ADI values (0.001 mg/kg bw/day and 0.100 mg/kg bw/day) appears to be relatively low for adults and children.

Aggregating exposures & cumulating risk for semivolatile organic compounds: A review

Increasingly, health risk assessment is addressing multiple pathway exposures to multiple contaminants. We reviewed aggregated exposure and cumulative risk approaches for contemporary and ubiquitous semivolatile organic compounds (SVOC). We identified 22 studies aggregating exposure pathways, and 31 cumulating risk. Exposure aggregation is based on the addition of pathway-specific doses, using kinetic modeling where it exists, and classic external dose equations otherwise. In most cases, exposure is dominated by a single route or source of exposure - mainly the oral pathway - via dietary or non-dietary exposure. Preferential routes and sources of exposure are influenced by SVOC physical-chemical properties such as vapor pressure. The cumulative risk approach for contaminants is based on dose addition. Simple sum of hazard quotient (Hazard Index: HI) is the most commonly used cumulative risk assessment approach, while Relative Potency Factor (RPF) appeared to the best suited - although this calls for a level of toxicological information that limits the number of compounds that can be studied simultaneously. Where both were performed, moving from HI to more refined approach produced similar results. In conclusion, both approaches - exposure aggregation and cumulative risk - rely on simple assumptions. Nevertheless, they allow uncertainty to be reduced, in comparison with source-by-source or chemical-by-chemical approaches.

Dissipation of S-metolachlor in plant and soil and effect on enzymatic activities

The present study aimed at evaluating the dissipation of S-metolachlor (S-MET) at three doses in maize growing on diverse physico-chemical properties of soil. The effect of herbicide on dehydrogenase (DHA) and acid phosphatase (ACP) activity was estimated. A modified QuEChERS method using LC-MS/MS has been developed. The limit of quantification (0.001 mg kg^-1) and detection (0.0005 mg kg^-1) were very low for soil and maize samples. The mean recoveries and RSDs for the six spiked levels (0.001-0.5 mg kg^-1) were 91.3 and 5.8%. The biggest differences in concentration of S-MET in maize were observed between the 28th and 63rd days. The dissipation of S-MET in the alkaline soil was the slowest between the 2nd and 7th days, and in the acidic soil between the 5th and 11th days. DT₅₀ of S-MET calculated according to the first-order kinetics model was 11.1-14.7 days (soil) and 9.6-13.9 days (maize). The enzymatic activity of soil was higher in the acidic environment. One observed the significant positive correlation of ACP with pH of soil and contents of potassium and magnesium and negative with contents of phosphorus and organic carbon. The results indicated that at harvest time, the residues of S-MET in maize were well below the safety limit for maize. The findings of this study will foster the research on main parameters influencing the dissipation in maize ecosystems.

Dissipation of chlorantraniliprole, chlorpyrifos-methyl and indoxacarb-insecticides used to control codling moth (Cydia Pomonella L.) and leafrollers (Tortricidae) in apples for production of baby food

Dissipations of three insecticides: chlorantraniliprole, chlorpyrifos-methyl and indoxacarb in apples were studied following their foliar application on apples intended for production of baby food. The apples were sprayed with formulations for control of codling moth (Cydia Pomonella L.) and leafrollers (Tortricidae). Six experiments were conducted; each insecticide was applied individually on dessert apples. A validated gas chromatography-based method with simultaneous electron capture and nitrogen-phosphorus detection (GC-ECD/NPD) was used for the residue analysis. The analytical performance of the method was satisfactory, with expanded uncertainties ≤36% (a coverage factor, k = 2, and a confidence level of 95%). The dissipations of insecticides were studied in pseudo-first-order kinetic models (for which the coefficient of determination, R ² , ranged between 0.9188 and 0.9897). Residues of studied insecticides were below their maximum residue limits of 0.5 mg/kg at an early stage of growth of the fruit. The half-lives of chlorantraniliprole, chlorpyrifos-methyl and indoxacarb were 16-17, 4-6 and 20-24 days, respectively. The initial residue levels declined gradually and reached the level of 0.01 mg/kg in 1 month for chlorpyrifos-methyl, 2 months for chlorantraniliprole and 2.5 months for indoxacarb. To obtain the insecticide residue levels below 0.01 mg/kg, which is the default MRL for food intended for infants and young children, the application of the studied insecticides should be carried out at recommended doses not later then: 1 month before harvest for chlorpyrifos-methyl, 2 months for chlorantraniliprole and 2.5 months for indoxacarb.