Acute Dietary Risk Research Articles

Residue levels and dietary risk assessment of fluopimomide, pyraclostrobin and its metabolite BF-500-3 in garlic ecosystems under field conditions.

To evaluate the residue levels of fluopimomide, pyraclostrobin and its metabolite BF-500-3 in garlic ecosystems, supervised garlic field trials with a commercial formulation (pyraclostrobin·fluopimomide 30% suspension concentrate (SC)) were conducted in six regions of China according to the Good Agricultural Practices (GAP). The residues of fluopimomide, pyraclostrobin and BF-500-3 in field samples were determined using a QuEChERS method combined with high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The average recoveries of all target compounds were 76-94% with relative standard deviations (RSDs) of 1.0-14.5% and limits of quantitation (LOQs) of 0.002mg/kg. At the recommended pre-harvest interval (PHI, 10days), the residues of fluopimomide, pyraclostrobin and BF-500-3 were below 0.16, 0.77 and 0.12mg/kg in garlic chive; below 0.027, 0.22 and 0.002mg/kg in garlic scape; and below 0.002, 0.002 and 0.002mg/kg in garlic, respectively. Dietary intake risks were calculated using risk quotients (RQs) based on field residual data, toxicological data and dietary patterns. The chronic dietary risk quotients (RQc) of pyraclostrobin and fluopimomide were 48.42% and 0.36%, respectively. The acute dietary risk quotients (RQa) of pyraclostrobin in garlic were 0.06-0.15%. These results indicated a low dietary risk for consumers. This study could provide scientific guidance for the application of pyraclostrobin and fluopimomide in garlic.

Residue levels and risk assessment of pesticides in litchi and longan of China

A total of 57 pesticide residues were analyzed in 155 litchis and 153 longan samples collected from the three main producing provinces of China. They were studied by the QuEChERS extraction method based on analysis using ultra performance liquid chromatography–triple quadrupole mass spectrometry (UPLC–MS/MS) and gas chromatography (GC) techniques. Health risks from litchis and longans for humans were evaluated by hazard quotient (HQ) and hazard index (HI). Sixteen different pesticides were detected in litchi samples. In longan samples, 19 different pesticides were detected. A total of 72% litchi samples and 52% longan samples contained at least one pesticide residue. Carbendazim, chlorbenzuron and diflubenzuron were found in 25.2%, 28.4%, and 34.8% of the litchi samples, respectively, and 21.6%, 11.8%, and 21.6% of the longan samples, respectively. The banned pesticides carbofuran and omethoate were detected in two litchi samples and one longan sample, respectively. Residue concentrations did not exceed the maximum residue levels (MRLs) in all litchi and longan samples except for carbofuran. Dietary risk assessment results showed that the chronic and acute dietary risks (HQc and HQa) of individual pesticides and the cumulative chronic dietary risks (HIc) of all pesticide residues for adults and children were all less than 100%. However, the cumulative acute dietary risk (HIa) of all pesticide residues from litchi samples for children was 99.85%, which was close to the unacceptable level and should be given more attention. The contributions of insecticide to HIc and HIa were 89.3% and 87.3% in litchi samples and 91.7% and 55.0% in longan samples.

Dissipation behavior, residue transfer, and safety evaluation of chlorantraniliprole and indoxacarb during tea growing and brewing by ultrahigh-performance liquid chromatography-tandem mass spectrometry.

A reliable and simple analytical method was developed and validated to simultaneously determine chlorantraniliprole and indoxacarb in tea using ultrahigh-performance liquid chromatography-tandem mass spectrometry. The average recoveries of chlorantraniliprole were in the range of 86-110%, with the precision of intraday (n = 5) and interday (n = 15) ranging from 1.9 to 8.4% and from 2.4 to 8.8%, respectively. The average recoveries of indoxacarb were in the range 81-105%, with the precision of intraday (n = 5) and interday (n = 15) ranging from 2.0 to 9.8% and from 2.7 to 9.1%, respectively. The limits of quantification (LOQs) were all 0.01mg/kg. The results based on the supervised field trials showed that chlorantraniliprole and indoxacarb in two tea samples followed first-order kinetics models with half-lives of 2.2-4.7days and 2.5-3.5days, which could be regarded as a moderately degrading pesticide. The terminal residues of chlorantraniliprole and indoxacarb in made tea were below 6.7 and 4.5mg/kg, respectively, lower than their corresponding maximum residue limits (MRLs) established by several major countries and organizations (50 and 5mg/kg). The leaching rates of chlorantraniliprole and indoxacarb during the tea brewing ranged from 4.78 to 12.62% and 4.13 to 10.67%, respectively. The chronic intake risk quotient (RQc) values for chlorantraniliprole and indoxacarb were 0.24% and 35.10%, while the acute dietary risk assessment (RQa) value of indoxacarb was 5.8%, which were all much lower than 100%. The results in the present study indicated that the health risk posed by the chlorantraniliprole and indoxacarb mixture pesticides was negligible in tea for consumers at the recommended dosages.

Dissipation Behavior and Acute Dietary Risk Assessment of Thiamethoxam and Its Metabolite Clothianidin on Spinach.

Thiamethoxam and its metabolite clothianidin residues pose a potential threat to human health. This study aims to investigate the residue behavior and acute dietary risk assessment of thiamethoxam and clothianidin on spinach. Thiamethoxam and clothianidin were extracted using a quick, easy, cheap, effective, rugged, safe (QuEChERS) method and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). At spike levels from 0.01 to 5 mg kg−1, the average recoveries of both analytes were in the range of 94.5–105.5%, with relative standard deviations (RSDs) of 3.8–10.9%. The dissipation behavior of thiamethoxam followed first-order kinetics, with half-lives of ≤1.6 days. Clothianidin appeared readily as a plant metabolite with highest level exhibited during 3 to 5 days after application. Temperature and light may be two main factors for degradation of thiamethoxam. Besides, acute risk assessment of thiamethoxam and clothianidin was evaluated with risk quotients (RQs) <100%, which suggested a low health risk for all consumer groups of Chinese residents.

Residual levels and dietary risk assessment of bifenthrin and dinotefuran and its major metabolites in open wheat field conditions.

To evaluate the residual levels of bifenthrin and dinotefuran, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) and high-performance liquid chromatography-tandem mass spectrometry method for simultaneous detection of bifenthrin and dinotefuran and its major metabolites in wheat was developed and validated. Dietary risk assessments were further performed based on the relevant residual data from 12 wheat fields, toxicology data and dietary patterns. In wheat grain and straw, the recoveries of all analytes ranged from 77 to 102% with the relative standard deviation <9.7% and the limit of quantitation 0.05 mg kg-1 . The highest terminal residue of bifenthrin in wheat grain was 0.069 mg kg-1 and dinotefuran was 0.34 mg kg-1 . Residual concentrations of bifenthrin and dinotefuran decreased to <0.05 and 0.15 mg kg-1 at 21 days (pre-harvest interval), respectively. The chronic risk quotient ranged from 6.4 to 62.7% and the acute risk quotient varied from 0.38 to 17.73%. The chronic and acute dietary risks caused by the terminal residues of the two insecticides were negligible for Chinese populations. The recommended pre-harvest interval was proposed to ensure safe wheat consumption. These data could provide a scientific reference to establish the Chinese maximum residue limit of dinotefuran in wheat.

Pesticide Residue Behavior and Risk Assessment in Celery after Se Nanoparticles Application.

This study investigates pesticide levels in celery, and compares their degradation, dissipation, distribution, and dietary risk after spraying with selenium (Se) nanoparticles. Abamectin, imidacloprid, acetamiprid, thiamethoxam, and lambda-cyhalothrin were sprayed at 1.6, 6.8, 2.0, 1.0, and 0.7 g a.i. ha−1 followed by a 2 g·ha−1 Se nanoparticle application during the growing period. Thiamethoxam, abamectin, imidacloprid, lambda-cyhalothrin, and acetamiprid in celery degraded following a first order kinetic model after 2 g·ha−1 Se nanoparticles application. With the exception of acetamiprid, the half-lives of thiamethoxam, abamectin, imidacloprid, and lambda-cyhalothrin were reduced from 2.4, 0.5, 1.2, 4.2 days without Se nanoparticles application to 1.4, 0.2, 0.9, 3.7 days with the addition of Se nanoparticles (2 g·ha−1), respectively. The chronic dietary exposure risk probability (RQc) and the acute dietary exposure risk probability (RQa) of celery after Se nanoparticles application were within acceptable limits for consumption except for abamectin.

Dietary Risk Assessment and Ranking of Multipesticides in Dendrobium officinale

The presence of pesticide residues in Dendrobium officinale (D. officinale), a commonly used herbal medicine, has attracted much attention in recent years. Therefore, this study presents the levels of 141 pesticide residues in forty D. officinale samples, which were measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). And we used a deterministic estimate model to assess chronic and acute dietary exposure risk, as well as the cumulative risks for adults, children, and specific groups of consumers. Furthermore, the residual risk of individual pesticides was sorted by adapting the matrix-ranking scheme. In 92.5% of the samples, 43 pesticides were detected, of which difenoconazole had the highest detection frequency. Multiple residues were detected in 85.0% of the samples, and one sample contained even up to 17 pesticides. The chronic hazard quotient (HQc) and the acute hazard quotient (HQa) were far below 100%, and both cumulative chronic and acute hazard indices (HI) did not exceed 100%. The risk scoring scheme showed that four pesticides were considered to pose a comparatively potential high risk, including difenoconazole, carbofuran, fipronil, and emamectin benzoate. The results indicated that the occurrence of pesticide residues in D. officinale could not pose a serious health problem to the public.

Residual dynamics and dietary exposure risk of dimethoate and its metabolite in greenhouse celery.

This study aimed to explore the residual dynamics and dietary risk of dimethoate and its metabolite omethoate in celery. Celery was sprayed with 40% dimethoate emulsifiable concentrate (EC) at either a low concentration of 600 g a.i./ha or a high concentration of 900 g a.i./ha. Plants in the seedling, transplanting, or middle growth stages were sprayed once, and the samples were collected 90 days after transplantation. Plants in the harvesting stage were sprayed two or three times. The samples were collected on days 3, 5, 7, 10, 14 and 21 after the last pesticide application. The dimethoate and omethoate compounds were extracted from the celery samples using acetonitrile, and their concentrations were detected using ultra-performance liquid chromatography-tandem mass spectrometry. Also, the dietary risk assessments of dimethoate and omethoate were conducted in various populations and on different foods in China. The metabolism led to the formation of omethoate from dimethoate in the celery. The degradation dynamics of dimethoate and total residues in greenhouse celery followed the first-order kinetic equation. The half-lives of the compounds were 2.42 days and 2.92 days, respectively. The celery which received one application during the harvesting stage had a final residue of dimethoate after 14 days, which was lower than the maximum residue limit (MRL) 0.5 mg kg−1 for Chinese celery. The final deposition of the metabolite omethoate after 28 days was less than the maximum residue limit of 0.02 mg kg−1 for Chinese celery. Furthermore, the risk quotients of dimethoate in celery were less than 1; therefore, the level of chronic risk was acceptable after day 21. Only children aged 2–7 years had an HQ of dimethoate more than 1 (an unacceptable level of acute risk), while the acute dietary risks to other populations were within acceptable levels. It was recommended that any dimethoate applications to celery in greenhouses should happen before the celery reached the harvesting stage, with a safety interval of 28 days.

Dissipation behavior, residue dynamics, and dietary risk assessment of forchlorfenuron in postharvest kiwifruits during simulated cold chain logistics and store shelf life.

Forchlorfenuron (CPPU) is often applied during the cultivation of kiwifruit to produce larger fruit. To address degradation patterns of CPPU during simulated cold chain logistics and simulated shelf life of the fruit after harvest, appropriate storage methods and safe consumption behavior can be investigated. In this study, an ultra-high-performance liquid chromatography-tandem mass spectrometry method was adopted to detect CPPU residues under different conditions. CPPU in kiwifruit stored at 6°C had a half-life of 40.8-77.0days. However, when kiwifruit was stored at 0°C under simulated cold chain storage conditions, the half-life of CPPU was 63.0-115.5days, implying that lower storage temperatures can reduce the degradation rate of CPPU. The residues of CPPU in kiwifruit pulp declined with time, and the reduction followed the first-order kinetics equation. More CPPU residues were present in the pulp of postharvest kiwifruit treated with exogenous ethylene than in the pulp of untreated kiwifruit. Thus, using exogenous ethylene for artificial ripening after harvest is not recommended. We determined that the appropriate cold chain storage temperature is 6°C. It is recommended that the public select kiwifruit stored for at least 2weeks. The estimated chronic and acute dietary risk quotients of CPPU are ≤ 0.79% and ≤ 0.11%, respectively. Therefore, it is highly unlikely that consumers will be poisoned by CPPU due to kiwifruit consumption. Our results provide scientific evidence regarding the adoption of appropriate kiwifruit storage methods and consumption behavior to enhance consumption safety.

Dissipation and distribution of pyraclostrobin in bananas at different temperature and a risk assessment of dietary intake

ABSTRACT In this study, the safety and risk of pyraclostrobin as an indoor fungicide against banana anthracnose were evaluated for the first time. The dissipation and distribution of pyraclostrobin for 14 days in banana peel and pulp were determined and studied by HPLC after simple, rapid pre-treatment at different indoor temperatures. The mean recovery was 83.46 ~ 95.67%, and the relative standard deviation was 4.01 ~ 10.99%. Results showed that the half-lives of pyraclostrobin in peel and pulp were 8.1 days (25°C), 12.4 days (12°C) and 12.8 days (25°C), 16.1 days (12°C). During the whole storage period of banana after application of pesticide, the residue of banana pulp was lower than the maximum residue level established in China. The potential risk of pyraclostrobin exposure through the dietary intake of bananas to different populations was also studied. According to the results of dietary risk assessment, the residual level of pyraclostrobin was within the acceptable range of chronic and acute dietary risk in different populations in China at 150 mg/kg. Our results show that pyraclostrobin as a fungicide in the indoor control of banana anthracnose has high safety and low risk, and can provide a reference for the safe and reasonable use of pyraclostrobin as an indoor fungicide and risk assessment.

Dietary risk assessment of pesticide residues on Tremella fuciformis Berk (snow fungus) from Fujian Province of China

ABSTRACT To assess the dietary exposure risks of pesticide residues in snow fungus for the general population and young children, 91 snow fungus samples were collected from major production areas in Fujian Province, China and the presence of 44 pesticides was determined. A total of thirteen pesticides were detected; 65.9% of the samples contained one or more pesticide residues. The most frequently found pesticide was carbofuran, followed by acetamiprid and then imidacloprid. Data obtained were used for chronic, acute, and chronic cumulative dietary exposure risk assessments. The chronic hazard quotient (cHQ) was extremely low for both the general population and young children. The %ADI values of cumulative dietary exposures to organophosphorus pesticides and carbamates ranged from 0.53% to 1.49%, and did not exceed their corresponding ADIs. However, the acute dietary risks from all 13 pesticides, especially carbofuran and methamidophos, were of concern due to the relatively high acute hazard quotient. The risk ranking scheme showed that carbofuran could pose a high risk to snow fungus consumers. Finally, suggestions are made about the potential use in snow fungus cultivation of the pesticides with detected residues.

Determination, risk assessment and processing factors for pyridaben in field-incurred kiwifruit samples

Field trials in six agricultural sites were carried out to investigate the dissipation and residue levels of pyridaben in kiwifruit. Each sample was extracted with acetonitrile, purified with octadecylsilane and analyzed with high-performance liquid chromatography-tandem mass spectrometry. The method had good linearity (R2 > 0.99), accuracy (recoveries of 78.53–98.00%) and precision (relative standard deviation of 0.86–6.11%). The dissipation of pyrdaben in kiwifruit followed first-order kinetics with a half-life < 8 d, and terminal residues in kiwifruit were lower than 0.5 mg/kg after 14 d of application. Risk assessment indicated that both chronic and acute dietary intake risk values were far below 100%, suggesting that pyridaben residues in kiwifruit were relatively safe to humans. Moreover, the effects of traditional household processes on kiwifruit were investigated. The processing factors (PFs) indicated that peeling and peeling-juicing processes could remove pyridaben residues from kiwifruit, and the former was more effective than the latter (PF at 0.15 vs. 0.51). Nevertheless, drying kiwifruit with an oven increased the amount of pyridaben (PF at 1.05). These results could provide guidance for the safe and reasonable use of pyridaben in agriculture and may be helpful for the Chinese government to determine maximum residue limit of pyridaben in kiwifruit.

Dissipation and distribution of difenoconazole in bananas and a risk assessment of dietary intake.

The dissipation and terminal residues of difenoconazole in whole bananas and pulp were investigated under field conditions. The residual levels of difenoconazole in various parts of bananas grown in Guangdong, Hainan and Yunnan were determined by a GC-ECD detection method after simple, rapid pretreatment. The mean recovery was 80.66~107.40%, and the relative standard deviation was 3.36~9.84%. The results showed that the half-lives of difenoconazole in whole bananas and in the pulp were 12.16~13.33days and 17.77~20.38days, respectively. At harvest intervals of 28 and 35days after the last application, the terminal residues of difenoconazole in whole bananas and pulp were 0.45~0.84mg/kg and 0.19~0.37mg/kg, respectively, which were lower than the maximum residue level established in China. The distribution of difenoconazole in banana pulp and peels was studied. The results showed that until harvesting, the residue in the peels was always 2.19~12.30 times larger than that in the pulp. Difenoconazole was mainly absorbed by the banana peels but did not easily penetrate into the pulp. Based on dietary risk assessment results, the residual levels of difenoconazole at the sampling interval of 28days after the last application were within acceptable limits for chronic and acute dietary risks in different populations in China. This study can provide a reference for the safe and rational use of difenoconazole as a fungicide and for the future research and application of banana pulp and peels.

Residual behavior and risk assessment of prochloraz in bayberries and bayberry wine for the Chinese population

The bayberry is an important economic fruit as well as a minor crop in China, and few pesticide products are registered for bayberry. Prochloraz is a widely used fungicide with a high detection rate on bayberry. This study evaluated the potential dietary risk of prochloraz for different populations in China based on field trial data and market surveillance. The results indicate that one-time applications at dosages of 1000 and 1500mg/kg with a recommended preharvest interval of 20days do not pose a chronic or acute dietary risk. However, applying the above dosages twice will cause a potential short-term dietary risk. Risk assessment results conducted on surveillance samples indicated acceptable long-term risks for the general population, with a hazard quotient < 0.82. Furthermore, simulated washing and wine production processes were performed to mimic household practices to investigate residue transfer and distribution. We found that rinsing with tap water for 1min was an effective way to remove residue, and the processing factors of prochloraz for both bayberry and wine were < 1, indicating that wine production could reduce residue levels. Prochloraz had a strong capacity to transfer to wine due to its high log Kow value, with transfer percentages up to 43%. This study supports the recommendation on good agricultural practices for prochloraz application and provides a guide for safe consumption.

Residue behavior and dietary risk assessment of chlorothalonil and its metabolite SDS-3701 in water spinach to propose maximum residue limit (MRL)

Dietary risk assessment generally combines food consumption data and the concentration of pesticide by using the risk quotient (RQ) method. Chlorothalonil is the second popular fungicide in the world, and its residue and risk assessment in water spinach remain unknown. In this paper, the field trials of chlorothalonil in water spinach were operated under good agricultural practice (GAP) in China to human health protective. The dissipation experiments demonstrated that chlorothalonil was rapidly degraded in water spinach, with the half-lives of 1.8–3.2 days, and the amount of its metabolite SDS-3701 (4-hydroxy-2,5,6-trichloroisophthalonitrile) taken up through the water spinach roots from the soil was minor. The terminal experiments disclosed that the average residues of chlorothalonil and SDS-3701 in water spinach were below 6.59 mg/kg and 0.01 mg/kg, respectively. The results suggested the chronic dietary risk probability of chlorothalonil was 51.95–59.15% in terms of all registered crops, and the acute dietary risk probability of chlorothalonil was 12.30%–63.01% in water spinach, highlighting that the dietary risk of chlorothalonil in water spinach under GAP was acceptable. MRL of chlorothalonil was proposed as 7 mg/kg for water spinach and 5 days was recommended as a safe pre-harvest interval (PHI) for chlorothalonil application in water spinach field.

Dissipation of Prothioconazole and Its Metabolite Prothioconazole-Desthio in Rice Fields and Risk Assessment of Its Dietary Intake

Rice is an important food crop, with a long history of cultivation in China, and is one of the important staple foods for Chinese today. However, the occurrence of rice diseases has had a substantial impact on its yield. At present, chemical control is the main means of prevention and control of rice diseases. As a high-efficacy and broad-spectrum fungicide, prothioconazole shows an ideal effect on the prevention and control of common rice diseases, but the residuals that remain after its use may have an impact on human health. In this paper, ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to develop a residue analysis method and explore the dissipation of prothioconazole and its metabolite prothioconazole-desthio in rice grain, rice husk, and rice plants, and the risks of chronic and acute dietary intake of prothioconazole in different Chinese populations were evaluated. The results showed that at a concentration range of 0.005-5.0 μg/mL, prothioconazole and its metabolites showed good linear correlations, and the correlation coefficients were all above 0.9992. The average recoveries of prothioconazole in three matrixes ranged from 80.0% to 99.7%, the RSD was between 1.54% and 11.0%, and the limit of quantitation was less than 0.01 μg/g. The sensitivity, accuracy, and precision of the established method all met the measurement requirements. The dissipation experimental results showed that the parent compound prothioconazole was rapidly metabolized to prothioconazole-desthio in the rice field environment, and the dissipation half-life in rice plants after application was 2.5-10.1 d. According to the results of dietary risk assessment, under the standardized residue test conditions, the residual level of rice at the sampling interval of 7 days was within the acceptable range for the chronic and acute dietary risks of different populations in China. Our research is important for directing the scientific application of pesticides in China.

Risk assessment of pesticide residues in domestic ginsengs

The study aims at taking risk assessment of pesticide residues in ginseng and high risk pesticides were picked up in order to provide a scientific basis for the establishment of maximum residue limits(MRLs) for pesticides in ginseng. Residues of 246 pesticides in 80 ginseng samples collected from different place were detected by GC-MS/MS and LC-MS/MS method. Acute and chronic intake risks were evaluated by using deterministic approach, and the matrix ranking developed by the Veterinary Residues Committee of the United Kingdom was referred to assess risk score of pesticides. The 25 kinds of pesticide residues were detected in ginseng samples, the detection rate of quintozene(PCNB) was 78%, which was the most frequently detectable pesticide. The chronic dietary intake risks of 25 pesticide residues expressed as %ADI were 0.00%-2.6%, and their acute dietary intake risks expressed as %ARfD were 0.00%-104.2%. Among them the acute dietary intake risks of PCNB was 104%,which was the highest. The 25 pesticides were divided into 3 groups by risk score, high risk group(4 pesticides), medium risk group(6 pesticides), and low risk group(15 pesticides). Hexachlorobenzene, phorate, PCNB and BHC were classified as high risk group. It is necessary and effective to establish the limit of residual organic chlorine in ginseng from Chinese Pharmacopoeia(2015 edition). MRLs for PCNB and hexachlorobenzene in ginseng were proposed to be revised based on the results of risk assessment.

Dissipation, residues, and risk assessment of imidacloprid in Zizania latifolia and purple sweet potato under field conditions using LC-MS/MS

A shortened version of Quick, Easy, Cheap, Effective, Rugged, and Safe method (QuEChERS) for determining the dissipation and residue of imidacloprid present in Zizania latifolia and purple sweet potato was established by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The average recoveries of imidacloprid in the two crops ranged from 82.12 to 113.79%, with relative standard deviation (RSD) of <7.32%. The dissipation dynamics of imidacloprid in Z. latifolia plants and purple sweet potato plants followed first-order kinetics, with half-lives of 3.2–5.5 days in each of sampling locations. The terminal imidacloprid residues in Z. latifolia and purple sweet potato at each of location were <0.005–0.120 mg kg−1. According to the risk assessment results, both the acute dietary risk quotient and chronic dietary risk quotient values were <1, indicating that imidacloprid is unlikely to pose health risks to humans with normal recommended use. The present study may serve as a valuable reference for the safe and reasonable use of imidacloprid in Z. latifolia and purple sweet potato fields.

National short-term dietary exposure assessment of a selected group of pesticides in Argentina

ABSTRACTAn evaluation of acute dietary exposure to pesticide residues, applying deterministic and stochastic methods, was performed for a selected group of pesticides in two representative age groups from Argentina. Thus, 28 active ingredients (a.i.) and 75 food items were evaluated for the group of 2–5-year-old children, while 9 a.i. and 59 food items were considered for the 10–49-year-old women group. A deterministic assessment was conducting following the Food and Agriculture Organization (FAO) and World Health Organization (WHO) procedure but using the national maximum residue limits (MRLs) as pesticide residue concentration data, while in the stochastic approach, a theoretical distribution modeled with the available information was used. Food consumption data were obtained from the 2004–2005 comprehensive national nutrition and health survey. The risk was estimated by comparing the short-term dietary exposure with the acute reference dose (ARfD) values for each pesticide-food combination evaluated. In the deterministic assessment, 173 (39.1%) and 40 (31.3%) combinations exceeded the ARfD thresholds for the 2–5-year-old children and 10–49-year-old women groups, respectively. This conservative study generated relevant information as a first stage of acute dietary risk assessment in Argentina.

Residue analysis and dietary exposure risk assessment of tebufenozide in stem lettuce (Lactuca sativa L. var. angustana Irish)

Tebufenozide, a newly-developed nonsteroidal ecdysone agonist, is in pre-regulation phase (before approval for use) on stem lettuce in China. Aiming at the safe application of tebufenozide, the dissipation and terminal residue trials on stem lettuce were performed under good agricultural practice (GAP). The dissipation trials shown that tebufenozide was rapidly degraded in stem lettuce, with half-lives of 5.0–8.2 days. Pre-regulation dietary exposure risk assessments were evaluated to recommend maximum residue limits (MRLs) based on risk quotients (RQ) method. Relevant toxicological parameters including ADI (acceptable daily intake) and ARfD (acute reference dose) were applied to assess the potential dietary exposure risk. The results indicated the chronic dietary exposure risk probability (RQc) of tebufenozide ranged from 36.4% to 70.0%. The acute dietary exposure risk probability (RQa) of tebufenozide was 2.88%–8.49% in lettuce stems and 14.0%–20.0% in lettuce leaves, respectively. On the basis of supervised field trial data and dietary exposure risk assessment results, the MRLs of tebufenozide were recommended as 3 mg/kg for lettuce stems and 10 mg/kg for lettuce leaves, respectively. The results demonstrated that the dietary exposure risk of tebufenozide used in stem lettuce under GAP was negligible and would not pose unacceptable health risk to Chinese consumers.