National probabilistic risk assessment of newly registered pesticides in agricultural products to propose maximum residue limit (MRL).

Following the EPA recommended method, a chronic diet risk assessment for pesticides was recently performed for adults and children in the Iranian population. The National Theoretical Maximum Daily Intake (NTMDI) for 32 pesticides was computed using the theoretical maximum residue limits (MRLs) of food consumption regulations and data from the comprehensive database of the Iranian Research Institute of Plant Protection (IRIPP). The risk was assessed by comparing TMDI with the acceptable daily intakes (ADI) evaluated by FAO. From 32 investigated pesticides, 10 pesticides had TMDI > 65% of the ADI. Some of these ADI-exceeding compounds (spirodiclofen, abamectin, trifloxystrobin, spiromesifen, fipronil, difenoconazole, tetraconazole) were found in citrus, cucumber, grapes, tomato, and potato as the foods that have played the most roles in the consumption of these pesticides. Furthermore, a probabilistic risk assessment was performed to estimate the contingency of extravagance of the ADI. In the current research, only cyazofamid in potato for children consumers exceeded the 1 of the HQ. However, carcinogenic risk (CR) due to spirodiclofen in citrus fruit and difenoconazole in tomato was higher than the 1E-6 value; therefore, consumers were at considerable carcinogenic risk in these commodities. This scrutiny is essential for improving the activities' risk assessment, regulation, and surveillance.

Determination of multi-class pesticides residues of cow and human milk samples from Iran using UHPLC-MS/MS and GC-ECD: A probabilistic health risk assessment.

Raw, pasteurized, powdered cow milk and human milk samples from Tehran, Iran were investigated for the residual of fifty pesticides with the aid of gas chromatography coupled with electron capture detector (GC-ECD) and mass detector for confirmation; and ultra-high performance liquid chromatography-tandem mass spectroscopy (UHPLC-MS/MS). No pesticide residue was determined in more than 91% of examined samples. However, the dimethoate residue was detected in 3 raw milk samples in levels higher than EU recommended MRL. While in 3 human milk samples, organochlorine pesticides residue, p,p'-DDT, and p,p'-DDD was recognized below MRLs, only in 1 human sample residue of p,p'-DDE was more than CODEX recommended MRL. HI in adults and children were 0.72 and 3.55, respectively. However, the health risk assessment based on HI demonstrated that adult consumers are not at considerable risk. The HI, higher than 1 in children, confirms the risks raised due to ingestion of organochlorine (OCP) and organophosphorus (OPP) pesticides via milk consumption. In addition, no carcinogenic risk to milk consumers was calculated. Therefore, implementation of good farming practices on farms, improving the knowledge and consciousness of pesticide users, use other safe methods for pest control such as biotechnology-based, and use a rational program for application of pesticides, continuous monitoring of pesticides in crops, and strict government regulations on pesticide residues in food are recommended.

Carcinogenic and non-carcinogenic risk assessment induced by pesticide residues in commercially available ready-to-eat raisins of Iran based on Monte Carlo Simulation.

Pesticide residues in fruits lead to serious public health and environmental problems. This study was undertaken to analyze 57 pesticides residues in 60 commercially available ready-to-eat packed raisins samples from Iran's markets using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) approach along with acetonitrile for the extraction, surface adsorbents for clean-up procedure, following with an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Moreover, the probabilistic health risk assessment includes non-carcinogenic and carcinogenic risk were estimated by hazard quotient (HQ), Hazard Index (HI) and cancer risk (CR) using the Monte Carlo Simulation (MCS) method. The respective numbers attributed to LOD and LOQ were 0.001-0.03 mg kg-1 and 0.005-0.05 mg kg-1. Results showed that 23% of samples were contaminated by at least one pesticide according to national MRLs. The rank order of pesticides based on HQ was carbendazim > acetamiprid > thiodicarb > iprodione for raisins with percentile 95% benchmark. The HI amount in the adult's age group was 0.001, and in the children's age group was obtained to be 0.006. According to the risk assessment results (HQ and HI < 1 in both age groups), it can be acknowledged that consumption of raisins may not pose remarkable health hazards in short term exposures. The rank order of pesticides based on CR was thiodicarb > iprodion. But total CR (TCR) was lower than 1E-6 value (7.6E-8), so consumers were not at considerable carcinogenic risk in this commodity. Acetamiprid and carbendazim does not pose a cancer risk to humans. Therefore, a dietary exposure assessment for the purpose of assessing cancer risk is unnecessary.

Pesticide residues in green-house cucumber, cantaloupe, and melon samples from Iran: A risk assessment by Monte Carlo Simulation.

This research aims to analyze 56 pesticide residues in 100 green-house cucumber and 150 cantaloupe and melon samples collected from markets in Iran by Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction method based on analysis with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). In addition, non-carcinogenic and carcinogenic probabilistic health risk assessments were evaluated by Hazard Quotient (HQ), Hazard Index (HI), and Carcinogenic Risk (CR) based on the Monte Carlo Simulation (MCS) method. According to Iranian regulation, 18% of cucumber and 22% of cantaloupe and melon samples were contaminated by at least one pesticide. Arrange pesticides based on HQ ranking was diazinon > thiacloprid > imidacloprid tebuconazole for cucumbers and chlorpyrifos > thiacloprid > imidacloprid > metalaxyl for cantaloupes and melons. In addition, HI for adults was 0.067 in cucumber and 0.24 in cantaloupe and melon; and for children, 0.30 in cucumber and 0.60 in cantaloupe and melon. Arrange pesticides based on CR ranking was thiacloprid > imidacloprid > metalaxyl > chlorpyrifos > tebuconazole > diazinon. However, CR was more than 1.0E-6 value due to thiacloprid, so consumers were at considerable carcinogenic risk in these commodities.

Combination of paper-based thin film microextraction with smartphone-based sensing for sulfite assay in food samples.

Herein, a simple, green, and novel paper-based headspace-thin film microextraction in combination with smartphone-based on-cell detection was introduced. Sulfite was selected as a model compound to study the performance of the method. The method was based on converting sulfite to SO2 by acidification of the sample solution. A piece of cellulose paper impregnated with Fe(III), 1,10-phenanthroline, and acetate buffer (pH = 5.5) was used for headspace-thin film microextraction. The sulfur dioxide adsorbed on the thin film reduced Fe(III) to Fe(II). The red color complex formed between Fe(II) and 1,10-phenanthroline was on-cell detected by a smartphone. The effect of various parameters on the method sensitivity was investigated. The method had three individual linear ranges (0.1-1.0, 1-50, and 50-700 µg L-1) with a detection limit of 0.04 µg L-1. The method provided a simple and green assay for the determination of sulfite in food samples. Recoveries were higher than 94% with the relative standard deviations lower than 4.8%. Expensive and complicated facilities were not required in the method.