Monitoring of pesticides in surface water, pesticides removal efficiency in drinking water treatment plant and potential health risk to consumers using Monte Carlo simulation in Behbahan City, Iran

Occurrence and health risk estimate of organochlorine pesticides in fruits and vegetables matrices

Occurrence of 20 organochlorine pesticides (OCPs) in 60 organic and non-organic fruits and vegetables matrices was undertaken using QuEChERS Method EN 15662 for sample preparation analyzed by gas chromatography-mass spectrometry (GC-MS/MS). The procedural method was validated by spiking the OCP standard solutions at three fortified levels at 10, 50, and 100 µg/kg wet weight (ww) to the real matrix of fruit and vegetable with good recovery ranging from 75 to 108% with relative standard deviation (RSD) ≤ 11%, and the limits of detection and quantification (LODs and LOQs) were 0.002-0.02 μg/kg and 0.004-0.1 μg/kg ww, respectively. The assessment of health risks associated with pesticide residues through consumption of vegetables and fruits and the effect of washing and peeling on concentration of various pesticides were also studied. The results showed that the concentration levels of 60% of samples were lower than the LOQs, while the rest was contaminated by OCP residues. Organic fruits and vegetables showed the absence of OCPs, while several of the studied compounds were detected from conventional agriculture. Skin removal (peeling) was the most effective strategy to eliminate or decrease pesticide residues, and should be one of the solutions to reduce the health impact of pesticides in fruits and vegetables. The analysis of health risk assessment was based on the use of the estimated average daily intake (EDI), hazard index (HI), and hazard ratio (HR) for individuals in two weight categories: children (weighing 16.7 kg) and adults (weighing 60 kg). The HI values were less than 1 suggesting that there was no probable non-carcinogenic health effect, except for heptachlor for children (HI of 1.285). However, the values of HR revealed that children were more susceptible to the carcinogenic health effect associated with consuming contaminated vegetables.

Residual levels, phase distributions, and human health risks of OCPs in the middle reach of the Huai River, China

Are the residues of organochlorine pesticides (OCPs) in freshwater in China still of concern after prohibition and restriction for decades? The scarcity of monitoring data on OCPs in freshwater in China over the past few years has hampered understanding of this issue. In this study, water and suspended particulate matter (SPM) samples were collected from the middle reach of the Huai River for OCP analyses. Residues of ∑OCPs in water and SPM ranged from ND to 8.6 ng L-1 and 0.50 to 179 ng L-1, with mean concentrations of 1.7 ± 1.3 ng L-1 and 6.1 ± 31 ng L-1, respectively. ∑HCHs (α-, β-, γ-, and δ-HCH) and ∑HEPTs (heptachlor and heptachlor epoxide) were the most predominant pesticides in the dissolved phase and SPM, respectively, accounting for 43 ± 35% and 27 ± 29% of ∑OCPs. HCHs and heptachlor epoxide mainly existed in the dissolved phase, while heptachlor mainly existed in SPM. The isomeric composition pattern of HCHs in water differed from that in SPM. Briefly, β-HCH dominated in water, while δ-HCH dominated in SPM. However, the composition pattern of DDT and its metabolites in water was similar to that in SPM. o,p'-DDD and p,p'-DDE dominated in both water and SPM. The ratios of α-/γ-HCH and (DDD + DDE)/DDTs indicated that HCHs and DDTs were mainly derived from historical residues. Risk assessments indicated that OCPs may not pose carcinogenic and non-carcinogenic risks to residents.

Pesticide contamination pattern from Morocco, insights into the surveillance situation and health risk assessment: a review

The widespread application of pesticides in Morocco's agriculture renders their monitoring in food and environmental samples very necessary. Recent years have witnessed a growing interest in reporting studies related to the monitoring of pesticide residues in food, water, groundwater, and soil as well as their quantitative health risk assessment. Most published studies have been done by university researchers. However, the lack of research reproducibility remains a problem that considerably limits the possibility of exploiting data from the literature. Our study involves an extensive literature review utilizing search engines with keywords like "pesticide residues," "monitoring," "vegetables and fruits," "water and soil," "risk assessment," and "Morocco" from 2009 to 2023. Analysis of pesticide residues in foodstuffs and environmental samples highlights concerns over compliance with EU regulations, the health risks associated with pesticide exposure, and the necessity for comprehensive monitoring and risk assessment strategies. This paper could help influence policies to develop a strategy and action plan for the sound management of pesticides, including measures to reduce their use, raise awareness, and monitor compliance. Also, this paper could be useful for scientists interested in understanding the current situation and challenges regarding pesticide residues in Morocco, as well as countries with which commercial links exist.

Pesticide residues in drinking water treatment plants and human health risk assessment: a case study from Northern Iran

These days, the presence of pesticide residues in drinking water sources is a serious concern. In drinking water treatment plants (DWTPs), various methods have been proposed to remove pesticide residues. This study was designed with the objectives of monitoring the occurrence and seasonal variations of pesticides in the output of drinking water treatment plants in two Northern provinces of Iran, Gilan and Golestan, and identifying their human health risks. Seventeen pesticide residues from different chemical structures were determined by using a gas chromatograph-mass spectrometer (GC-MS). The results showed that only Alachlor, Diazinon, Fenitrothion, Malathion, and Chlorpyrifos were detected. The pesticide concentrations ranged from ND to 405.3 ng/L and were higher in the first half-year period. The total non-carcinogenic human health risks was in safe range for infants, children, and adults (HI < 1). The carcinogenic human health risks of Alachlor for infants, children, and adults were in the range of 4.3 × 10-7 to 1.3 × 10-6, 2.0 × 10-7 to 9.6 × 10-7, and 1.1 × 10-7 to 5.5 × 10-7, respectively. These values do not pose health risks for adults and children, but may present a possible cancer risk for infants in two DWTPs of Golestan. In conclusion, considering the possibility of exposure to these pesticides through other routes, simultaneously, it is suggested to carry out a study that examines the level of risk by considering all exposure routes. We also propose stricter regulations for the sale and use of pesticides in Iran.

Uncertainty and associated risks in the analysis of pesticides in homogeneous paprika samples

In this study, risk estimation based on sampling and subsampling uncertainty was performed for pesticide analysis in homogeneous spice products such as paprika. The results of the subsampling were also used to estimate the minimum weight necessary in subsampling to minimize overall uncertainty. The results show that subsampling has more uncertainty than sampling in the product due to high homogeneity in the manufacturer's batch. On the other hand, results using the Monte Carlo (MC) simulation on the size of the subsample indicate that uncertainty is lower for weights between 20 and 30 g and increases for sample sizes of 100 g. A sample size of 30 g was used for saffron, and the values simulated with the MC method were confirmed.

Toxicity effects of pesticides based on zebrafish (Danio rerio) models: Advances and perspectives

Pesticides inevitably enter aquatic environments, posing potential risks to organisms. The common aquatic model organism, zebrafish (Danio rerio), are widely used to evaluate the toxicity of pesticides. In this review, we searched the Web of Science database for articles published between 2012 and 2022, using the keywords "pesticide", "zebrafish", and "toxicity", retrieving 618 publications. Furthermore, we described the main pathways by which pesticides enter aquatic environments and the fate of their residues in these environments. We systematically reviewed the toxicity effects of pesticides on zebrafish, including developmental toxicity, endocrine-disrupting effects, reproductive toxicity, neurotoxicity, immunotoxicity, and genotoxicity. Importantly, we summarized the latest research progress on the toxicity mechanism of pesticides to zebrafish based on omics technologies, including transcriptomics, metabolomics, and microbiomics. Finally, we discussed future research prospects, focusing on the combined exposure of multiple pollutants including pesticides, the risk of multigenerational exposure to pesticides, and the chronic toxicity of aquatic nanopesticides. This review provides essential data support for ecological risk assessments of pesticides in aquatic environments, and has implications for water management in the context of pesticide pollution.

Evaluating the spatial and temporal distribution of emerging contaminants in the Pearl River Basin for regulating purposes

Little information is available on how the types, concentrations, and distribution of chemicals have evolved over the years. The objective of the present study is therefore to review the spatial and temporal distribution profile of emerging contaminants with limited toxicology data in the pearl river basin over the years to build up the emerging contaminants database in this region for risk assessment and regulatory purposes. The result revealed that seven groups of emerging contaminants were abundant in this region, and many emerging contaminants had been detected at much higher concentrations before 2011. Specifically, antibiotics, phenolic compounds, and acidic pharmaceuticals were the most abundant emerging contaminants detected in the aquatic compartment, while phenolic compounds were of the most profound concern in soil. Flame retardants and plastics were the most frequently studied chemicals in organisms. The abundance of the field concentrations and frequencies varied considerably over the years, and currently available data can hardly be used for regulation purposes. It is suggested that watershed management should establish a regular monitoring scheme and comprehensive database to monitor the distribution of emerging contaminants considering the highly condensed population in this region. The priority monitoring list should be formed in consideration of historical abundance, potential toxic effects of emerging contaminants as well as the distribution of heavily polluting industries in the region.

Measurement of polycyclic aromatic hydrocarbons in edible oils and potential health risk to consumers using Monte Carlo simulation, southwest Iran

Persistent organic pollutants, such as polycyclic aromatic hydrocarbons, are hazardous trace contaminants frequently observed in food ingredients, such as edible oils. This study aimed to measure PAHs in forty brands of edible oils marketed in southwest Iran. Additionally, we characterized the daily intake of MOE and ILCR using Monte Carlo simulation. To analyze the content of PAHs, the liquid-liquid extraction method followed by GC-MS was utilized. The average concentration of PAHs was mostly lower than the maximum value for individual PAH (2 μg/Kg); however, the average concentration of fluorene (3.86 μg/Kg) and benzo(a)anthracene (3.13 μg/Kg) was more than the permitted level. The highest residual concentrations of PAHs were mostly observed in canola and corn oils. The daily intake of BaP and 4-PAH for 95% of consumers was 0.01 ng/kg BW/day and 0.04 ng/kg BW/day, respectively. Also, MOE was more than 10,000 for the percentiles of 5%, 50%, and 95%. The modeled ILCR showed that consumption of oil does not currently pose a cancer risk for Iranian consumers due to PAHs exposure. Concerning potential health risks, consumption of edible oils is safe; however, regular monitoring and assessment are required.

Efficacy of a large-scale integrated constructed wetland for pesticide removal in tail water from a sewage treatment plant

The higher and higher detection frequencies of micro-pollutants such as pesticides in water are nowadays intensifying the investigation for strategies to provide effective engineering methods that could mitigate such substances. Traditional sewage treatment plants (STP) do not design specific processes for micro-pollutants removal in water. As an environmentally-friendly measure, some laboratory-scale wetlands have been proved to be effective in the removal of pesticides in water, but such studies are rarely carried out in large-scale wetlands, especially when they are adopted as a polishing step of STPs. Therefore, the further removals of micro-pollutants in tail water of STPs through the large-scale wetlands and the relevant removal mechanism are still knowledge gaps. In this study, 44 target pesticides were detected in the water of a large-scale integrated constructed wetland (ICW) for four seasons. The ICW was established to further process the tail water from a STP, whose drainage was from domestic sewage of local residents. There were 19, 16, 17, and 19 pesticides detected in spring, summer, autumn, and winter, respectively. The removal values for Σ₁₉ pesticides ranged from 49.99% to 84.96% during the study period, and the removal of these pesticides followed significant seasonal trends, which was likely because the microorganisms responsible for biotic degradation were markedly influenced by seasonal temperature fluctuations. Proteobacteria, Chloroflexi, Acidobacteria, Planctomycetes, and Bacteroidetes were the dominant phyla, and might be associated with the biodegradation of organic pollutants in the ICW. Removal of pesticides by the ICW resulted in overall toxicity reductions in water, but butachlor and chlorpyrifos were still at non-ignorable ecological risks. This study highlights the potential of constructed wetlands for micro-pollutants removal in water as a polishing step in STPs.

Exposure Routes and Health Risks Associated with Pesticide Application

Pesticides play an important role in agricultural development. However, pesticide application can result in both acute and chronic human toxicities, and the adverse effects of pesticides on the environment and human health remain a serious problem. There is therefore a need to discuss the application methods for pesticides, the routes of pesticide exposure, and the health risks posed by pesticide application. The health problems related to pesticide application and exposure in developing countries are of particular concern. The purpose of this paper is to provide scientific information for policymakers in order to allow the development of proper pesticide application technics and methods to minimize pesticide exposure and the adverse health effects on both applicators and communities. Studies indicate that there are four main pesticide application methods, including hydraulic spraying, backpack spraying, basal trunk spraying, and aerial spraying. Pesticide application methods are mainly selected by considering the habits of target pests, the characteristics of target sites, and the properties of pesticides. Humans are directly exposed to pesticides in occupational, agricultural, and household activities and are indirectly exposed to pesticides via environmental media, including air, water, soil, and food. Human exposure to pesticides occurs mainly through dermal, oral, and respiratory routes. People who are directly and/or indirectly exposed to pesticides may contract acute toxicity effects and chronic diseases. Although no segment of the general population is completely protected against exposure to pesticides and their potentially serious health effects, a disproportionate burden is shouldered by people in developing countries. Both deterministic and probabilistic human health risk assessments have their advantages and disadvantages and both types of methods should be comprehensively implemented in research on exposure and human health risk assessment. Equipment for appropriate pesticide application is important for application efficiency to minimize the loss of spray solution as well as reduce pesticide residuals in the environment and adverse human health effects due to over-spraying and residues. Policymakers should implement various useful measures, such as integrated pest management (IPM) laws that prohibit the use of pesticides with high risks and the development of a national implementation plan (NIP) to reduce the adverse effects of pesticides on the environment and on human health.

Spatial distribution, ecological and health risk assessment of organophosphorus pesticides identified in the water of Naseri artificial wetland, Iran

Agricultural development is inevitable to meet the growing need for food. But along with this development, there are unintended and undesirable consequences for human life and the environment that need, found a solution and corrected. One of the most important adverse consequences of agricultural development is the pollution of surface and groundwater resources, which results from various factors such as soil erosion and improper use of different pesticides. This study aimed to conduct an environmental monitoring program in Naseri wetland to determine the concentrations of organophosphorus pesticides (OPP_s) in water samples and also to evaluate the potential risks (ecological and health risk assessment) of these pesticides. The salting-out assisted liquid-liquid extraction method was used to extract pesticides. The residual concentrations of OPP_s evaluated by gas chromatography/mass spectrometry (GC/MS). In this study, the ecological risk of OPP_s calculated for wetland ecosystem, based on the acute risk quotient (RQ_i) formula with maximum (RQ_max), mean (RQ_mean), and mixture (RQ_mix) concentrations of organophosphorus pesticides in the wetland water. Also, to assess the health risk of consuming contaminated fish with organophosphate pesticides, the potential non-carcinogenic and carcinogenic risks were determined by the hazard quotient (Index) (HQ, HI) and incremental lifetime cancer risk (ILCR) indices, respectively. The mean ± SD concentration of OPP_s (Chlorpyrifos, Malathion, Ethion, Dichlorvos, Trifluralin and Diazinon) in samples of wetland water ranged from 0.14 ± 0.08 to 0.35 ± 0.12 and 0.054 ± 0.06 to 0.2 ± 0.1 (μg/L) in summer and autumn, respectively. The mean ± SD of OPP_s in fish varied from 0.68 ± 0.86 to 3.94 ± 2.7 (μg/kg). Overall, the concentrations of pesticides in all water and fish samples were below the maximum residue limit (30 μg/kg) during the study period, according to the Environmental Protection Agency (EPA) and the World Health Organization (WHO). The results of acute risk quotient were in summer (RQ_max = 3.49E-4 to 0.067, RQ_mean = 5.8E-5 to 0.029, RQ_mix = 0.139-0.026, 0.018-3.42E-3) and autumn (RQ_max = 8E-4 to 0.051, RQ_mean = 7.74E-6 to 0.018 RQ_mix = 0.1-0.013, 6E-3- 1.5E-3). The non-carcinogenic and carcinogenic risk indexes due to fish consumption for adults and children were (HQ = 0.026-4.68E-4, HI = 0.041, ILCR = 1.7E-7) and (HQ = 1.85E-3-1.3E-5, HI = 0.041, ILCR = 5.55E-8), respectively. The risk of OPP_s was generally low. But cumulative risk (pesticide mixtures), should not be ignored.

Emerging Pollutants in Wastewater, Advanced Oxidation Processes as an Alternative Treatment and Perspectives

Emerging pollutants are present in wastewaters treated by conventional processes. Due to water cycle interactions, these contaminants have been reported in groundwater, surface water, and drinking waters. Since conventional processes cannot guarantee their removal or biotransformation, it is necessary to study processes that comply with complete elimination. The current literature review was conducted to describe and provide an overview of the available information about the most significant groups of emerging pollutants that could potentially be found in the wastewater and the environment. In addition, it describes the main entry and distribution pathways of emerging contaminants into the environment through the water and wastewater cycle, as well as some of the potential effects they may cause to flora, fauna, and humans. Relevant information on the SARS-CoV-2 virus and its potential spread through wastewater is included. Furthermore, it also outlines some of the Advanced Oxidation Processes (AOPs) used for the total or partial emerging pollutants removal, emphasizing the reaction mechanisms and process parameters that need to be considered. As well, some biological processes that, although slow, are effective for the biotransformation of some emerging contaminants and can be used in combination with advanced oxidation processes.

Functionalized hybrid magnetic catalytic systems on micro- and nanoscale utilized in organic synthesis and degradation of dyes

Herein, a concise review of the latest developments in catalytic processes involving organic reactions is presented, focusing on magnetic catalytic systems (MCSs). In recent years, various micro- and nanoscale magnetic catalysts have been prepared through different methods based on optimized reaction conditions and utilized in complex organic synthesis or degradation reactions of pharmaceutical compounds. These biodegradable, biocompatible and eco-benign MCSs have achieved the principles of green chemistry, and thus their usage is highly advocated. In addition, MCSs can shorten the reaction time, effectively accelerate reactions, and significantly upgrade both pharmaceutical synthesis and degradation mechanisms by preventing unwanted side reactions. Moreover, the other significant benefits of MCSs include their convenient magnetic separation, high stability and reusability, inexpensive raw materials, facile preparation routes, and surface functionalization. In this review, our aim is to present at the recent improvements in the structure of versatile MCSs and their characteristics, i.e., magnetization, recyclability, structural stability, turnover number (TON), and turnover frequency (TOF). Concisely, different hybrid and multifunctional MCSs are discussed. Additionally, the applications of MCSs for the synthesis of different pharmaceutical ingredients and degradation of organic wastewater contaminants such as toxic dyes and drugs are demonstrated.