Global distribution of pesticides in freshwater resources and their remediation approaches

What potential do mosses have as biomonitors of POPs? A comparative study of hexachlorocyclohexane sorption

Persistent organic pollutants (POPs) pose a significant global threat to human health and the environment, and require continuous monitoring due to their ability to migrate long distances. Active biomonitoring using cloned mosses is an inexpensive but underexplored method to assess POPs, mainly due to the poor understanding of the loading mechanisms of these pollutants in mosses. In this work, Fontinalis antipyretica (aquatic moss) and Sphagnum palustre (terrestrial moss) were evaluated as potential biomonitors of hexachlorocyclohexanes (HCHs: α-, β-, γ-, δ-HCH), crucial POPs. Moss clones, grown in photobioreactors and subsequently oven-dried, were used. Their lipid composition and distribution were characterized through molecular and histochemical studies. Adsorption experiments were carried out in the aqueous phase using the repeated additions method and in the gas phase using an active air sampling technique based on solid-phase extraction, a pioneering approach in moss research. F. antipyretica exhibited greater lipid content in the walls of most cells and higher adsorption capacity for all HCH isomers in both gaseous and liquid environments. These findings highlight the need for further investigation of POP loading mechanisms in mosses and open the door to explore other species based on their lipid content.

Analysing agricultural plant protection product concentrations in groundwater in Germany: Nationwide database with site and compound insights

Pesticides from agricultural practices are among the most pressing reasons why groundwater sources do not reach the good chemical status standards as required by the European Water Framework directive. Complementary to previous federal pesticide reports, we analysed groundwater-monitoring data from 13 German Länder assembled in a database consisting of 26.192 groundwater measuring sites sampled between 1973 and 2021 of in total 521 parent compounds and metabolites. This study focuses on agricultural plant protection products. The monitored substance spectrum and site density developed over time and differs between Länder. More than 95 % of all samples lie below the respective (multiple) limits of quantification (LOQ). We thus report the frequency of exceedance above concentration thresholds, which allows to compare measurements temporally and spatially. Pesticide detections were found in all aquifer types, land uses and well screen depths. Most detections of higher concentrations were found in agricultural areas, at shallow screen depth in porous aquifers. Karst aquifers showed also a higher percentage of samples in higher concentration classes. Metabolites with high mobility and persistence were found in higher concentration ranges. Herbicides and metabolites thereof dominate the top 20 of pesticides that most frequently exceed 0.1 μg L-1. The ranking for 2010-2019 includes both authorised and banned compounds and their occurrence is discussed in the context of their mobility, persistence and underlying monitoring density. Yearly exceedance frequencies above 0.05, 0.1 μg L-1 and higher thresholds of metazachlor and its esa-metabolite, and national sales data of the parent compound did not show a temporal correlation in subsequent years. This study stresses the need for the harmonisation of heterogeneous pesticide data. Further, a characterisation of the groundwater data used to analyse pesticide occurrence in selected concentration ranges for relevant site factors and compound properties and provides a pesticide ranking based on exceedance frequencies is provided.

Expeditive carbofuran pesticide degradation by submerged thermal plasma and its accelerated mineralization by persulfate addition

Rapid degradation of carbofuran (CBF) pesticide is effectively achieved by submerged thermal plasma (STP) without and with the addition of persulfate (PS) at two different concentrations (10 and 20 ppm). Degradation efficiency was examined using high-performance liquid chromatography (HPLC), and mineralization percentage was determined by total organic carbon (TOC) analysis. Adding 10 ppm PS showed higher degradation and mineralization percentages of 99.5% and 65.2%, respectively, than mere plasma treatment and 20 ppm PS addition to CBF solution. A relatively higher energy yield of 40 mg/kWh and a first order kinetic reaction rate of 0.262 min-1 were obtained in the 10 PS added STP treatment. Liquid chromatography mass spectrometry (LCMS) analysis illustrated reaction intermediates formed during plasma treatment. Scavenger investigation implied that •OH radical is the prime cause of CBF degradation, as degradation percentage declined to 50% in all conditions. Toxicity assessment of CBF and its degradation products was predicted using Toxicity estimation software tool (TEST), and plasma treated solutions (PTS) were experimentally investigated on Eudrilus eugeniae earthworms by monitoring its mortality rate, self-assemblage, and histopathological analysis. A lower mortality rate (46%) and self-assemblage (167 s) of earthworms were detected for plasma treated CBF than for the other conditions. The results reveal that PTS is less toxic for earthworms than untreated CBF solution. These findings imply that STP is an effective technique for bio-recalcitrant pollutants degradation in agrochemical industries.

A critical review of sustainable pesticide remediation in contaminated sites: Research challenges and mechanistic insights

Incidental pesticide application on farmlands can result in contamination of off-target biota, soil, groundwater, and surrounding ecosystems. To manage these pesticide contaminations sustainably, it is important to utilize advanced approaches to pesticide decontamination. This review assesses various innovative strategies applied for remediating pesticide-contaminated sites, including physical, chemical, biological, and nanoremediation. Integrated remediation approaches appear to be more effective than singular technologies. Bioremediation and chemical remediation are considered suitable and sustainable strategies for decontaminating contaminated soils. Furthermore, this study highlights key mechanisms underlying advanced pesticide remediation that have not been systematically studied. The transformation of applied pesticides into metabolites through various biotic and chemical triggering factors is well documented. Ex-situ and in-situ technologies are the two main categories employed for pesticide remediation. However, when selecting a remediation technique, it is important to consider factors such as application sites, cost-effectiveness, and specific purpose. In this review, the sustainability of existing pesticide remediation strategies is thoroughly analyzed as a pioneering effort. Additionally, the study summarizes research uncertainties and technical challenges associated with different remediation approaches. Lastly, specific recommendations and policy advocacy are suggested to enhance contemporary remediation approaches for cleaning up pesticide-contaminated sites.

A systematic review on the current situation of emerging pollutants in Mexico: A perspective on policies, regulation, detection, and elimination in water and wastewater

Emerging pollutants (EPs) emerged as a group of new compounds whose presence in the environment has been widely detected in Mexico. In this country, different concentrations of pharmaceutical compounds, pesticides, dyes, and microplastics have been reported, which vary depending on the region and the analyzed matrix (i.e., wastewater, surface water, groundwater). The evidence of the EPs' presence focuses on the detection of them, but there is a gap in information regarding is biomonitoring and their effects in health in Mexico. The presence of these pollutants in the country associated with lack of proper regulations in the discharge and disposal of EPs. Therefore, this review aims to provide a comprehensive view of the current environmental status, policies, and frameworks regarding Mexico's situation. The review also highlights the lack of information about biomonitoring since EPs are present in water even after their treatment, leading to a critical situation, which is high exposure to humans and animals. Although, technologies to efficiently eliminate EPs are available, their application has been reported only at a laboratory scale thus far. Here, an overview of health and environmental impacts and a summary of the research works reported in Mexico from 2014 to 2023 were presented. This review concludes with a concrete point of view and perspective on the status of the EPs' research in Mexico as an alert for government entities about the necessity of measures to control the EPs disposal and treatment.

Associations between dietary pesticide residue mixture exposure and mortality in a population-based prospective cohort of men and women

BACKGROUND

There is a concern that pesticide residues, regularly detected in foods, might pose a health risk to the consumer, but epidemiological evidence is limited. We assessed the associations between dietary exposure to a mixture of pesticide residues and mortality.

METHODS

Food consumption was assessed in 68,844 participants from the Swedish Mammography Cohort and the Cohort of Swedish Men, 45-83 years at baseline (1997). Concentrations of pesticide residues detected in foods on the Swedish market (1996-1998), mainly fruits and vegetables, were obtained via monitoring programs. To assess mixture effects, we summed per food item the ratios of each single pesticide mean residue concentration divided by its acceptable daily intake to create for each participant a Dietary Pesticide Hazard Index (adjusted for energy intake and expressed per kilogram of body weight). Multivariable-adjusted Cox proportional hazards models were used to estimate hazard ratios (HR) and 95 % confidence intervals (95 %CI).

RESULTS

During 15 years of follow-up (1998-2014), a total of 16,527 deaths occurred, of which 6,238 were caused by cardiovascular disease (CVD) and 5,364 by cancer. Comparing extreme quintiles of Dietary Pesticide Hazard Index, the highest category was inversely associated with CVD mortality HR, 0.82 (95 % CI, 0.75-0.90) and with cancer mortality HR 0.82 (95 % CI 0.75-0.91). In analyses stratified by high/low Dietary Pesticide Hazard Index, similar inverse associations were observed by increasing fruit and vegetable consumption.

CONCLUSIONS

We observed no indications that dietary exposure to pesticide residue mixtures was associated with increased mortality, nor any clear indications that the benefits of fruit and vegetable consumption on mortality was compromised. Yet, our results need to be interpreted with caution.

Fate of pesticides in agricultural runoff treatment systems: Occurrence, impacts and technological progress

The levels of pesticides in air, water, and soil are gradually increasing due to its inappropriate management. In particular, agricultural runoff inflicts the damages on the ecosystem and human health at massive scale. Present study summarizes 70 studies in which investigations on removal or treatment of pesticides/insecticides/herbicides are reported. A bibliometric analysis was also done to understand the recent research trends through the analysis of 2218 publications. The specific objectives of this study are as follows: i) to inventorize the characteristics details of agriculture runoff and analyzing the occurrence and impacts of pesticides, ii) analyzing the role and interaction of pesticides in different environmental segments, iii) investigating the fate of pesticides in agriculture runoff treatment systems, iv) summarizing the experiences and findings of most commonly technology deployed for pesticides remediation in agriculture runoff including target pesticide(s), specifications, configuration of technological intervention. Among the reported technologies for pesticide treatment in agriculture runoff, constructed wetland was at the top followed by algal or photobioreactor. Among various advanced oxidation processes, photo Fenton method is mainly used for pesticides remediation such as triazine, methyl parathion, fenuron and diuron. Algal bioreactors are extensively used for a wide range of pesticides treatment including 2,4-Dichlorophenoxyacetic acid, 2-methyl-4-chlorophenoxyacetic acid, alachlor, diuron, chlorpyrifos, endosulfan, and imidacloprid; especially at lower hydraulic retention time of 2-6 h. This study highlights that hybrid approaches can offers potential opportunities for effective removal of pesticides in a more viable manner.

Recent trends in pesticides in crops: A critical review of the duality of risks-benefits and the Brazilian legislation issue

Due to the increasing population worldwide, in recent years, an exponential increase in agricultural practices has occurred in order to attend to the growing demand for food. Unfortunately, this increase is not associated with the supply of foodstuffs free of environmental pollutants. In Brazil, agriculture is one of the most important economic pillars, making the country one of the largest consumers of pesticides around the world. The intense use of pesticides, mainly glyphosate, 2,4-D, and atrazine, constitutes an essential factor in the viability of this great agricultural productivity. Sugarcane, corn, soybean, and citrus crops consume around 66% of the total pesticides worldwide, representing 76% of the planted area. Pesticide residues have been frequently detected in food and the environment, becoming a significant concern for human health. Monitoring programs for pesticide use are essential to reduce the potential negative impacts on the environment and improve the overall efficiency and sustainability of their use. However, in Brazil, the approval status of pesticide-active ingredients is very discrepant compared to other agricultural countries. Moreover, the duality of benefits and risks of pesticide application creates an economic and toxicological conflict. In this paper, we have critically reviewed the duality of risks-benefits of the use of pesticides in agriculture and the current Brazilian legislation issues. We have also compared this flawed legislation with other countries with high economic potential. Due to the negative environmental impacts on soil and water by the high levels of pesticides, remediation techniques, sustainable agriculture, and the development of new technologies can be considered some viable alternatives to reduce the levels in these compartments. Besides, this paper includes some recommendations that can be included in the coming years.