High pesticide inhalation exposure from multiple spraying sources amongst applicators in Eswatini, Southern Africa

Risk assessment of airborne agricultural pesticide exposure in humans in rural China

Continuous exposure to airborne pesticides causes their gradual accumulation in the human body, eventually posing a threat to human health. To the best of our knowledge, risk assessment study of pesticide non-occupational exposure to residents in agricultural areas has not been conducted in China. In this study, air samples (gas and dust) were collected from inside and outside residences of seven households and an area near the field in a grain-growing area (wheat and maize rotation) for eight months, and the pesticides present were examined both qualitatively and quantitatively. Using a 95% confidence interval, 9 out of 16 pesticides were detected, namely acetamiprid, acetochlor, atrazine, flucarbazone-sodium, imidacloprid, methyldisulfuron-methyl, nicosulfuron-methyl, pendimethalin, and beta-cyhalothrin, and their safety was subsequently evaluated. The results showed that the inhalation exposure of households to beta-cyhalothrin exceeded the acceptable range in the first residential, and the excess lifetime cancer risk of acetochlor inhalation exposure in six households and area around the field exceeds 1E-6, which highlights the need to strengthen preventive screening for cancer risk.

Strategies for mitigation of pesticides from the environment through alternative approaches: A review of recent developments and future prospects

Chemical-based peticides are having negative impacts on both the healths of human beings and plants as well. The World Health Organisation (WHO), reported that each year, >25 million individuals in poor nations are having acute pesticide poisoning cases along with 20,000 fatal injuries at global level. Normally, only ∼0.1% of the pesticide reaches to the intended targets, and rest amount is expected to come into the food chain/environment for a longer period of time. Therefore, it is crucial to reduce the amounts of pesticides present in the soil. Physical or chemical treatments are either expensive or incapable to do so. Hence, pesticide detoxification can be achieved through bioremediation/biotechnologies, including nano-based methodologies, integrated approaches etc. These are relatively affordable, efficient and environmentally sound methods. Therefore, alternate strategies like as advanced biotechnological tools like as CRISPR Cas system, RNAi and genetic engineering for development of insects and pest resistant plants which are directly involved in the development of disease- and pest-resistant plants and indirectly reduce the use of pesticides. Omics tools and multi omics approaches like metagenomics, genomics, transcriptomics, proteomics, and metabolomics for the efficient functional gene mining and their validation for bioremediation of pesticides also discussed from the literatures. Overall, the review focuses on the most recent advancements in bioremediation methods to lessen the effects of pesticides along with the role of microorganisms in pesticides elimination. Further, pesticide detection is also a big challenge which can be done by using HPLC, GC, SERS, and LSPR ELISA etc. which have also been described in this review.

Impacts of Agricultural Pesticide Contamination: An Integrated Risk Assessment of Rural Communities of Eswatini

Marked reductions in mean annual rainfall associated with climate change in Eswatini in Southern Africa have encouraged the recycling of irrigation water and the increased use of pesticides in agricultural production, raising concerns about potential ecological and health risks due to long-term exposure to pesticide residues in soil and irrigation water. This probabilistic integrated risk assessment used liquid chromatography with tandem mass spectrometry to analyze the concentrations of four commonly used agricultural pesticides (ametryn, atrazine, pendimethalin, and 2,4-dichlorophenoxyacetic acid (2,4-D)) in irrigation water and topsoil samples from farmlands in Eswatini to assess potential ecological and health risks due to exposure. The concentrations of these pesticides ranged from undetectable to 0.104 µg/L in irrigation water and from undetectable to 2.70 µg/g in soil. The probabilistic multi-pathway and multi-route risk assessments conducted revealed hazard indices exceeding 1.0 for all age groups for ametryn and atrazine, suggesting that the daily consumption of recycled irrigation water and produce from the fields in this area may pose considerable health risks. The indices pertaining to ecological risks had values less than 0.1. Adaptation measures are recommended to efficiently manage pesticide use in agriculture, and further research will ensure that agriculture can adapt to climate change and that the general public and ecosystem are protected.

Incorporating Bioaccessibility into Inhalation Exposure Assessment of Emamectin Benzoate from Field Spraying

The inhalation exposure of pesticide applicators and residents who live close to pesticide-treated fields is a worldwide concern in public health. Quantitative assessment of exposure to pesticide inhalation health risk highlights the need to accurately assess the bioaccessibility rather than the total content in ambient air. Herein, we developed an in vitro method to estimate the inhalation bioaccessibility of emamectin benzoate and validated its applicability using a rat plasma pharmacokinetic bioassay. Emamectin benzoate was extracted using the Gamble solution, with an optimized solid-to-liquid ratio (1/250), extraction time (24 h), and agitation (200 rpm), which obtained in vitro inhalation bioaccessibility consistent with its inhalation bioavailability in vivo (32.33%). The margin of exposure (MOE) was used to assess inhalation exposure risk. The inhalation unit exposures to emamectin benzoate of applicators and residents were 11.05-28.04 and 0.02-0.04 ng/m³, respectively, varying markedly according to the methods of application, e.g., formulations and nozzles. The inhalation risk assessment using present application methods appeared to be acceptable; however, the MOE of emamectin benzoate might be overestimated by 32% without considering inhalation bioaccessibility. Collectively, our findings contribute insights into the assessment of pesticide inhalation exposure based on bioaccessibility and provide guidance for the safe application of pesticides.

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.