Toxic effects of organophosphate pesticide monocrotophos in aquatic organisms: A review of challenges, regulations and future perspectives

UV-activated calcium peroxide system enables simultaneous organophosphorus degradation, phosphate recovery, and carbon fixation

Advanced oxidation processes are a desirable technology for treatment of contaminants of emerging concern. Nevertheless, conventional advanced oxidation of organophosphorus compounds releases inorganic phosphate, posing downstream concerns related to eutrophication. For this reason, we evaluated the ultraviolet light-activated calcium peroxide (UV/CaO2) system for effective treatment of organophosphorus compounds and concurrent capture of the mineralization products, phosphate. The degradation mechanisms, reaction kinetics, and mineralizations were assessed to determine the overall efficiency and performance of the UV/CaO2 process. Knowledge gaps related to photocatalysis in the UV/CaO2 system were not only addressed, but also leveraged to identify unique advantages for removal of organophosphorus compounds and their degradation products. Experimental results confirmed that the UV/CaO2 system effectively mineralized organophosphorus compounds and recovered inorganic phosphate; additionally, collaborative carbon fixation performance of the system reveals the potential of carbon utilization. These outcomes were facilitated by the alkaline environment generated by CaO2. The recovered solids contained most of the phosphorus and carbon from the parent compounds. Ultimately, these findings provide transformative, new insights into the development and application of advanced oxidation processes that prevent downstream concerns related to mineralization products, especially inorganic phosphorus and carbon.

Synergistic insights into pesticide persistence and microbial dynamics for bioremediation

Rampant use of fertilizers and pesticides for boosting agricultural crop productivity has proven detrimental impact on land, water, and air quality globally. Although fertilizers and pesticides ensure greater food security, their unscientific management negatively impacts soil fertility, structure of soil microbiome and ultimately human health and hygiene. Pesticides exert varying impacts on soil properties and microbial community functions, contingent on factors such as their chemical structure, mode of action, toxicity, and dose-response characteristics. The diversity of bacterial responses to different pesticides presents a valuable opportunity for pesticide remediation. In this context, OMICS technologies are currently under development, and notable advancements in gene editing, including CRISPR technologies, have facilitated bacterial engineering, opening promising avenues for reducing toxicity and enhancing biological remediation. This paper provides a holistic overview of pesticide dynamics, with a specific focus on organophosphate, organochlorine, and pyrethroids. It covers their occurrence, activity, and potential mitigation strategies, with an emphasis on the microbial degradation route. Subsequently, the pesticide degradation pathways, associated genes and regulatory mechanisms, associated OMICS approaches in soil microbes with a special emphasis on CRISPR/Cas9 are also being discussed. Here, we analyze key environmental factors that significantly impact pesticide degradation mechanisms and underscore the urgency of developing alternative strategies to diminish our reliance on synthetic chemicals.

A novel ultrafast and highly sensitive NIR fluorescent probe for the detection of organophosphorus pesticides in foods and biological systems

The threat posed by organophosphorus pesticides (OPS) to food safety, human health, and the ecological environment is significant, which underscoring the need for the development of new detection tools. We designed and synthesized a NIR fluorescent probe PT-CES which targets carboxylesterase (CES), for the detection of OPS based on the principle of enzyme inhibition. The PT-CES is capable of instantaneous response to CES, exhibiting excellent stability, anti-interference capability. PT-CES realizes the quantitative detection of CES and OPS. It is noteworthy that PT-CES shows excellent stable and accurate detection ability in vegetable pesticide testing. It also enables the monitoring of CES activity in cells and liver tissue. This provides a novel tool for tracking the effect of OPS on CES activity in biological systems. Furthermore, it provides a useful method for ensuring food safety and enhancing pesticide residue analysis.

The toxicity assessment of phosmet on development, reproduction, and gene expression in Daphnia magna

The use of pesticides to control pests, weeds, and diseases or to regulate plant growth is indispensable in agricultural production. However, the excessive use of these chemicals has led to significant concern about their potential negative impacts on health and the environment. Phosmet is one such pesticide that is commonly used on plants and animals against cold moth, aphids, mites, suckers, and fruit flies. Here, we investigated the effects of phosmet on a model organism, Daphnia magna using acute and chronic toxicity endpoints such as lethality, mobility, genotoxicity, reproduction, and gene expression. We performed survival experiments in six-well plates at seven different concentrations (0.01, 0.1, 1, 10, 25, 50, 100 μM) as well as the control in three replicates. We observed statistically significant mortality rates at 25 µM and above upon 24 h of exposure, and at 1 µM and above following 48 h of exposure. Genotoxicity analysis, reproduction assay and qPCR analysis were carried out at concentrations of 0.01 and 0.1 μM phosmet as these concentrations did not show any lethality. Comet assay showed that exposure to phosmet resulted in significant DNA damage in the cells. Interestingly, 0.1 μM phosmet produced more offspring per adult compared to the control group indicating a hormetic response. Gene expression profiles demonstrated several genes involved in different physiological pathways, including oxidative stress, detoxification, immune system, hypoxia and iron homeostasis. Taken together, our results indicate that phosmet has negative effects on Daphnia magna in a dose- and time-dependent manner and could also induce lethal and physiological toxicities to other aquatic organisms.