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Organophosphates are one of the major constituent of herbicides, pesticides, insecticides and nerve gas. Azinophos-methyl, chlorpyrifos, diazinon, fonofos and disulfoton are well-known organophosphate pesticides (OPs) having extensive applications in agriculture, horticulture, pest control, plastic making, flame retardants and for several household applications. OPs are the ester forms of phosphoric acid, usually considered as safe for agriculture use due to their relatively fast degradation rates. Acute or chronic exposure to OPs can produce varying levels of toxicity in humans, animals, plants, and insects. These are known to inhibit acetylcholinesterase activity, not only in insects but also in aquatic and terrestrial organisms leading to respiratory, reproductive, nervous, hepatic and renal abnormalities. OPs disrupt the growth promoting mechanism by inhibiting various enzymes, transcuticular diffusion and permeability which is essential for the growth of plants. Regular use of OPs subside the microbial community and reduces soil fertility. Due to environmental concerns associated with the accumulation of OPs in food products and water supplies, there is an urgent need to develop rapid, reliable and economical method amenable to onsite applications. Here, we review different classes of organophosphate pesticides, their environmental issues, analytical techniques for estimation, and eco-friendly biodegradation approaches for its efficient bioremediation. [ABSTRACT FROM AUTHOR]

The phytochemical content and toxicity (mg/kg) of aqueous extracts of Calotropis procera and Persea americana,were evaluated. The roots of C. procera and seeds of P. americana were powdered and percolated in water for 24 hours for aqueous extract. The toxicity was evaluated in two phases (I and II) according to Lorke's method. Twenty-six Wistar rats were divided into two supergroups for two plants. For each extract thirteen rats were divided into, nine rats for phase I and the remaining four for phase II tests. In phase I, nine rats were placed into three groups, each of three ratsandadministered with 10,100, and 1000mg/kg of the extract. In phase II, the remaining four rats were each administered with 2000, 4000, 8000, and 16000mg/kg of the extract respectively. Results showed that the plant samples after a maximum equivalent dose of 16000mg/kg were relatively harmless. Phytochemical analysis of the aqueous seed and root extract showed the presence of flavonoids, cardiac glycoside and absence of tannins, alkaloids and saponins in Calotropis procera while resin was absent in both extracts. In conclusion the aqueous seed of P. americana and root of C. procera may be relatively safe and the acclaimed medicinal property associated with these plants may be due to the presence of this particular phytochemical. [ABSTRACT FROM AUTHOR]

Chromium is detected in most ecosystems due to the increased anthropogenic activities in addition to that developed from natural pollution. Chromium contamination in the food chain results due to its persistent and non-degradable nature. The release of chromium in the ecosystem accretes and thereafter impacts different life forms, including humans, aquatic and terrestrial organisms. Leaching of chromium into the ground and surface water triggers several health ailments, such as dermatitis, eczematous skin, allergic reactions, mucous and skin membrane ulcerations, allergic asthmatic reactions, bronchial carcinoma and gastroenteritis. Physiological and biological treatments for the removal of chromium have been discussed in depth in the present communication. Adsorption and biological treatment methods are proven to be alternatives to chemical removal techniques in terms of cost-effectiveness and low sludge formation. Chromium sensing is an alternative approach for regular monitoring of chromium in different water bodies. This review intended to explore different classes of sensors for chromium monitoring. However, the spectrochemical methods are more sensitive in chromium ions sensing than electrochemical methods. Future study should focus on miniaturization for portability and on-site measurements without requiring a large instrument provides a good aspect for future research. [Display omitted] • Effective processes for chromium removal from wastewater are evaluated. • Discussion on chromium removal technologies along with advantages and limitations. • New sensing technologies for the monitoring of chromium have been explored. • Spectrochemical methods are more sensitive in chromium sensing over electrochemical methods. [ABSTRACT FROM AUTHOR]

With millions of tonnes of plastic pollution generated every year, small-sized plastic particles, including micro- and nanoplastics, end up in freshwater systems. Due to the very small size and very large specific surface area of nanoplastics, they are known to be persistent and toxic in our environment. These particles are also known to react with other water-borne contaminants and cause acute toxicity in organisms. Nanoplastics are prone to biomagnification and can be transported to humans through various pathways. This study aims to contribute towards understanding the behaviour of nanoplastics in our environment, specifically through identification of various sources, detection techniques, toxicity estimation, health risk in humans, environmental fate, recovery and reuse, and future challenges and limitations. Detailed review on the toxic effects of nanoplastics on various organisms and their degradation rates in soil and water matrices are provided. The suitability of small- and large-scale separation techniques for the removal of nanoplastics in wastewater treatment plants is also discussed. Current challenges and future perspectives in understanding the fate and transport of nanoplastics in the environment are also discussed. Research gaps, including the development of quantification techniques, estimation of degradation mechanisms, transport in marine ecosystems, and development of sensors to examine nanoplastics in the environment, are explored. Finally, we can limit the release of nanoplastics to the environment through reduction, reuse and recycling (3 Rs) of bulk plastic products. [Display omitted] • Degradation of micro (nano) plastics and its toxicity in the environment are discussed. • Micro (nano) sources, detection, risk, fate, and future challenges are presented. • Opinion on micro (nano) removal techniques, recovery and reuse are provided. • Development of sensors to assess micro (nano) plastics are suggested in future work. [ABSTRACT FROM AUTHOR]