Search

In developing countries, rapid urbanization and industrialization cause heavy metal contamination, including lead (Pb). India is one of the most developing countries where anthropogenic sources are the chief generators of Pb contaminants. Mining, smelting Pb containing paints, papers, gasoline, and municipal sewage sludge enriched with Pb come in contact with a natural drain subsequently used for irrigation and cultivation of food crops and vegetables. Wastewater irrigated crops tend to cause contamination with Pb and thus pose a threat to the environment and human beings. The present review explored the anthropogenic sources of Pb and its bioaccumulation in vegetables and further consequences on human health. It also focused on reducing the phyto-bioavailability and accumulation of Pb in vegetables by using various improved strategies. Approaches like biochar application, microbes and their combination with biochar, co-remediation, co-cropping, nanoparticle-based method, biofilters, and fertilizers might hinder the subsequent transfer of Pb and other heavy metals in the food chain system and reduce the health risk. [ABSTRACT FROM AUTHOR]

This study investigates the occurrence and characterization of microplastic (MP) in sewage sludge from 3 different cities along the Ganga River, India and their toxic impact while applying sludge for crop production. MP occurred in the ranges of 29.2–60.8 × 103 particles kg−1 with an abundance of 1–5 mm (11.12%), <1 mm–100 μm (32.65%), and 20–100 μm (56.23%) size particles. ATR-FTIR analysis suggested polypropylene, polyethylene, nylon, and polycarbonate as sludge's most common MP polymer. In lab scale trials, sludge MP showed significant toxicity in Vigna radiata and reduced vegetative growth and plant weight was recorded with sludge-inoculated setups. Seedlings with sludge exhibited higher activities of catalase, superoxide dismutase, hydrogen peroxide (H 2 O 2), and malondialdehyde than the control setups. Furthermore, fluorescence microscopy confirmed the MP bioaccumulation in tested seedlings. In summary, our results suggested that wastewater treatment plants (WWTPs) sink large volumes of MP in sewage sludge, which could be hazardous while applying such biosolids for crop production. MP seasonal dynamics in local WWTPs and their role in the mobilization of other toxicant chemicals could be investigated in future studies in this series. [Display omitted] • MP load in sewage sludge ranged between 29.2 and 60.8 × 103 particles/kg. • MP-sized 20–100 μm were higher in sludge. • The plant grown in sludge showed low growth but high oxidative stress. • Fluorescence microscopy confirms the MP accumulation in seedling roots. [ABSTRACT FROM AUTHOR]