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Polycyclic aromatic hydrocarbons (PAHs) are a class of organic compounds found ubiquitously in the environment and pose serious threat to the environment and humans. PAHs have received considerable attention due to their carcinogenic properties. In this study, the 16 EPA priority PAHs were determined in agricultural surface soils (0–5 cm) from diverse agricultural land use systems in central India. ∑16 PAHs of different agricultural soil samples ranged from ND–122.52 µg/kg. Total concentration of 7 carcinogenic PAHs ranged between ND and 101.64 µg/kg. The levels of PAHs in different agricultural soil samples varied widely. In general, we observed that ∑16 PAHs concentrations in agricultural soils have followed the order: sewage irrigated soil ≥ fly ash treated agricultural soil samples > horticulture land use soil > conservation agriculture soil > organic farming soil. PAH levels in fly ash-treated soils were 2–5 times higher than that in sewage-irrigated soils. PAHs containing four to five rings were the most common. Soil organic carbon (SOC) was positively correlated with ∑16 PAHs (p < 0.05). The principal sources of PAHs in these samples according to diagnostic ratios were biomass burning (grass, wood, crop residue) and coal combustion. In addition, it was found that agricultural soils treated with fly ash and sewage irrigated soils showed higher carcinogenic potential based on B[a]Peq TEQs. PAHs with higher carcinogenic potency in these contaminated soils indicate a higher level of health risk for humans. [ABSTRACT FROM AUTHOR]

A simple procedure was developed for the direct determination of As(III) and total inorganic arsenic in water samples using continuous-flow hydride generation atomic absorption spectrometry without prereduction of As(V). Under optimized conditions, As(III) was determined using 1% w/v of NaBH4 and 0.2 mol L-1 of HCl, and total arsenic using 5% w/v of NaBH4 and 6 mol L-1 of HCl. The concentration of As(V) was determined by the difference between total inorganic arsenic and concentration of As(III). Interferences from methylated arsenic species, mutual hydride-forming, and transition elements in the determination of As(III) and total arsenic were evaluated. With the proposed procedure, detection limits of 0.1 µg L-1 for As(III) and 0.25 µg L-1 for total arsenic were achieved. The relative standard deviations were 2.0% for 2 µg L-1 of As(III) and 3.5% for 2 µg L-1 of As(V) determined as total arsenic. Spike recoveries were in the range of 91-111% for As(III) and 91-114% for As(V). The method was validated by analysing certified reference materials SRM-1640 and NASS-5. The developed methodology constitutes an economic, simple, and reliable way to determine inorganic arsenic species in natural waters and other similar samples with negligible or no content of methylated arsenic species. Speciation analysis was satisfactorily applied to different types of natural water samples. [ABSTRACT FROM AUTHOR]

Hydride generation (HG) coupled with AAS, ICP-AES, and AFS techniques for the speciation analysis of As, Sb, Se, and Te in environmental water samples is reviewed. Careful control of experimental conditions, offline/online sample pretreatment methods employing batch, continuous and flow-injection techniques, and cryogenic trapping of hydrides enable the determination of various species of hydride-forming elements without the use of chromatographic separation. Other non-chromatographic approaches include solvent extraction, ion exchange, and selective retention by microorganisms. Sample pretreatment, pH dependency of HG, and control of NaBH4/HCl concentration facilitate the determination of As(III), As(V), monomethylarsonate (MMA), and dimethylarsinate (DMA) species. Inorganic species of arsenic are dominant in terrestrial waters, whereas inorganic and methylated species are reported in seawater. Selenium and tellurium speciation analysis is based on the hydrides generation only from the tetravalent state. Se(IV) and Se(VI) are the inorganic selenium species mostly reported in environmental samples, whereas speciation of tellurium is rarely reported. Antimony speciation analysis is based on the slow kinetics of hydride formation from the pentavalent state and is mainly reported in seawater samples. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are ubiquitous in terrestrial and marine environments. This research work studied the occurrence, distribution of MPs and heavy metals associated with these MPs in soils of different land- use types viz. residential, commercial, and industrial areas. We identified 15 types of MP polymers, of which polypropylene (15.51%), polyethylene (12.28%), polyamide (9.57%) were dominant. MPs abundance ranged from 8.54 × 104 to 8.51 × 105 particles/kg of soil. Average abundance of MPs in the three fractions viz. < 1 mm, 1–2 mm, and 2–5 mm were 1.85 × 105, 1.31 × 105, and 697.5 particles/kg of soil, respectively. Among the three land use types, MPs abundance in < 1 mm and 1–2 mm soil fractions were significantly higher in residential areas than that in commercial and industrial areas, i.e. <1 mm: 3.4 × 105, 1.26 × 104 and 9.0 × 104, and 1–2 mm: 2.35 × 105, 8.36 × 104, and 7.50 × 104 particles/kg, respectively, for residential, commercial and industrial areas respectively. The average concentration of Cr, Fe, Mn, Cd, Co, Ni, Cu and Pb in soils were 31.79, 11047.29, 423.92, 0.05, 11.86, 17.53, 125.95 and 28.29 mg/kg, respectively, whereas that in MPs were 6.27, 2181.64, 277.36, 0.24, 6.43, 8.29, 47.05 and 9.24 mg/kg, respectively. Concentration of Cd sorbed on MPs was higher than those found in soils. Also, Pb and Cd in MPs were positively correlated to MPs abundance, indicating MPs can be vectors of heavy metals in soils. The synergistic effect of MPs and heavy metals might put soil organisms at risk. [ABSTRACT FROM AUTHOR]

Synthetic polymers with additives are used in the manufacturing of face masks (FMs); hence, FMs could be a potential source of exposure to phthalic acid esters (PAEs). India stands second in the world in terms of the FMs usage since the beginning of Covid-19 pandemic. However, little is known about the PAEs content of FMs used in India. Some PAEs, such as DEHP and DBP are suspected endocrine disrupting chemicals (EDCs); hence, wearing FM may increase the risk of exposure to these EDCs. In this study, we collected 91 samples of FMs from eight Indian cities and analyzed for five PAEs viz. DMP, DEP, DBP, BBP, and DEHP. The PAEs contents in FMs ranged from 101.79 to 27,948.64 ng/g. The carcinogenic risk of N 95 with filter, N-95, and cloth masks was higher than the threshold levels. The findings indicate the need to control PAEs in FMs through regulatory actions. [ABSTRACT FROM AUTHOR]