The study investigated the levels of organochlorine pesticides (OCPs) in different types of vegetables grown in periurban area of National Capital Region (NCR), India. Vegetable sampling was carried out in winter and summer season of 2012. A total of 20 different OCPs were determined using gas chromatography (GC) assembled with electron capture detector (ECD). Obtained results showed that average levels of ∑(20)OCP ranged from 83.8 ± 25.5 ng g(-1) in smooth gourd to 222.4 ± 90.0 ng g(-1) in cauliflower. The mean concentrations of different OCPs were observed in order of ∑HCH > ∑CHLs > drins > ∑endosulfan > ∑DDT in all vegetables except in brinjal and smooth gourd. Most of the OCP residues recorded in vegetable samples exceeded the maximum residue levels (MRLs) set by international and national regulatory agencies. Health risk assessment suggests that daily dietary OCP exposure via vegetable consumption was higher for children (mean value 4.25E-05) than adults (mean value 2.19E-05). The hazard quotient (HQ) and lifetime cancer risk (LCR) estimated from dietary exposure of these vegetables were above the acceptable limit and can be considered as a serious concern for Delhi population.

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The present study investigates the characteristics of carbonaceous species like organic carbon (OC) and elemental carbon (EC) in ambient total suspended particulates (TSP) at Bhimtal (high altitude urban, 1413 m asl) and Pantnagar (lowland urban, 224 m asl) sites of Kumaon province in Uttarakhand, Indian Himalayan region during winter and summer 2017–2018. Ambient TSP samples were taken on quartz filters with high volume sampler followed by OC and EC quantification using IMPROVE_thermal optical reflectance protocol. Results showed that distinct seasonal differences in carbonaceous species levels were observed at both sites, while day- and night-time concentrations did not show notable variations. Further, total carbonaceous aerosols (TCA) at Pantnagar were approximately 3.0 and 1.3 times higher than Bhimtal for winter and summer, respectively, where estimated TCA accounted for ~ 30% to total TSP at both sites. Among quantified eight carbon fractions, OC2 and OC3 at Bhimtal while EC1 and EC2 at Pantnagar were the most abundant components. The char-EC and soot-EC concentrations showed a similar seasonal pattern where char contributed significantly as 89–90% to total EC at both sites. The observed OC/EC ratios suggested the formation of secondary organic carbon and char-EC/soot-EC ratios implied biomass burning as major sources for carbonaceous aerosols. Pearson correlation analysis indicated that char-EC showed significant higher correlations with OC and EC than soot-EC which infers different formation mechanisms of char and soot. Most of the carbonaceous parameters exhibited contrasting positive and negative correlations with the boundary layer height, temperature, and solar radiation at Bhimtal and Pantnagar, respectively.

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