Preliminary analysis was performed to assess human health risks of exposure to 16 polycyclic aromatic hydrocarbons (PAHs) by way of inhalation by children and adults living in urban area of Amritsar, Punjab, India. In particular, the United States Environmental Protection Agency's (USEPA's) 16 priority PAH compounds were analyzed in air particulate matter (PM10) from different geographical locations by high-volume air sampler. Sum concentrations of PAHs (37-274 ng m(-3)) were comparable with those of other cities in India as well many cities on a global scale. Pyrene, naphthalene, acenaphthene, acenaphthylene, fluoranthene, fluorene, and dibenzo(a,h)anthracene accounted for >80% of ∑16PAH concentrations. Furthermore, the contribution of seven carcinogenic PAHs accounted for 12% of ∑16PAHs. The estimated carcinogenicity of PAHs in terms of benzo(a)pyrene toxic equivalency (BaPTEQ) was assessed and confirmed that dibenzo(a,h)anthracene was the dominant PAH contributor (88.7%) followed by benzo(a)pyrene (6.67%). Homolog pattern and diagnostic ratios of PAHs suggested that mixed pyrogenic sources--including biomass burning, coal combustion, and petrogenic sources, such as vehicular emissions--are dominant PAH sources in Amritsar. Health risk of adults and children by way of PAHs was assessed by estimating the lifetime average daily dose (LADD) and corresponding incremental lifetime cancer risk (ILCR) using USEPA guidelines. The assessed cancer risk (ILCR) was found to be within the acceptable range (10(-6)-10(-4)).

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in agricultural soils from the northern states of India. The average concentration of OCPs was 37.67 ± 0.33 ng/g (dry weight − DW) while HCHs alone accounted for 93% followed by DDT (4.27%) and endosulphan (2.51%). The α/γ ratio of HCH (< 0.01–8.64) reflects the use of technical as well as lindane formulations. The ratio of p,p’-DDT/p,p’-DDE (0.16) and o,p’-DDT/p,p’-DDT (< 0.01) indicates the contamination of soils with the past use of technical DDT. The mean concentrations of endosulphan and dieldrin were 0.95 ± 0.53 ng/g (DW)and 0.16 ± 0.07 ng/g (DW), respectively. The average concentration of PCBs was 13.44 ± 0.06 ng/g (DW). The toxic equivalency (TEQ) calculated using WHO 2005-TEFs ranged from 0.01 to 105.40 pg WHO 2005-TEQ/g (DW) with the mean of 13.78 ± 0.11 pg WHO 2005-TEQ/g (DW). PCB-105 (25%), PCB-114 (18%), and PCB-118 (18%) were the dominant congeners and accounted for 61% while a non ortho PCBs contributed only 18% to total DL-PCBs. The contamination of soils is a matter of concern but is not alarming because the observed levels were lower than those given by the Canadian soil quality guidelines.

Inadequate nutrient management is one of the major challenges for sustainable soybean production in semi-arid climatic conditions. Hence, a 3-year (2015–2017) field experiment was conducted to assess the effect of foliar application of macro- and micronutrients on the growth, productivity, and profitability of soybean. Eight foliar nutrient sprays at the pod initiation stage—water spray (WS), 2% urea solution, 2% di-ammonium phosphate solution (DAP2%), 0.5% muriate of potash solution (MOP0.5%), 2% solution of 19:19:19 nitrogen phosphorus and potassium (NPK2%), and a 0.5% solution each of molybdenum (Mo0.5%), boron (B0.5%), chelated-zinc (Zn 0.5%) and no-foliar nutrition (NFN)—were compared with a basal-applied recommended dose of fertilizers (RDF: 30 kg N, 75 kg P, and 40 kg K ha−1) in a randomized block design (RBD), replicated three times. Foliar-applied chelated Zn@0.5% (Zn0.5%) at the pod initiation stage resulted in more pods per plants. In addition to Zn0.5%, urea2%, NPK2%, and B0.5% significantly improved the pods per plant over treatment by no-foliar nutrition (NFN). The RDF-supplied soybean subsequently sprayed with Zn0.5% produced the highest seed yield, which was 18.5–37.8% higher than that of NFN treatment Yield improvement due to the application of B0.5%, DAP2%, and urea2% varied between 19.2–23.7, 16.6–20.4 and 18.6–20%, respectively. Foliar nutrition showed the largest net returns from Zn0.5%. The water-use efficiency (WUE) and production efficiency increased by 18.4–37.6 and 34.9–37.5%, respectively, due to Zn0.5% over the efficiencies from NFN treatment. Monetary efficiency (ME) gains due to Zn0.5% were 24% higher, while ME efficiency gains due to urea2%, NPK2%, and B0.5% varied between 15–16%. Thus, this study suggested that the foliar application of 0.5% Zn and B, urea, NPK fertilizer, and DAP at 2%, along with RDF. is a profitable nutrient management option for quality soybean production in a semiarid region. However, nutrient partitioning, changes in soil chemical and biological indicators, and environmental aspects need critical examination in future studies.

Distribution of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in urban soils, and their risk for humans was evaluated and presented in this article. The average concentration of ∑16PAHs, ∑carcinogenic PAHs, ∑28PCBs and ∑dioxin-like PCBs was 631.6 ± 244.5 μg kg(-1), 568.8 ± 238.8 μg kg(-1), 11.57 ± 2.00 μg kg(-1) and 2.58 ± 0.34 μg kg(-1), respectively. Environmental and human health risk assessment parameters such as benzo(a)pyrene total potency equivalent (BaP TPE), index of additive cancer risk (IACR), life time average daily dose (LADD) and incremental lifetime cancer risk (ILCR) have been estimated and discussed. The average benzo(a)pyrene total potency equivalent (BaP TPE) estimate was 0.194 mg kg(-1) and ranging between 8.9×10(-4) to 0.87 mg kg(-1). The incremental life time cancer risk (ILCR) of PAHs through soil ingestion for adults and children was estimated as 8.1×10(-6) and 4.2×10(-5), respectively. However, the cancer risk (ILCR) from non-dioxin-like PCBs and dioxin-like PCBs for adults and children ranged between 3.31×10(-8) to 1.741×10(-7) and 1.46×10(-5) to 7.56×10(-5), respectively. These estimated risks were lower than acceptable limits, based on incremental cancer risk from soil exposure. Overall, index of additive cancer risk (IACR) and hazard quotient (HQ) for PAHs and PCBs was lower than safe limit of 1, indicating no environmental and human health risk from PAHs and PCBs in this area of study.

Polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) are toxic, persistent and bioaccumulative long-range atmospheric transport pollutants. These are transported worldwide affecting remote regions far from their original sources, and can transfer into food webs with a wide range of acute and chronic health effects. India ratified the Stockholm Convention with the intention of reducing and eliminating persistent organic pollutants (POPs), and encouraged the support of research on POPs. Despite the ban and restriction on the use of these chemicals in India, their contamination of air, water, sediment, biota and humans has been reported. In this study, surface water samples were collected during January 2012 from the Yamuna River in Delhi, India, and analyzed for PCBs and organochlorine pesticides (OCPs). The concentrations of ΣPCBs and ΣOCPs ranged between 2-779 ng L^–1 and from less than 0.1 to 618 ng L^–1 (mean 99±38 ng L^–1 and 221±50 ng L^–1, respectively). The PCB homolog was dominated by 3-4 chlorinated biphenyls. In calculating the toxicity equivalent of dioxin-like PCBs (dl-PCBs)using World Health Organization toxic equivalency factors, dl-PCBs accounted for 10% of a total of 27 PCBs. The concentration of ΣHCH ranged between less than 0.1 and 285 ng L^–1 (mean 151±32 ng L^–1). However, ΣDDTs concentrations varied between less than 0.1 and 354 ng L^–1 (mean 83±26 ng L^–1). The concentrations were lower than the US guideline values; however, levels of lindane exceeded those recommended in guidelines. Further in-depth study is proposed to determine the bioaccumulation of these pollutants through aquatic biota to assess the risk of contaminants to human health