Dharmendra Kumar Singh

Effect through inhalation on human health of PM1 bound polycyclic aromatic hydrocarbons collected from foggy days in northern part of India.

We investigated the health risk from 16 polycyclic aromatic hydrocarbons (PAHs) adsorbed on submicron particles and also reported their concentrations, spatial distribution and possible sources during foggy days at Kanpur. Twenty-four urban foggy days samples gathered from Kanpur, an urban center in North India and most densely populated city in the Indo-Gangetic plain of India, were examined for 16 PAHs (2-6 rings).The mean concentration of PM1 was found to be 160.16±37.70μg/m(3). ∑16PAHs concentrations were 529.17ng/m(3) with a mean of 33.07ng/m(3). The compounds of higher molecular weight (4-6 rings) added to 70.67% of ∑PAHs mass concentration in the foggy days samples. The results of source identification by using principle component analysis (PCA) and diagnostic ratios proposed that the primary sources of PAHs were vehicular emission (primarily driven by diesel fuel) and coal combustion and the secondary source. Exposure to total PAHs in the ambient air resulted in, 95% probability total Incremental Lifetime Cancer Risk (TILCR) 3.57×10(-5) for adults and 2.08×10(-5) for children or (∼35 cancer case per million in adults and ∼20 cancer case per million in children) due to inhalation in terms of ILCR were higher than the baseline value of acceptable risk (one cancer case per million people) suggesting moderate health risk to resident human population.

Chemical characterisation and source apportionment of PM1 during massive loading at an urban location in Indo-Gangetic Plain: impact of local sources and long-range transport

This study assesses temporal variability and source contributions of PM1 (particles with aerodynamic diameter ≤ 1.0 µm) samples (n=51; November 2009–February 2010) from an urban location at Kanpur (26.30°N; 80.13°E; 142 m above mean sea-level) in the Indo-Gangetic Plain (IGP). A study period from November to February is preferred owing to massive loading of particulate matter in entire IGP. PM1 varies from 18 to 348 (Avg±SD: 113±72) µg m−3 in this study. A total of 11 trace metals, five major elements and four water-soluble inorganic species (WSIS) have been measured. Mass fraction of total metals (∑metals=trace+major) centres at 18±14 %, of which nearly 15 % is contributed by major elements. Furthermore, ∑WSIS contributes about 26 % to PM1 mass concentration. Abundance pattern among assessed WSIS in this study follows the order: ≈ > > Cl−. The K-to-PM1 mass fraction (Avg: 2 %) in conjunction with air-mass back trajectories (AMBT) indicates that the prevailing north-westerly winds transport biomass burning derived pollutants from upwind IGP. A recent version of positive matrix factorisation (PMF 5.0) has been utilised to quantify the contribution of fine-mode aerosols from various sources. The contribution from each source is highly variable and shows a strong dependence on AMBT. Events with predominant contribution from biomass burning emission (>70 %) indicate origin of air-masses from source region upwind in IGP. One of the most interesting features of our study relates to the observation that secondary aerosols (contributing as high as ~60 % to PM1 loading) are predominantly derived from stationary combustion sources ( / ratio: 0.30±0.23). Thus, our study highlights a high concentration of PM1 loading and atmospheric fog prevalent during wintertime can have a severe impact on atmospheric chemistry in the air-shed of IGP.

Source apportionment and risk assessment of PM1 bound trace metals collected during foggy and non-foggy episodes at a representative site in the Indo-Gangetic plain

The concentration, spatial distribution and source of 13-PM1 bound trace metals (Fe, Cu, Mn, Cr, Zn, Cd, Ni, K, Mg, Na, Ca, Pb and V) and adverse health effects of 5-PM1 bound trace metals (Mn, Zn, Ni, Cr and Cd) collected during foggy and non-foggy episodes are presented. Twenty-four samples from each period (foggy and non-foggy episodes) were collected from Kanpur, a typical densely populated city and the most polluted representative site in the Indo-Gangetic plain of India, and were analyzed for carcinogenic (Ni, Cr and Cd) and non-carcinogenic metals (Mn and Zn). The average mass concentration of PM1 during foggy and non-foggy episodes was found to be 160.16±37.70 and 132.87±27.97μg/m(3). Source identification via principle component analysis suggested that vehicular emission and anthropogenic, industrial and crustal dust were the dominant sources in this region. During both episodes the decreasing order of hazard quotient (Hq) for adult and children was as Mn>Cr>Cd>Ni>Zn. In a non-foggy episode the hazardous index (Hi) values of these 5 trace metals were found to be ~3.5 times higher than a foggy episodes exposed population, respectively. In a foggy episode, due to the exposure to total carcinogenic trace metals (Ni, Cr and Cd) present in the ambient air, 95% probability total incremental lifetime cancer risks (TIlcR) were ~687 cancer cases and ~402 cancer cases per million in the adult population and children population respectively. These cancer cases were ~1.6 times higher than a non-foggy episodes exposed population.

Risk assessment of submicron PM-bound hexavalent chromium during wintertime

ABSTRACT This study reports health risk assessment of PM1-bound carcinogenic hexavalent chromium [Cr(VI)] from central part of Indo-Gangetic plain (IGP) (PM1: particulate matter with aerodynamic diameter ≤1µm). Cr(VI) concentration has been estimated utilizing spectrophotometer with a modified novel method. Average ratio of Cr(VI)/CrT was 0.39 ± 0.07 (CrT: Total chromium) in the central IGP (Kanpur). Our study reports that mass fraction of Cr(VI) averaging at 0.39 is ∼3 times higher than that assumed conventionally [Cr(VI)/CrT: 1/7]. Cancer risk assessment has been performed by assessing excess cancer risk (ECR) for the Cr(VI). ECR determined due to Cr(VI) was 57 and 14.3 (in one million) for adults and children, respectively. Our study suggests that risk due to Cr(VI) reported in previous studies were being underestimated by a factor of three. The Cr(VI)/CrT average ratio of 0.39 determined in this study was utilized to calculate risk assessment due to Cr(VI) from other locations in the IGP. Owing to large population of India (∼125 million), the cancer risk due to Cr(VI) inhalation itself would become very significant. Thus, future research should focus on metal speciation of PM-bound samples from different locations to better constraint the toxicological risk assessment on a regional-to-global scale.

Consultative Jurisdiction of Supreme Court of India: Assessment and Critical Analysis

This research paper deals with the analysis of Article 143 of Consultative Jurisdiction and its nature and scope. An effort has been made to present the advantages of Consultative Jurisdiction of Supreme Court of India. The main attribute of this research paper is that some suggestive measures have been given for the cautious use of Consultative Jurisdiction. This paper also points out the criticism of Consultative Jurisdiction of Supreme Court of India and assesses the criticism with a radical approach.