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The study reports snow chemistry and long range transport of pollutants at Gulmarg in north-western Himalayan region of India during winters of 2012-2013. The pH of snowmelt varied between 5.16 and 7.68 with an average of 5.90. The frequency distribution of pH of snowmelt showed that the maximum number of samples (31%) had pH between 6.81 and 7.20. However, 12% samples were observed to be acidic (below 5.6 respectively. Both local emissions as well as long range transport (LRT) of pollutants were found to be the sources of these ionic species. Backward airmass trajectory calculations showed that this site received airmasses from six major sectors i.e., i) North Atlantic Ocean origin (NAO), ii) African origin (Af), iii) Middle East origin (ME), iv) European origin (Eu), v) Western India origin (InW), vi) Pakistan origin (Pk). The highest average pH (7.58) of the snowfall was noticed during InW airmasses which had the lowest ratios of nssSO 4 2-/nssCa 2+ and NO 3 -/nssCa 2+ . Very high pH has been observed in precipitation samples at Indian sites due to buffering of acidic components by atmospheric dust rich in CaCO 3 . The lowest pH (4.94) was noticed for ME airmasses which had the highest nssSO 4 2-/nssCa 2+ and NO 3 -/nssCa 2+ ratios. Data of present study was compared with a study reported almost three decades ago. We noticed a drastic increase in the concentrations of anthropogenic components such as nssSO 4 2-(114%), NO 3 -(109%) and NH 4 + (90%). This is probably due to increase in LRT of pollutants as well as local activities during past three decades.

This study reports dustfall deposition on foliar surfaces of two medicinally important plant species i.e., Arjun (Terminalia arjuna) and Morus (Morus alba) in relation with its impact on biochemical constituents and surfaces morphology of the foliar. The study was carried out at a residential (JNU) and an industrial site (SB) of National Capital Region (NCR) Delhi. The results showed that at the industrial site, the dustfall fluxes were almost 2.5 times higher than that at the residential site. Dustfall fluxes were noticed higher on Morus foliar than Arjun foliar as the roughness of Morus foliar is greater. ) ions were also calculated by analyzing aqueous extract of dustfall at both the site. The results showed that with the increase in dustfall fluxes on the foliar surfaces, the levels of photosynthetic pigments and soluble sugar decreased while the levels of ascorbic and proline amino acid were increased at both the sites for both the plants. Dustfall fluxes had distinct seasonality having the order of fluxes as winter > summer > monsoon. Surface morphological study revealed that dust deposition adversely affects the foliar surface, cuticle and epidermal layers. Dust particle deposition ruptures and blocks the stomatal pores. As compared to the residential site, the foliar samples collected from the industrial site showed a more significant impact of dust on biochemical constituents and surface morphology.

Abundance of CaCO3 rich soil dust is a typical feature of atmospheric environment in the Indian region. During prevailing dry weather conditions, dustfall is deposited onto the foliar surfaces of plant affecting their morphology, stomata and the levels of biochemical constituents. This study reports the chemical characteristics of dustfall, its effect on foliar morphology and biochemical constituents of a medicinal plant (Morus alba) at two sites which are differentiated on the basis of landuse pattern, viz., (i) residential, Jawaharlal Nehru University (JNU), and (ii) industrial, Sahibabad (SB), located in the National Capital Region (NCR) of Delhi. Dustfall was characterized for major anions (F(-), Cl(-), NO3 (-) and SO4 (--)) and cations (Na(+), NH4 (+), K(+), Mg(++) and Ca(++)). Biochemical parameters such as chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, proline and ascorbic acid were determined in foliar samples. The results showed that the dustfall fluxes of all the major ions were found to be higher at the industrial site (SB) as compared to the residential site (JNU). Foliar analysis revealed that the levels of biochemical parameters were more affected at SB site due to higher levels of dust SO4 (--) contributed by various anthropogenic sources resulting in more stressful conditions affecting the biochemistry of the plant. The possible entry pathways for dust SO4 (--) into foliar cells are also discussed in the paper. It was noticed that the deposition of urban dust was responsible for the damage of trichome, epidermis, cuticle and stomatal guard cells significantly affecting foliar morphology. SB exhibited more damage to these morphological parts suggesting that industrial dust is harmful to the plants.