Rail is a significant mode of transport to move people and freight

Rail is a significant mode of transport to move people and freight. Generally, diesel-engine trains have a great impact on air quality (Putz et al, 2014). The various research investigations on Air Quality evaluation in several Indian cities (Kolkata, Delhi, Mumbai, Chennai, and Kochi) reveal that the presence of particulate matter (PM2.5 and PM10) has a significant impact on health, resulting in a decrease in lung function (Kumar et al., 2014). There are 8000-8500 railway stations in India. Out of these, 112 railway stations are present in the state of Assam. The railway station of Jorhat, one of the main stations in upper Assam of Northeast India, is part of Tinisukia railway division of Northeast frontier railway zone. Jorhat is also one of the fastest developing cities of Assam after Guwahati and having a population density of 383 people Km?2. The station is situated in the main town area. In India, the air quality around the train station is not well documented, with no information on the air quality impacts associated with rail transport for residents stations close to the rail traffic. In recent year, particulate matter has been broadly studied due to its potential environmental and health impacts and its control (Sharma and Maloo, 2005). Diesel trains emit a complex mixture of aerosol, including NOx, SO2, NH3, organic compounds PAHs/VOCs, and various aldehydes (NIOSH, 1988). Mineral particles are also a major constituent of atmospheric aerosols. Suspended mineral particles, termed as aerosols or mineral dust, ranging in size from 0.001 to 10 µm. The particulate (PM10) emission from diesel is the main source of elemental carbon (EC) to the atmospheric environment (Schauer et al, 1996) which could affect the elemental carbon ratio in airborne particulates in diurnal patterns (Harley, 2005). These particles originate from different natural and anthropogenic sources such as wind erosion, volcanic eruption, sea salt spray, desert dust, agricultural land management, biomass burning, fossil fuel, and road transport. the fine (0.1-2.5µm) and ultra-fine (0.1 µm) particulate matter may stay in the atmosphere for days or weeks and it can also travel thousands of km from their source (Tyagi, 2009). Based on source, formation, and aging, airborne particles are composed of a wide variety of natural and anthropogenic materials including silicates (clays and quartz), oxides (such as iron and uranium), sulphates (gypsum, anglesite), carbonates (dolomite, calcite), and carbonaceous particles (such as soot) (Gieré and Vaughan, 2011). Emissions from diesel fuel and fossil fuel burning may lead to the formation of secondary aerosol which is formed from dimethyl sulphide (DMS) (Haywood, 2000). Aerosol particles play a key role in regional and global climate change (Jian et al., 2012). These include both the particulate matters and suspending gas. When the sizes of the aerosol particles are sufficiently large, it becomes visible as haze, fog, and smoke. Airborne aerosols are present in an extremely variable concentration in the atmosphere. It is because of very large heterogeneity in aerosol sources and their relatively short residence time in the atmosphere (hours to a week). The ultrafine particles consisting of diameters less than 100 nm are associated with several health effects (Brand et al., 2013; Brown et al., 2001; Seigneur, 2009). Recent investigation reveals that particulate matter can enter the cell membranes and even reach the human brain (Kesper et al., 2007). Certain particulates and minerals formed by anthropogenic activities are associated with harmful respiratory health effects are well established (Abelson, 1998). Annually 3.1 million deaths may occur due to the emissions of particulate matter from different sources (WHO 2012).
According to the World Health Organization, diesel particulate matter is classified as being carcinogenic to humans (WHO, 2012; U.S.DHHS, 2011). Many atmospheric organic pollutants (polycyclic aromatic hydrocarbons) are associated with aerosols which are carcinogenic, genotoxic, and mutagenic in small concentrations (ElAssouli et.al., 2007; Claxton and Woodall Jr, 2007; Poli et.al., 1992; Saikia et. al., 2016).
Airborne particulates can more readily penetrate into the lungs and are, therefore, more likely to have long and short-term effects such as on lung functions and alternations in lung tissue, premature death, increased respiratory symptoms and disease (Sharma and Maloo, 2005).
Since road dust and diesel exhaust particulate matter are useful indicators of the atmospheric environmental quality of a railway station, it was decided to assess the air quality and to measure the concentrations of particulate matters around of it. The main objective of the present investigation is to the physico-chemical characterization of PM10 (aerodynamic size of 10 µm) collected around Jorhat Railway station platform were analyzed using advanced analytical techniques like Ion Chromatography, XRD, FT-IR, ICP-OES, HPLC, FE-SEM, HR-TEM, and XPS. The result will serve as emission inventory for precautions of measure by the concerned authority.