Development of an indigenous sensor for sub-micron aerosol monitoring in India

Abstract

Environmental pollutants might be present in different media as well as they can easily migrate between air, water and soil. These contaminants can migrate from one media to another. Many epidemiological studies have linked particulate matter (PM) and especially the PM2.5 (aerodynamic diameter dp < 2.5 μm) mass to adverse cardiovascular and respiratory health effects. These health effects include premature mortality, asthma exacerbation, decreased lung function, and increased risk of myocardial infarction among others. These tiny inhalable particles are composed of various heterogeneously mixed chemical species including sulfate, nitrate, ammonium ions, sea salt, organic and elemental carbon, metals, and biological material. Past studies have suggested that specific toxic components like heavy metals, PAHs or biological components like endotoxins are responsible for irregular heart and lung function in animal models. Accurate measurement of contaminants in various media is the first step towards their effective control. This chapter describes the lab development and field evaluation of an inertial impaction based indigenous sensor for sub-micron aerosol monitoring developed at IIT Kanpur. Submicron particles (PM1) were collected during the winter season at Kanpur, India. These samples were chemically characterized for various species like As, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, Ti, V, Zn, F-, Cl-, NO3-, SO42- and NH4+. These quantitative details were used to apportion air pollutant sources using Positive Matrix Factorization (PMF) coupled with conditional probability function (CPF) to determine the likely direction of each source from receptor site. This low cost instrument is now commercially available in the Indian market.