D. G. Gajghate

Particle Size Distribution in Ambient Air of Delhi and Its Statistical Analysis

Particle size distribution in ambient air has been studied in an urban city, Delhi. Different activity sites namely; kerbside, industrial and residential were selected for the study. The statistical analysis was carried out to study the frequency distribution and sources of different particle size fractions. The dominance of coarse particles attributed to local activities was observed at all the sites. It was observed that at kerbside sites, up to 52% of the particles were lower respiratory tract and up to 47% of the particles were upper respiratory tract particles. At residential and industrial sites, up to 40% and 31% were lower and upper respiratory tract particles, respectively. Factor analysis results indicated auto-exhaust as the dominant source of particulate matter at two of the kerbside sites. Resuspended dust was dominant at remaining two kerbside and residential sites. It was inferred using geometric standard deviation of particle size fractions that these were from different sources at residential and industrial site and from similar sources at three of the kerbside sites.

Assessment of air pollution from small scale industry

Air pollution due to small scale industries have been found tocause serious occupational health hazards and adverse effects on vegetation and heritage. The study for air pollution impactassessment for brick kiln industries was undertaken. The stackmonitoring exercise was carried out to estimate the pollution level of SPM, SO2, and NOx. The ambient air quality was also measured in the vicinity of brick kilns to assess the impact of stack emission on ground level concentration. Characterisation of SPM for toxic metals were studied. Modelling exercise was carried to predict the impact of emission of brick kiln on surrounding environment. To minimise the emission level and ground level concentration, airpollution mitigation measures are suggested.

Assessment of Airborne Fine Particulate Matter and Particle Size Distribution in Settled Chalk Dust during Writing and Dusting Exercises in a Classroom

Airborne PM1, PM2.5, PM5 and PM10 generated during writing with three types of chalk sticks on a board and particle size distribution of chalk dust fall during writing and dusting of board were studied by portable aerosol spectrometer and particle size analyzer. ‘Local Gypsum’ chalk led to the highest increase in airborne particulate matter while ‘Clean-Write’ the least during writing. About 10% of particles in chalk dust fall during writing were finest from: ‘Clean Write’ (0.5 µm) followed by ‘Abroad Quality’ (0.67 µm) and ‘Local Gypsum’ (1.15 µm), while 50% was finest in abroad quality (5.12 µm) followed by ‘Clean Write’ (6.36 µm) and ‘Local Gypsum’ (77.65 µm). In dusting samples, 10%, 50% and 90% of particles were finest in ‘Clean Write’ followed by ‘Abroad Quality’ and ‘Local Gypsum’ chalks. ‘Clean Write’ chalk produced least total amount of PM1, PM2.4 and PM5 and PM10 per unit time in dust fall during writing. Although short-term exposure to airborne fine chalk particles may be low in classrooms, several years of exposure may be a matter of concern. Purpose of this work was to provide data that would lead to measures for minimization of health risk due to chalk dusts in classrooms.

Chemical Characterization of PM10 for Metals in Ambient Air of Chennai, India

AbstractThe study was undertaken to assess the effect on ambient air concentration of PM10 and metals attributed to various localized activities at different land-use locations in Chennai City, India. The study for PM10, toxic metals, and correlation of metal and source apportionment analysis has been carried out at industrial, commercial and residential locations in the city. The monthly PM10 levels showed a significant variation among locations, and annual averages of PM10 were below the CPCB standards. Among the metals analyzed, Zn was found to dominate in all the monitoring locations. The source apportionment studies have indicated that oil burning emissions, waste incinerators and resuspension of road dust are major sources of PM10 in the study region.

Interaction of Urban Vegetation Cover to Sequester Air Pollutants from Ambient Air Environment

Acute air pollution problem is being faced in urban agglomeration due to economic expansion, increase in population, increased industrial activities and exponential growth in automobiles. The air pollution from these sources is imposing threat to urban human health. The morbidity and mortality caused by air pollution result in long term reduction of productivity and ultimately in overall deterioration of economic condition (Dockery & Pope, 1994; Anderson et al., 1992; Schwartz et al., 1996). In India the particulate matter problem is very significant due to the huge number of vehicles plying on the road, number of power plants, combustion processes, dust storms and domestic emissions (Gurjara et al., 2004). In the recent studies, exceeding levels of PM10 are observed (TERI, 1997; Chelani et al., 2001). The trees in urban environment are continuously exposed to air pollutants, which play an important role in maintaining ecological balance by actively participating in the nutrients cycle. Many trees are effective for trapping and absorbing air pollutants and acts as sink to several air pollutants (Allan & Krupa, 1986; Bell & Treshow, 2002; Farmer, 1993; Barker & Tingey, 1992; De Kok & Whaltey 1984; De Kok & Stulen, 1998; Treshaw & Anderson, 1989; Nowak et al. 1997; Shyam et al., 2006). Hence it is more beneficial to see the impact of pollution on vegetation especially on roadside trees. (Gajghate & Hasan, 1999; Kotoh et al. 1989; Kozhauharov et.al. 1985; Ninave et.al., 2001; Mellios et al., 2006; Mutena, 2004; Tommervik et al., 1995). Nagpur City is the best place to study the interactions of atmospheric pollutants such as SO2, NO2 and suspended particulate matter (SPM) on vegetation, as it is high traffic zone with industrial area on the outskirts as well as have good vegetation cover in the city. Nagpur city is very well known as second Green City in India. Plantations are actively carried out every year in the city with the active participation of local administration and non-governmental organizations (NGOs). The city is also richly dotted by well maintained parks, plantations, forest patches and agricultural fields. This has given lush green aesthetic appearance to the Nagpur city. Present research is carried out, to study the status of urban pollution in relation to biodiversity in the Nagpur city using ambient air quality monitoring, remote sensing for landuse cover, ground truth and anatomical and biochemical responses of the trees to air pollution.

Assessment Of Impacts Of A Fossil Fuel Based Power Plant

Prediction of air pollution impacts of a proposed fossil fuel-based power plant has been made using meteorological data, information on stack characteristics and emission rate, baseline air quality and validated model condition. It is observed that under normal operation, the emission rate of SO 2 and NO 2 is significant, while under a worst case scenario, the SPM emission rate is significant. It has been predicted that 24-hr average SO 2 , NO 2 and SPM concentrations due to proposed plant in normal operation would be around 38 w g/m 3 , 40 w g/m 3 and less than 1 w g/m 3 , respectively, beyond the site boundary. The total 24-hr average SPM concentration under the worst case beyond site boundary would be below the national air quality standard for SPM in a mixed industrial area. Therefore, the impact of proposed power plant on local air quality would be acceptable. However, the implementation of a green belt comprising various tree spacies which will act as dust attenuators around the site boundary alongwith efficient control measures at source would efficiently mitigate and minimised pollution impacts from the proposed power plant.