G.G. Pandit

Urban air quality in the Asian region

Over the past decade, member states of the Regional Co-operation Agreement (RCA), an intergovernmental agreement for the East Asia and Pacific region under the auspices of the IAEA with the assistance of international organizations and financial institutions such as the World Bank and the Asian Development Bank, have started to set in place policies and legislation for air pollution abatement. To support planning and evaluate the effectiveness of control programs, data are needed that characterizes urban air quality. The focus of this measurement program describe in this report is on size segregated particulate air pollution. Such airborne particulate matter can have a significant impact on human health and urban visibility. These data provide the input to receptor models that may permit the mitigation of these impacts by identification and quantitative apportionment of the particle sources. The aim of this report is to provide an overview of the measurements of concentrations and composition of particulate air pollution in two size fractions across the participating countries. For many of the large cities in this region, the measured particulate matter concentrations are greater than air quality standards or guidelines that have been adopted in developed countries.

Volatile organic compounds in indoor environments in Mumbai, India

Air samples, representing different types of indoor environments, were collected and analyzed for eight hydrocarbons namely, n-hexane, benzene, heptane, toluene, p- and o-xylene, ethyl benzene and n-decane using a cryogenic preconcentration system and a gas chromatograph with a flame-ionization detector. Simultaneous outdoor samples were also collected to determine indoor to outdoor (I/O) ratios for every compound at each location. In all, seven different types of indoor environments were investigated for VOC levels. Toluene concentration levels were found to be high in a hall which was recently renovated. The indoor environment of a kitchen in which a kerosene stove was used and smokers rooms showed high levels of benzene. The concentrations of VOCs during painting were found to be high and the levels of VOCs depended on the type of paint used. The study revealed that the indoor concentrations of selected VOCs on occasions could be significantly high due to various sources. The data presented here can be useful in developing air quality standards for indoor air.

Monitoring of indoor volatile organic compounds and polycyclic aromatic hydrocarbons arising from kerosene cooking fuel

Air samples, representing indoor environments of a kitchen in which a kerosene stove was used were collected and analysed for volatile organic compounds (VOCs) viz., n-hexane, benzene, heptane, toluene, p- and o-xylene and n-decane using a cryogenic preconcentration system and a gas chromatograph with a flame-ionisation detector. Simultaneous outdoor samples were also collected to determine indoor to outdoor (I/O) ratios for each compound. Reversed phase high performance liquid chromatography (HPLC) with ultra violet absorption detection was optimised for separation and quantification of polycyclic aromatic hydrocarbons (PAHs) in air particulate matter. Concentration of total suspended particulate matter (TSPM), benzene soluble organics and the PAHs in air samples collected in indoor environment of some tenements at Trombay, Mumbai where kerosene is used as cooking fuel are discussed in relation to the concentration of the same in outdoor environment in vicinity of the tenement. VOCs and PAHs results from samples collected in kitchens in Trombay are discussed in relation to indoor air pollution.

Precipitation scavenging of polycyclic aromatic hydrocarbons in Mumbai, India

The concurrent rain and air sampling was conducted for thirteen rain events between the last week of May and end of June 2001. Concentration of total PAHs varied from 84.25 to 777.49 ng/l whereas that in air was in the range of 4.05 to 34.42 ng/m(3). In rainwater the lower molecular weight PAHs (e.g. Phenanthrene, Fluoranthene and Pyrene) were found to be more prominent than the higher molecular weight compounds. The gas phase scavenging ratio (Wg) was found to increase with the molecular weight of the compound. The particle phase scavenging ratio (Wp) values for the more volatile PAHs were generally much higher than those for less volatile PAHs. The higher MW PAHs have Wg values equal to or larger than their Wp values.

Long-range transport of soil dust and smoke pollution in the South Asian region

Transboundary transport of air pollution in the South Asian region has been an issue of increasing importance over the past several decades. Long–range transport of anthropogenic pollution is contrasted with that of pollution produced by natural processes such as dust storms or natural forest fires. Airborne particulate matter datasets covering the period from 2002 to 2007 from the neighboring countries like Bangladesh, India, Pakistan and Sri Lanka were used to find the source areas that are primarily responsible for long range transported pollutants. All four countries collected samples with the same type of sampler and follow the same technique for mass and BC measurements. It was found that high fine soil contributions were from dust storms. On the other hand, smoke in this region mainly comes from northern India where agricultural waste is often burned.

Vertical distribution of polychlorinated biphenyl congeners in sediment core from Thane Creek area of Mumbai, India

In recent years there has been a growing concern all over the globe about the marine pollution due to persistent organic pollutants. Sediments, which is an important component of marine environment can serve as sorbent or concentrator for various persistent organic pollutants including Polychlorinated Biphenyls (PCBs). Transport and fate of PCB congeners in sediment depends on their physicochemical characteristics. In this study, the depth profile of accumulated PCBs in Thane Creek sediments of Mumbai, India, was studied. The sediment core samples were collected using a gravity corer, processed and analysed for different PCB congeners. Analysis of PCBs in the sediment samples were carried out using gas chromatography system equipped with electron capture detector. The study on vertical distribution of PCBs in sediment could reflect the geochemical history including changes due to anthropogenic releases into the system. The surface segment shows the downward trend for these compounds, indicating slow phase out of PCBs after ban. The concentration and composition of different homologues varies at different depth. An attempt has also been made to find out the various sources of PCBs which could have contributed to these compounds by performing factor analysis over the observed concentrations of the PCB compounds in the core sediment.

Elemental characterization of coal, fly ash, and bottom ash using an energy dispersive X-ray fluorescence technique.

A total of 18 elements viz. Si, Al, Fe, Ca, Mg, K, Na, Sr, V, Zn, Mn, Cr, Cu, Pb, Ni, Co, As and Cd were analyzed in coal, fly ash and bottom ash samples collected across India using an EDXRF technique. Various indices such as element enrichment ratio, enrichment factor (with respect to crustal average) and mineral composition were calculated. Around 95% of mass was reconstructed using the concentration of elements in this study for fly and bottom ash.

Natural radioactivity assessment of a phosphate fertilizer plant area

Abstract Rock phosphate ore processing and disposal of phosphogypsum contribute to enhanced levels of natural radionuclides in the environment. The concentration of naturally occurring radionuclides in soil, rock phosphate and phosphogypsum samples collected around a phosphate fertilizer plant were determined. Also the external background gamma levels were surveyed.238U, 232Th, 226Ra and 40K activities in soil samples were 21–674 Bq/kg, 11–44 Bq/kg, 22–683 Bq/kg and 51–295 Bq/kg respectively. The external background gamma radiation levels in the plant premises were ranging from 48 to 133nGy/h.

Depth profile of major and trace elements in estuarine core sediment using the EDXRF technique.

Distribution and enrichment of elements in sediment are influenced by their texture, mineralogical composition, and physical transport. The vertical concentration profiles of sixteen elements in core sediment samples, namely Na, Mg, Al, K, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Sr, and Pb were measured using the energy dispersive X-ray fluorescence (EDXRF) technique. To check the anthropogenic input various indices (enrichment factor, contamination factor, index of geoaccumulation and pollution load index) were calculated and compared.

Distribution and source apportionment of atmospheric non–methane hydrocarbons in Mumbai, India

Concentrations of non–methane hydrocarbons (NMHCs) in atmosphere were measured at six urban sites in Mumbai from February 2005 to January 2006. Seventeen hydrocarbons, i.e., ethane, ethylene, acetylene, propane, propylene, iso–butane, n–butane, iso–pentane, n–pentane, hexane, benzene, heptane, toluene, ethyl benzene, p–xylene, o– xylene and n–decane have been identified in 254 urban air samples using a cryogenic pre–concentration system attached to a Gas Chromatograph (GC) with a Flame Ionization Detector (FID). C2–C5 hydrocarbons were determined on 2 m x 2 mm i.d., stainless steel (S.S.) column packed with n–octane/Poracil C. The components of C6 and above are determined on a 3 m x 2 mm i.d., S.S. column filled with 10% OV – 101 on chromosorb WAW. All these species show well–defined winter season (November–February) high and summer season (March–June) low values. Factor analysis (FA), a receptor modeling technique, has been used for quantitative source apportionment. Varimax rotated factor analysis identified five possible sources. The mean percent contribution from the vehicular exhausts was found to be 33% while that from refinery sources contribute 21%. Petrochemical industries and paint solvent contributed 15% and 11% respectively. Eight percent of the NMHCs were coming from polymer manufacturing industries. The remaining 12% is contributed by other unidentified sources.