Air quality status during Diwali festival of India: a case study.

The PM(2.5) and PM(10) samples were collected during Diwali celebration from study area and characterized for ionic concentration of four anions (NO(3) (-), NO(2) (-), Cl(-), SO(4) (2-)) and five cations (K(+), Mg(2+), NH(4) (+), Ca(2+), Na(+)). The results showed that the ionic concentrations were three times compared to those on pre and post Diwali days. Predominant ions for PM(2.5) were K(+) 33.7 µg/m(3), Mg(+) 31.6 µg/m(3), SO(4) (2-) 22.1 µg/m(3), NH(4) (+) 17.5 µg/m(3) and NO(3) (-) 18 µg/m(3) and for PM(10) the ionic concentrations were Mg(+) 29.6 µg/m(3), K(+) 26 µg/m(3), SO(4) (2-) 19.9 µg/m(3), NH(4) (+) 16.8 µg/m(3) and NO(3) (-) 16 µg/m(3). While concentration of SO(2) and NO(2) were 17.23, 70.33 µg/m(3) respectively.

Source identification of different size fraction of PM10 using factor analysis at residential cum commercial area of Nagpur city.

Particulate size distribution of PM(10) and associated trace metal concentrations has been carried out in residential cum commercial area of Mahal at Nagpur city. Sampling for size fraction of particulate matter was performed during winter season using eight-stage cascade impactor with a pre-separator and toxic metals were analyzed using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The average concentration of PM(10) and fine particulate matter (effective cut of aerodynamic diameter ≤2.2 µm) was found to be 300 and 136.7 µg/m(3), respectively which was exceeding limit of Central Pollution Control Board. Maximum mass concentration of 41 µg/m(3) in size range of 9.0-10.0 µm and minimum mass concentration of 19 µg/m(3) in size range 2.2-3.3 µm was observed. Metals (Sr, Ni and Zn) were found to large proportions in below 0.7 µm particle size and could therefore pass directly into the alveoli region of human respiratory system. Factor analysis results indicated combustion and vehicular emission as the dominant source in fine mode and resuspended dust was dominant in medium mode while crustal along with vehicular source was major in coarse mode of particulate matter.

Impact assessment of respirable suspended particulate matter from diesel generator sets used for pumping station.

Prediction of respirable suspended particulate matter impacts of diesel generator sets used for pumping station has been made using meteorological data, information on stack characteristics and emission rate, baseline ambient particulate matter and Industrial Source Complex Short Term (ISCST-3) model. It is observed that particulate matter emission from pumping station-S workplace diesel generator sets ranged from 2.4 to 436.5 mg Nm⁻³ and while at pumping station-C, it ranged from 23.2 to 186.5 mg Nm⁻³. The predicted and ambient respirable suspended particulate matter concentrations are below the national air quality standard for respirable suspended particulate matter in a mixed industrial area. Metals contents in respirable suspended particulate matter indicate the origin of crustal and mobile sources. Therefore, the impact of diesel generator sets used for pumping of crude oil on local air quality would be acceptable.

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.

Source apportionment of PM10 in Mumbai, India using CMB model.

Source apportionment study is carried out to identify the sources of particulate matter of size less than 10 microm in Mumbai using chemical mass balance model. Various locations representing different activity zones as low activities (control), normal activity including commercial and residential areas and traffic sites (kerbside) are selected for this purpose to represent the city. It is observed that at control sites industrial contributions prevail, the other significant contributions are from marine and vehicular activities. At normal activity sites, vehicular, industrial and soil dust contributions are observed to be dominant. At two of the kerbside sites, marine contributions are observed to be significant which was due to the proximity of the sites to sea. The vehicular and soil dust contributions are observed to be significant at remaining kerbside sites. The study is useful for preparing the particulate matter reduction action plan for Mumbai, which can be extended further to other cities of India.

Monitoring of environmental parameters for CO2 sequestration: a case study of Nagpur City, India.

Carbon dioxide concentration is an index of total amount of combustion and natural ventilation in an urban environment and therefore required more careful attention for assessment of CO(2) level in air environment. An attempt was made to monitor CO(2) levels in ambient air of Nagpur city at industrial, commercial and residential sites. In addition to this a remote sensing studies and biotic survey for floral biodiversity were carried out to study the green cover at respective sampling locations. The observations showed that the largest amount of CO(2) occurred at night due to absence of photosynthesis and lowest concentration of CO(2) was observed in the afternoon due to photosynthesis at its maximum level. The most pollution tolerant species found in Nagpur city are having higher Air Pollution Tolerance Index (APTI) value, which acts as a natural sink for CO(2) sequestration. In case of commercial site the CO(2) level is highest (366 ppm) because of lowest vegetation and vehicular pollution. The generation of database of CO(2) concentration and floral biodiversity along with percentage of green cover helps to formulate the strategy for prevention of global worming phenomenon.

Characterisation of particulate matter for toxic metals in ambient air of Kochi city, India.

Measurement of respirable suspended particulate matter (RSPM) and analysis of toxic metals in air of Kochi city was carried out for a period of one year, 1997. Seasonal variations of RSPM and toxic metals are analysed to identify the influence of meteorological parameters. The air pollution problem with respect to RSPM and lead is moderately significant especially in winter season. The profile of other toxic metals in RSPM is not much significant. Domestic fuel used mainly coal/wood and petrol/diesel fueled motor vehicles are the major contributors to the RSPM and toxic metals. Various control strategies are delineated for reduction of ambient RSPM and toxic metals in air of Kochi city.

Assessment of air pollution from small scale industry.

Air pollution due to small scale industries have been found to cause serious occupational health hazards and adverse effects on vegetation and heritage. The study for air pollution impact assessment for brick kiln industries was undertaken. The stack monitoring 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, air pollution mitigation measures are suggested.

Prediction of ambient PM10 and toxic metals using artificial neural networks.

In this study, an artificial neural network is employed to predict the concentration of ambient respirable particulate matter (PM10) and toxic metals observed in the city of Jaipur, India. A feed-forward network with a back-propagation learning algorithm is used to train the neural network the behavior of the data patterns. The meteorological variables of wind speed, wind direction, relative humidity, temperature, and time are taken as input to the network. The results indicate that the network is able to predict concentrations of PM10 and toxic metals quite accurately.

Short-term concentration of CO2 in the ambient air of Nagpur city.

Carbon dioxide concentration is an index of total amount of combustion and natural ventilation in an urban environment and therefore required more careful attention for assessment of CO2 level in air environment. First time, an attempt was made to monitor CO2 levels in Ambient Air of Nagpur during August 2001-December 2001 at Industrial, Commercial and Residential sites. The largest amount of CO2 occurred at night due to darkness which depresses the photosynthesis to its lowest level. The lowest concentration of CO2 was showed in afternoon hours when photosynthesis is at its maximum. The average concentration of CO2 was found to be 361, 366 and 339 ppm at Industrial, Commercial and Industrial sites respectively. This generation of database of ambient CO2 will help to formulate the strategy for prevention of global warming phenomenon.