This study compares the ambient air particulate matter (PM10) data of 15 different coal mine environments. For most of these mine environments, the monitoring was carried out by different researchers using respirable dust sampler (RDS) that separates PM10 by centrifugal inertial separation. At two sites--Padmapur and Ghugus (Chandrapur, Maharashtra, India)--mass inertial impaction-based sampler was used for PM10 monitoring. It is observed that the spatiotemporal average value of ambient air PM10 monitored using mass inertial impactor reports relatively higher values (240-372 μg/m(3)) compared to those monitored using RDS (<227 μg/m(3)). In order to realize the severity of mine area pollution, it is compared with PM10 values found in an urban area (Delhi, India). It is found that PM10 values in Delhi (using mass inertial impactor) are much higher (300-400 μg/m(3)) than those reported for the mine environment. The data seems to indicate that the mine environment is relatively cleaner than urban air and therefore raises doubt about the appropriateness of using either mass impactor or RDS for PM10 sampling.

No abstract

The estimates of airborne fine particles (PM2.5) concentrations are possible through rigorous empirical correlations based on the monitored PM10 data. However, such correlations change depending on the nature of sources in diverse ambient environments and, therefore, have to be environment specific. Studies presenting such correlations are limited but needed, especially for those areas, where PM2.5 is not routinely monitored. Moreover, there are a number of studies focusing on urban environments but very limited for coal mines and coastal areas. The aim of this study is to comprehensively analyze the concentrations of both PM10 and PM2.5 and develop empirical correlations between them. Data from 26 different sites spread over three distinct environments, which are a relatively clean coastal area, two coal mining areas, and a highly urbanized area in Delhi were used for the study. Distributions of PM in the 0.43-10 µm size range were measured using eight stage cascade impactors. Regression analysis was used to estimate the percentage of PM2.5 in PM10 across distinct environments for source identification. Relatively low percentage of PM2.5 concentrations (21, 28 and 32 %) in PM10 were found in clean coastal and two mining areas respectively. Percentage of PM2.5 concentrations in PM10 in the highly urbanized area of Delhi was 51%, indicating a presence of a much higher percentage of fine particles due to vehicular combustion in Delhi. The findings of this work is important in estimating concentrations of much harmful fine particles from coarse particles across distinct environments. The results are also useful in source identification of particulates as differences in the percentage of PM2.5 concentrations in PM10 can be attributed to characteristics of sources in the diverse ambient environments.

Air change rates and ventilation of a room was determined by CO Tracer Decay Technique. The tracer was generated by burning bulk amount of mosquito coils, an easy and low cost method of CO generation. The temporal decay in CO concentration in indoor air under closed and open room conditions were determined by collecting indoor air periodically at a few minutes interval in Tedler Bags and analyzing the same for CO. The air changes rate per hour (ACH) was calculated from the temporal decline of indoor CO concentration in indoor air. The study indicated that CO generated by a low cost and easily applicable method like combustion of organic materials could be used as a tracer to determine ACH and ventilation rate. Background CO in air could be suitably used for ventilation studies in rural/urban slum dwellings in India and many other countries where substantial CO is found indoors due to combustion of biomass, incense sticks and mosquito coils.