Indoor air pollution resulting from combustion of biomass fuels in rural households of developing countries is now recognized as a major contributor to the global burden of disease. Accurate estimation of health risks has been hampered by a paucity of quantitative exposure information. In this study we quantified exposures to respirable particulate matter from biomass-fuel combustion in 436 rural homes selected through stratified random sampling from four districts of Tamil Nadu, India. The study households are a subset of a larger sample of 5,028 households from the same districts in which socioeconomic and health information has been collected. Results of measurements for personal exposures to respirable particulate matter during cooking were reported earlier. This has been extended to calculation of 24-hr exposures with the aid of additional measurements during noncooking times and the collection of time-activity records. Concentrations of respirable particulate matter ranged from 500 to 2,000 micro g/m(3) during cooking in biomass-using households, and average 24-hr exposures ranged from 90 +/- 21 micro g/m(3) for those not involved in cooking to 231 +/- 109 micro g/m(3) for those who cooked. The 24-hr exposures were around 82 +/- 39 micro g/m(3) for those in households using clean fuels (with similar exposures across household subgroups). Fuel type, type and location of the kitchen, and the time spent near the kitchen while cooking were the most important determinants of exposure across these households among other parameters examined, including stove type, cooking duration, and smoke from neighborhood cooking. These estimates could be used to build a regional exposure database and facilitate health risk assessments.

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Rivers are the lifeline of an ecosystem, since every member of the ecosystem depends directly or indirectly upon them for their sustenance. Changes in the riparian conditions would strongly impact the ecosystem-toorganism interactions and inter-organism interactions. Due to lack of regulations and widespread use of technology for industrial wastewater treatment, most of the industrial discharge ends up in the river. This leads to increased toxicity and river pollution and can be remedied only through restoring the ecological conditions of the river. Eco-restoration of rivers is meaningless without addressing the reason behind river pollution hence feasible industrial wastewater treatment methods are discussed in this study, with emphasis on their practicality and effectiveness.