Domestic smoke pollution from biomass fuel combustion and increased prevalence of cataracts in Jammu and Kashmir, India

Smoke produced by the use of domestic fuels is an important source of indoor air pollution, especially in the rural population of developing countries, like India. It has been estimated that on an average, an Indian housewife spends >90% of her time indoors and similar is the case with infants, young children, old, and the disabled -the most susceptible population to the adverse health effects of indoor air pollution. ^[1],[2] Common fuels used for cooking and heating in India include biomass fuels (e.g., dried dung cakes, crop residues, agricultural wastes, and firewood), kerosene oil, liquid petroleum gas, and coal. ^[2],[3] Most typically the biomass fuel is commonly used on a traditional Chullah (fixed mud hearth) which is made of clay and stone, closed on three sides, usually built inside the poorly ventilated dwellings made of wood and crop residues, the Jonpdis, having mud walls with roofs made of wood and crop residues, covered with clay. ^[1],[3],[4]

We studied the prevalence of cataracts in the rural community of Bishnah area of Jammu, India, where people commonly live in Jonpdis. The examination was part of a multispecialty survey conducted by the Chittrajan Mobile Teaching-cum-Services Hospital of Government Medical College, Srinagar, Kashmir, from January to March 2006. Among the 6200 individuals examined, cataract was found in 1572 (25.3%) cases. Out of these, 1108 (70.4%) were nonsmoker housewives, having an average daily exposure time of 6-8 h to the smoke produced from biomass combustion in the household. The high occurrence of cataracts had significant correlation with the exposure to indoor air pollution, caused by smoke produced from the combustion of biomass (χ² = 92.3; df = 3; P < 0.001).

The above data represent the highest reported prevalence of cataract in India so far. Previous studies in India by Minassion and Mehra revealed prevalence of 5-18%, ^[5] where as another study conducted by Chatterji and co-workers in Punjab, India had observed a prevalence rate of 15.3% for people over 30 years. ^[6]

Moreover, there are studies demonstrating the role of indoor air pollution by smoke produce from biomass combustion compared to other fuels, in causation of cataract, with supportive evidences that, the toxins from biomass fuel smoke could get absorbed systemically and get accumulated in the lens, resulting in development of cataract. ^[7]

The additional factor possibly responsible for increased occurrence of cataracts in housewives in our study was the exposure of eyes to direct heat while blowing air into the fire place. However, further studies are needed to establish the nature of toxins, and the possible role of genetic predisposition in the etiopathogenesis of cataracts. Prevention would involve change in the living standard of such populations, which includes provision of sufficient electricity as the cleanest and safest source of fuel, through appropriate government policy.

Source of Support: None, Conflict of Interest: None