A deep breath of fatal dust
SILICOSIS -- an incurable lung disease caused by the inhalation of silica, a component of dust -- has debilitated several workers in cement and brick factories and sandstone mines in the country, recent research reveals. In its later stages, the disease can lead to respiratory or cardiac failure.
The finding was made following surveys conducted by the occupational health and safety division of the Delhi-based Society for Participatory Research in Asia (PRIA), in the sandstone mines of Jodhpur district, Rajasthan, and at the Orissa Cement and Refractory Limited in Rajgangpur in Sundargarh district, Orissa.
Says Harsh Jaitley of PRIA, "Silicosis is one of the most deadly occupational lung diseases in India, but it is usually wrongly diagnosed." He estimates that about 7 lakh workers suffer from silicosis and other dust-related diseases such as byssinosis (caused by cotton dust), asbestosis (usually afflicting workers in asbestos mines), or coalminer's pneumoconiosis -- all of which are incurable. Most silicosis patients are diagnosed as suffering from tuberculosis and expensive but wrong drugs are usually administered by ill-informed doctors.
Extremely small silica particles -- with their diameter between 0.5 and 5 microns (a micron is one-millionth of a metre) -- are the deadliest because they can enter the little air sacs in the lungs known as alveoli -- where the exchange of respiratory gases takes place -- and block them. The silica particles inside the lungs show up in X-rays as small opacities. Experts say that it is now well-established that silicosis increases the risk of contracting tuberculosis.
In their survey of 170 workers at the refractory brick factory in Orissa, which produces silica and alumina bricks used to line furnaces, PRIA researchers found about 11 per cent of the workers suffered from lung disorders suspected to be silicosis or silico-tuberculosis. In comparison, the national prevalence of tuberculosis is 18 in every 1,000 people. The researchers also found that those who had worked longer in the factory had severer symptoms of the disease. The workers worse affected were those who were employed in the silica mill house where dust levels were the highest. An examination of some X-rays confirmed that several workers were suffering from silicosis and silico-tuberculosis. The study undertaken in the sandstone mines in Jodhpur district yielded similar results. Of the 82 sandstone mine workers medically examined by doctors from the S N Medical College in Jodhpur, about 18 people or some 22 per cent, were suffering from either silicosis, tuberculosis or silico-tuberculosis.