Prevention and control of silicosis: A national challenge

Pneumoconiosis is resulting from exposure to free silica may be the commonest and most extensively studied occupational disease of the lung and even today, it continues to be among the most serious occupational diseases. The problem of silicosis is confined not only to the developing nations, but is also not uncommon in industrialized nations.

The distribution of silicon in nature is similar to the distribution of carbon in organic matters. Silicon contributes to about 28% of the earth's crust. Silicon being very reactive does not remain in the element form but combines either with oxygen alone and forms free silica (SiO2) or with oxygen and other elements and forms silicates, e.g. asbestos. Silica and silicates constitute the bulk of most kind of rocks, clays and sands. Mining, tunneling, sand stone industry, stone quarrying and dressing, iron and steel foundries, flint crushing are the occupations most closely related to the hazard of silica exposure. Some of the occupations such as slate pencil industry and agate grinding industry which carry high risk of silicosis are peculiar to India. Though mining and metallurgy in India were practiced much earlier than that in Europe, Caplan and Burden described the first cases of silicosis in this country in 1940s in gold miners of Kolar. The term silicosis is reserved for the lung disorder caused by inhalation of free silica, which is an untreatable progressive disease and is the commonest and most widespread of all occupational diseases. Exposure to large amount of free silica can pass unnoticed because, silica is odorless, non-irritant and does not cause any immediate noticeable effect and hence is confused with ordinary dust. Chronic exposure to silica predisposes to tuberculosis, which is still a major health problem in developing countries including India. Recently crystalline silica has been classified as a human carcinogen (Group I) by International Agency for Research on Cancer (IARC). Hence NIOSH has said, “Silica is not just dust but it is dangerous dust”. Silicosis increases the risk of contracting Tuberculosis and possibility of developing lung cancer in the future. Silicosis is strongly associated with scleroderma and rheumatoid arthritis.

There are very few epidemiological studies on silicosis in India where the prevalence of silicosis varies from 3.5% in ordnance factory to 54.6% in slate pencil industry. The varying prevalence in various sectors is attributed to the silica concentration in the work environment and duration of exposure to Silica.

The problem of silicosis is much more severe in the unorganized sector of industries like slate pencil cutting, stone cutting and agate industry. The flaw here is that most industries belonging to the unorganized sector do not fall under the purview of the statutory tools such as the Factories Act aimed to protect the health and safety of the working population. Moreover, the employers lack the will to provide safe working environment for the workers. It is probably economic compulsions that the workers choose to work in hazardous environments and are subjected to exploitation. Considering the huge population employed in mines, surface industries and unorganized sector that are at risk of silica exposure, it can be presumed on the basis of available studies that several hundred thousand workers in India suffer from silicosis.[1]

In the absence of specific therapy for silicosis, there is a need for planning a national strategy for the prevention and control of silicosis. The concern for prevention and control should be focused on unorganized sector like stone-cutting for slate pencil, Artisans involved in working with stones, some areas of construction sector, Glass and bangle workers and Agriculture workers. The strategy to prevent and control Silicosis in the Country should focus on the following components:

• Identify the population at risk nation wide in various sectors specially in the unorganized sector

• Define “Diagnostic criteria- What constitutes a case of Silicosis?

• Dynamic sample survey in the high-risk sectors.

• Central nodal agency that consolidates data on Silicosis from all sectors.

• Creating awareness among all stake holders and sensitizing community consciousness for Silicosis.

• Involve Print, TV media and NGO's to build and sustain pressure on lobbies with vested interest and Regulatory authorities.

• Implementation of the actual control measures.

• Capacity building, Training family physicians and Primary Health Care doctors.

• Ambulatory and Participatory Occupational Health Service for the unorganized sector.

• Vested environmental activism should be discouraged.

The success of prevention programme will largely depend upon the active cooperation of all the stakeholders. Silicosis is an age-old occupational disease and remains a major occupational health problem in India. It is responsible for high morbidity and mortality in industrial workers. Since there is no specific therapy for this progressive and irreversible disease, all steps should be taken for its prevention. A mechanism needs to be in place for addressing compensation issues and rehabilitation of affected workers. The benefits of prevention include the economic benefits such as increased production by healthy workers, reduction of sickness absenteeism and less expenditure on health care and above all the alleviation of human suffering.