Mineral dusts and prevention of silicosis, vol 4; No.2, September 1997Editorialby S.K. Saxena |
EDITORIAL 2/1997
Rapid population growth, urbanisation and industrial development, and the desire for a higher standard of living pose challenges to workers' safety and health in many economic sectors mainly in manufacturing, mining, ports and docks, construction and agriculture. At any workplace, workers are exposed to dust.
Dust which arises from the mechanical comminution of coarser material during handling, grinding, drilling, blasting, milling and crushing operations can be either a nuisance or toxic to the human body. Nuisance dusts are those arising from substances that do not exert toxic effects, whereas toxic dusts such as silica dust and asbestos dust can be harmful. Lung diseases caused by dust, which have occurred since antiquity, are among the oldest occupational diseases known.
There are two distinct risks associated with dust; namely, the risk of explosion and the health risk. Most combustible mineral dusts such as the dusts present in coal mining and in facilities where coal is handled, e.g. thermal power plants can cause explosions if ignited when in cloud form. Anthracosilicosis, an occupational lung disease, is caused by exposure to mixed dust in which free silica is the dominant fibrogenic component. Many years of exposure to dust levels that are low but above the exposure limits has been demonstrated to have distinct systemic toxic effects.
The problem of quartz dust is present in a number of industrial activities. Silicosis is the most common "pneumoconiosis" worldwide. Caused by exposure to dust containing free silica, silicosis usually develops gradually over an exposure period of at least ten years. However, the extent of disease depends on a number of factors, including the nature of the dust, its concentration and the duration of exposure as well as individual susceptibility. Particularly in developing countries, epidemiological studies are needed for the following reasons: to determine the morbidity of silicosis in relation to occupation, work area or types of exposure; to identify the risks involved; to gather data on exposures; and to determine the effects of preventive measures.
The International Labour Organisation (ILO) and the World Health Organization (WHO) are concerned with workers' health. In the field of occupational health, these international organisations contribute vigorously to ensuring progress and continuity of action for the protection of workers' health, particularly in developing countries. Since its inception in 1919, the ILO has adopted about 175 Conventions, some 40 per cent of which pertain to workers' health. On the basis of the provisions contained in these Conventions, most Member States of the ILO have enacted statutes designed to protect workers' health.
Occupational health services contribute to the enforcement of the statutes on occupational safety, occupational health and the working environment advocated by the ILO Occupational Safety and Health Convention (No. 155) and Recommendation (No. 164), 1981. The ILO Occupational Health Services Convention (No. 161) and Recommendation (No. 171), 1985 provide for a comprehensive approach to occupational health, which includes primary, secondary and tertiary prevention, and is consistent with the general principles of primary health care. These instruments also provide guidance on the manner in which occupational health services should be made available to working populations. Moreover, the ILO Convention (No. 170) and Recommendation (No. 177), 1990 deal with safety in the use of chemicals at work.
During the past 15 20 years, the WHO Workers' Health Programme has focused on technical and scientific aspects of occupational health services. The targets of attention have included, e.g. the following: development of occupational health services, and the infrastructure and functions of occupational health care; methodologies for setting health- related standards, such as assessment of the health risks presented by some chemical factors (e.g. heavy metals and mineral dusts) and physical factors; promotion of research with a view to early detection of occupational diseases; and the exchange of information on occupational health as well as relevant education and training.
The WHO Global Strategy on Occupational Health for All is a new step forward, covering the specific period of 1996 to 2001. The strategy is a practical and integrated response to meet the challenges and emerging problems of occupational health in the years to come. Continuous development of occupational health and safety, collaboration and co- ordination at all levels are the keys to successful implementation of the Global Strategy. Recently, WHO and the ILO have jointly devised a worldwide initiative, Global Action on Silicosis Elimination.
Proper assessment of the risks posed by dust during various activities/ operations is a more acute issue than ever before. Effective control of the risks caused by dusts at the workplace requires an efficient flow of information at each level of activities/operations involving the material emitting dust. Furthermore, precautions are needed to contain potential hazards and to ensure safety. A special issue of the Asian-Pacific Newsletter dealing with mineral dusts and the prevention of silicosis the one in hand has been designed to address these subjects.
The articles contained in this issue have been written by experts in the relevant fields of safety and health. We hope that this issue will encourage technical personnel and workers in industry, occupational health and safety professionals, researchers, and environmentalists to review risk assessments and to strengthen overall safety precautions and control measures against mineral dusts, thereby reducing exposures and the risk of silicosis. I am sure that the information provided in these articles will be a great help to those concerned with improving the status of occupational safety and health.
S.K. Saxena
Director General
Factory Advice Service &
Labour Institutes
Ministry of Labour, Govt. of India
MUMBAI, INDIA