Dust Control Techniques for Prevention of Pneumoconiosis

Slate Pencil Industry

To reduce the risk of silicosis, NIOH recommended intervention program to the Ministry of Labor, Government of Madhya Pradesh. An exhaust system with air cleaning device was developed specially for the slate pencil industry and it was installed on ten cutting machines. The industrial hygiene survey showed that the exhaust system was effective in controlling about 95% of the total airborne dust and 97% of the respirable airborne dust. The residual dust levels were very close to the TLV. At present, all the slate pencil factories of Mandsaur District are using one or other form of the local exhaust system.

Agate Industry

NIOH studies showed that the main source of dust in the agate industry is the grinding process. For the control of dust, a local exhaust system containing air-cleaning device was developed. Evaluation of the exhaust system by dust monitoring showed that there was 94% reduction in dst levels with the use of exhaust system. The exhaust system did not interfere with the work and the workers found it very useful as it facilitated the work by removing the dust, which hampered their sight. However, the owners complained of excessive power consumption. To reduce the power consumption without compromising with its dust control efficacy, a dust control device incorporated in the grinder has been developed. At present many small units have installed this type of exhaust system.

The Ministry of Health & Family Welfare, Govt. of India has allocated Rs. 84.00 lakhs for the Programme on “Prevention and Control of Silicosis in Agate Workers”. Under this programme, the Institute Scientists are making constant endeavors to develop the best possible machine.

Quartz Crushing Industry

Quartz grinding is one of the most hazardous occupations causing exposure to almost 100% free silica leading to silicosis in a matter of few months. NIOH scientists identified the sources of dust generation and recommended appropriate dust control measures like, enclosure of dust source, use of powerful exhaust and humidification of work environment. After implementation of these control measures, the industrial hygiene survey showed that the reduction in the total and respirable air borne dust levels, in the six factories studied previously, ranged from 80 to 96%. Under one of the programmes sponsored by the Ministry of Health and Family Welfare, Govt. of India, NIOH will take up National Programme on Elimination of Silicosis in which the problems of stone grinders and stone cutters are going to be the major areas of intervention.

Asbestos Cement Industry

Automatic asbestos fiber feeding, health education and personal protective measures were implemented as preventive measures. The levels of asbestos fibers in Ahmedabad and Hyderabad factories which were higher than permissable levels came down to below the permissible levels.

Asbestos Milling Units, Cuddapah (AP)

Automatic asbestos fiber feeding, health education and personal protective measures were implemented as preventive measures. The levels of asbestos fibers in Ahmedabad and Hyderabad factories which were higher than permissable levels came down to below the permissible levels.