India still uses Amphibole Asbestos along with Chrysotile

The Minister for Mines Sis Ram Ola April 10, 2008 announced the details of the National Mineral Policy. The Minister also spokes about the revision of royalty rates and dead rent. The main highlights of the revised rates are:-Royalty rates for minerals like amphibole asbestos is going to be shifted from tonnage basis system of royalty to ad valorem basis.

Rajasthan state in India is credited to cater more than 90% of total production of asbestos in this country, of which around 60% is processed there in unorganized sectors including milling and manufacturing of asbestos-based products.

According to a paper "Monitoring and identification of airborne asbestos in unorganized sectors, India" published in Chemosphere journal (Qamar Rahman et al Volume 68, Issue 4, June 2007), Unorganized asbestos units particularly mills showed unhealthy occupational conditions, therefore industrial hygiene study was carried out focusing on the prevalence of asbestos fibres in air at work zone area of asbestos milling units. Fibre levels were in the range of 2.00–5.09 f/cm3 and 4.07–15.60 f/cm3 in unorganized asbestos mills of Rajasthan located at Beawer and Deogarh districts, respectively.

Like asbestos concentration, fibre type and length are also vital factors in the health risk assessment of industrial workers. Phase contrast and polarized light microscopic study of asbestos fibres showed their amphibole nature registering about 90% as tremolite and rest as anthophyllite. Fibre length measured micrometrically were sub-grouped in <10 μm, 11–20 μm, 21–30 μm and >30 μm. About 30–40% fibres belonged to sub-group <10 μm.

The paper concludes that unorganized asbestos mills bear poor industrial unhygienic conditions reflected specifically from their manyfold higher fibre concentrations than the Indian and International standards. Poor industrial unhygienic conditions are attributable to obsolete milling technology, lack of pollution control devices and escape from regulatory control.

Natural asbestos is found in two varieties: serpentine asbestos and amphibole asbestos. Approximately 90% of serpentine is the variety chrysotile, while amphibole asbestos includes crocidolite, amosite, anthophyllite asbestos, actinole asbestos, and tremolite asbestos.

Asbestos has been observed to cause four health disorders. Asbestosis results in stiffening of the lung, and has resulted in the deaths of many miners. Lung cancer has a higher incidence in miners who also smoke, with the chance of developing cancer roughly proportional to the amount smoked. Asbestos-induced cancer is found only rarely in nonsmokers. Among the various type of asbestos, chrysotile workers have the lowest incidence of cancer. Mesthelioma involves the development of a fatal tumor. The time between diagnosis and original exposure is commonly 30 years or more. Family members of miners are also at risk. Among the general population, 70-80% of all mesothelioma cases are caused by exposure to asbestos. A staggering 18% of all mortalities in crocidolite workers are the result of mesothelioma. Benign pleural changes also occur to an extent proportional to exposure, but rarely cause functional impairment.