This research has been carried out to highlight, how the mal-practices including mining , milling, product manufacturing and use have changed the characteristics of various industrial and economical minerals i.e, asbestos , asbestiform talc and silica into potential sources responsible for environmental and health hazards in northern Pakistan. A detailed study was conducted to identify the sources, types, industrial practices and health hazards of asbestos, asbestiform talc and silica in different parts of NWFP including federally Administered Tribal Areas (FATA), Provincially Administered Tribal Areas (PATA) and the settled areas.
Geologically most of the asbestos deposits identified in northern Pakistan are associated with the ophiolitic complexes along Main Mantle Thrust (MMT). Prominent localities include Alpurai Behram Dheri district Charsadda and at Boya, Khost valley in Waziristan. Mining is carried out by primitive methods such as blasting and hammering and results in heaps of waste. Asbestos is also imported as raw and in the form of scraps of old ships (asbestos sheet) form Canada, USA, Europe and South Africa.
Rock and powder samples collected from various asbestos mines and milling units, located in the target areas, a re identified chrysotile, antigorite, anthophyllite and tremolite. The imported raw asbestos samples collected form multinational companies and from Gaddani ship yard (Baluchistan) as well as from the product-manufacturing units at Sarai Kili, Mardan are classified as chrysotile and anthophyllite. Samples collected from building materials (Corrugated sheets, ceiling tiles) mostly contain chrysotile. Asbestos containing products including electric heaters, drainage, sewerage and insulation pipes, furniture( tables, beds) and doors were also sampled and are found as made of mainly anthophyllite. Apart from various types of asbestos minerals, talc, chamosite calcite and crystalline quartz also identified in these samples.
The X-Ray diffraction and scanning electron microscope analytical of indoor and outdoor airborne samples collected from mines, milling, product manufacturing and storage units show the presence of anthophyllite and chrysotile having length >10 µm and width/diameter <0.45µm.The concentration of airborne Total Suspended Particulates (TSP) and Respirable Particulate Matter (RPM) range form 10-0.25 µ is thousands to half million times greater than the international permissible Exposure Limits (PEL). The concentration of airborne asbestos fibers is also thousand times greater than the PEL in the indoor and outdoor environment of the study area and thus considered as carcinogenic. Hospital statistics show that more than 1000 cases of general incidence and cohort cases of mesothelioma were reported during 1995-2004. SEM analysis of a biopsy sample of lung tissues collected from a patient suffering from mesothelioma, admitted in the pulmonary ward Khyber Teaching Hospital, Peshawar proved presence of asbestiform fibers.
The petrographic study of talcum powder samples of local and imported brands collected from the local market indicate that all the samples contain different types of asbestos (chrysotile, tremolite, anthophyllite), and other minerals including calcite, mica, chlorite, magnesite, quartz, sulphides, chromium oxide, zinc and are minerals. The grain size of the asbestiform fibers identified under SEM, ranges between 0.8-5µm and can be thus classified as carcinogenic. The epidemiological data indicate that extensive use of asbestiform talc may be one of the major risk factor responsible for the epidemics of ovarian cancer among women in NWFP.
Silica generally occurs in natural form in the Indian shelf rocks as pegmatitic and metamorphosed quartzo-feldspathic and quartzite veins. The wet chemical analyses of the rock samples of silica (quartz) contain 90-93 % SiO2. The X-Ray Diffraction analyses of the same samples display the peaks of crystalline isomorphs of silica as alpha quartz and the sample collected from ceramics industries as synthetic quartz. Air sample data of silica shows higher concentration in ambient and indoor environment and are above the international permissible limits and thus hazardous. Epidemiological data of occupational and Para-occupational groups collected form crushing and grinding units and their surroundings show that many people of the age between 10-60 have died of, silicosis, lung cancer and other silica related diseases.
The above data shows that during all types of mining, milling, cutting, product manufacturing and use, of asbestos, asbestiform talc and silica no protective and precautionary measurements were adopted. A lot oaf airborne dust and waste of asbestos, and silica are generated during these processes and can be seen even through naked eye in the indoor and outdoor environment which indicated that the mal-practicing activities, taking place during the recovery, milling and product manufacturing and sue of asbestos, asbestiform talc and silica are the main sources responsible for releasing asbestos fibers and silica in different parts northern Pakistan. The unaware people are highly exposed to huge amount of respirable asbestos and silica and thus are at risk to various fatal diseases. Based on the findings of this study detailed recommendations are formulated for the sustainable management of mineral resources with special reference to asbestos, asbestiform talc and silica from being wasted and to save the environment and inhabitants from its potential risk.