India is one of the largest users of the hazardous metal mercury in the world. The average use of mercury over the last decade has been of the order of 170 to 190 mtons/a., that is, 7 to 10% of the total global mercury use. The different sectors that consume mercury are: chlor-alkali (16%), batteries (16%), thermometer and other measuring equipments (14%), thermostats (12%) and lighting (4%), accounting for 62% of the total mercury use. According to available statistics, 38% of mercury imported remains unaccounted for. Based on our surveys on artisanal and small scale gold mining (ASGM) in different parts of India it is proposed here that the major part of this unaccounted mercury is actually utilized in recovery of gold through amalgamation and subsequent burning, causing significant environmental pollution. Most of these miners are poor indigenous tribal people and a substantial part of the work force comprises women.
Gold occurrences in India are mainly confined to the Precambrian rocks of Dharwar craton in south India. The other primary gold occurrences are scattered in central and eastern India: in Mahakoshal belt in eastern Uttar Pradesh, in the Sakoli basin of Maharashtra, in the Dongargarh Group in Chattisgarh and in the Singhbhum region of Jharkhand state. In the west, gold occurrences are known in the Banswara district of Rajasthan. All these areas are known for ASGM.
Primary auriferous quartz reefs are worked by local communities in the Wynad gold field, in the contiguous parts of Tamil Nadu and Kerala, particularly in the abandoned mines and adits in Pannur, Pandalur-Devala areas. Similarly, in the Hosur area of northern Karnataka, illegal ASGM is carried out in the abandoned shafts and inclines of the Bharat Gold Mines Ltd. in the Gadag gold field.
ASGM is carried out extensively in the Nilambur region, south of the Wynad gold field, in the alluvial tracts of the Cheliyar and Punna Puzha Rivers and also in the nearby Attapady valley of Pallakkad district in Kerala by the local Paniyar tribe. Alluvial gold mining is practiced by local villagers in Maru River (a tributary of Waynganga) bed in Bhiwapur in Nagpur district of Maharashtra, in the wide alluvial tract of the Subarnarekha River in Jharkhand and in the Himalayan foothills near Rampur in Himachal Pradesh, in the bed of the meandering Sutlej River.