at Dompoase, Ashanti Region, Ghana, on 12 November 2009, when 18 workers were killed, including 13 women. Many women work at such mines as porters. It was the worst mining disaster in Ghanaian history. In order to maximize gold extraction, mercury is often used to amalgamate with the metal. The gold is produced by boiling away the mercury from the amalgam. Mercury is effective in extracting very small gold particles, but the process is hazardous due to the toxicity of mercury vapour. Especially after the Minamata Convention has been ratified, there are initiatives to replace or reduce the use and emissions of mercury in the extraction of gold. There are an estimated 600,000 children working in illegal artisanal gold mines. For hours, children dig, crush, mill, and haul ore in the hot sun. Children stand in water, digging sand and silt from riverbeds. They carry heavy bags of mud with their heads to designated sieving and washing sites. Children suffer the effects of noise, vibration, overexertion, poor ventilation, and exhaustion. Children's lives are put at risk by rock fall, explosions, the collapsing of tunnels and mine shafts, falling into open shafts and pits, and breathing air polluted by dust and toxic gas. Having immune systems that are not fully developed makes children especially vulnerable to dust and chemical exposure. Injuries include serious respiratory conditions, constant headaches, hearing and sight problems, joint disorders and various dermatological, muscular and orthopaedic ailments and wounds. Large companies Adverse effects and responses Gold mining can significantly alter the natural environment. For example, gold mining activities in tropical forests are increasingly causing deforestation along rivers and in remote areas rich in biodiversity. Other gold mining impacts, particularly in aquatic systems with residual cyanide or mercury (used in the recovery of gold from ore), can be highly toxic to people and wildlife even at relatively low concentrations. However, there are clear moves by many in the non-governmental organization community to encourage more environmentally friendly and sustainable business practices in the mining industry. The primary way this is being achieved is via the promotion of so-called 'clean' or 'ethical' gold. The aim is to get all end users/retailers of gold to adhere to set of principles that encourage sustainable mining. Campaigns such as 'No Dirty Gold' are driving the message that the mining industry is harmful (for the reasons noted above), and so must be cleaned up. Also,