By Matthew Owens
A paper recently published in the open access journal PLoS ONE highlights the potentially damaging toxic effects of mercury exposure in children in Chile and points to the biggest risk factors associated with artisanal mining in the country. The international team of researchers that includes Universidad Diego Portales in Santiago conclude that the largest risk of high levels of mercury in the body for children came from playing in a house where mercury was used to process metal ore. Mining is big business in Chile; in 2009 exports of metals like copper and gold accounted for as much as 57% of Chile’s total exports. In addition to large industrial scale mines, there are numerous smaller scale operations across the country that provide a source of income for artisanal miners, or “Pirquineros”, who practice a traditional, yet hazardous, method of mining.
As the authors of the study explain, workers typically descend into narrow pits to retrieve the gold ore which is then ground down and mixed with liquid mercury, forming an amalgam. This compound is then burned to release the mercury, leaving behind the prize of pure gold. The problem is that mercury vapours easily enter the blood stream through inhalation and given that the amalgamation process often takes place within the homes of the workers, anyone in the immediate vicinity, including family members, can become exposed to the mercury which can cross the blood-brain barrier exerting toxic effects, perhaps particularly damaging to the developing brain of a child. Levels of mercury in artisanal workers have previously been shown to be higher than normal in artisanal gold workers who suffer neurological and neuropsychological deficits. Banning the use of mercury in private homes may be the necessary step to prevent damage to developing children and adults alike. At the same time, safer working environments should be developed to ensure that artisanal families continue with their livelihood.