Mercury pollution is a big problem today and mining, one of its main sources. In this economic activity, which is done from the time of the Romans, the heavy metal is used to separate gold from other elements in the earth in a very similar way to the process of distillation (Drasch, Böse-O’Reilly, Beinhoff, Roider, & Maydl, 2001). Although Colombia is one of the most contaminated by mercury in Latin America countries, the products of this pollution are caused by illegal actions so it is difficult to quantify how much of this metal is introduced to the natural resources of our country. However, in Colombia there are institutions that seek to establish the extent of the problem and propose solutions. This is the case of the Colombian Network of Nanoscience and Nanotechnology that in June 2015 organized the National Forum on Mercury Contamination in Colombia whose main objective was to reduce the use of mercury in mining so that Colombia could be accepted into the OECD. Thanks to the efforts of this organization, it is estimated that at least 300 tons of mercury are thrown to Colombian ecosystems every year and this affects at least 18 departments, among which is Choco, one of the most vulnerable (Medina, 2015). In that forum they were established three main objectives: to use sensors to detect and quantify the amounts of mercury in air, water or soil; replacing the use of metal in artisanal and small-scale gold mining for new materials; and remediation techniques to recover contaminated areas with the use of nanomaterials.
How mercury contamination occurs?
As mentioned previously mercury has been used in mining, taking advantage of it because it forms an amalgam with certain metals such as silver and gold, to seperate them of any impurities. After purifying gold or silver, leftovers are thrown into the air or water sources and consumption for all kinds of animals is toxic in very low amounts. Although there are other techniques for extracting gold and other precious metals, less insecure, this method is much cheaper, easy to use and is preferred artisanal mining and illegal, two common activities in Colombia (Revista de Logística - Colombia, 2012).
Another industrial process such as the production of chlorinated compounds and combustion of fossil fuels since the latter are naturally incorporated mercury. They also produce this metal contamination, in less amounts cement production and burning of some wastes (UNEP, s.f)
Although older are generally affected water sources, it should be noted that Colombia has in some regions mercury levels in air higher world (Red Colombiana de Nanoscience and Nanotechnology, 2015) In Colombia there are other methods for more "safe" mercury mining but not used either because of ignorance or lack of resources to use. For all these reasons the Congress of the Republic proclaimed the Law No. 1658 on 15 July 2013 where it aims to eliminate mercury in mining in 5 years and the industry at 10. Despite this, it should not be taken lightly the damage caused by the mercury in the environment and the health of many living beings, including of course humans. (Congress of Colombia, 2013). The severity of this problem is mainly in mercury being a metal can not be degraded, the amount in living things grow exponentially as one moves through the food chain and is toxic at very low amounts (from 2 micrograms begin to have symptoms), however, the diagnoses for mercury poisoning are usually below 10 ug / l (Ibrahim, Froberg, Wolf, & Rusyniak, 2006).
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Mercurio (Hg) Propiedades químicas y efectos sobre la salud y el medio ambiente. (n.d.). Retrieved February 13, 2015, from http://www.lenntech.es/periodica/elementos/hg.htm
Revista de Logística - Colombia. (n.d.). Retrieved May 19, 2015, from http://www.revistadelogistica.com/Mineria-de-oro-en-Colombia-auge-y-problematica.asp
Drasch, G., Böse-O’Reilly, S., Beinhoff, C., Roider, G., & Maydl, S. (2001). The Mt. Diwata study on the Philippines 1999 — assessing mercury intoxication of the population by small scale gold mining. Science of The Total Environment, 267(1–3), 151–168. http://doi.org/10.1016/S0048-9697(00)00806-8