Total mercury in terrestrial systems (air-soil-plant-water) at the mining region of San Joaquin, Queretaro, Mexico

摘要

La deficiente minerfa de cinabrio dejo a San Joaqui'n altas concentraciones de mercurio en terreros de mina (2.4 - 4164 mg kg~(-1)). Numerosas minas contribuyeron a la dispersion de mercurio en suelos agrfcolas (0.5 - 314 mg kg~(-1)) y suelos forestales (0.2 - 69.0 mg kg~(-1)). Los sedimentos son un medio de transporte natural del mercurio, que ocasionan su dispersion, especialmente en areas cercanas a las bocaminas (0.6 - 687 mg kg~(-1)). La cercanfa de los cultivos de mai'z a las minas favorece la acumulacion de mercurio en sus distintas estructuras como la rafz, el tallo, la hoja y el grano (0.04 - 8.2 mg kg~(-1)), que se relacionan con la acumulacion y volatilizacion de mercurio en suelos. El vapor de mercurio presente en la poblacion puede indicar una volatilizacion constante de los terreros y suelos (22 - 153 ng m~3). Los niveles de mercurio encontrados en suelos, en los granos de mafz y en el aire resultaron superiores a los estandares reportados por la Norma Oficial Mexicana y la Organizacion Mundial de la Salud. El mercurio en el agua de lluvia se debe principalmente a las partfculas atmosfericas suspendidas y depositadas mas tarde en la su-perficie (1.5 - 339 μg l~(-1)). En el agua potable se encontro disolucion de mercurio (10 - 170 ng l~(-1)), siendo las concentraciones menores a las establecidas por la NOM Y OMS. La contaminacion existente en la region de San Joaqufn no Mega a los niveles de los maximos productores de Hg en el mundo: Almaden (Espafia) e Idrija (Eslovenia); sin embargo, se asemeja a la hallada en otros importantes distritos de segundo nivel mundial como Guizhou (China). La poblacion de San Joaqufn y su ambiente presentan una exposicion constante a la contaminacion del mercurio, por lo que es necesario un monitoreo a largo plazo para determinar sus alcances, en especial para el hombre.%Deficient management of cinnabar mining left the San Joaqufn region with high concentrations of mercury in its soils (2.4 - 4164 mg kg~(-1)). Numerous cinnabar mines have contributed to the dispersion of mercury into agricultural (0.5 -314 mg kg~(-1)) and forest (0.2 - 69 mg kg~(-1)) soils. Sediments are a natural means of transportation for mercury, causing its spreading, especially in areas near mine entrances (0.6 - 687 mg kg~(-1)). The nearness of maize crops to mines favors mercury accumulation in the different plant structures, such as roots, stems, leaves, and grain (0.04 - 8.2 mg kg~(-1)); these being related to mercury volatilization and accumulation in soils. Mercury vapor present in the settlements could indicate a constant volatilization from lands and soils (22 - 153 ng m~3). The mercury levels found in the soils, in maize grain, and in the air resulted greater than the standards reported by the Official Mexican Norm (NOM) and the World Health Organization (WHO). Mercury in rainwater is due mainly to the presence of suspended atmospheric particles, later deposited on the surface (1.5 - 339 μg l~(-1)). Mercury dissolution was found in the drinking water (10 - 170 ng l~(-1)), with concentrations below those established by the NOM and the WHO. The contamination existing in the San Joaqufn region does not reach the levels of the world's greatest mercury producers: Almaden (Spain) and Idrija (Slovenia). It is, however, like that found in other important second degree world producers such as Guizhou (China). The population of San Joaqufn, as well as its surrounding environment, are constantly exposed to mercury contamination, thus making a long term monitoring necessary to determine its effects, especially to people.