Soil pollution related to the mercury mining legacy at Asturias (Northern Spain)

Abstract

Asturias (NW Spain) is regarded as an important metallogenic province with particular emphasis on mercury (Hg) and arsenic (As). Different Hg mineral species, as well as As-rich minerals, are found in the ore deposits in this part of Spain. Metallurgical activity to extract Hg from these ores was also carried out at many sites. Consequently, the combination of emissions during mining of the ore and additional releases during the inefficient roasting operation gave rise to significant releases of Hg and As to the surrounding soils. All the Hg mines of the district were abandoned before the introduction of any environmental regulations; consequently, the environment is globally affected. Mean Hg contents in soils range from 42 to 155 mg kg⁻¹, whereas average As concentrations range from 17 to 831 mg kg⁻¹.

Keywords:

• Hg mining
• polluted soils
• Asturias Hg mining district