Assessment of the impact of small-scale mining on soil contamination by mercury and hydrocarbons in the kadey catchment (East Cameroon).

The objective of the present study was to assess soil contamination by mercury and hydrocarbon products used in gold mining in the Kadey catchment area. The results obtained show that gold mining by the small mine is the cause of chemical contamination of the soil caused by hydrocarbon products with concentrations 800 times higher than the threshold value on certain points of the former mining sites. The use of mercury has led to an increase in its concentration to values that are still below the critical thresholds. It also appears from this work that organic matter plays a very important role in the retention of mercury on the soil surface. In the case of hydrocarbons are concerned, although high concentrations above are found exclusively at the surface, the rainfall contributes to their infiltration into the soil and to a horizontal redistribution of the contamination.