Abandoned mine areas soil of Hinabangan, Samar [Philippines] analyzed

The shutting down of many mining operations leaves the used area with traces of heavy metals. These heavy metals enter the environment through the soil whenever these or their compounds are pulverized, heated, or dissolved during industrial usage. Geochemical 'neonomalies' which may contain up to 1,000 times the normal trace element content and may often be toxic rather than helpful to organisms, thus pollute the environment. To determine the extent of trace metal pollutants in an abandoned mine area in Bagacay, Hinabangan, Samar [Philippines], Nasayao et al. (DENR-R8) [Eastern Visayas, Philippines] conducted soil analysis. This was done to come up with recommendations for the future rehabilitation of the area. Findings of the study revealed the following: The soils' physical characteristics varied from clay loam to sandy loam to sand. Almost all soils sampled had ultra acid to extremely acid pH as low as 2.290. Areas with high pH were mostly vegetated indicating the importance of soil pH in establishing vegetation in the abandoned area. In all sites, metal concentrations in the soil were all above the maximum permissible amount. Copper (Cu), cadmium (Cd), and lead (Pb), the pollutants present in the abandoned mine area, were all above average. Cu had the highest value at 6202.88 me/kg. From previous studies, Cu-enriched plants' material can be hazardous to animals, while Cd, considered one of the most dangerous environmental pollutants affects primarily the kidneys. Pb, a major chemical pollutant, is highlyb toxic to man. Total nitrogen (N) and exchangeable calcuim (Ca) were both very low to extremely low. Exchangeable phosphorus (P) was low to very low while exchangeable potassium (K) values were very high to extremely high. Other minerals such as magnesium (Mg) were also very high to extremely high, while iron (Fe), manganese (Mn), and zinc (Zn) concentrations were higher than the normal values. These values were indicative of the imbalance in the soil nutrient content. The study recommended the revegetation of the area and establishment of soil erosion control structures so that pollution of rivers and adjacent agricultural fields can be avoided. Fast-growing species, with high litter fall turnover, fast decomposition rate and drought-, acid- and saline- resistance, should be planted to improve the nutrient status of the soil. These species include acacia, 'agoho', 'bitaog', and even bamboo. Endemic fruit trees such as 'duhat' and 'camachile' could also be planted.