COMPARED BACKGROUND AND REFERENCE VALUES IN SOURCES OF CADMIUM-ENRICHED SOILS FROM BRAZIL

The complexity of the assessment process of variations in contamination levels of soils is in part due to distinct sources, natural or by some anthropic activities. Compare these different substances sources, backgrounds and guiding values is very important to introduce directions and contributions for regulations or environmental protection legislation in general, for heavy metals contents, among other chemical components, and are pointing to more restrictive use of phosphate fertilisers, rich in those pollutant elements, in many countries around the world. Recognize and characterize contaminated soils is a serious concern with issues that whole society have to deal with today and one of the largest and most neglected problems in Brazil. This works intends to obtain an insight in the natural sources and loads of heavy metals, especially cadmium to soils in Brazil, mainly with the application of huge volume of mineral fertilisers, directly linked with their dangerous concentrations. This is a threat to public health in many regions, and it is one of the priorities to protect it from all sources of anomalous concentration in the ground. Decreasing soil quality by means of contamination and pollution by heavy metals is now recognized also as a serious risk for environmental quality and to the health of people.