Soll metal accumulation in the area under industrial chimney influence (Valparaíso Province, V Region)

Sergio González M.1 y Regina Ite D.1

A surface soil sampling (0-20 cm) within the area under influence of atmospheric emissions from industries located at Ventanas (Valparaíso Province, V Región Chile), was carried out during 1991 to determine the changes in total metal contents after eight years. Seven out of nine seiected sites were also included in the survey carried out in 1983. According to the obtaíned data, significant increases in copper, lead, zinc and cadmiun contents were detected after the 8-year period. For copper, the 1991/1983 change rate ranged from 8.9 to 1.7, being the rate magnitude associated mainly to distance and direction from the industrial zone; lead and zinc changed concordantly, showing ranges from 9.1 to 1.1 and 10.8 to 1.3, respectively. Cadmium contents showed the same trend but rate values cannot be calculated as total contents in 1983 samples are not available. Arsenic total contents in surface soils (not determinad in 1983 samples) haya reached high levels of accumulation, clearly over the natural background of the area, estimated in a value around 3 mg/kg. In the nearest site to the industries, the arsenic excess was 241 times over the background. Taking metal spatial distribution modal into account, the industrial origín emerges as the unique possibility for this surface soil metallic enrichment. According to metal identity and importance, it is clear that the copper smelter must be the main source of metal contamination, being the thermoelectric plant a secondary participant of the process.

Keywords: copper, lead, zinc, cadmiun, arsenic, soil accumulation.
1 Estación Experimental La Platina (INIA), Casilla 439, Correo 3, Santiago, Chile.