MERCURY CONTAMINATION IN SANDY SOILS SURROUNDING AN INDUSTRIAL EMISSION SOURCE (ESTARREJA, PORTUGAL)

This study reports the degree and the extent of mercury contamination in sandy soils surrounding a chloralkali plant at Estarreja, Portugal. Total mercury concentration in the soils studied is at a maximum in t he upper 5 cm, ranging from 117 to 49,233 mu g kg(-1). The profile dis tribution pattern for total mercury together with the results of a seq uential extraction suggest that the element is strongly retained by th e soil components. An upper limit of acceptable levels of mercury for this area is proposed based both on statistics and regulatory guidelin es from other countries. Taking that limit, geostatistical methods wer e used to delimit a zone of heavy contamination. Atmospheric fall-out seems to be the main source of contamination of the soils studied. (C) 1998 Elsevier Science B.V. All rights reserved.