Selenium in soils, spermatophytes and bryophytes around a Zn–Pb smelter, New South Wales, Australia

Abstract

Selenium concentrations and its spatial distribution in soils, spermatophytes and bryophytes (mosses) around the Cockle Creek Zn–Pb smelter, New South Wales were studied from May to November 2000. Selenium was determined by ICP-MS on soils digested in nitric and hydrochloric acid (HNO 3:HCl=3:1), and plant samples digested in distilled concentrated nitric acid. At distances greater than 3 km, selenium in soils, spermatophytes and bryophytes converge to uniform values, which are considered to represent the background value. Mean selenium in soils around the smelter is two times higher than the background value. Mean concentration of selenium in plants around the smelter is three times greater than that for background plants. Selenium from ‘in site’ bryophyte is twice that found in the background bryophyte. The transfer coefficients of selenium between plants and soils are low, especially at a distance less than 1 km from the smelter. However, mosses show the reverse trend. This study indicates that the Zn–Pb smelter is one of the anthropogenic point sources of selenium pollution in the Lake Macquarie district.