Urban soil quality assessment in green areas of two medium-sized Finnish cities, Lahti and Joensuu

Abstract

In this study, contamination levels and ecotoxicity in 29 urban soils in two medium-sized Finnish cities, Lahti and Joensuu were evaluated. It was established that Cd concentration exceeded the natural background level in all soils tested. The estimated number of soil samples contaminated with Pb, Ni, Cu and Zn was 1, 3, 1 and 23 respectively. The total content of polyaromatic hydrocarbons (⅀16PAH) was analyzed in urban soil samples. It was found that in soils ⅀16PAH ranged from 23.78 to 831.42 ng*g-1 (Lahti) and from 14.38 to 1173.95 ng*g-1 (Joensuu). No correlation was found between the levels of total metals and total PAHs. Ecotoxicity was analyzed by bioassay of elutriate using Paramecium caudatum (R = 0.75). The ecotoxicity index levels (LID10) ranged from 1 to 40. A strong correlation was observed between total metal content and soil ecotoxicity levels.