A PLANT LIFE-CYCLE BIOASSAY FOR CONTAMINATED SOIL, WITH COMPARISON TOOTHER BIOASSAYS - MERCURY AND ZINC

Citation
Sc. Sheppard et al., A PLANT LIFE-CYCLE BIOASSAY FOR CONTAMINATED SOIL, WITH COMPARISON TOOTHER BIOASSAYS - MERCURY AND ZINC, Archives of environmental contamination and toxicology, 25(1), 1993, pp. 27-35
Citations number
48
Categorie Soggetti
Toxicology,"Environmental Sciences
ISSN journal
00904341
Volume
25
Issue
1
Year of publication
1993
Pages
27 - 35
Database
ISI
SICI code
0090-4341(1993)25:1<27:APLBFC>2.0.ZU;2-A
Abstract
Bioassays using rapid-cycling plants allow measurement of multiple end points and assessment of impacts on both growth and reproduction. Sele ctions of Brassica rapa develop rapidly in a broad range of soils and are very consistent in production of flower and seed. Their sensitivit y to variation in growth conditions was investigated to define the var iables that most affect performance. Yield differences between soils w ere substantial, indicating the need for careful selection and use of control treatments. The sensitivity to contaminants was investigated w ith applications of mercury (Hg) and zinc (Zn) to three soils. In a sa nd soil, bloom initiation was slowed by < 10 mg Hg kg-1 soil and < 50 mg Zn kg-1 soil. In contrast, lettuce emergence and earthworm survival were less sensitive to these metals in this soil. Survival of Daphnia magna and the Microtox(R) assay in soil extracts were more sensitive to Hg than bloom initiation, but less sensitive to Zn. A similar relat ionship among the bioassays was observed for two finer-textured soils, although for these, effects were usually apparent only at soil metal concentrations > 200 mg kg-1. Enzyme assays were included for comparis on, but were not sensitive to Hg contamination. Rapid-cycling B. rapa selections are suitable for routine bioassays, and are representative of several widely distributed and utilized species.