L. Pollumaa et al., Toxicological investigation of soils with the solid-phase flash assay: Comparison with other ecotoxicological tests, ATLA-ALT L, 28(3), 2000, pp. 461-472
A new direct-contact toxicity test, the solid-phase flash assay, which util
ises photobacteria in direct contact with soil particles during the exposur
e, was evaluated on four soil samples. Samples HTNT1 and HTNT2 originated f
rom former military sites in Germany, and were highly contaminated with nit
roaromatics (approximately 20g/kg), lead and polycyclic aromatic hydrocarbo
ns. Samples LMKW1 and LMKW2, from bioremediation stacks in Germany, were ma
inly contaminated with mineral oils. The solid-phase flash assay was applie
d to soil-water slurries, and the results were compared with the toxicity d
ata for soil-water extracts obtained by using various conventional ecotoxic
ological tests, in which photobacteria, crustaceans, protozoa and algae wer
e used as test organisms. The LMKW1 and LMKW2 samples were not toxic (EC20
> 12.5%) according to all the tests applied, except for the Photobacterium
phosphoreum conventional luminescence-inhibition test for LMKW1 (15-minute
EC20 = 5.4%). The HTNT1 and HTNT2 samples were toxic according to all the t
ests applied, with the majority of EC20 values being lower than 1%. The sol
id-phase flash assay (1 minute of extraction and 30 seconds of exposure tim
e) gave comparable results to the conventional tests. Therefore, this flash
assay could be applied as a fast screening test in parallel with conventio
nal toxicity tests that use soil 24-hour extracts. The flash assay results
will be ready by the start of the conventional assays, and could serve as r
ange-finders for these slower and more expensive tests.