Toxicity of trichloroethylene (TCE) on some algae and cyanobacteria.

The toxicity of trichloroethylene was tested in both glass enclosures and in polystyrene immunological plates, and resulted in insignificant correlation of EC₅₀ (evaluated as OD 750 nm). In enclosures, EC₅₀ evaluated as O₂ evolution and as pH increment was highly significant. The optimal time for the assay of TCE in enclosures was 48-72 h; and in plates ca 200 h. After a longer time (e.g. 300 h) TCE diffused from the plates and growth was revived. TCE in low concentrations (ca. 0.1-0.2 g/L) stimulated the growth of some tested organisms, both in plates and in enclosures. Toxicity occurred from ca. 0.35-0.6 g/L (EC₅₀). The testing procedure in enclosures was a suitable method for some volatile substances, giving rapid results.