Toxicity of haloacetic acids to freshwater algae.
Haloacetic acids (HAA), such as trichloroacetic acid (TCA), are commonly occurring by-products from disinfection and bleaching processes using sodium hypochlorite. Currently, the lowest no observed effect concentration (NOEC) for TCA is reported to be 8.7microgL(-1), which was derived from a toxicity study conducted in 1981 on Chlorella pyrenoidosa. The purity of the test material was not documented and it is unknown if other halogenated impurities or co-formulants were present. However, this NOEC is used to derive a predicted no effect concentration, which is used in various regulatory risk assessments. We present a range of algal toxicity studies conducted on five different algal species and two HAAs and observed no toxicity of TCA to C. pyrenoidosa at 115mgL(-1). The most sensitive species to TCA (NOEC, 3mgL(-1)) were Pseudokirchneriella subcapitata and Scenedesmus subspicatus, demonstrating that the toxicity of TCA to algae is over two orders of magnitude less sensitive than previously reported.
Roberts
Jayne F
JF
Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK.
van Egmond
Roger
R
Price
Oliver R
OR
D002708:Chlorella / Q000187:drug effects / Q000254:growth & development; D056890:Eukaryota / Q000187:drug effects*; D044444:Scenedesmus / Q000187:drug effects; D018675:Toxicity Tests; D014238:Trichloroacetic Acid / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D014874:Water Pollutants, Chemical; D014238:Trichloroacetic Acid