Comparison between two Microtox test procedures

Journal Article · Sun Oct 01 04:00:00 EDT 1989 · Ecotoxicology and Environmental Safety; (USA)

DOI:https://doi.org/10.1016/0147-6513(89)90081-X· OSTI ID:5023846

Tarkpea, M; Hansson, M ^[1]

---

1. National Swedish Environmental Protection Board, Nykoeping (Sweden)

A comparison between the two Microtox test procedures, the standard test and the 100% test, has been made. In the standard Microtox bioassay, effluents can be tested up to a concentration of 45%. The 100% test method, however, has been developed for screening effluents with an EC50 value greater than 45%. The relationship between 5-min EC50 values according to the two methods has been studied with a two-way ANOVA analysis for 14 effluents or process waters and one unpurified municipal wastewater sample. All samples were tested twice with a 3-month interval. An F ratio of 15.46 (n = 56) showed that the test methods differed significantly at the 0.1% level. Nevertheless none of the samples had a drastically different EC50 value when tested by the two methods. Both the treatment of the bacteria and the calculation of the EC50 values, which also affect the width of the 95% fiducial limits, differ in the two procedures. The confidence intervals were found to be 10.4 times broader in the 100% tests than in the corresponding standard test. Although the methods differ from each other both in performance and in statistical comparison of the results, both of them could be useful as prescreening methods for determining toxicity to aquatic organisms.

• OSTI ID: 5023846
• Journal Information: Ecotoxicology and Environmental Safety; (USA), Journal Name: Ecotoxicology and Environmental Safety; (USA) Vol. 18:2; ISSN EESAD; ISSN 0147-6513
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540320 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
CHEMICAL EFFLUENTS
COMPARATIVE EVALUATIONS
HYDROGEN COMPOUNDS
LIQUID WASTES
LUMINESCENCE
MICROORGANISMS
OXYGEN COMPOUNDS
POLLUTION
SCREENING
SENSITIVITY
TOXICITY
WASTE WATER
WASTES
WATER
WATER POLLUTION