Bioassay standardization for water quality monitoring in Mexico

✍ Scribed by Y. Pica-Granados; G. D. Trujillo; H. S. Hernández

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 139 KB
• Volume: 15
• Category: Article
• ISSN: 1520-4081
• DOI: 10.1002/1522-7278(2000)15:4<322::aid-tox8>3.0.co;2-f

✦ Synopsis

In Mexico, bioassays for water toxicity testing can be useful tools for water quality control programs and environmental risk evaluation. However, since many bioassays have not been standardized, their application and acceptance in pollution monitoring and control sectors are limited. In an effort ( ) to overcome this limitation, the Mexican Institute of Water Technology MIWT agreed to participate in an ( ) international laboratory network WaterTox , sponsored by the International Development Research ( ) Centre IDRC . The Centre seeks to evaluate the analytical repeatability and reproducibility of six ( bioassays Allium, Hydra, Daphnia magna, and Panagrellus assays; lettuce seed germination and ) Fluctuation tests and to determine their sensitivity patterns and the manner in which they are complementary or redundant in a core test battery. In addition, the Mexican team added the Vibrio fischeri Microtox toxicity test to the evaluation. A series of 24 blind samples were analyzed over a 1-year period. Results indicated that precision, or repeatability, was acceptable for most bioassays. For blind sample replicates, the overall coefficient of variation was less than 22%, except for the Muta-Chro-( ) ( ) moPlate test 60% and the nematode assay greater than 100% . While most toxic samples were detected by D. magna and Hydra attenuata assays, those that produced little effect on these two organisms affected lettuce and onion root elongation. The complementary nature of these tests provides a wide spectrum of toxicant detection, in contrast to the Microtox test which showed a more limited and redundant sensitivity pattern when compared against a battery comprised of the four inexpensive bioassays.