ISSN:
1432-0703
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Medicine
Notes:
Abstract An investigation of bioassay systems employingDaphnia, Hyalella, Culex, orPalaemonetes was initiated in response to the need for rapid, sensitive, and inexpensive screening procedures for toxicants in food and feed. The procedures may also be useful to determine whether farm workers may safely reenter fields treated with pesticides. The evaluation of inherent toxicities related to types and amount of organic solvents commonly used in such systems indicated that dimethyl sulfoxide (DMSO) and methanol (MeOH) were least toxic in the aqueous test media. These solvents were then used in 18-hr tests to determine sensitivities of the four organisms to a representative compound from six classes of pesticides,i.e., dieldrin, parathion, carbaryl, atrazine,o-phenylphenol, and maneb. Stress factors such as the amount of organic solvent and volume of test medium were adjusted to determine their effects on three of the organisms tested against dieldrin and parathion. The highest sensitivity obtained with dieldrin (50% mortality with 2 ng in a 25-ml test medium) was withCulex stressed with 2% of MeOH in a reduced test volume.Hyalella stressed with 2% of MeOH were most sensitive to parathion (50% mortality with 85 pg in a 100-ml test medium); further stress imposed by reducing the volume of test medium diminished sensitivity.Daphnia, which were also very sensitive to dieldrin and parathion, were most sensitive to the other four pesticides which exhibited low toxicities to all test organisms.Daphnia would, therefore, be the organism of choice if only one could be used. The amounts of carbaryl, atrazine,o-phenylphenol, and maneb required to yield 50% mortality withDaphnia in 25-ml test systems (0.4% MeOH) were about 0.05, 15, 47 and 2.4μg, respectively. Preliminary experiments with various extracts of animal feed indicate that an extensive effort will be required to develop a method that will provide extracts that are compatible with the bioassay systems.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01057571
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