Aquatox Research staff actively engage in professional activities related to the presentation of study results either in a generic fashion or with the approval of study sponsors. The citations listed below reflect a minor portion of the activities of Aquatox Research staff in the area of standard toxicity testing/biomonitoring. Reprints of each of these publications are available upon request.
Need for Environmental Quality Guidelines Based
on Ambient Freshwater Quality Criteria in Natural Waters-Case Study "Zinc" (Edited
R.J. Magliette, F.G. Doherty, D. McKinney, and E.S. Venkataramani.
1995. Bulletin of Environmental Contamination and Toxicology 54(4):626-632
The toxicity of zinc bromide to the freshwater crustaceans Daphnia magna and Ceriodaphnia dubia under static exposure conditions, and the chronic toxicity to fathead minnows, Pimephales promelas, under renewal conditions were investigated. The tests indicated that Ceriodaphnia dubia was the most sensitive species tested. Measured concentrations of zinc at the end of the tests demonstrated a reduction in soluble zinc of up to 41%, due to the combined effects of alkaline pH and hardness of the test dilution water. In natural waters, suspended solids and dissolved organic compounds are likely to contribute to additional removal of bioavailable zinc. National ambient freshwater quality criteria for zinc fail to account for site-specific water quality effects and resident aquatic ecosystem sensitivity. Inclusion of both into ambient freshwater quality criteria will result in scientifically valid approaches that rely less on generic numerical values.
Standard Operating Difficulties and Practical Limitations in the Conductance of Effluent Toxicity Tests (Abstract)
F.G. Doherty. 1993. TAPPI Proceedings Environmental Conference Book
The use of toxicity tests (or biological monitoring) with fish (e.g. fathead minnows, Pimephales promelas ) and invertebrates (e.g. water fleas, Ceriodaphnia dubia) to assess the environmental acceptability of industrial and municipal (POTW) effluents discharged to surface water systems has increased steadily over the past several years. While these tests are relatively simplistic in design, straight-forward to set-up and monitor, and tend to reduce the costs associated with demonstrating compliance with discharge permit requirements (as opposed to analytical-based permit requirements), a variety of technical and operational factors can interfere with the completion of a successful test or the identification of the causes for a failed test. These factors include, but are not necessarily limited to test organism health and diet, acceptability of culture and test water, cleanliness of culture and test glassware, and experience levels of both the contractor's and regulated facility's staff for conducting effluent toxicity tests. Failure of an individual to perform a critical function in any one area of support can result in test failure. Consequently, successfully conducted effluent toxicity tests require an integrated effort by all personnel involved in the testing effort from sample collection to test completion and data analysis. Examples of common errors and deficiencies in laboratory operations and test conductance are presented to illustrate the above-cited points.
Quality Assurance in Effluent Monitoring (Abstract)
F.G. Doherty. 1991. Environmental Auditor 2(4):249-257
Biological monitoring is an important aspect of environmental auditing that attempts to assess the environmental acceptability of effluents from point-source discharges released to surface waters through standardized laboratory toxicity tests with freshwater and marine organisms. Quality Assurance (QA) programs employed in laboratories conducting effluent toxicity tests attempt to ensure the integrity of the data generated through a series of guidelines designed to limit deviations from standard protocols. In general, QA programs in these facilities have been adopted from programs that have existed for a decade or more in chemical toxicity testing laboratories. Unfortunately, QA programs can only ensure the generation of quality data to the extent allowed by current state-of-the-art knowledge. This article attempts to advance the state-of-the-art in biomonitoring by assessing the degree to which certain factors contribute to the variability associated with effluent toxicity test results.
Detoxification Rates of Chlorinated Solutions as Determined
by the Half-Life of Biological Activity with Daphnia magna. (Abstract)
F.G. Doherty. 1985. Environmental Toxicology and Chemistry 4:97-105
Data are presented that discourage the use of total residual
chlorine (TRC) and free residual chlorine (FRC) levels in setting water quality
criteria for chlorine and chlorinated carrier molecules. Repetitive static
acute toxicity tests for aging solutions of chlorinated complexes with Daphnia magna permit
generation of biological half-lives for direct comparison with analytically
derived concentrations of TRC and FRC. The results indicate a strong similarity
in the decline of toxic effects on D. magna and TRC for an aging
solution of 1,3-dichloro-5,5-dimethylhydantoin (DCDMH), although no such similarity
exists exists between these two measures for aging solutions of chlorine and
trichloro-S-triazinetrione (TCTT). Repetitive toxicity tests with aging DCDMH
generated toxic decay curves with coefficients of determination (r2) exceeding
73% while exhibiting a minimum decay rate of -0.10. TRC data for DCDMH exhibited
an r2 of 93% and a decay rate of -0.07. The r2 values for the chlorine series
ranged from 15 to 60% for the toxic effects decay curve, as compared with 76%
for analytically derived data. The TCTT r2 values for these same parameters
were 23 to 64 and 84%, respectively. Both chlorine and TCTT presented definable,
consistent decreases in TRC levels over the course of the studies, while the
observed biological effects oscillated widely from test to test within a series.
These results demonstrate that the standard reported parameters of TRC and
FRC are inadequate for setting effluent limitations on chlorinated discharges
because they are inconsistent in measuring the toxic constituents of these
Interspecies Correlations of Acute Median Lethal Concentration
for Four Standard Testing Species (Abstract)
F.G. Doherty. 1983. Environmental Science & Technology
Correlation and regression analyses were conducted on acute
median lethal concentration (LC50) data for various compounds comparing
the species rainbow trout (Salmo gairdneri ), bluegill sunfish
(Lepomis macrochirus), fathead
minnow (Pimephales promelas), and the water flea (Daphnia magna).
Predictive equations were developed on data extracted from the literature
and generated internally at Betz Laboratories, Inc., for the period 1965-1982.
Results indicate there is a high level of correlation (r>88%) among these
four species in all combinations. The degree of demonstrated predictability
is sufficient to allow the use of D. magna as the first species screened in primary level hazard
assessment schemes, permitting a greater latitude of choice in the second species
subjected to acute toxicity testing.