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Dive into the research topics where David J. Schaeffer is active.

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Featured researches published by David J. Schaeffer.


Archives of Environmental Contamination and Toxicology | 1982

Organic constituents of mutagenic secondary effluents from wastewater treatment plants

David D. Ellis; Cyrenius M. Jone; Richard A. Larson; David J. Schaeffer

The organic constituents of mutagenically active secondary effluents from industrial plants and publicly-owned treatment works in Illinois were analyzed by capillary gas chromatography-mass spectroscopy. Tentative identification of 243 compounds, 20 of which are U.S. Environmental Protection Agency priority pollutants, was achieved, including 33 not previously reported as water constituents. Among the compounds detected in one or more of the effluents were aromatic hydrocarbons, phenols, plasticizers, chloro- and bromo-compounds, anilines, indoles, and triazine herbicides. However, onlyN-nitrosodimethylamine ando-toluidine, among the identified compounds, are known to be carcinogens or mutagens.


Ecotoxicology and Environmental Safety | 1984

Quantitative comparisons of acute toxicity of organic chemicals to rat and fish

Srinivas K. Janardan; Clark S. Olson; David J. Schaeffer

Relationships between the acute toxicity of chemicals to fish (LC50) and rat (LD50) were analyzed using a Model II regression analysis after logarithmic transformation. (Model II regression assumes errors in both variables.) Significant correlations were found among bluegill and fathead minnow LC50S and rat LD50 values for the priority pollutants. Fathead minnow and bluegill LC50S for 48 pesticides were highly correlated. No correlations were found between fish and rat for carbamate plus organophosphate pesticides. Correlations were obtained among all species for the combined priority pollutant plus pesticide data and for chlorinated pesticides.


Journal of Toxicology and Environmental Health | 1980

Identification of cocarcinogens and promoters in industrial discharges into and in the illinois river

Satu M. Somani; Robert G. Teece; David J. Schaeffer

Organic compounds were isolated from grab or composite samples of industrial and municipal discharges and of the Illinois River by liquid-liquid extraction or adsorption on activated carbon or XAD-2 resin columns. Of the 213 different compounds identified and semiquantitated by gas chromatography-mass spectrometry in 16 samples, 74 were long-chain hydrocarbons or their derivatives. Although their toxicological significance in the environment at the levels found is unknown, the widespread presence of these cocarcinogens and promoters (often found in conjunction with known initiators) may make them significant environmental toxicants. Some evidence for this is the fact that serial dilutions of the extracts were highly toxic to Salmonella typhimurium in the Ames assay, while weak mutagenicity was occasionally detected.


Ecotoxicology and Environmental Safety | 1983

Brine shrimp (Artemia salina) nauplii as a teratogen test system

Harold W. Kerster; David J. Schaeffer

Brine shrimp increase in length rapidly after hatching. A teratogen test system is based on disruption of elongation between 24 and 48 hr after wetting of the cysts. Teratogenicity of substances dissolved in the medium is assayed by comparison of average lengths of animals raised for the test period in suspect solution with average lengths of controls. The system is fast, inexpensive, and requires little skill. Brine shrimp are suited to testing industrial wastes, chemical formulations, drugs, and food additives that can be dissolved in water at 25 degrees C. The method appears unsuited to testing the teratogenicity of gases, particulates, very dilute wastes, or natural waters. Cadmium, mercury, lead, zinc, bromoform, n-butylphthalate, 1,2-dichloroethane, nitrobenzene, tetrachloroethylene, toluene, 1,2,4-trichlorobenzene, and 1,1,3-trichloroethane were found teratogenic. Chromium (III), chromium (VI), copper, chlorobenzene, chloroform, dimethyl sulfoxide (DMSO), and phenol were found not teratogenic. Other aquatic organism teratogen test systems are surveyed.


Environmental Management | 1980

Grab versus composite sampling: A primer for the manager and engineer

David J. Schaeffer; Harold W. Kerster; Konanur G. Janardan

Effluent subsamples are usually aggregated into flow or time proportional samples before analysis. Although this provides information on average process conditions, that on process variability is lost by compositing. Fishers information is defined and used to estimate the loss due to compositing. The results of simulations based on parameters derived from actual waste streams support the fact that random grabs serve as well as composite samples for monitoring purposes. These findings favor changes in regulatory practice to allow compliance to be demonstrated by grab sample averages. Reporting requirements based on moving averages are shown to be inferior to those based on averages taken over nonoverlapping time periods.


Environmental Management | 1985

The environmental audit. I. Concepts

David J. Schaeffer; Harold W. Kerster; Jim A. Perry; David K. Cox

Extensive criticism of water quality monitoring programs has developed as costs are compared with the benefits produced by monitoring efforts. Collecting water quality data while developing understanding of the functional character of the environment will improve water quality monitoring data utility in environmental management. The “environmental audit” characterizes the attributes of the natural environment (that is, attribute type, intensity, and variability), providing a theoretical as well as practical foundation for data interpretation. In the view proposed here, traditional monitoring means the very narrow activity of collecting samples and perhaps analyzing them and storing the analyses. In the environmental audit, these activities are a mechanism to systematically improve environmental monitoring and assessment by improving the design and implementation of environmental programs. Major reasons why existing programs fail to meet the needs of legislators, regulators, and conservationists are identified.


Ecotoxicology and Environmental Safety | 1985

Estimating the mass of mutagens in indeterminate mixtures

David J. Schaeffer; Harold W. Kerster

A method is shown for estimating the quantity (mass) of genotoxic compounds in complex mixtures without prior identification of components. This method uses fractiles of the probability distribution of responses from the assay of interest and dose-response of the mixture. The method depends upon the assumption of additivity, on average, in the interaction of mutagens and on lognormality of the distribution of mutagen molecular weights. Mass estimates are necessary for hazard characterization, risk estimation, and risk assessment. The method is illustrated using Ames assay results from a coke plant wastewater.


Environmental Management | 1982

Monitoring toxics by group testing

David J. Schaeffer; Harold W. Kerster; Konanur G. Janardan

Monitoring the environment for a large list of organic compounds present at low levels is costly. The primary purpose of such monitoring is to assure that hazardous levels of such compounds are not released into, or present in, the environment. Viewing this as a quality control problem, we suggest that samples from different sources can be composited using group testing procedures prior to analysis. Our purpose is to describe the basic concepts and suggest problems requiring study.


Environmental Management | 1979

Illinois redesigns its ambient water quality monitoring network

Thomas R. Wallin; David J. Schaeffer

Illinois has been operating an ambient water quality network of almost 600 stations for several years. In 1977 changes in program emphasis toward intensive monitoring, the need for improved procedures and quality control in monitoring operations, and the desire to create a single data base of all Illinois State monitoring data, resulted in a redesign of the ambient monitoring program.A unique cooperative program between the Illinois Environmental Protection Agency and the US Geological Survey provides for their monitoring a portion of the network. The Survey provides flow data at most network stations as well as extensive manpower training, equipment, data processing, and program quality control. Informal agreements with other agencies have permitted a great reduction in the monitoring effort required by the Illinois Environmental Protection Agency.


Environmental Management | 1980

Graphical effluent quality control for compliance monitoring: What is a violation?

David J. Schaeffer; Konanur G. Janardan; Harold W. Kerster; M. Soma Shekar

Demonstration of compliance with discharge (effluent) requirements suffers because Discharge Monitoring Reports (DMRs) give neither the discharger nor the regulator information on the process mean which ensures compliance. To obtain this information, a simple graphical method is presented which takes into account process variability. This technique provides quality control specifications for the monitoring data and the process itself.

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Konanur G. Janardan

University of Illinois at Springfield

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Harold W. Kerster

California State University

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Satu M. Somani

Southern Illinois University Carbondale

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B. Raja Rao

University of Pittsburgh

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Jim A. Perry

University of Minnesota

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Charles Corley

Illinois Environmental Protection Agency

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Clark S. Olson

Illinois Environmental Protection Agency

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David K. Cox

Illinois Environmental Protection Agency

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Don B. Campbell

Western Illinois University

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Harris Chien

Illinois Environmental Protection Agency

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