Harold W. Kerster

Ecosystem health: I. Measuring ecosystem health

Ecosystem analysis has been advanced by an improved understanding of how ecosystems are structured and how they function. Ecology has advanced from an emphasis on natural history to consideration of energetics, the relationships and connections between species, hierarchies, and systems theory. Still, we consider ecosystems as entities with a distinctive character and individual characteristics. Ecosystem maintenance and preservation form the objective of impact analysis, hazard evaluation, and other management or regulation activities. In this article we explore an approach to ecosystem analysis which identifies and quantifies factors which define the condition or state of an ecosystem in terms of health criteria. We relate ecosystem health to human/nonhuman animal health and explore the difficulties of defining ecosystem health and suggest criteria which provide a functional definition of state and condition. We suggest that, as has been found in human/nonhuman animal health studies, disease states can be recognized before disease is of clinical magnitude. Example disease states for ecosystems are functionally defined and discussed, together with test systems for their early detection.

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

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.

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

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.

Assessing Ecosystem Impacts from Simulant and Decontaminant Use

Abstract Environmental effects from chemical release depend on factors which include the routes and rates of release, the modes of dissemination and degradation, and toxicities to local organisms. Data used for ecosystem risk characterization varies in quality and quantity, making it difficult to detemine the relative ecohazards of compounds. The problem addressed in this paper is: “Given particular chemicals, use scenarios and natural communities, how can the toxicological effects of future chemical use be projected using available data?” A method which uses available qualitative and quantitative data on physical and chemical properties, toxicity, and usage was devised to rank the ecological hazard of compounds. The ecohazard of a compound is determined using a decision key and a risk rank matrix which can initially use qualitative data. We regard the risk matrix as an algorithm for quantitatively expressing ecosystem risk. The risk characterization is refined by incorporating quantitative data in successive iterations through the process. The method was used to rank the anticipated ecosystem risk for over 40 chemicals used in military training.

The environmental audit. I. Concepts

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.

Estimating the mass of mutagens in indeterminate mixtures

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.

Monitoring toxics by group testing

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.

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

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.

The environmental audit. II. Application to stream network design

The planning and execution of water quality management programs requires careful collection and analysis of data coupled with a systematic review and analysis of programmatic success. The environmental audit is a tool which facilitates improved water quality planning and management. This article demonstrates the utility of the environmental audit by reviewing portions of a comprehensive review of the water quality management program for the state of Idaho. The audit is a tool which forces careful design of a sampling program before data are collected. In the audit approach, program objectives are clearly stated prior to initiation of sampling. Stated objectives are also evaluated regularly to identify tension points, that is, conflicts between expectations and reality. In the example taken from Idaho, a management review team followed a directive to redesign the water quality monitoring program. We present a summary of the redesign as proposed by that team, to illustrate the results of a typical review of monitoring programs. That summary is followed by an example of how the proposed program would differ if the audit approach had been used. The two approaches offered both coincident and conflicting recommendations. Management review team and audit recommendations for lake sampling programs were similar even though a different process was used to develop the recommendations. The most striking contrast between the two results lies in the review teams approach to the problem. The directives followed, and the teams responses, concentrate on tools, such as increasing biological monitoring or reliance on monthly BWMP stations. In contrast, the audit results stress addressing management questions for which clear objectives have been stated, depending on specific tools only as needed to meet stated objectives. Although the audit does integrate externalities in its structure, it is little affected by economic or political influences. A major strength of the audit approach is its ability to provide defensible data for management decision making.

Threshold estimation from the linear dose-response model: Method and radiation data

The linear dose-response model is considered a conservative, nonthreshold relationship. This is based on a confusion between the sufficient condition (that is, zero slope at zero dose) and the necessary condition (that is, response distinguishable from zero). Once the threshold is properly defined, it is shown that the linear model predicts thresholds for radiation data in good agreement with experimental results.