Toxicity studies and environmental impact assessment

Abstract

/ There is abundant evidence that many factors can influence the toxicity of a particular pollutant including environmental fluctuations, season of the year, stage in life cycle, size, and sex. All of these factors should be assessed before making a judgment of the effect on natural populations. Such an assessment can be conceptualized using a simple population model through which "control gates" operate as functions of 1). the direct self-maintainance feedback from existing adult population biomass and 2). the recruitment of new individuals due to the maturation of larvae. By extracting general principles of organismic response to pollutants it is possible to incorporate the information into large-scale ecosystem models which would serve as working tools for answering environmental decision-making problems.Studies of the effects of pollutants on organisms have increased markedly over the past few years. While many early investigations were limited to mortality studies of adult organisms over a given period, more recent experiments have emphasized sublethal effects. For example, it has been demonstrated that low level concentrations of toxicants can affect growth rates and metamorphosis (Bookhout et al., 1972;Bresch and Arendt, 1977;DeCoursey and Vernberg, 1972;Shealy and Sandifer, 1975); regeneration rates (Weis, 1977); respiratory responses (Calabrese et al., 1975; Thurberg and Dawson, 1974, Vernberg et al., 1973Vernberg and Vernberg, 1972); osmoregulatory control (Roesijadi et al., 1976, a,b); and behavior patterns (Barthalmus, 1977;DeCoursey and Vernberg, 1972; Hansen et ah, 1973;Kania and O'Hara, 1974;Vernberg et al., 1973Vernberg et al., , 1974. To complicate the analysis of pollutant effects further it has also been amply demonstrated that larval stages are often more sensitive to a particular toxicant than are adults (DeCoursey and Vernberg, 1972;Rosenberg and Costlow, 1976;Wisely and Blick, 1967) and environmental factors, such as temperature and salinity, can interact to influence toxicity (O'Hara, 1973;Vernberg et al., 1973Vernberg et al., , 1974Vernberg and Vernberg, 1972;Weis, 1977). The substantial documentation from these and other similar studies has made it abundantly clear that sublethal quantities of pollutants can modify the physiological and behavioral functioning of many species of animals. Given this considerable body of knowledge, the question that now arises is translation of the results of such studies into a manageable form that can be used in the decisionmaking process necessary for environmental protection.KeyWords: Toxicity, Pollution, Modeling, Environmental Impacts, Population Model. Environmental Management, Vol. 2, No. 3, One method of approaching this problem is to view the functional responses of an animal in the context of its life cycle in nature. One species for which there is a considerable body of knowledge on various stages of development is the fiddler crab, Uca pugilator; this animal is one of the most abundant species of crabs found along the borders of east...

Strukturchemische Eigenschaften und Spurenstoffverhalten in aquatischen Ökosystemen

“…Daten zu biologisch determinierten Stofftransformationen und zur Toxikokinetik. Im Hinblick auf Veriinderungen von Okosystemen konnen die Ergebnisse nur bedingt verallgemeinert werden (VERNBERO et al;KORTE 1980 (1) z , = AFz-AF, = K ,…”