Ecosystems, micro

The human and environmental protection goals in EUSES are human populations (workers, consumers, and man exposed via the environment) and ecological systems (micro-organisms in sewage treatment systems, aquatic ecosystems, terrestrial ecosystems, sediment ecosystems, and predators). Repeated dose toxicity, fertility toxicity, maternal toxicity, developmental toxicity, carcinogenic risk, and lifetime cancer risk can be calculated for the cases that literature data is available. 

Following an aviation kerosin spill, hydrocarbons were detected in trout stream sediments and fish up to 14 months after the spill [13]. After a fire at a weed treatment plant in 1970 a large area of mixed forested ecosystem became contaminated with polycyclic aromatic hydrocarbons and creosote [66], High polyaromatic concentrations in stream sediments adversely affected micro- and meiobenthic communities at all trophic levels. Stein et al. [67] have studied the uptake by bethnic fish (English sole, Parophrys vetulus) of benzopyrene and polychlorinated biphenyls from sediments. Accumulation of contaminants from sediments was a significant route of uptake by English sole. 

At least for the present, it seems impractical to hope that we will be able to identify, empirically, all the environmental impacts that should be evaluated. Increasingly, researchers are working on collections of cells, micro-organisms, and entire mini-ecosystems, in which a broad range of subjects and surrogates are combined with mathematical models in an attempt to develop a more-accurate and holistic prediction or measurement of the effect of a chemical on an ecosystem. 

Laboratory micro ecosystems have been developed, and with the aid of Relabeled compounds, chemicals and their metabolites can be followed through the plants and terrestrial and aquatic animals involved. 

Can micro-organisms transported through the atmosphere as outlined above affect ecosystem evolution ... 

Semifield tests, sensu stricto, are experimental ecosystems that run under fieldlike outdoor conditions. Aquatic micro- and mesocosms have been widely used in assessing effects of substances under semilield conditions (Stephenson et al. 1986 Arnold et al. 1991 Hill et al. 1994 van den Brink et al. 1996 Kennedy et al. 1999 van den Brink and Ter Braak 1999 Culp et al. 2000a, 2000b Sibley et al. 2001a, 2001b, and many others). Also, terrestrial model ecosystems (TMEs) have been developed that are, in contrast to the use of field plots, separated from their source site and run under laboratory conditions (Knacker et al. 2004). Because experience is limited, they will be considered here only marginally. 

Bunch, J.N. (1987) Effects of petroleum releases on bacterial numbers and micro-heterotrophic activity in the water and sediment of an Arctic marine ecosystem. Arctic 40, 172-183. 

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