Ecological principles environmental specificity

Environmental toxicology is based on the premise that the amount of chemical reaching an active site in, or on the surface of, an organism determines whether a compound will exert a specific beneficial or adverse effect or pose an ecological or health risk. This basic toxicological principle is embodied in the expression attributed to Paracelsus that it is "the dose that makes the poison."... 

Basic and applied research efforts show that the oxidative transformation of renewable feedstocks represents a promising approach for the production of high-value chemicals under environmentally acceptable conditions. Many laboratory-scale processes are carried out under mild conditions, and the employment of molecular oxygen ensures ecological and economic advantages. In these processes, a crucial role is played by the catalytic step that requires a specific selectivity toward the desired product. In principle, either enzymatic catalysis or chemical catalysis can be effectively employed in a given process and, in some cases, the performance of the different processes is quite similar as presented in the following sections. 

Risk may arise from any chemicals released into the environment, intentionally or by accident, during manufacture, use or dissipation of the products. The expected concentration time profile for chemicals at specific locations in the various environmental media - water, air, soil and biota - may result in hazards to humans and the environment. Hence, ecological risk assessment must evaluate the probability whether the exposure level of potential contaminants may exceed effective (i.e. toxic) concentrations in the environmental compartment of concern. The basic principle is the comparison of the environmental and the toxic concentrations of the contaminants ... 

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