The rather excessive public preoccupation of the immediate past with
what has been labeled the 'environmental crisis' is now fortunately
being replaced by a more sus- tained and rational concern with pollution
problems by public administrators, engineers, and scientists. It is to
be expected that members of the engineering profes- sion will in the
future widely be called upon to design disposal systems for gaseous and
liquid wastes which meet strict pollution control regulations and to
advise on possible improvements to existing systems of this kind. The
engineering decisions involved will have to be based on reasonably
accurate quantitative predictions of the effects of pollutants
introduced into the atmosphere, ocean, lakes and rivers. A key input for
such calculations comes from the theory of turbulent diffusion, which
enables the prediction of the concentrations in which pollutants may be
found in the neighborhood of a release duct, such as a chimney or a
sewage outfall. Indeed the role of diffusion theory in pollution
prediction may be likened to the role of applied mechanics (, strength
of materials') in the design of structures for adequate strength. At
least a certain group of engineers will have to be proficient in
applying this particular branch of science to practical problems. At
present, training in the theory of turbulent diffusion is available only
at the gra- duate level and then only in a very few places.