Ambient concentrations and correlations of hydrocarbons and halocarbons in the vicinity of an airport

Concentrations of sixteen volatile hydrocarbons present in internal combustion engine exhaust gases and two halogenated hydrocarbons have been measured in ambient air samples at six sites around Gatwick Airport. Correlations between their concentrations have been drawn in an attempt to establish the exact nature of the sources of these emissions, together with consideration of the overall hydrocarbon profiles.     

Enhanced recycling through a materials tax

This article attempts to evaluate whether an appropriate consumption-based tax is likely to be successful in reducing demand for certain exhaustible resources, thereby curtailing their rate of depletion and increasing the demand for, and utilization of, secondary materials. The nature of such a tax and anticipated effects (including environmental impact) of its imposition on certain primary materials are considered, concentrating here on one metal, aluminium. The study concludes that a tax based on the exhaustible resources and energy used in the production of a good is likely to create more savings for fossil fuels than for other exhaustible resources.     

Vocal regulation of use of space by groups of titi monkeys Callicebus moloch

Summary The daily movements and the resulting activity and calling fields are described for three groups of titi monkeys Callicebus moloch. Groups move to the periphery of their home range in the early morning and then call. Playback experiments confirmed that both proximity and location of calling by neighboring animals affect the group's response. Subsequent countercalling often regulates the approach of neighboring groups to a boundary. After encountering adjacent groups, animals return to areas near the home range center. Movements, calling behavior, and the response to neighboring groups all increase the probability of intergroup encounters in the early morning. Encounters define and reinforce the conventional location of boundaries. Boundaries decrease the probability of intergroup encounters at other times and allow exclusive use of space.     

Book reviews

Planning in the Public Domain: From Knowledge to Action

John Friedmann. Princeton University Press, 1987, 501pp.

New Communities for Urban Squatters: Lessons from the Plan that Failed in Dhaka, Bangladesh

Charles L. Choguill, Plenum Press, New York 1987, pp. 213.

Models of Urban and Regional Systems in Developing Countries

George Chadwick, Oxford, Pergamon Press, 1987, xv +320pp.

Price: £17.50.