Trees, shrubs, and other vegetation can absorb and assimilate certain air pollutants if the pollutants are present within tolerable levels. This concept is being increasingly used in developing strips of vegetation, often called 'greenbelts' around sources of pollution. But several intricacies are associated with the exercise of effective and optimal designing of greenbelts. The pattern of dispersion of air pollutants, as effected by the density of the gaseous plume and the meteorology of the area, must be studied with great precision because these aspects would determine the location and the geometry of the greenbelt. The species composition in the greenbelt should confirm to the pollutants to be attenuated as to the geoclimatic conditions of the region. Decisions on the tree heights, and the sequence of plantation of trees and other vegetation also similarly require complex inputs. In this paper, the authors have addressed these issues and have presented a set of mathematical models, which may help in the rational and optimal design of greenbelts.