MATCH: Measurement and Modelling of Exposure to Air Toxic Concentrations for Health Effect Studies

Principal Investigator: Professor Roy Harrison

Project Coordinator: Dr Juana Maria Delgado-Saborit


The term “air toxics” embraces a range of substances associated mainly but by no means exclusively with emissions from road vehicles. Whilst they may be associated with a number of adverse health outcomes, the most important, especially in the public mind, is likely to be cancer. Currently, however, evidence for carcinogenicity derives very largely from epidemiological studies of occupationally-exposed individuals, or even from laboratory studies with animal models. In the case of pollutants such as benzene and the polycyclic aromatic hydrocarbons (PAH) where the evidence for carcinogenicity deriving from occupational exposures is very strong, the exposures greatly exceed typical environmental concentrations to which the general public are exposed, and therefore evaluation of carcinogenic risk other than through extrapolation is very difficult.

This project is concerned primarily with the issue of differentiating personal exposures to air toxic substances according to documented exposure to emissions from specific sources such as road traffic and environmental tobacco smoke (ETS). The aim is to provide a validated approach to personal exposure estimation such that exposure can be estimated from a lifestyle questionnaire allowing differentiation of individuals into a range of personal exposure groupings which could be used in a subsequent epidemiological study of either a case control or an ecological (spatial analysis) design.

Since air toxics substances do not arise uniformly from a single source, their concentrations may not correlate between different exposure environments and therefore it is desirable to measure microenvironment concentrations of a wide range of such substances to establish their inter-relationship whilst also determining the relationships between microenvironment concentrations and personal exposure by direct measurements and modelling.

The project is funded by the Health Effects Institute in USA.

For any comments or questions please contact the project coordinator:
Dr Juana Maria Delgado-Saborit (