The prevalence of self-reported symptoms of respiratory disease and community belief about the severity of pollution from various sources.

It is postulated that health effects of air pollution may be direct and indirect through people's perception about the severity of pollution and concerns over its impact on their health. A cross sectional postal survey of some 6,559 households was conducted in the area of Ellesmere Port and Neston Borough Council. A total of 3,402 (51.9%) usable questionnaires were returned and included in the subsequent analyses. Childhood asthma was associated with central heating. Adult asthma was associated with the number of people in the house who had ever smoked and 'crowding'. General adult respiratory symptoms were associated with perception of industrial air pollution and neighbour noise in univariable but not multivariable analyses. In the multivariable model number of people in the household who had ever smoked, exposure to traffic fume pollution, crowding and living in rented accommodation. This suggests a complex relationship between actual levels of pollution (though not directly measured in this study), social deprivation, socio-behavioural factors and people's perceptions about pollution. A model of the relationship of these factors is proposed and it is argued that studies of the health impact of air pollution that concentrate only on chemical exposure will be flawed unless they are placed in the context of perception and socio-behavioural factors.