IS LIVING NEAR A COKING WORKS HARMFUL TO HEALTH - A STUDY OF INDUSTRIAL AIR-POLLUTION

Objective - To determine whether there was excess ill health in people living near a coking works, and if so whether it was related to expos ure to coking works' emissions. Design - Populations varying in proxim ity to the coking works were compared with control populations. Health data were correlated with available environmental data. Methods - Ana lysis of routinely collected mortality, cancer registration, and birth statistics; community survey using self completed postal questionnair es; retrospective analysis of general practice (GP) records; tests of respiratory function; and analysis of available environmental data. Ma in results - Study and control populations were comparable in terms of response rates, gender, and most socioeconomic indicators. For adults , age standardised mortality and cancer rates of the population closes t to the coking works were comparable with those for the district as a whole. Gender ratios, birthweight, and stillbirth rates were comparab le in the study and control populations. For several indicators of res piratory health including cough, sinus trouble, glue ear, and wheeze ( but not for asthma and chronic bronchitis) there was a gradient of sel f reported ill health, with the highest prevalence in areas closest to the works. For example, sinus trouble was reported by 20% of adults a nd 13% of children in the area closest to the works compared with 13% and 6% respectively in the control area. GP consultations for respirat ory disorders increased when pollution (measured by SO2 levels) was hi gh: annual consultation rates per 1000 varied from 752 in the top grou p of daily pollution levels to 424 in the bottom group. Analysis of lo cally collected smoke and SO2 data indicated that SO2 concentrations w ere highest closest to the works and, after closure of the coking work s, the number of days on which SO2 and smoke levels exceeded 100 mu g/ m(3) and 90 mu g/m(3), respectively, fell steeply. Conclusion - Routin ely available indicators failed to provide convincing evidence that th e coking works had harmed health. Self report and GP consultations ind icated that respiratory ill health in the people living close to the w orks was worse than expected. Some of the excess probably resulted fro m exposure to coking works emissions. The health effects of relatively low level but intermittently high air pollution from a point source m ay be subtle, contributing to respiratory morbidity, but not apparent in analysis of routine health indicators.