A Statistical Study on Relations between the Symptom Prevalence of Chronic Bronchitis and Air Pollution

Abstract

From 1970 through 1972, the symptom prevalence of chronic bronchitis was studied in people over 40 years of age living in 7 districts in Osaka by Osaka Prefecture and Sakai city. On the basis of the data obtained a statistic analysis was made of the symptom prevalence of chronic bronchitis in reference to air pollution in those districts with the following results:
1) The relations between the symptom prevalence of chronic bronchitis and sulfur dioxide level which was used as air pollution index led to
y=1.94α+2.87
where y: the symptom prevalence of chronic bronchitis in people over 40 years of age, in percent, and α: sulfur dioxide values measured by the PbO₂ method in mgSO₃/day/100cm².
2) The value from this formula was 2.2% higher than what was obtained previously from a 1962-1966 survey in Osaka city.
3) The relations between the symptom prevalence of chronic bronchitis and the nitrogen oxide level, instead of the sulfur dioxide level, were formulated as
y=0.88β+2.81
where β: nitrogen oxide values estimated on conjecture by the smoke diffusion equation in pphm.
4) A combined effect of sulfur dioxide and nitrogen oxide might be
y=1.0(α-1.0)+0.6β+2.7