Abstract

Ozone is a strongly oxidising matter that might be abundant in the air we breath in concentrations that could harm living organisms. For humans ozone’s toxicity is mainly concentrated to the lung and high levels can cause decreased lung function and irritation in the pulmonary system. There are also studies indicating that ozone might increase the effects of airborne allergens.

Tropospheric ozone is often measured using monitoring stations placed at road or roof top level. However, in order to conduct measurements of the populations true exposure to ozone there is a need to correlate these measures with true personal exposure measurements.

The aim of this study was to examine the population in Malmö (third largest city in Sweden) exposure to ozone in comparison to urban background levels. Forty randomly chosen citizens (18–65 years of age) were requested to participate in the study and equipped with a portable measurement device that they carried close to their breathing zone for a week, thus generating a weekly mean of their ozone exposure. Twenty of these participant also participated in repeated measures during the autumn in 2014 and eighteen during the spring in 2015 (additional six participants were recruited for the spring campaign). The urban background concentrations of ozone was being registered at a roof top monitoring station in the same city during these screening periods.

The results show that there is a large seasonal variation, both in urban background levels and personal exposure, where the spring levels are more than twice as high as the autumn levels. However, the personal exposure to tropospheric ozone was far below measured urban background levels.

There was a significant (p>0.001) correlation between individuals with repeated measures during the autumn campaign - indicating that individual factors, such as life style or housing, might have influence on ozone exposure.