Air pollution in perspective: Health risk s of air pollution expressed
in equivalent numbers of passively smoked cigarettes
abstract
Background: Although the health effects of long term exposure to air pollution are well established, it is
difficult to effectively communicate the health risks of this (largely invisible) risk factor to the public and
policy makers. The purpose of this study is to develop a method that expresses the health effects of air
pollution in an equivalent number of daily passively smoked cigarettes.
Methods:Defined changes in PM2.5, nitrogen dioxide (NO2) and Black Carbon (BC) concentration were
expressed into number of passively smoked cigarettes, based on equivalent health risks for four outcome
measures: Low Birth Weight (o 250 0 g at term), decreased lung function (FEV1), cardiovascular mortality and lung cancer. To describe the strength of the relationship with ETS and air pollutants, we
summarized the epidemiological literature using published or new meta-analyses.
Results: Realistic increments of 10 m g/m3 in PM2.5 and NO2concentration and a 1 mg/m3
increment in BC concentration correspond to on average (standard error in parentheses) 5.5 (1.6), 2.5 (0.6) and 4.0 (1.2)
passively smoked cigarettes per day across the four health endpoints, respectively. The uncertainty reflects differences in equivalence between the health endpoints and uncertainty in the concentration
response functions. The health risk of living along a major freeway in Amsterdam is, compared to a
counterfactual situation with ‘ clean’ air, equivalent to 10 daily passively smoked cigarettes..
Conclusions: We developed a method that expresses the health risks of air pollution and the health
benefits of better air quality in a simple, appealing manner. The method can be used both at the national/
regional and the local level. Evaluation of the usefulness of the method as a communication tool is
needed.