The role of air pollution in adult-onset asthma: a review of the current evidence.
The causes of adult-onset asthma are poorly established, and the asthmogenic role of air pollution has been investigated primarily in children. This review assesses the current evidence of the association between air pollution and asthma incidence among subjects free of asthma at least until late childhood. Seven publications from five study populations fulfilled the inclusion criteria (one case-control and six cohort studies). All but one used markers of local traffic-related air pollution to characterize long-term exposure. Those studies reported similar associations with traffic-related air pollution. However, protocols, definitions of asthma, and exposure assignment were rather heterogeneous, and three publications relied on the same study; thus we abstain from meta-analytic summaries. Reported patterns of effect modification (e.g., by sex, atopy, or smoking) were inconsistent. Overall, the role of traffic-related air pollution in adult-onset asthma is less conclusive than in childhood asthma. Larger studies with more consistent definitions of phenotypes and exposure assessment for local traffic-related pollutants (e.g., ultrafine particles) are needed. Pooling existing cohorts such as in the ongoing European ESCAPE and TRANSPHORM consortia are promising steps. There is, however, a need for large-scale megacohorts to investigate these effects in standardized ways and to identify the most susceptible populations.
Centre for Research in Epidemiology and Population Health, Villejuif, France.
Benedicte
B
Jacquemin
Tamara
T
Schikowski
Anne Elie
AE
Carsin
Anna
A
Hansell
Ursula
U
Krämer
Jordi
J
Sunyer
Nicole
N
Probst-Hensch
Francine
F
Kauffmann
Nino
N
Künzli
D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects*; D000818:Animals; D001249:Asthma / Q000453:epidemiology / Q000209:etiology*; D002648:Child; D004781:Environmental Exposure / Q000009:adverse effects; D006801:Humans; D052638:Particulate Matter / Q000009:adverse effects; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D001335:Vehicle Emissions / Q000633:toxicity
D000393:Air Pollutants; D052638:Particulate Matter; D001335:Vehicle Emissions