• asthma;
  • ethnicity;
  • meta-analysis;
  • wood;
  • work

To cite this article: Pérez-Ríos M, Ruano-Ravina A, Etminan M, Takkouche B. A meta-analysis on wood dust exposure and risk of asthma. Allergy 2010; 65: 467–473.


Work-related asthma is the most common occupational respiratory disorder in the industrialized countries. It has been postulated that wood dust exposure may increase the risk of work-related asthma. The objective of this study was to assess, through a meta-analysis, the risk of developing work-related asthma associated with wood dust exposure. A systematic search of the literature was performed. Inclusion and exclusion criteria were applied and a quality scale used to measure the quality of the included studies was developed. Using standard meta-analysis techniques, studies were pooled using both random and fixed effects models. Nineteen studies were included which consisted of three cohort studies, twelve case–control studies and four mortality studies. The pooled relative risk (RR) of asthma among workers exposed to wood dust was 1.53 (95% CI 1.25–1.87). When the analysis was restricted to studies carried out on Caucasian populations, the pooled RR was 1.59 (95% CI 1.26–2.00) while the pooled RR of studies on Asian populations was 1.15 (95% CI 0.92–1.44). Wood workers present a higher risk of asthma. Future research should include careful evaluation of ethnicity and nativity as risk modifiers.