Atopy is not generally used as an outcome variable in occupational asthma studies. Nonetheless, several recent studies have shown that certain exposures may offer protection against atopy (e.g. occupational endotoxin exposure [26]), whereas others have shown that exposures such as diesel exhaust may increase the risk of atopy [27]. The present study is the first to show a positive association between pine dust exposure and atopy. A previous study in western red cedar workers showed a lower prevalence of atopy compared to non exposed controls [23].