Particulate air pollution is also known to increase cardiovascular morbidity and mortality. Still the existing scientific knowledge and foundation for evaluating the underlying mechanisms and influence of particle exposure on human immune system are limited. Wood smoke particles, at levels that can be found in smoky indoor environments, seem to affect inflammation. Barregard et al observed a significant increase in S-Amyloid and Faktor VIII/vWf after 0, 3 and 20 hours of exposure to wood smoke. After 20 hours also and increase in Faktor VIII was registred. Surpise-lingly, an IL.-6 decrease was observed after 3 hours. [Barregard et al, 2006]. The particles may also act by increasing blood coagulation factors [Seaton et al 1995]. Both effects may be involved in the mechanisms whereby particulate air pollution affects cardiovascular morbidity and mortality.