Figure 1From: Cytokine release from alveolar macrophages exposed to ambient particulate matter: Heterogeneity in relation to size, city and seasonRelease of IL-6 after exposure of alveolar rat macrophages to increasing concentrations of coarse (lane A) and fine (lane B) fractions of ambient PM collected in Oslo, Rome, Lodz and Amsterdam during spring (upper), summer (middle) and winter (lower) seasons. Values are mean ± SEM (n = 3).Back to article page