Fig. 4From: Contrasting biological potency of particulate matter collected at sites impacted by distinct industrial sourcesInflammatory response to particles collected at industrial sites. Cytokine responses were measured in cell culture supernatants of J774A.1 cells exposed to size-fractionated particles (n = 3 independent experiments). a Interleukin (IL)-6 levels released by J774A.1 cells in response to a 24 h exposure to UFP, PM0.1–2.5, PM2.5–10 and PM>10 from industrial sites. Three-way ANOVA, Dose x Site x Size interaction, p = 0.002. For simplicity, only significant dose effects relative to 0 μg/cm2 within a Site and Size are presented (*p < 0.05, Holm-Sidak). b Hierarchical clustering of particles according to cytokine response in J774A.1 cells. The heat map displays particle potency estimates determined for each cytokine from the slope of the dose-effect relationship. General descriptions of the clusters are presented on the right. Red, increased expression; green, decreased expression. HB, Hamilton Beach steel mill; MA, Montréal petrochemical refinery; MC, Montréal copper smelter; SR, Sarnia petrochemical refinery; SW, Shawinigan aluminum smelterBack to article page