Effects of simulated downwind coal combustion emissions on pre-existing allergic airway responses in mice

Context: Coal-fired power plant emissions can contribute a significant portion of the ambient air pollution in many parts of the world.Objective: We hypothesized that exposure to simulated downwind coal combustion emissions (SDCCE) may exacerbate pre-existing allergic airway responses.Methods: Mice were sensitized and challenged with ovalbumin (OVA). Parallel groups were sham-sensitized with saline. Mice were exposed 6 h/day for 3 days to air (control, C) or SDCCE containing particulate matter (PM) at low (L; 100 μg/m3), medium (M; 300 μg/m3), or high (H; 1000 μg/m3) concentrations, or to the H level with PM removed by filtration (high-filtered, HF). Immediately after SDCCE exposure, mice received another OVA challenge (pre-OVA protocol). In a second (post-OVA) protocol, mice were similarly sensitized but only challenged to OVA before air/SDCCE. Measurement of airway hyperresponsiveness (AHR), bronchoalveolar lavage (BAL), and blood collection were performed ~24 h after the last exposure.Results: SDCCE si...