Health effects of particulate matter air pollution in underground railway systems - a critical review of the evidence.

asthmatic volunteers in the Stockholm underground study and 12,13-diHOME was close to significance ( p = 0.1), none of these were significantly increased in the Stockholm underground following exposure vs. no exposure, and further examination of the Stockholm underground study shows that the significance threshold for analysis between asthma status was likely attained not simply because of an increase in levels of these oxylipins in healthy lavage fluid, but also because of a decrease in their levels in asthmatics.

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Conversely, magnetite particles had only a small effect (trending towards significance) on the former, and none on the latter.

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