The two biggest factors for PM2.5 are mites inside your home, and the traffic density immediately near your home. That's why I recommend that you live at least 100 meters and preferably 300 meters from a major road (300 meters is about the size of three football fields). At the same time, encourage tougher government standards on pollution by writing the Environmental Protection Agency (EPA), your senator, and your representative. More stringent guidelines for certain pollution (particles in the 2.5-to-10-micron range, often produced by coal plants and diesel fuel) provide reasonable goals for most urban environments.
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