A new study suggests the notion of clean, country air might be misleading.
Traditionally, air quality has been measured by the size of pollution particles or, more scientifically, particulate matter with a diameter of 2.5 micrometers or less. Considered that way, urban air tends to be more polluted than rural air because the size of pollution particles is generally larger.
But a University of Illinois team looked at the toxicity of those particles, scientifically known as the oxidative potential, and found that pollution particles in rural areas can be twice as toxic even though they may be smaller.
