The University of Twente (UT) has devised a concrete capable of converting the nitrogen oxide from car exhaust--the source of smog and acid rain--into a nitrate, another chemical that will wash away in the rain.

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Of all the allergies the most common is dust mites. Most people are not even aware they are allergic to these microscopic insects. For them the symptoms generally only show up upon waking. For a few hours they suffer a runny nose, sneezing or itchiness.

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Using a popular process called ionization, air purifiers can actually generate ozone levels in a room that exceed the worst smog days in Los Angeles, a new study finds. Ozone high in the atmosphere protects Earth from damaging ultraviolet radiation. Down here, it is called smog.

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