Stop! Don't throw out those old, discarded skin cells! They may be protecting you from the deadly gas - ozone. Yes, they're only protecting you to a minute degree, but everyone should take every opportunity to put off dusting.
Ozone is a molecule consisting of three oxygen atoms linked together. In the stratosphere, where ninety percent of it is concentrated, it's an important barrier to harmful solar radiation. At ground level, it's a harmful gas that corrodes rubber, damages lungs, stunts the growth of plants, and is the main component in smog. (It also smells faintly of geraniums. If any io9er smells geraniums right now, they are either being poisoned by ozone or near some geraniums. I encourage them to look around and find out.)
Ozone is created by chemicals in car exhaust and the burning of fuels; both causes created primarily by humans. It turns out that humans are also helping to alleviate ozone, at least at ground level. Humans shed skin cells at the rate of 500 million a day. That much skin only adds up to about two tenths of a gram per hour, but all of those cells contain an oil called squalene. Squalene, and some other skin oils, sequester the oxygen molecules from ozone, taking away the gas's harmful potential. Two human occupants in an office can reduce ozone by half. In a simulated airplane, ozone was also cut in half by the exposed skin of the plane's passengers. Scientists believe that the shedding of skin cells, and the constant production of new cells with more squalene, significantly reduce ozone levels in indoor environments. The air in homes, offices, and daycare centers is made a little more clean by leaving the surfaces a little more dirty.
And the process of a human shedding their skin is 'desquamation'. How cool is that? Ten points to the io9er who finds a way to work that into one of their conversations today.