Q: I'm a little worried that our older refrigerator may be leaking CFCs. Is there a way to be sure without calling a repairman?
A: Yes. Have a columnist call a repair person for you. Here's what my repair person said: The CFCs that are the coolant in your refrigerator are in a sealed, pressurized system. These rarely leak. When they do, however, you know it because your refrigerator stops cooling pretty quickly, and your freezer will defrost.
If this has happened, you will have to call a repair person in to fix the system. Make sure the company you call has equipped its employees with a container in which to recapture the CFCs. Though no one is recycling refrigerator coolant yet, some companies, including Whirlpool and General Electric, are storing until the recycling technology is available.
Car-air conditioner coolant can be recycled. If your car air-conditioner needs work, make sure you take it to a place that recycles coolant. This can be done on the spot.
How will you know, in February, that your car air-conditioner has broken? Because the Household Environmentalist recommends that you run it at least once a month for 10 minutes. This keeps the rubber seals in the system lubricated and extends the life of the system.
Q: I read with interest your column about the hazards of chlorine released from water vapor and its possible human health effects. It raised a related concern with me and I wondered if you might be able to track down an answer.
Chlorine has been identified as a major cause of ozone depletion in the stratosphere. The ozone hole over the Antarctic has become a major environmental concern, in that the ozone layer protects the earth from harmful radiation from the sun.
Is it possible that treatment of water with chlorine could be a major source of the release of chlorine into the upper atmosphere? Could the water vapor from hot water be a contributor to ozone depletion?
A: Good question. I did track down an answer, from Dennis Hartmann, professor of atmospheric sciences at the University of Washington. The answer is: No. What follows is a grossly oversimplified version of his explanation.
The forms of chlorine gas that come out of tap water, your swimming pool, chlorine bleach and most other chlorinated compounds are very unstable. They don't want to stay a gas any longer than they have to, and so they quickly form compounds that aren't gases. Because they aren't gases, they can't become airborne. Because they are not airborne, they cannot rise in the wind to reach the ozone, high up in the stratosphere.
However, certain artificial, industrially produced chlorine gases, namely chlorofluorocarbons (CFCs) and a few others, are extremely stable and long-lasting. They accumulate in the atmosphere and are slowly carried up to the stratosphere in the warm air rising above the tropics. Scientists have found that about 80 percent of the chlorine in the upper atmosphere is in the form of man-made chemicals, most of them CFCs.
High in the stratosphere, CFCs encounter powerful ultraviolet rays that don't normally reach the earth. These rays shatter the strong bonds gluing the CFCs together, releasing chlorine atoms miles above their natural habitat.
Like foxes in a henhouse, these freed, terribly unstable chlorine molecules make a grab for whatever they can get. They go through a complex evolution, but to make a long story short, what they eventually grab are oxygen molecules, in the form of O3 -- ozone.