EMFs, Vinyl and Ozone.

Should I Worry About ... Airports, Siding and CFCs?

Does the airport near where I live emit any kind of magnetic or electrical waves that will impact my health? --B. Sachau

Living near an airport poses no special risk from electromagnetic fields (EMFs), though there is both air and noise pollution to consider. The National Council on Radiation and Measurement has never heard of people being affected by the radar used by air traffic controllers. EMF Health and Safety Digest says that the radio frequencies used by airport communications systems are the same ones used by police departments. Their power levels are low, ranging from three to 100 watts, presenting no harm to anyone more than three feet away.

The data on EMFs are inconclusive. A recent study positively linking EMFs from electric power lines to cancer, conducted by Robert P. Liburdy of Lawrence Berkeley National Laboratory, was found to contain falsified data. But Liburdy maintains that only minor details were at issue; he stands by his study's basic conclusions.

The National Institute of Environmental Health Sciences believes that the case for an EMF health risk is "weak," but it does point out a small but consistent rise in leukemia cases among people exposed to EMFs. Just such a link was recently made at the University of Toronto, which concluded that children exposed to EMFs before birth and prior to the age of two faced two-and-a-half times higher risk of contracting leukemia before they turned six. Weighed against this is the fact that 20 studies since 1992 have found little evidence for a cancer/EMF connection, according to the National Institutes of Health.

Despite the conflicting studies, Dr. Samuel Milham, an epidemiologist with the Washington State Department of Health, declares, "I believe there is ample evidence that EMF exposure is associated with increased cancer in humans." CONTACT: National Council on Radiation and Measurement, 7910 Woodmount Avenue, Suite 800, Bethesda, MD 20814/[phone].

How are we doing in replenishing the ozone layer? --Ross Weaver

The short answer is that we're making progress in reducing damage to the ozone layer, but the healing process will take some time. The chlorofluorocarbons (CFCs) in refrigerants and aerosol sprays kill the ozone molecules faster than they can reproduce themselves, causing the infamous "hole" in the layer. The problem is most acute over Antarctica, where last year an area more than two-and-a-half times the size of Europe was affected. Thinning ozone impacts human health and ecosystems through greater exposure to ultraviolet light. This translates into more skin cancers, eye cataracts and lowered disease immunity, as well as damage to ocean ecosystems and reduced plant yields.

In 1987, 24 countries signed the Montreal Protocol, designed to reduce CFC production worldwide. CFCs are now banned in most countries, and usage is expected to decline after peaking in 2000. Unfortunately, black market trading in CFCs continues, and without accurate information researchers can only guess when ozone levels will return to normal. The date of recovery has been most reliably fixed as between 2045 and 2050. Without the Montreal treaty, by 2050 atmospheric chemical concentration could be as much as five times greater. CONTACT: Ozone Action, 1700 Connecticut Avenue NW, Suite 300, Washington, DC 20009/[phone].

Given that PVC is reportedly dangerous, should I cancel plans to put vinyl siding on my house? -- Charles Leach

Plasticizer and phthalate, used to soften children's toys, are the contraversial elements in polyvinyl chloride (PVC). According to Greenpeace and other environmental groups, children chewing on these toys can ingest dangerous amounts of toxic chemicals. The PVC in vinyl siding is a hard material, therefore no plasticizer or phthalate is added. So even if you plan to chew on your house, you are in no immediate danger. You should, however, be aware that acid smoke and the carcinogen dioxin are released when vinyl siding burns or melts in a house fire. It is not unusual, fire fighters say, for people trapped in building fires to die of chemically toxic fumes before the flames actually reach them. A vinyl scrap yard fire forced the evacuation of 200 people from a Virginia community in 1997, and another the same year in Ontario created a major dioxin hazard. Dioxin is also produced by medical waste incinerators, which burn vinyl intravenous bags. Brent Khnoch of the Environmental Information Association advises people to "avoid PVC ... simply because of the dangers involved in its creation and disposal." CONTACT: Greenpeace USA, 1436 U Street NW, Washington, DC 20009/[phone].

Send your questions about environmental issues, from the personal to the political, to Ask E, PO Box 5098, Westport, CT 06881, or by e-mail to [e-mail]. Please keep your questions brief and type them double-spaced. Include your full name and address and a daytime phone number.