The much-discussed hole in the ozone layer over the South Pole isn’t really a “hole.” It’s more like a bald spot, a region of greatly pronounced ozone depletion, which expands in the winter and contracts in the spring. It’s caused by a complex set of conditions. For one thing, the air over the Antarctic is naturally isolated from the rest of the atmosphere in the wintertime by a wind structure known as the polar vortex, so ozone-depleting chemicals do their thing without any fresh ozone drifting in from the tropics. Also, the extreme winter cold creates ice crystals, which speed the breakdown of ozone molecules. As CFC levels have increased, the bald spot in the ozone layer has increased, now reaching the southern tip of South America.
But this bald spot isn’t the only region where ozone is disappearing. A satellite called Nimbus 7 has recorded a 0.5 percent loss of the world’s ozone supply per year, every year from 1978 to 1985, and slightly more every year since 1985. Because of the way the atmosphere circulates, though, this thinning is uneven, a kind of ozone pattern baldness. Unfortunately, according to Teramura, one of these thin spots is right over the Central Pacific.
Right over us.
Of course, even with a flawless ozone layer, Hawaii would still receive more UV radiation than the Mainland. This is because rays coming at Hawaii cut straight through the ozone layer, while rays headed for the Mainland travel through the layer at an angle and so have a greater chance of being absorbed. Then there are our beautiful, clear skies and lack of air pollution, conditions which also allow UV to pass unimpeded.
Which brings us to the effects of ozone depletion. Radiation is serious business, causing serious effects. And, according to Teramura, UV levels in Hawaii are the highest they’ve been in 20 years, due to the ozone thinning that has already happened, and is bound to get worse before it gets better. (See “What Are Our Chances?” at the end of the article). Here are a few things you can expect in Hawaii as a result of ozone depletion:
More skin cancer in humans. According to the United Nations Environment Program report Environmental Effects of Ozone Depletion: 1994 Assessment, edited in part by Dr. Teramura, it’s estimated that every 1 percent thinning of the ozone layer results in a 2 percent increase of non-melanoma skin cancer (treatable, nonmalignant skin cancer) in light-skinned people.
According to the Hawaii Medical Journal (May 1993), the incidence of malignant melanoma “has consistently increased 6 percent a year and the death rate has increased 2 percent a year since 1950. The highest melanoma incidence in the United states is found in Hawaii.”
It’s estimated that 70 people a year in Hawaii are diagnosed with malignant melanoma and that 20 of them will die. Non-melanoma skin cancers strike more than a hundred every year—852 melanomas were diagnosed in Hawaii between 1985 and 1991. While most of these cases involved Caucasians, no race is immune. In a Cancer Research Center of Hawaii study of melanoma patients, Hawaiians and part-Hawaiians were the second largest group, right behind Caucasians. On top of all this, the sun’s ability to make your face look like wrinkled leather is well documented.
Because of these effects, the National Weather Service started announcing a daily UV index forecast for Hawaii in 1994, on a scale of 0-10. On a day in June 1994, while most Mainland cities had indexes of 6 or 7, Honolulu was right at 10, along with San Juan.