In September, when the trees flourish, the Chilean people start feeling the romanticism of the season and also an exaggerated reaction and a kind of panic for the depletion of the ozone layer in the stratosphere.

In spring, the inhabitants of the city of Punta Arenas are exposed to higher levels of ultraviolet radiation; nevertheless, these have not exceeded the levels reached in the central zone of Chile during summer.

During this season there is only a drastic change in the radiation levels. This shouldn't be compared to that which affects the people who live in the higher latitudes or in the Equator. Dr. Juan Honeyman, Director of the Department of Dermatology at the Hospital Clínico de la Universidad de Chile says that it is necessary to educate and prevent the Chilean people about this topic, but do not alarm them.

In an interview published by "El Mercurio", a Chilean newspaper, the specialist informed about this prudent measures and revealed the latest official results about the effects of the UV-B radiation on the inhabitants of the Region of Magallanes.

This study, requested by the Ministry of Health Care, is similar to that carried out, for the first time, in 1992.

According to Dr. Honeyman there are some points related to this topic that make people confused. The ozone hole, which is formed over the Antarctic (located at 12 kilometers of height), only reaches the end of the South American Continent and does not extend to the rest of our country.

As we are not located in the Equator, the sunrays reach the earth in an angular way, not vertically. This means that the radiation stays longer in the atmosphere, from which is greatly absorbed. Consequently, the amount of UV-B radiation that penetrates this protecting layer is more important than the Dobson units, which measure the thickness of the ozone layer.

This radiation is higher in Magallanes during spring, but it does not reach the levels to which people from Santiago are exposed during summer. According to some figures given by Dr. Sergio Cabrera, who also works for the Hospital Clínico de la Universidad de Chile, the radiation rate registered in Santiago during summer is equal to 9 microwatts per square centimeter. As for the situation of Punta Arenas, the radiation rate in winter is equal to 8 microwatts per cm², in summer to 5.7 microwatts per cm², in spring it reaches 3.2 microwatts per cm², but it may vary from day to day, reaching summer highest levels. When this happens, people from Magallanes is put on the red alert, as during the past ten years, there had not been such unexpected variations.

Dr. Juan Honeyman affirms that this is not an alarming situation neither in Chile nor in the rest of the world, in spite of the fact that it has been detected a global depletion of the ozone layer, equivalent to the 2% in the last decades. He explains that the biological effects of the UV-B radiation have increased as nowadays, more people go frequently to the beaches or swimming pools and want their bodies to get suntanned. At the same time, the life expectancy rate has increased, so the solar radiation is accumulated for more years. Unfortunately, he says, the tan that people get for being long exposed to sun, (with a rise in the natural pigment called melatonin), only protects from the serious effects of the radiation, like the sunburns. In other words, the melatonin does not prevent absolutely those chronic skin diseases like the photoaging and the first signs of different kinds of skin cancer.

Consequently, it is advisable to use, (factor 15) sun creams, in great quantities on the face and neck. If you use it in low quantities, for instance a half spoon dose, it would be equivalent to use a (factor 4) sun cream. The specialist confirms the effectiveness of these products, as his researching group has been controlling them in the market for 8 years. He also informs the population that the peak hours in Chile, the time of higher radiation and precaution is not at midday like in the Equator but about 2 o'clock in the afternoon. Dr. Honeyman advises that any person can evaluate his/her sun exposure by measuring the shadow that his/her body projects: if your shadow is small, the risk increases. Try it.

LACK OF EDUCATION

The study carried out in the Region of Magallanes did not show significant consequences from the health care point of view, regarding the fact that 8 years had passed since the last study. In this survey, 125 inhabitants were evaluated, most of them women and men, whose average age was 42.6; all of them from the cities of Punta Arenas, Puerto Natales and Porvenir. The results of the examinations showed neither changes in the immune system nor a rise in diseases like cataracts and skin cancer.

However, the 84% of the people suffered from some cutaneous lesion, practically all of them were benign. Some of them are the solar lentigo (frecklelike spots on the skin that appear after middle age), melanism (dark spots similar to those that appear during pregnancy), herpes, photoaging, quelitis actínica (dry lips), eczema and erythema solare (caused by sunburn).

What it drew the researchers attention was the result revealed by this study, particularly in 110 cases, as the skin typology was also studied in this mainly white population. The 64% of them have never used sun creams, the 41.5% have never worn sunglasses and the 55.5% of them had suffered from sunburns sometime in their lives. It seems that instead of scaring and confusing people, it is necessary that the authorities inform them clearly and correctly about this topic.