During the first days at the seaside it is advisable not to expose the skin to direct sunlight and protect it well; in fact, sun umbrellas limits irradiation by just 50% so the ultraviolet radiation reflected by sand are enough to stimulate the production of melanin.
The ideal time for exposure to the sun is in the morning (8-11) and late afternoon (after 4 p.m.). The hottest hours of the day (from 11 to 4) should be avoided.
At the beginning, it is preferable to limit sun exposure to short periods of time whilst moving around, so that the sun’s rays are distributed uniformly over the entire body. It will take about ten days or so before the skin starts to develop a long-lasting tan. It is now possible to spend more time in the sun.
In summer even on grey days, UV rays filter through the clouds without the person experiencing the sensation of heat on the skin.
Do not exaggerate in the use of sunscreens as they contain chemicals that can accumulate and, in the long run, may prove to be toxic for the skin. Exposure to the sun should be reduced to a minimum throughout the year.
Perfume and make-up should never been used in the sun: they may leave hyperpigmented marks or stains on the skin or trigger allergic reactions, due to photosensitivity from UV rays. Even during short exposures.
People taking certain types of medication (anti-inflammatory drugs, oral antidiabetic agents, tetracycline antibiotics, oral contraceptives, certain high blood pressure medicines, etc.) must be especially careful when exposing their skin to the sun.
Always be wary of exceptional home-made remedies that promise rapid and intense sun tans.
The same precautions are applicable to children; in addition, white cotton clothing should be used, if possible, along with protection for their eyes with UV filter lenses; once again, exposure should be limited to just a few minutes and whilst in motion. The melanocytic cells, sebaceous glands and the perspiratory glands in young children, especially during the first few years of life, have not fully developed and, for example, still emit low amounts of sweat. The immune system is still developing! This is why you must pay careful attention and take all the necessary precautions; aggressions and damage caused by the sun during childhood may be irreversible with the possibility of developing melanoma later on.
Experimental data show that only 3% of sun rays are reflected by a green lawn, compared to 18% of sand, 22% of water and 80% of fresh snow.
Altitude -> 6% increase of UV irradiation every 1000 m
Watch out for the UV Index
Originally the UV index was defined in different ways in different countries and was used to inform the population on the risks related to UV rays. Following its definition it was then standardised and published by the World Health Organization (WHO). The UV index is recommended as a media used to inform the public of the health risks resulting from exposure to UV radiation, and recommend the protective measures to be adopted. Cloudiness and other relevant environmental variables are taken into account when calculating the UV Index, by latitude and longitude. It is easy for everyone to check the index as it appears on the main weather sites on the web and on the weather pages in all major national newspapers.