{"id":12851,"date":"2026-03-31T15:56:00","date_gmt":"2026-03-31T14:56:00","guid":{"rendered":"https:\/\/seecheck.org\/?p=12851"},"modified":"2026-06-26T19:24:09","modified_gmt":"2026-06-26T18:24:09","slug":"exposure-to-sunlight-has-benefits-but-uv-radiation-also-has-many-harmful-effects","status":"publish","type":"post","link":"https:\/\/seecheck.org\/index.php\/2026\/03\/31\/exposure-to-sunlight-has-benefits-but-uv-radiation-also-has-many-harmful-effects\/","title":{"rendered":"Exposure to Sunlight Has Benefits, but UV Radiation Also Has Many Harmful Effects"},"content":{"rendered":"\n
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Original article<\/a> (in Croatian) was published on 30\/3\/2026; Author: Matea Grgurinovi\u0107<\/p>\n<\/blockquote>\n\n\n\n

Spending time in the sun can improve mood, enhance sleep and reduce symptoms of seasonal depression, but it is important not to overlook the significant risk of melanoma. Over the past several years, the incidence of melanoma in Croatia has increased by around 300 percent.<\/p>\n\n\n\n

A video promoting the benefits of exposure to sunlight has been viewed more than 7,000 times, while at the same time criticising doctors who warn about the dangers of excessive sun exposure.<\/p>\n\n\n\n

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\u201cWhat do the experts say? Only 10 minutes in the sun?\u2026\u201d<\/p>\n<\/blockquote>\n\n\n\n

This is the caption accompanying a video shared on Facebook by the profile \u017div\u010dana \u017dirafa, a frequent spreader of misinformation<\/a>. The video falsely suggests that \u201cwe have been lied to about the sun.\u201d<\/p>\n\n\n\n

\"screenshot:<\/figure>\n\n\n\n

In the 39-second video (archived here<\/a>), the author highlights the health benefits of exposure to sunlight, such as the production of vitamin D and serotonin. However, it also criticises doctors who advise against spending too much time in the sun, claiming that people should ideally not stay in the sun for longer than ten minutes. According to the video, such advice has resulted in serotonin and vitamin D being sold as pharmaceutical supplements.<\/p>\n\n\n\n

While it is true that exposure to sunlight \u2013 as well as spending time outdoors in fresh air \u2013 offers a number of health benefits, it is equally true that prolonged and excessive exposure to the sun increases the risk of melanoma and other forms of skin cancer.<\/p>\n\n\n\n

Benefits of Sun Exposure<\/strong><\/p>\n\n\n\n

According to the Croatian Institute of Public Health<\/a> (HZJZ), moderate sun exposure is beneficial because it strengthens the body’s immune defences and increases calcium levels in the blood and bones by converting 7-dehydrocholesterol in the skin into cholecalciferol, the circulating form of vitamin D that is essential for bone mineralisation.<\/p>\n\n\n\n

According to a publication by the University Hospital Centre Rijeka<\/a>, research has shown that exposing just five percent of the body to sunlight for five minutes a day, two or three times a week, provides sufficient vitamin D to support healthy bones and teeth and help prevent certain bone diseases, such as rickets. However, spending more than 20 minutes in the sun does not further increase vitamin D benefits, while the risk of skin damage rises with prolonged exposure.<\/p>\n\n\n\n

Moreover, although avoiding sunlight and using sunscreen can reduce vitamin D production in the skin, sunlight is not the only source of vitamin D<\/a>. It can also be obtained through diet, including foods such as milk and orange juice.<\/p>\n\n\n\n

Harmful Effects of Sun Exposure<\/strong><\/p>\n\n\n\n

At the same time, there is extensive scientific evidence showing that prolonged and excessive sun exposure increases the risk of skin cancer. Excessive exposure to ultraviolet (UV) radiation damages the skin, the eyes and the immune system<\/a>. The incidence and mortality of skin cancer continue to rise, making it an increasingly important public health issue<\/a>. In Croatia, the incidence of melanoma has increased by approximately 300 percent<\/a> over the past several years.<\/p>\n\n\n\n

UV radiation, particularly UVA rays, can also damage the eyes by contributing to the early development of cataracts, or clouding of the eye’s lens. Exposure to ultraviolet radiation may also lead to macular degeneration, one of the leading causes of vision loss.<\/p>\n\n\n\n

According to the graduate thesis The Impact of UV Radiation on the Development of Skin Cancer<\/a>, UV radiation has numerous harmful effects. It causes direct DNA damage through the formation of cyclobutane pyrimidine dimers, induces genetic mutations, oxidative stress, immunosuppression and inflammatory responses, and is the primary cause of skin cancer in between 65 and 90 percent of cases.<\/p>\n\n\n\n

The depth to which each type of UV radiation penetrates the skin depends on its wavelength. UVC radiation affects only the outermost layers of the skin, UVB reaches the basal layer of the epidermis, while UVA penetrates deeper into the dermis.<\/p>\n\n\n\n

Climate change is also making exposure to sunlight increasingly hazardous over time<\/a>. Among the consequences of climate change are reductions in cloud cover and Earth’s ice cover. Both processes reduce the planet’s albedo<\/a>, affecting how much UV radiation reaches the Earth’s surface and how much is reflected back into space.<\/p>\n\n\n\n

These are gradual but important changes. In Eastern Europe, surface UV radiation has been increasing by an additional 5 to 8 percent per decade. A 2025 review<\/a> conducted by a group of Chinese researchers found that climate change is significantly contributing to the growing number of people diagnosed with skin cancer.<\/p>\n\n\n\n

Recommendations Are Gradually Changing<\/strong><\/p>\n\n\n\n

It is also worth noting that recommendations regarding sun exposure have gradually begun to evolve. For many years, discussions about sun exposure focused primarily on its harmful effects on the skin and the risk of melanoma, with the potential dangers generally viewed as outweighing any health benefits.<\/p>\n\n\n\n

More recently, however, increasing attention has been paid to the many positive effects of moderate sun exposure. For example, spending more time in the sun has been associated with lower blood pressure, while one study found that people who reported spending more time outdoors in sunlight were less likely to develop heart failure, as reported by The New York Times<\/a>.<\/p>\n\n\n\n

Sunlight has also been shown to improve mood, reduce symptoms of seasonal depression and help regulate sleep patterns.<\/p>\n\n\n\n

Our circadian rhythm<\/a> \u2013 the biological cycle that regulates wakefulness, sleep, hunger and satiety \u2013 depends on exposure to natural light. When we are exposed to daylight, the brain receives a signal<\/a> to reduce the production of melatonin, one of the key hormones involved in regulating sleep.<\/p>\n\n\n\n

In short, exposure to sunlight increases energy levels, improves cognitive function and contributes to better sleep quality. However, research into the full range of the sun’s potential health benefits is still in its early stages, making it difficult to determine with certainty all of its positive effects.<\/p>\n\n\n\n

At the same time, the risk of skin cancer is well established, making it essential to follow recommendations for safe sun exposure.<\/p>\n\n\n\n

The Croatian Institute of Public Health advises<\/a> limiting the amount of time spent in direct sunlight. Whenever possible, people should avoid being outdoors between 10 a.m. and 5 p.m. during the hottest summer months, wear appropriate protective clothing and use sunscreen. It is also important to remember that certain medications can increase the skin’s sensitivity to sunlight, making sunburn more likely.<\/p>\n\n\n\n

In conclusion, it is true that exposure to sunlight offers many health benefits, ranging from vitamin D production to improved mood and reduced symptoms of depression. However, it is equally important to follow recommendations for safe sun exposure, pay attention to UV intensity, use sunscreen, wear protective clothing such as hats and avoid prolonged unprotected exposure, as this significantly increases the risk of skin cancer and melanoma.<\/p>\n","protected":false},"excerpt":{"rendered":"

Original article (in Croatian) was published on 30\/3\/2026; Author: Matea Grgurinovi\u0107 Spending time in the sun can improve mood, enhance sleep and reduce symptoms of seasonal depression, but it is important not to overlook the significant risk of melanoma. Over the past several years, the incidence of melanoma in Croatia has increased by around 300 […]<\/p>\n","protected":false},"author":6,"featured_media":12852,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[316],"tags":[128,29,819,820],"class_list":["post-12851","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-fact-checks","tag-climate-change","tag-croatia","tag-sun","tag-uv-light"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/posts\/12851","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/comments?post=12851"}],"version-history":[{"count":2,"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/posts\/12851\/revisions"}],"predecessor-version":[{"id":12855,"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/posts\/12851\/revisions\/12855"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/media\/12852"}],"wp:attachment":[{"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/media?parent=12851"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/categories?post=12851"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/seecheck.org\/index.php\/wp-json\/wp\/v2\/tags?post=12851"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}