Thought of summer definitely reminds all of us about the scorching sunlight, burning our skin and making us feel hot. But there is much more related to sunlight and sun rays.
Scott W Menzies, an associate professor, at University of Sydney, Sydney Melanoma Diagnostic Centre, Royal Prince Alfred Hospital, Camperdown, and 2050 NSW, AUSTRALIA recognizes and finds out that sun exposure is one of the major causes of melanoma, the skin cancer, basically among the white population. And this has been observed by multiple observations.
The exposed body parts are the anatomical site of low and high sun exposure predictspatterns of melanoma. In general, the relative density of melanomais highest on body sites receiving more sun exposure and lowest on sites receiving little.
The incidence of melanoma is also much higher in people of races who tend to burn rather than tan. This is consistent with sun exposure being a strong independent predictor of risk of melanoma.
Case-control studies confirm intermittent sun exposure and sun burn as risk factors for melanoma. Two meta-analyses of case-control studies found that chronic exposure was either negatively associated or not associated. In contrast, there were positive associations with intermittent exposure, lifetime sunburn,and childhood sunburn.
Although studies in children areunclear whether total or intermittent exposure conveys riskof melanoma, all studies published since the last meta-analysissupport the positive association of sun exposure and melanoma risk.
Overall, case-control studies have not shown a reduction inthe incidence of melanoma with sunscreen use. However, sunscreens are used to prolong intentional sun exposure, theytend to be used by people at higher risk of melanoma, and thestudies did not assess the sun protection factor or correctapplication of sunscreens. Nevertheless, the incidence of melanomaamong young adults in Australia fell from 1983 to 1996, coincidingwith strong public health messages to use sun protection.
In white populations of mainly European origin there is evidenceof clear associations between sun exposure and melanoma incidence.A comparison of US white people and black people, in which the melanoma incidence of black people was taken as the non-exposed incidence whereas in white people gave an estimate that 96% of melanoma in men and 92% in women was caused by sun exposure. Sun exposureis clearly a major cause of this disease.