Geographical correlation between ambient UVB level and mortality risk of leukemia in Japan

Relationship between cancer mortality/incidence and ambient ultraviolet B irradiance in China

“…This association was demonstrated again recently in the same population (using average annual solar radiation levels rather than just latitude) and also reported for mortality from cancers of the esophagus, stomach, colon, rectum, and gallbladder and bile ducts [14,15]. Another recent Japanese study found direct rather than inverse associations between ambient solar UVB radiation and mortality from lymphoid neoplasms [16]. A study reported in 1989 found that gastric, liver and rectal cancer mortality increased with increasing latitude in women in 65 counties in China in 1973-1975 while mortality from cancers of the esophagus and colon did not [17].…”

Sun exposure and risk of lymphoid neoplasms in Singapore

“…These findings led to the suggestion that ultraviolet (UV) irradiation may be a common risk factor for both these cancers, possibly through its effects on the immune system. The theory appeared to be supported by several ecologic studies that found positive associations between ambient UV radiation at various geographical latitudes and incidence and mortality from NHL [12][13][14]. But other similar studies did not support this association [15,16] or reported inverse associations instead [17][18][19].…”

A prospective investigation of serum 25‐hydroxyvitamin D and risk of lymphoid cancers

“…The potentially lymphomagenic role of solar ultraviolet (UV) radiation was first suggested by the parallel rise in non-Hodgkin lymphoma (NHL) and cutaneous melanoma over the past several decades (2–5). Although this hypothesis was supported by some ecologic studies in Europe (6) and other regions (7;8), which showed a positive association between lymphoma and estimated UV-B or its surrogates, U.S. studies revealed an inverse relationship (9;10). In addition, several case-control studies, though not all (11;12), found evidence for a protective effect of sunlight, based on residential sun exposure (13), outdoor hours on working (13) or non-working days (14;15), sun-seeking behavior such as vacations in sunny climate or sunbathing (14–17), history of sunburn (16;18), and host susceptibility (18).…”