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Estimates of beneficial and harmful sun exposure times during the year for major Australian population centres
Author(s) -
Samanek Amanda J,
Croager Emma J,
Gies Peter,
Milne Elizabeth,
Prince Richard,
McMichael Anthony J,
Lucas Robyn M,
Slevin Terry
Publication year - 2006
Publication title -
medical journal of australia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 131
eISSN - 1326-5377
pISSN - 0025-729X
DOI - 10.5694/j.1326-5377.2006.tb00267.x
Subject(s) - sunburn , erythema , medicine , vitamin d and neurology , population , ultraviolet radiation , sun exposure , sunlight , vitamin , environmental health , demography , dermatology , toxicology , biology , physics , astronomy , sociology , chemistry , radiochemistry
Objective: To examine the influence of geographical and seasonal factors on duration of solar ultraviolet (UV) radiation exposure of skin to produce recommended vitamin D levels without producing erythema. Design and setting: An ecological study using daily Ultraviolet Index (UVI) data collected in major population centres across Australia for 1 year (1 January – 31 December 2001) to calculate sun exposure times for recommended vitamin D production and erythema. Main outcome measures: Sun exposure times to produce either serum vitamin D concentrations equivalent to an oral intake of 200–600 IU/day or erythema for people aged 19–50 years with fair skin (Fitzpatrick type II skin) exposing 15% of the body. Results: In January, across Australia, 2–14 minutes of sun three to four times per week at 12:00 is sufficient to ensure recommended vitamin D production in fair‐skinned people with 15% of the body exposed. However, erythema can occur in as little as 8 minutes. By contrast, at 10:00 and 15:00, there is a greater difference between exposure time to produce erythema and that to produce recommended vitamin D levels, thereby reducing the risk of sunburn from overexposure. From October to March, around 10–15 minutes of sun exposure at around 10:00 or 15:00 three to four times per week should be enough for fair‐skinned people across Australia to produce recommended vitamin D levels. Longer exposure times are needed from April to September, particularly in southern regions of Australia. Conclusion: Our study reinforces the importance of existing sun protection messages for the summer months throughout Australia. However, fair‐skinned people should be able to obtain sufficient vitamin D from short periods of unprotected sun exposure of the face, arms and hands outside of the peak UV period (10:00–15:00) throughout Australia for most of the year. The greater variability in sun exposure times during winter, means that optimal sun exposure advice should be tailored to each location.