Ultraviolet index levels in Recife, Brazil: an ecological study to identify low-erythemal-risk sunlight exposure windows for infants

OBJECTIVE: Current pediatric guidelines recommend avoiding direct sun exposure for infants under six months. However, these recommendations may offset other potential benefits of sunlight exposure. The authors aimed to examine the Ultraviolet Index (UVI) levels in Recife, Brazil, particularly during early-morning and late-afternoon periods. METHODS: Ecological descriptive study using secondary data from the National Institute for Space Research (INPE - UV-Brazil Project). Hourly UVI averages at 6:00, 7:00, 8:00, and 9:00 a.m. and 3:00, 4:00, and 5:00 pm. for the year 2025 were collected, considering seasonal variations (rainy vs. dry season). RESULTS: In Recife (8°S), the mean and maximum UVI remain ≤ 2.0 (low category) until 7:00 a.m. and after 04:00 pm. throughout the year according to WHO classification. During most of the rainy season (May-July), maximum UVI drops below 2.0 after 3:00 pm. CONCLUSION: In Recife, Northeast Brazil, maximum UVI values are in the WHO low category (≤ 2) until 7:00 a.m. and after 4:00 pm., indicating a low likelihood of acute erythema. However, these ecological data do not establish long-term carcinogenic safety in infants.