Assessing the role of umbrella color for effective UV-AB radiation shielding at UP Manila CAS Tambayan

Abstract

Ultraviolet (UV) radiation poses serious health risks, particularly in tropical regions like the Philippines, where UV exposure is consistently high. This study examines how umbrella color affects UV-AB (Ultraviolet-A and Ultraviolet-B) radiation attenuation by measuring transmission through umbrellas of different colors—white, red, orange, yellow, green, blue, violet, and black—and comparing them to direct sunlight. Measurements were taken hourly from 8:30 AM to 4:30 PM over two days with varying cloud cover. Statistical analyses, including Kruskal-Wallis and Wilcoxon Signed-Rank tests, were used to assess differences in UV blocking efficiency. Results show black umbrellas provided the greatest UV protection, while white allowed the most UV to pass through. Colors with shorter wavelengths like blue and violet performed better than longer-wavelength colors such as red and orange. Notably, only the white umbrella showed significant variation across weather conditions. These findings highlight the importance of umbrella color in UV protection and support using darker shades for more consistent shielding. Future studies may explore additional factors like fabric composition and UV-resistant coatings.