Abstract

Skin cancer is a global health threat with significant international implications and a major concern in countries like Bangladesh, where population awareness, preventive behavior, and correct sunscreen application are staggeringly low. This investigation was designed to accomplish two objectives: (i) to evaluate the ultraviolet B radiation (UVB) protection efficacy of commercially available sunscreens (n = 30) in vitro using the Mansur spectrophotometric method, and (ii) to assess sunscreen awareness and usage patterns among 222 university students. University students represent the educated segment of society; if a noticeable lack of awareness about sunscreen use is observed in this group, it strongly indicates lower awareness among uneducated and marginalized populations. In vitro analyses revealed that 93.3% of products exhibited measured SPF values substantially lower than their labeled claims (mean measured SPF: 15.2 ± 12.4 vs. mean labeled SPF: 45.0 ± 20.1) under UVB wavelengths (290–320 nm). The cross-sectional survey indicated that 58.56% of participants (Male: 50.77%; Female: 49.23%) did not regularly apply sunscreen, with male students exhibiting lower usage. These results suggest discrepancies between the UVB protection labeled and the UVB protection measured, as well as gaps in sunscreen knowledge and usage practices. The results underscore the necessity of enhanced quality control, more explicit product labeling, regulatory monitoring, and targeted educational initiatives, rather than concluding that prevention of skin cancer or broad-spectrum protection is achieved.

Key words: Skin cancer, Bangladesh, sunscreen, Sun Protection Factor (SPF), Mansur method, Photoprotection, Public health