Sun Exposure Awareness and Sunscreen Use among Adults in Mumbai, India: A Cross-sectional Study

Background: Ultraviolet (UV) radiation is a well-established risk factor for skin damage and skin cancer. In a tropical city like Mumbai, where sun exposure is frequent throughout the year, understanding public awareness and protective practices is important. Aim: This study aimed to evaluate awareness of sun exposure risks, patterns of sunscreen use, and perceptions regarding bio-based sunscreens among adults in Mumbai, India. Methods: A cross-sectional online survey was conducted between November 2024 and April 2025 using a structured questionnaire available in English, Hindi, and Marathi. Adults aged 18 years and above residing in Mumbai were recruited through convenience sampling. A total of 2501 completed responses were included in the analysis. Descriptive statistics were calculated, and associations were examined using chi-square tests. Ordinal logistic regression was performed to identify predictors of sunscreen usage frequency, with statistical significance set at p < 0.05. Results: Of the participants, 51% were female and the majority (66%) were aged 18–25 years. Notably, 66% of respondents reported limited awareness of the harmful effects of prolonged sun exposure. Significant gender differences were observed in awareness-related variables, with females demonstrating higher awareness levels compared to males (p < 0.001). However, sunscreen usage frequency did not significantly differ by gender (p = 0.087). Awareness of sun damage was not an independent predictor of sunscreen use (AOR = 1.08, p = 0.181). Perceptions regarding bio-based sunscreens were nearly evenly divided, with no significant association with gender. Conclusion: The findings reveal considerable gaps in public awareness and highlight a disconnect between knowledge and actual sunscreen practices. These results suggest that awareness alone may not be sufficient to promote protective behaviour. Public health strategies should therefore focus on both improving knowledge and encouraging consistent sun-protection habits in tropical urban populations.