Epidemiological Assessment of Cosmetic Skin Bleaching Practices and Toxic Exposure Among Vulnerable Women in Zanzibar: Public Health Perspective

The widespread use of skin-bleaching cosmetics among women in Zanzibar poses a growing public health concern due to chronic exposure to toxic substances present in many products sold through informal markets and beauty salons. These cosmetics are suspected to contain hazardous compounds such as mercury, hydroquinone, and potent corticosteroids, which are associated with dermatological damage, endocrine disruption, nephrotoxicity, and adverse reproductive outcomes. This study assessed the epidemiology of skin-bleaching practices and evaluated associated health risks using integrated population-based data and laboratory analysis of cosmetic products. A cross-sectional study was conducted among women of reproductive age in selected urban and peri-urban areas of Zanzibar. Structured questionnaires collected data on cosmetic use patterns, duration and frequency of exposure, reproductive history, and self-reported health outcomes. Commonly used skin-lightening products were concurrently <i>sampled</i> from salons and retail outlets. Metallic content was quantified using inductively coupled plasma optical emission spectroscopy (ICP-OES), while restricted organic compounds were identified through product label claims. Detected concentrations were compared with international cosmetic safety standards. Results indicated a high prevalence of regular skin bleaching, characterized by prolonged daily application and limited awareness of product composition and health risks. ICP-OES analysis detected mercury concentrations exceeding permissible limits in several products, while label claims confirmed the presence of hydroquinone and corticosteroids, substances prohibited or strictly restricted under regulatory standards. Epidemiological findings showed associations between long-term cosmetic use and dermatological disorders, menstrual irregularities, and symptoms suggestive of renal and hormonal dysfunction. Health professionals further raised concerns regarding potential prenatal exposure and adverse maternal and infant health outcomes. Interpreted within the Donabedian framework, these findings underscore systemic weaknesses in cosmetic regulation, product surveillance, and public health education. Strengthened regulatory enforcement, routine laboratory monitoring, and targeted public health interventions are urgently required to reduce toxic cosmetic exposure and protect women’s reproductive and maternal health in Zanzibar.