SANGARE Naminata SOUMAHORO^1,, ZRAN Vanh Eric-Simon¹, GNONSORO Urbain Paul², KOFFI Koffi Didier¹

Toothpaste, a widely used oral hygiene product, can constitute a pathway for exposure to metallic trace elements (ETM) due to their composition and manufacturing processes. Although these products are subject to regulations, the presence of toxic ETMs (Cd, Pb, Ni, Fe et Zn) remains a concern, particularly in developing countries where quality controls may be limited. This study aims to quantify the concentrations of Cd, Pb, Ni, Fe, and Zn in toothpastes sold in Abidjan, and assess the health risks associated with their use by ingestion and dermal route. Five brands of toothpastes were selected based on their popularity. Twenty-five samples were analyzed by X-ray fluorescence spectrometry (MESA-50). Non-carcinogenic and carcinogenic risks were calculated according to USEPA protocols. Results showed that average Zn concentrations (0.004–0.937 mg/kg) is higher in 60% of samples. Cd had high levels in P3 (0.055 mg/kg). Dermatological non-carcinogenic risk calculations QD values < 1 for all different toothpastes, thus would not constitute a potential hazard to the consumer. However, hazard quotients (HQs) by ingestion were >1 for Cd (38.99), Ni (1.16), and Pb (5.90), indicating a potential toxic risk. Carcinogenic risks (CR) were particularly high for Cd (253.4. 10^-6), exceeding the acceptable threshold (1 × 10^-6). This study reveals significant contamination by certain TMEs, particularly Zn and Cd, in toothpastes marketed in Abidjan. Although cutaneous risks are negligible, chronic ingestion could lead to cumulative toxic effects. Strengthened quality controls and awareness campaigns are recommended.

Trace metal elements, Toothpastes, Risk assessment, X-ray fluorescence, Population health