Heavy metal composition of hair cream products, their risk quotients and health effects on human male users in Lafia Metropolis, Nasarawa State

Abstract

Exposure to heavy metals poses significant health risks, prompting regulatory agencies to establish safety thresholds. This study investigated the concentrations of selected heavy metals (Zn, Se, Cd, Pb, Fe, As) in hair cream products from Lafia Metropolis, Nigeria, and evaluated their health implications using Risk Quotient (RQ) analysis. Standard analytical procedures were employed, with triplicate measurements yielding mean concentrations and standard deviations. Statistical significance was set at P < 0.05. Results revealed detectable levels of all heavy metals in the products, ordered as Zn > Se > Cd > Pb > Fe > As. Comparative analysis of human hair samples showed no significant difference (P < 0.05) in iron levels between grey (0.04 ± 0.01 mg/L) and undyed hair (0.06 ± 0.02 mg/L), both below the reference value (0.8 mg/L), suggesting limited iron accumulation in these hair types. Zinc levels were significantly higher in grey hair (0.48 ± 0.10 mg/L) but remained below the reference threshold (12.0 mg/L). RQ analysis identified elevated risks for Se, Cd, and As in hair creams, with values exceeding the safety threshold (RQ > 1). Arsenic in sample HDC posed the highest risk (RQ = 228.13), while
cadmium in dyed female hair (0.24 ± 0.20 mg/L) slightly surpassed the reference limit (<0.1 mg/L). In male hair, Cd approached risk thresholds in dyed (RQ = 0.90) and grey hair (RQ = 0.80). Other metals (Pb, Fe, Zn) in hair samples were within safe limits. Although most hair metal concentrations were below reference values, the high RQs in hair creams indicate potential systemic exposure risks. These findings underscore the need for stricter regulatory oversight and routine monitoring of cosmetic products to safeguard consumer health.