Health effects of selected trace elements in hairdressing cosmetics on hairdressers in Enugu, Nigeria

Could trace elements in hairdressing cosmetics prove carcinogenic to hairdressers, who use them regularly as raw materials in hairdressing business? The toxic effects of selected trace elements contained in hairdressing cosmetics on hairdressers were investigated by regressing the quality of life values for hairdressers with their blood/urine levels of the toxic metals A hundred subjects were randomly drawn from a cluster of hairdressers. Blood lead level, 17.47 ± 4.59 µg/dL, confirmed that the hairdressers were regularly exposed to lead. Mean blood mercury level, 25.06 ± 4.11 ng/dL, was above the normal blood mercury concentration of less than 10–20 ng/mL. Mean blood cadmium level, 3.64 ± 1.87 µg/dL, was within the normal range, < 5.0 µg/dL. Mean urine arsenic level, 96.16 ± 38.34 µg/L, was above normal range, ≤ 50 μg/dL, but within high normal range, > 50 to < 200 μg/dL. Blood nickel level, 0.49 ± 0.20 µg/dL, was above both the healthy range, 0.14–0.65 µg/dL, and the most reliable value of 0.2 µg/dL. Negative correlations existed between the quality of life and levels for lead (R = − .017), mercury (R = − .008), arsenic (R = − .072) and nickel (R = − .168), but there was positive correlation with cadmium level (R = .123). At 0.096, the probability value (p value) for nickel was significant at 10%. P value as insignificant at 1%, 5% and 10% for lead (0.868), mercury (0.940), cadmium (0.224) and arsenic (0.475). Therefore, Ni contained in hairdressing cosmetics might have carcinogenic effects that affected the quality of life of hairdressers, unlike other trace elements tested, namely, lead, mercury, cadmium and arsenic. Further research with the tumor markers assessment is recommended to confirm the carcinogenic effect of Ni.