A study by researchers at the Kwame Nkrumah University of Science and Technology, Kumasi (KNUST), has found that commonly used nail polish brands sold in Ghana contain detectable levels of some metals but do not pose significant health risks to consumers, with all tested products falling within internationally accepted safety limits.

The study, published in the Journal of Environmental Science and Health, analysed 20 nail polish brands purchased from cosmetic shops in Kumasi’s Adum and Kejetia markets for six metals: lead, cadmium, aluminium, chromium, manganese and copper.

The research, led by Ms. Maame Tabitha Kuukua Osiban-Fordjour, found that aluminium was the most prevalent metal, reaching concentrations of up to 77.50 mg/L, followed by chromium at 25.66 mg/L and copper at 2.13 mg/L. Lead, cadmium and manganese were below detection limits in all samples.

Ms. Osiban-Fordjour undertook the experimental work under the supervision of Prof. Marian Asantewah Nkansah, with support from Dr. Caroline Rosemyya Kwawu.

The researchers concluded that all samples analysed were below permissible limits and that hazard quotient and hazard index values remained below one, indicating no significant health risks from inhalation, ingestion or dermal exposure associated with their use.

As part of the research, the team surveyed 400 KNUST students to assess awareness of potential exposure to heavy metals through nail polish use.

The findings revealed that about half of respondents used nail polish and also ate with painted nails. While some were aware that nail polish could pose health risks, many had limited knowledge of the specific dangers associated with heavy metal contamination.

The researchers noted that aluminium concentrations were higher than those of the other metals detected, likely due to the use of aluminium-based pigments that produce a wide range of colours in cosmetic products. Chromium and copper were also detected in some samples, possibly originating from pigments and additives used to create glossy finishes.

Although the detected metal levels were not considered alarming, the researchers cautioned that repeated exposure over long periods could lead to accumulation in the body.

They therefore recommended routine monitoring of cosmetic products and increased public awareness of potential risks associated with prolonged use.

The study also called for stronger regulatory oversight and periodic testing of cosmetic products on the Ghanaian market, arguing that mandatory disclosure of heavy metal content could help consumers make more informed choices.