Mercury and hydroquinone content of skin toning creams and cosmetic soaps, and the potential risks to the health of Ghanaian women

In most communities across the globe, fairness is branded as beauty, grace and high social status. This perception encourages most women to engage in skin bleaching. Skin-lightening or bleaching has reached epidemic levels in many nations across the world especially in African countries like Ghana, Nigeria, Mali, Kenya and Tanzania (Harada et al. 2001; Adebajo 2002; Mahe et al. 2004; Lewis et al. 2009; Voegborlo et al. 2008). The production of skin-bleaching products is on the rise and in high demand across the world (Perry 2006). Many African women want to keep their skin toned and beautiful by indulging in skin care products that bleach the skin. Most of these bleaching cosmetic products contain different kinds of harmful chemicals such as hydroquinone, mercury, kojic acid and vitamin C, which can affect their health (Amponsah et al. 2014).

Cosmetic preparations containing mercury for bleaching purpose is an old practice (Al-Saleh and Al-Doush 1997). Mercury is a toxic metal but found usefulness in many cosmetic preparations targeted at skin lightening by suppression of melanin production by the skin (Bourgeosis et al. 1986). Cosmetic products containing mercury in the form of inorganic mercury are mainly used by dark skinned people mostly in developing countries (Barr et al. 1973). Mercury is a volatile element and is harmful to the skin when used in an effort to lighten the skin. However, chronic exposure of the body to mercury at very low concentration can cause long-lasting neurological and kidney impairment (Hutson et al. 1999). Mercury in bleaching preparations can be absorbed through the skin and accumulates in body organs giving rise to severe toxicity (Sah 2012). A study conducted on Tanzanian gold miners who use mercury for amalgamation and people not engaged in gold mining activities revealed that the mercury found in their blood and urine was derived from cosmetic soaps and creams containing mercury (Kahatano et al. 1998). Glahder and Appell (1999) also reported high levels of mercury in imported soaps and creams bought in Tanzanian shops. An investigation of Kenyan women with damaged kidney also revealed that they suffered severely from higher incidence of nephritic syndrome, which was attributed to the use of creams containing mercury (Barr et al. 1973).

Hydroquinone is a potential carcinogenic ingredient used in skin lightening and treatment of hyper-pigmentation (Joseph et al. 1998). Hydroquinone does not actually bleach the skin but rather, a strong inhibitor of melanin production (Yoshimura et al. 2001). Hydroquinone used for topical application is known to cause serious health hazards when used excessively (Hutson et al. 1999). Hydroquinone toxicity can lead to severe side effects such as kidney and liver malfunction, blood poisoning, nausea, abdominal pains, convulsion and even coma. Animal test on rats, mice and rabbits showed that hydroquinone can cause acute toxicity (Aldrich 1990).

Most of the skins lightening creams and soaps on the Ghanaian market are imported from USA, Europe, Italy and Cote d’Voire (Voegborlo et al. 2008). The demand for skin-lightening products in Ghana is on the increase despite the health hazards associated with the use of these products. However, data on mercury and hydroquinone levels in skin-lightening soaps and creams sold on the Ghanaian market are lacking and only little work has been done on mercury (Voegborlo et al. 2008) even though concerns have been raised on the negative effect of skin-lightening creams and soaps on the skin. The aim of this work was to analyse the mercury and hydroquinone content in some skin toning creams and cosmetic soaps using automatic mercury analyser coupled with Cold Vapour Atomic Absorption Spectrophotometry (CV-AAS) and High Performance Liquid Chromatography.

Majority of the skin-lightening creams analysed in this study originated for Cote d’Voire (34 %), Italy (30 %) and India (13 %). The rest originated from UK, USA, Senegal, China, Germany, Nigeria and Ghana. T-mercury concentration (μg/g) in the skin-lightening creams imported from Cote d’Voire ranged from <0.001 to 0.327 ± 0.062, <0.001 to 0.250 ± 0.031 in creams imported for Italy and <0.001 to 0.182 ± 0.057 in creams imported from India. About 28% of the creams recorded T-mercury concentration below detection (<0.001 μg/g). The highest concentration of T-mercury was recorded in EG which is imported from Cote d’Voire. T-mercury concentration in soaps ranged from 0.003 ± 0.000 to 0.337 ± 0.073 μg/g. All the skin-lightening creams and soaps analysed had T-mercury concentration below 1.0 μg/g maximum limit set by the United States Food and Drug Administration (USFDA) (USFDA 2009). Similar results were reported by Voegborlo et al. (2008). However, previous studies conducted by Al-Saleh and Al-Doush (1997) on mercury concentration in creams obtained from the Saudi Arabians market which originated from Asia and Middle East contained T-mercury concentration above the US FDA limit. Results of T-mercury determined in cosmetic products obtained on Dares Salaam market in Tanzania also showed very high concentration of mercury in some creams and soaps above the US FDA limit with T-mercury ranged from 0.11 to 8665 μg/g in cosmetic soaps and 0.16–25.30 μg/g in cosmetic creams (Kinabo 2003).

Hydroquinone levels in the skin-lightening products ranged from below detection to 0.83 ± 0.51 % in creams imported from Cote d’Voire, 0.02 ± 0.01 to 0.51 ± 0.18 % in creams imported from Italy, below detection to 0.32 ± 0.16 % in creams imported from India. Creams originating from USA, Indonesia, Germany, Senegal, Ghana and China recorded hydroquinone levels below the detection limit. The highest concentration of hydroquinone was recorded in ZC (1.61 ± 0.72 %) imported from UK followed by CD (0.83 ± 0.51 %) imported from Cote d’Voire, Skin Solution Cream (0.51 ± 0.18 %) imported from Italy, DSC (0.40 ± 0.71 %) imported from Nigeria and CLC (0.32 ± 0.16 %) imported from India. Hydroquinone levels in the skin-lightening soaps ranged from below detection to 0.05 ± 0.03 %. Classic white soap and CTS recorded hydroquinone concentration of 0.05 ± 0.03 and 0.02 ± 0.01 %, respectively. Overall, 64 % of the creams and 75 % of soaps analysed recorded hydroquinone concentrations below detection. All the skin-lightening creams and soaps analysed recorded hydroquinone concentration below the US FDA threshold limit of 2 % (USFDA 2009). Doreen (2010) recorded levels of hydroquinone (0.001–3.45 %) in some skin lighteners in Ghana, which was higher than the present study. However, levels of hydroquinone (0.0002–0.0350 %) in body creams and lotions by Terer et al. (2013), Kenya are comparable with the present study.