In a subsequent study, many of the same investigators measured the accumulation of mercury in the tissues of albino and pigmented mice treated with the Rose or Fair & Lovely (with a mercury content of 0.304 plus or minus 0.316 mcg/g) brands of skin-lightening agents. Among 133 and 144 respective brain, kidney, and liver tissue samples of albino and pigmented mice, significantly more mercury was identified in tissues treated with Rose cream. The highest mercury concentrations were found in the tissues of mice, albino and pigmented, treated three times daily, whereas the smallest concentrations were in the tissues of mice treated once daily. The investigators also noted that mercury was readily absorbed into and accumulated in the tissues of albino and pigmented mice treated with either brand of skin-lightening agent. Tissues from pigmented mice were less affected, however, suggesting the protective capacity of melanin against mercury. Nonetheless, given the higher concentration of mercury in the Rose cream, this study reinforced the danger of repeated use of mercury-containing creams containing even low levels of the element, concluded the researchers (Biometals 2004;17:167-75)

In 2005, Al-Saleh et al. investigated the toxic effects on mice of Fair & Lovely, which is sold widely over-the-counter in Saudi Arabia and more than 35 other countries (Arthritis Rheum. 2007;56:1721). As in the previous work, the study period was 1 month and the agent was applied at different intervals, with mercury concentrations measured in brain, kidney, and liver samples from 75 adult female CD1 mice. Mean mercury concentrations in the tissues of treated mice were found to be significantly higher than in samples from controls (0.193 vs. 0.041 mcg/g). Treated mice also exhibited significant declines in body weight and histologic changes in kidney and, more moderately, in brain and liver tissue. The investigators concluded that histopathologic changes are associated with this mercury-containing skin-lightening agent, even though its mercury content falls below 1 ppm (Cutan. Ocul. Toxicol. 2005;24:11-29). Furthermore, as pointed out by Pollard and Hultman, Fair & Lovely can be purchased throughout the world and is available online (Arthritis Rheum. 2007;56:1721).

Given the widespread use of skin-lightening creams, primarily by women but also by men, and the substantial risks of mercury toxicity posed by the chronic use of these agents, especially to pregnant and nursing mothers, Al-Saleh et al. measured the mercury levels in 49 murine ovary tissue samples. They compared the ovaries of untreated mice, those treated with Rose skin-lightening cream, and those treated with Fair & Lovely skin-lightening cream. Mercury content increased with increasing frequency of application, and was highest in samples from mice treated twice daily with Fair & Lovely (87.79 ng/g) and once daily with Rose (3,515.61 ng/g). The researchers concluded that while more research is needed, significant mercury accumulation in the ovaries can result from dermal exposure to mercury-containing skin creams that can alter the reproductive system and lead to infertility.

While they suggested that banning such creams would be ideal, they acknowledged that circumventing the popularity of these products might be better achieved if public health officials urged the use of prescription treatments for skin pigmentation rather than over-the-counter solutions. The authors also warned that women who regularly use such products are at particular risk, because there are no symptoms of early exposure; mercury toxicity develops from chronic use (Biol. Trace Elem. Res. 2009;131:43-54).

Like indoor tanning, mercury-containing skin creams occupy a nexus between dermatology, human behavior, public policy, and the law. In addition to various national bans that have been enacted, some U.S. states have gotten in on the act. According to a report by the Associated Press, on Jan. 1, 2008, a Minnesota law took effect that prohibits mercury from mascara, eyeliners, and skin-lightening creams; federal law allows eye formulations to contain mercury up to 65 ppm.

Availability of Mercury-Containing Products

In the United States, regulations regarding over-the-counter products are much weaker than those pertaining to prescription drugs. As a result, mercury-containing substances have penetrated the market (and online purchasing is a loophole of the modern era) to an extent that may surprise many, particularly considering how mercury laden some of these products are.

For a story on this topic, Chicago Tribune reporters purchased 50 skin-lightening creams in Chicago stores or online, and sent them to a certified laboratory for testing. The laboratory results revealed that six of the creams contained illegal amounts of mercury (at 6,000 ppm or more in five of those formulations) (Chicago Tribune, May 18, 2010). The newspaper contacted retailers, who said they would remove the products from shelves, with two distributors claiming that they would stop selling these products. The worst offender had a mercury level close to 30,000 ppm. The six creams that tested high originated in China, India, Lebanon, Pakistan, and Taiwan. The Web site is tracking the number and names of skin-lightening products found to contain dangerous levels of mercury. According to the Tribune article, the FDA has fewer than 500 inspectors, and the agency has not considered mercury in skin creams since 2006.

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