Mercury

Mercury, long known as a toxic substance, is making a comeback in skin products, and dermatologists should familiarize themselves with both the dangers and the availability of this all-too-common cosmeceutical ingredient.

The ancient Egyptians and Romans used mercury to lighten the skin and in a variety of ointments, and the Greeks and Egyptians used it to treat skin infections (Environ. Health Perspect. 2002;110:11-23).

While versatile and used for diverse purposes for many years, such as in thermometers and in dental amalgams, mercury and its related compounds have long been known to be extremely toxic and should be avoided in food and skin care. Indeed, the wide-ranging adverse health effects of mercury-containing skin-lightening products have been known since the early 1970s (Arthritis Rheum. 2007;56:1721).

While mercury has been banned in skin care products sold in the United States since 1990, it is found in numerous skin-lightening agents sold elsewhere. In Europe, such a ban was enacted in 1976. Recently, some of these products have made their way onto U.S. shelves and, to the surprise of many, have been reported to contain toxic levels of mercury. This column will review some of the latest data on mercury-containing skin products and describe the current emerging controversy.

Renewed Popularity

Skin-lightening agents that contain mercury have become increasingly popular in recent years, especially among women with dark skin (Biometals 2004;17:167-75). In particular, skin-lightening cosmetics that contain hydroquinone, mercury, and/or corticosteroids are used widely in many African countries, and especially in sub-Saharan Africa (Med. Trop. 2007;67:627-34). While effective as a whitening agent, mercury is a toxic heavy metal that can produce deleterious effects on humans, through ingestion, skin contact, or inhalation.

The primary vectors for exposure have been metallic or elemental mercury in dental amalgams, ethylmercury in the form of thimerosal in vaccines, and methylmercury in seafood. Metallic mercury also is found in thermometers, organic mercury is used in paints and fungicides, and inorganic mercury compounds are used in medicinal and skin care formulations. The present surge in the use of mercury in skin-lightening formulations, as well as in some religious rituals, has added avenues for mercury exposure (Biol. Trace Elem. Res. 2009;131:43-54; Crit. Rev. Toxicol. 2006;36:609-62; J. Pediatr. Health Care 2007;21:307-14; Int. J. Dermatol. 2008;47:344-53; Environ. Health Perspect. 2002;110:11-23; Rev. Environ. Health 2005;20:39-56; Br. J. Dermatol. 1968;80:623-4).

Some researchers have noted that in Africa, percutaneous absorption is facilitated by the conditions under which these products are used, that is, for long periods, over a large body surface area, and in hot, humid weather. Palmer et al. showed in a human in vitro model that mercury was readily absorbed in the skin in a comparison between an aqueous formulation, which exhibited a significantly higher rate and further extent of absorption, and a proprietary formulation. Their study was prompted partly by the popularity of the mercurous chloride–containing beauty cream Crema de Belleza-Manning, a popular agent used to lighten and smooth the skin and to treat acne. The cream has been linked to elevated urinary mercury levels in hundreds of people in the southwestern U.S. border states (J. Toxicol. Clin. Toxicol. 2000;38:701-7).

Complications of Chronic Exposure

Olumide et al. have reported that the potentially serious results of the chronic use of these agents include exogenous ochronosis; compromised wound healing and wound dehiscence; fish odor syndrome; nephropathy; steroid addiction syndrome; predisposition to infections; and various cutaneous and endocrinologic complications of steroid use, including suppression of the hypothalamic-pituitary-adrenal axis and death (Int. J. Dermatol. 2008;47:344-53).

Other dermatologic complications associated with mercury include dyschromia, acne and hypertrichosis, striae, tinea corporis, pyoderma, erysipelas, scabies, and contact dermatitis (Med. Trop. 2007;67:627-34).

In 1997, Al-Saleh and Al-Doush evaluated 38 skin-lightening creams available on the Saudi Arabian market and elsewhere, and analyzed them for mercury. They found that about 45% of the tested samples contained mercury at levels far surpassing 1 ppm (the maximum permitted by the Food and Drug Administration) (J. Toxicol. Environ. Health. 1997;51:123-30).

In 2003, Al-Saleh et al. issued an urgent warning in relation to their mercury research. They examined the effects of Rose skin-lightening cream (with a mercury content of 77,513 plus or minus 71,063 ppm) topically applied on mice over a 1-month period at varying intervals. By collecting 58 brain, kidney, and liver samples, the researchers determined that the mercury content of the samples was significantly higher in mice treated three times daily, compared with those treated once weekly, although histopathologic changes were observed in all tissue samples. The authors concluded that their study highlighted the potential toxicity of skin-lightening creams containing mercury, and that banning their manufacture and use is warranted (J. Environ. Pathol. Toxicol. Oncol. 2003;22:287-99).

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 http://www.whiterskin.info/ 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.

At the international level, on June 11, 2010, a PR Newswire story reported that representatives of 132 countries, meeting under the auspices of the United Nations Environment Programme, paved the way toward a treaty to control mercury pollution. The gathering, dubbed the first Intergovernmental Negotiating Committee (INC) meeting, in Stockholm, has set the stage for developing the text of the treaty, the drafting of which will begin at the next INC meeting in Tokyo in January 2011. At the June meeting, a World Health Organization representative stated that the goal will be to halt production of skin-lightening cosmetics that contain mercury. Five INC meetings are expected to convene to complete the treaty before 2013.

Conclusion

It is incumbent upon dermatologists to use all of the tools in their arsenal to convince patients to accept their skin tone as it is. In other words, we should discourage those who attempt to lighten their skin for reasons not pertaining to correcting dyspigmentation, just as we discourage patients seeking to tan or darken their skin.

For patients resistant to such advice or cajolery, practitioners must warn them about using skin-lightening products that contain mercury and recommend alternative lightening agents. Clearly, formulations containing mercury, though banned in the United States, are becoming increasingly available, and as over-the-counter products they are not tightly regulated. These products pose a serious health risk.

Mercury, long known as a toxic substance, is making a comeback in skin products, and dermatologists should familiarize themselves with both the dangers and the availability of this all-too-common cosmeceutical ingredient.

The ancient Egyptians and Romans used mercury to lighten the skin and in a variety of ointments, and the Greeks and Egyptians used it to treat skin infections (Environ. Health Perspect. 2002;110:11-23).

While versatile and used for diverse purposes for many years, such as in thermometers and in dental amalgams, mercury and its related compounds have long been known to be extremely toxic and should be avoided in food and skin care. Indeed, the wide-ranging adverse health effects of mercury-containing skin-lightening products have been known since the early 1970s (Arthritis Rheum. 2007;56:1721).

While mercury has been banned in skin care products sold in the United States since 1990, it is found in numerous skin-lightening agents sold elsewhere. In Europe, such a ban was enacted in 1976. Recently, some of these products have made their way onto U.S. shelves and, to the surprise of many, have been reported to contain toxic levels of mercury. This column will review some of the latest data on mercury-containing skin products and describe the current emerging controversy.

Renewed Popularity

Skin-lightening agents that contain mercury have become increasingly popular in recent years, especially among women with dark skin (Biometals 2004;17:167-75). In particular, skin-lightening cosmetics that contain hydroquinone, mercury, and/or corticosteroids are used widely in many African countries, and especially in sub-Saharan Africa (Med. Trop. 2007;67:627-34). While effective as a whitening agent, mercury is a toxic heavy metal that can produce deleterious effects on humans, through ingestion, skin contact, or inhalation.

The primary vectors for exposure have been metallic or elemental mercury in dental amalgams, ethylmercury in the form of thimerosal in vaccines, and methylmercury in seafood. Metallic mercury also is found in thermometers, organic mercury is used in paints and fungicides, and inorganic mercury compounds are used in medicinal and skin care formulations. The present surge in the use of mercury in skin-lightening formulations, as well as in some religious rituals, has added avenues for mercury exposure (Biol. Trace Elem. Res. 2009;131:43-54; Crit. Rev. Toxicol. 2006;36:609-62; J. Pediatr. Health Care 2007;21:307-14; Int. J. Dermatol. 2008;47:344-53; Environ. Health Perspect. 2002;110:11-23; Rev. Environ. Health 2005;20:39-56; Br. J. Dermatol. 1968;80:623-4).

Some researchers have noted that in Africa, percutaneous absorption is facilitated by the conditions under which these products are used, that is, for long periods, over a large body surface area, and in hot, humid weather. Palmer et al. showed in a human in vitro model that mercury was readily absorbed in the skin in a comparison between an aqueous formulation, which exhibited a significantly higher rate and further extent of absorption, and a proprietary formulation. Their study was prompted partly by the popularity of the mercurous chloride–containing beauty cream Crema de Belleza-Manning, a popular agent used to lighten and smooth the skin and to treat acne. The cream has been linked to elevated urinary mercury levels in hundreds of people in the southwestern U.S. border states (J. Toxicol. Clin. Toxicol. 2000;38:701-7).

Complications of Chronic Exposure

Olumide et al. have reported that the potentially serious results of the chronic use of these agents include exogenous ochronosis; compromised wound healing and wound dehiscence; fish odor syndrome; nephropathy; steroid addiction syndrome; predisposition to infections; and various cutaneous and endocrinologic complications of steroid use, including suppression of the hypothalamic-pituitary-adrenal axis and death (Int. J. Dermatol. 2008;47:344-53).

Other dermatologic complications associated with mercury include dyschromia, acne and hypertrichosis, striae, tinea corporis, pyoderma, erysipelas, scabies, and contact dermatitis (Med. Trop. 2007;67:627-34).

In 1997, Al-Saleh and Al-Doush evaluated 38 skin-lightening creams available on the Saudi Arabian market and elsewhere, and analyzed them for mercury. They found that about 45% of the tested samples contained mercury at levels far surpassing 1 ppm (the maximum permitted by the Food and Drug Administration) (J. Toxicol. Environ. Health. 1997;51:123-30).

In 2003, Al-Saleh et al. issued an urgent warning in relation to their mercury research. They examined the effects of Rose skin-lightening cream (with a mercury content of 77,513 plus or minus 71,063 ppm) topically applied on mice over a 1-month period at varying intervals. By collecting 58 brain, kidney, and liver samples, the researchers determined that the mercury content of the samples was significantly higher in mice treated three times daily, compared with those treated once weekly, although histopathologic changes were observed in all tissue samples. The authors concluded that their study highlighted the potential toxicity of skin-lightening creams containing mercury, and that banning their manufacture and use is warranted (J. Environ. Pathol. Toxicol. Oncol. 2003;22:287-99).

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 http://www.whiterskin.info/ 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.

At the international level, on June 11, 2010, a PR Newswire story reported that representatives of 132 countries, meeting under the auspices of the United Nations Environment Programme, paved the way toward a treaty to control mercury pollution. The gathering, dubbed the first Intergovernmental Negotiating Committee (INC) meeting, in Stockholm, has set the stage for developing the text of the treaty, the drafting of which will begin at the next INC meeting in Tokyo in January 2011. At the June meeting, a World Health Organization representative stated that the goal will be to halt production of skin-lightening cosmetics that contain mercury. Five INC meetings are expected to convene to complete the treaty before 2013.

Conclusion

It is incumbent upon dermatologists to use all of the tools in their arsenal to convince patients to accept their skin tone as it is. In other words, we should discourage those who attempt to lighten their skin for reasons not pertaining to correcting dyspigmentation, just as we discourage patients seeking to tan or darken their skin.

For patients resistant to such advice or cajolery, practitioners must warn them about using skin-lightening products that contain mercury and recommend alternative lightening agents. Clearly, formulations containing mercury, though banned in the United States, are becoming increasingly available, and as over-the-counter products they are not tightly regulated. These products pose a serious health risk.

Mercury, long known as a toxic substance, is making a comeback in skin products, and dermatologists should familiarize themselves with both the dangers and the availability of this all-too-common cosmeceutical ingredient.

The ancient Egyptians and Romans used mercury to lighten the skin and in a variety of ointments, and the Greeks and Egyptians used it to treat skin infections (Environ. Health Perspect. 2002;110:11-23).

While versatile and used for diverse purposes for many years, such as in thermometers and in dental amalgams, mercury and its related compounds have long been known to be extremely toxic and should be avoided in food and skin care. Indeed, the wide-ranging adverse health effects of mercury-containing skin-lightening products have been known since the early 1970s (Arthritis Rheum. 2007;56:1721).

While mercury has been banned in skin care products sold in the United States since 1990, it is found in numerous skin-lightening agents sold elsewhere. In Europe, such a ban was enacted in 1976. Recently, some of these products have made their way onto U.S. shelves and, to the surprise of many, have been reported to contain toxic levels of mercury. This column will review some of the latest data on mercury-containing skin products and describe the current emerging controversy.

Renewed Popularity

Skin-lightening agents that contain mercury have become increasingly popular in recent years, especially among women with dark skin (Biometals 2004;17:167-75). In particular, skin-lightening cosmetics that contain hydroquinone, mercury, and/or corticosteroids are used widely in many African countries, and especially in sub-Saharan Africa (Med. Trop. 2007;67:627-34). While effective as a whitening agent, mercury is a toxic heavy metal that can produce deleterious effects on humans, through ingestion, skin contact, or inhalation.

The primary vectors for exposure have been metallic or elemental mercury in dental amalgams, ethylmercury in the form of thimerosal in vaccines, and methylmercury in seafood. Metallic mercury also is found in thermometers, organic mercury is used in paints and fungicides, and inorganic mercury compounds are used in medicinal and skin care formulations. The present surge in the use of mercury in skin-lightening formulations, as well as in some religious rituals, has added avenues for mercury exposure (Biol. Trace Elem. Res. 2009;131:43-54; Crit. Rev. Toxicol. 2006;36:609-62; J. Pediatr. Health Care 2007;21:307-14; Int. J. Dermatol. 2008;47:344-53; Environ. Health Perspect. 2002;110:11-23; Rev. Environ. Health 2005;20:39-56; Br. J. Dermatol. 1968;80:623-4).

Some researchers have noted that in Africa, percutaneous absorption is facilitated by the conditions under which these products are used, that is, for long periods, over a large body surface area, and in hot, humid weather. Palmer et al. showed in a human in vitro model that mercury was readily absorbed in the skin in a comparison between an aqueous formulation, which exhibited a significantly higher rate and further extent of absorption, and a proprietary formulation. Their study was prompted partly by the popularity of the mercurous chloride–containing beauty cream Crema de Belleza-Manning, a popular agent used to lighten and smooth the skin and to treat acne. The cream has been linked to elevated urinary mercury levels in hundreds of people in the southwestern U.S. border states (J. Toxicol. Clin. Toxicol. 2000;38:701-7).

Complications of Chronic Exposure

Olumide et al. have reported that the potentially serious results of the chronic use of these agents include exogenous ochronosis; compromised wound healing and wound dehiscence; fish odor syndrome; nephropathy; steroid addiction syndrome; predisposition to infections; and various cutaneous and endocrinologic complications of steroid use, including suppression of the hypothalamic-pituitary-adrenal axis and death (Int. J. Dermatol. 2008;47:344-53).

Other dermatologic complications associated with mercury include dyschromia, acne and hypertrichosis, striae, tinea corporis, pyoderma, erysipelas, scabies, and contact dermatitis (Med. Trop. 2007;67:627-34).

In 1997, Al-Saleh and Al-Doush evaluated 38 skin-lightening creams available on the Saudi Arabian market and elsewhere, and analyzed them for mercury. They found that about 45% of the tested samples contained mercury at levels far surpassing 1 ppm (the maximum permitted by the Food and Drug Administration) (J. Toxicol. Environ. Health. 1997;51:123-30).

In 2003, Al-Saleh et al. issued an urgent warning in relation to their mercury research. They examined the effects of Rose skin-lightening cream (with a mercury content of 77,513 plus or minus 71,063 ppm) topically applied on mice over a 1-month period at varying intervals. By collecting 58 brain, kidney, and liver samples, the researchers determined that the mercury content of the samples was significantly higher in mice treated three times daily, compared with those treated once weekly, although histopathologic changes were observed in all tissue samples. The authors concluded that their study highlighted the potential toxicity of skin-lightening creams containing mercury, and that banning their manufacture and use is warranted (J. Environ. Pathol. Toxicol. Oncol. 2003;22:287-99).

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 http://www.whiterskin.info/ 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.

At the international level, on June 11, 2010, a PR Newswire story reported that representatives of 132 countries, meeting under the auspices of the United Nations Environment Programme, paved the way toward a treaty to control mercury pollution. The gathering, dubbed the first Intergovernmental Negotiating Committee (INC) meeting, in Stockholm, has set the stage for developing the text of the treaty, the drafting of which will begin at the next INC meeting in Tokyo in January 2011. At the June meeting, a World Health Organization representative stated that the goal will be to halt production of skin-lightening cosmetics that contain mercury. Five INC meetings are expected to convene to complete the treaty before 2013.

Conclusion

It is incumbent upon dermatologists to use all of the tools in their arsenal to convince patients to accept their skin tone as it is. In other words, we should discourage those who attempt to lighten their skin for reasons not pertaining to correcting dyspigmentation, just as we discourage patients seeking to tan or darken their skin.

For patients resistant to such advice or cajolery, practitioners must warn them about using skin-lightening products that contain mercury and recommend alternative lightening agents. Clearly, formulations containing mercury, though banned in the United States, are becoming increasingly available, and as over-the-counter products they are not tightly regulated. These products pose a serious health risk.