Beware: Mercury in Skin Lightening Products Can Harm Your Kidneys

As the observance of the National Kidney Month this June draws to a close, the toxics watchdog group EcoWaste Coalition warned consumers against damage to the kidneys resulting from the application of skin lightening products with mercury content.

Citing information received from a scientist based at the National Taiwan University (NTU), the group emphasized that mercury in cosmetics marketed to lighten the skin color and fix other dermal woes can pose serious harm to the kidneys.

In a fact sheet prepared for the EcoWaste Coalition, Dr. Yu-Syuan Luo highlighted the kidney toxicity of mercury. A recipient in 2019 of the Renal Toxicology Award (first place) from the Society of Toxicology, Dr. Luo is Assistant Professor at the Institute of Food Safety and Health, College of Public Health, NTU.

“Mercury has been named the 3rd place on the Substance Priority List according to the Agency for Toxic Substances and Disease Registry (ATSDR), yet it still ubiquitously exists in inorganic or organic forms in cosmetics such as skin lightening creams,” said Dr. Luo.

The ATSDR’s Substance Priority List includes substances most commonly found at key facilities, which “pose the most significant threat to human health due to their known or suspected toxicity and potential for human exposure at these sites.”

“The kidney toxicity of mercury is well-documented. All forms of mercury are nephrotoxic, but inorganic forms appear more potent than organic ones,” Dr. Luo said. “Inorganic mercury poisoning following the use of skin-lightening creams commonly manifests with nephrotic syndrome and nephrotoxicity,” stressing “the kidney is the primary target organ for inorganic mercury salts.”

Dr. Luo summarized the renal outcomes of exposure to elemental mercury, inorganic mercury, and organic mercury as follows:
  • Exposure to elemental mercury resulted in dose- and duration-dependent increase in the incidence and severity of renal effects in animals
  • Exposure to inorganic mercury salts like mercury chloride can cause lesions in the proximal tubule in rodents, while consumption of high doses of such mercury compounds can result in severe renal damage in humans. 
  • Exposure to organic mercury is associated with renal dysfunction; however, the kidney is a less sensitive target for methylmercury compared to the neurological system.  Although quantitative data is limited, exposure to organic mercury has shown to cause dose-dependent increases in the incidence and severity of renal effect in animals.
According to the ATSDR, “the kidneys are also sensitive to the effects of mercury, because mercury accumulates in the kidneys and causes higher exposures to these tissues, and thus more damage.”

Aside from kidney damage, the inorganic mercury in skin lightening cosmetics may also lead to skin discoloration, rashes and scarring, reduced skin’s resistance to bacterial and fungal infections, and to anxiety, depression, psychosis and peripheral neuropathy, according to the World Health Organization.

“We thank Dr. Luo for the important information provided on mercury in cosmetics and kidney effects. This will come in handy as we step up our campaign to assist the authorities in ensuring the elimination of mercury-added products," said Aileen Lucero, National Coordinator, EcoWaste Coalition, noting that the Minamata Convention has phased out in 2020 the manufacture, export and import of skin lightening cosmetics with mercury above one part per million (ppm).