Infant lead poisoning traced to imported cosmetic
MedWire News: Imported cosmetics used by some ethnic groups to promote visual development and ward off evil in infants and young children can cause lead poisoning, health experts warn.
A 6-month old boy of Nigerian descent was found on a well-child visit to Boston Children's Hospital to have blood lead levels of 13 µg/dL, more than double the current reference value of 5 µg/dL as established by the Centers for Disease Control and Prevention (CDC).
After ruling out food and environmental sources of lead exposure, investigators from the hospital and the CDC's National Center for Environmental Health (NCEH) traced the source of the poisoning to a Nigerian cosmetic that had been applied to the child's eyelids three or four times each week since the age of 2 weeks. The product, known as "tiro" in the Yoruba language of Nigeria, was found to be composed of 82.6% lead.
"A single application of 10 mg of tiro would deliver 8 mg of lead to the infant's eyelids. The most likely routes of exposure were eyelid-hand-mouth and absorption from the conjunctival surfaces of the eyes or in ingested tears," write Behrooz Behbod (NCEH, Atlanta, Georgia) and colleagues in Morbidity and Mortality Weekly Report (MMWR).
"Analysis of the tiro by the US Geological Survey, using scanning electron microscopy (SEM), showed that the sample was dominated by lead sulfide, known as galena, which has relatively low bioavailability. No other minerals were observed by SEM, although small amounts of other minerals commonly found as microscopic inclusions in lead sulfide might have escaped detection," Behbod et al write.
Despite the high lead levels, the child appeared to be growing well, and had met all developmental milestones. At a visit 3 months after the parents stopped painting the boy's eyelids with the toxic compound, his blood lead level had decreased to 8 µg/dL.
An accompanying MMWR Editorial Note explains that the cosmetic, variously called tiro, tozali, or kwalli, is a Nigerian folk remedy traditionally applied to the eyelids of infants to promote visual development, enhance attractiveness, and ward off "the evil eye." It is also used to treat eye pain or soreness, prevent sun glare, and to prevent infection of circumcision sites or umbilical stumps.
"This case identifies tiro as a potential lead exposure among not only Nigerians living in the United States, but also among African, Asian, and Middle Eastern populations who use similar products. Public health educational campaigns can help identify and prevent further cases," the Note states.
By Neil Osterweil, MedWire Reporter