Young children who regularly ingest spices and ceremonial powders imported from India might be exposed to lead, U.S. doctors warn.

In the April issue of the journal Pediatrics, researchers said four children who had ingested such products were treated for lead poisoning at Children's Hospital in Boston between 2006 and 2008, based on a review of medical charts.

'Clinicians should be aware of these and other imported hazards and inquire about their use during routine health supervision visits.'— Study authors

Children younger than six are particularly vulnerable to lead poisoning, which causes no symptoms until dangerous levels have accumulated but can lead to neurological impairment. In 2009, a U.K. study suggested even low levels of lead in a child's bloodstream can lead to behavioural changes and cognitive impairment.

Three of the cases in Boston were linked to use of powders that are put on the body for religious, ceremonial or cultural reasons after other sources of lead in the home were ruled out. The fourth case involved spices.

Blood lead levels improved in all of the children after they were treated and the parents stopped using the products, the study's lead co-author Dr. Cristiane Gurgel Lin, now a pediatrician at Seton Medical Center in Austin, Texas, and colleagues said.

As part of the study, investigators bought and tested Indian spices and powders from 15 stores in the Boston area.

They found one-quarter of imported spices surveyed contained detectable lead.

On average, imported spices contained double the amount of lead found in U.S. brands. The U.S. Food and Drug Administration has no recommended maximum lead concentration for spices, but the levels were below the European Union's recommended limit for dried herbs of two to three micrograms per gram of product, the researchers said.

"Clinicians should be aware of these and other imported hazards and inquire about their use during routine health supervision visits," the study's authors concluded.

Examples of brands tested were listed but results by brand were not provided in the study.

Call for closer inspection

Half of the powders surveyed contained detectable lead. Some powders that were previously banned or recalled by the U.S. Food and Drug Administration were still for sale, the researchers said.

Of particular concern were the extremely high lead concentrations found in some readily available sindoor powders, the researchers said. Sindoor, also known as kumkum, is a powder applied to a woman's scalp as a sign of marriage. It is sometimes used ritually on children.

Although the powders are not meant for consumption, the study's authors speculated that infants might inadvertently ingest them by way of hand-to-mouth transfer when a parent handles food prepared for the infant.

"Because of the high lead concentrations found in some sindoor samples, import, sale and labelling of these items should be carefully monitored, and low-lead sindoor (less than five micrograms per gram) could be suggested as a safer alternative," the study said. "Closer inspection and testing of other religious products is warranted."

Health Canada and the World Health Organization consider acceptable lead levels in blood to be below 10 micrograms per decilitre. If levels rise above 25 micrograms, doctors will monitor them. At about 40 micrograms, treatment becomes necessary to reduce the lead load in the body.

The U.S. Food and Drug Administration recommends a six microgram per day tolerable limit for dietary intake of lead for children younger than six.

Case studies

The study described a 10-month-old Indian boy who had elevated lead levels of 43 micrograms per decilitre. His mother reported that she had rubbed religious powder on the boy's forehead since he was several weeks old.

Another nine-month-old Indian boy had levels of 21 micrograms per decilitre after his parents routinely applied orange shringar to his forehead.

A three-year-old Indian girl had levels of 18 micrograms per decilitre after regularly ingesting a powder containing 4,800 micrograms of lead per gram of powder. After the family stopped using the powder, her blood lead levels decreased to eight micrograms per decilitre.

One 12-month-old Indian boy in the case study showed lead poisoning after regularly eating imported spices such as turmeric, black mustard seed and asafetida that contained lead. After the family stopped using imported spices, the patient's lead level dropped to 14 micrograms per decilitre within six months.

The market tests showed lead levels as high as 7.6 micrograms per gram of spice in 22 of 86 spices tested. Lead levels were higher in the powders: of the 71 powders tested, 46 contained up to 41 micrograms of lead per gram of powder.

More than 150 products were analyzed, but the researchers noted the samples did not represent all types of Indian manufactured products, and that there may be lot-to-lot variability in lead concentration depending on manufacturing and packaging practices.

Other researchers have reported culture-specific non-paint lead sources, including Mexican tamarind candy, cosmetics such as kohl and henna, ayurvedic traditional medicines and Mexican digestive remedies.