A small study published in September found that some ceramic plates and bowls bought from South African chain stores are coated in glaze that contains lead, a toxic heavy metal which can damage multiple organs when consumed. This means that they have more than five micrograms of lead per 100ml of blood, the clinical threshold for lead poisoning set by the National Institute for Communicable Diseases.
But why are children in the country exposed to so much lead?
The recent paper on ceramics adds to a growing body of evidence that cookware and crockery also likely play a role.
Toxic pottery
Glaze is a liquid coating applied to ceramic to make it shinier and more durable. Once coated, the ceramic is fired, leaving it with a glossy sheen. Still, if the ceramic isn’t heated at a high enough temperature, the ice won’t completely solidify. In the case of ceramic pottery, this means that lead may run off into food or water prepared in these dishes, mainly if they are used for cooking or simply holding acidic foods.
Research in that country finds that children have more lead in their blood if they live in households where food is prepared in lead-glazed pottery. Recently, health inspectors in the US linked cases of lead poisoning to the use of ceramic cookware bought in Mexico. After the affected individuals stopped using the ceramics, their blood-lead levels decreased. To test whether lead is leaching off the South African ceramics, the SAMRC researchers left an acidic solution in the plates and bowls.
Only one was made initially in South Africa, and this item released lead. Additionally, even if lead-based ceramics don’t leach, producing these items may still cause harm. For instance, a study in Brazil found that children who lived near artisanal pottery workshops were more likely to have high amounts of lead in their blood. Caregivers of these children did not report having any lead-glazed ceramics or being involved in pottery making.
Thus, researchers suspect that children were simply breathing in lead dust generated by the nearby potters.
Lead leaching from cooking pots
Although this is the first time lead has been found in ceramic glazes in South Africa, other kinds of kitchenware products have previously been shown to contain information. In 2020, researchers published a study in which they purchased 20 cooking pots from informal traders and artisanal manufacturers across South Africa. Each pot was made from recycled aluminium. The researchers cut the banks up and boiled a piece from each one in an acidic solution.
The issue may extend past individual households, as the SAMRC has documented the use of artisanal aluminium pots in school feeding programs. Not only can lead-based artisanal pots cause lead poisoning by leaching into food, but researchers note that simply manufacturing them likely generates lead dust, as demonstrated in a small follow-up study on informal metal workshops in Kwazulu-Natal and Limpopo, which found that workers had a lot more lead dust on their hands by the end of the work day than at the start.
Are regulations on lead being ignored?
South Africa has already taken legislative steps to deal with lead coatings. These will only become enforceable once the finalised regulations are gazetted. A study last year found that paints produced by large companies being sold in Botswana but manufactured in South Africa were all below the lead threshold set by the 2009 law. However, the research on ceramics suggests the regulations have not always been adhered to, at least regarding glazes.
The only South African-made piece of crockery tested in the study described earlier had a coating that contained over 100 times the amount of lead legally permissible under the 2009 law. If additional research finds that the problem is widespread, Mexico’s experience may offer one path forward. NGOs in parts of the country have responded by assisting artisanal potters to switch to lead-free glazes and to develop higher-temperature kilns. This has been coupled with public awareness campaigns about the harms of lead-based pottery and a certification program for potters using lead-free coatings.
The South African Paint Manufacturing Association has previously urged the government to do more to enforce its regulations. The National Department of Health didn’t respond to a comment request at the time of publication.
Data and investment needed
In the United States, all children enrolled in Medicaid receive blood-lead tests at ages one and two. Overall, the CDC gets about four million lead test results nationwide each year. In addition, experts are increasingly calling for more outstanding international health financing for the prevention of lead poisoning in low- and middle-income countries. Last month, a group of experts, including researchers from Stanford and officials from UNICEF, released a joint statement on lead poisoning in developing nations.
It argues that despite the extraordinary health, learning, and economic toll attributable to lead, we find the global lead poisoning crisis remains almost absent from the global health, education, and development agendas. The statement argues that $350 million in international aid over the next seven years would significantly dent the problem. They provide a breakdown of these funds, which include international assistance with enforcing anti-lead laws, purchasing lead-testing equipment and assisting companies with moving away from lead-based sources.
This article is republished from the Spotlight special series on lead poisoning. You can read part one here.
