The cheap aluminium cookware seen in African cities and villages from Cape Town to Cairo are a threat to the health and lives of millions of people.
The locally-made cookware, ubiquitous throughout Africa and Asia, is manufactured from recycled scrap metal, including auto and computer parts, cans and other industrial debris.
Researchers say the cookware poses a serious, and previously unrecognized, health risk through the leaching of significant levels of lead, aluminium, arsenic and cadmium. Globally, lead alone accounts for more than 853 000 deaths a year.
The researchers at Ashland University, Ohio, and Occupational Knowledge International, in San Francisco, collected 42 locally manufactured and sold cookware samples from 10 countries, including Ivory Coast, Kenya and Tanzania.
ARSENIC, LEAD AND CADMIUM LEACH OUT DURING COOKING
They simulated cooking by boiling acidic solutions in the cookware for two hours and measuring the lead extracted in solution. The research showed 23 pots yielded detectable levels of arsenic and 36 had detectable lead levels.
The simulated cooking process leached up to 1 426 micrograms of lead per 250 ml serving. Aluminium levels were, on average, six times greater than WHO dietary guidelines.
Significant concentrations of cadmium leached from 31% of the cookware tested.
Cadmium is a carcinogen, neurotoxic in children, damaging to kidneys and associated with cardiovascular deaths. Lead exposure in children is linked to brain damage, mental retardation, lower educational performance, and a range of other negative health effects.
The tests were conducted on intact, new cookware items. Corrosion of damaged or older cookware may show different patterns.
The study showed no consistent differences in metal release from branded [pots] compared to unbranded pots.
REDUCED IQ AND POOR PERFORMANCE IN SCHOOL
“Our results indicate that cookware from every country tested yielded hazardous exposures to one or more metals,” say the researchers.
The WHO and the U.S. Centres for Disease Control and Prevention (CDC) have determined that there is no safe level of exposure to lead. A scientific advisory board to the CDC has recommended lowering the blood lead action level for children to 3.5 micrograms per deciliter (μg/dL), underlining the hazard of even low level lead exposures.
“Lead exposure from inexpensive aluminium cookware has the potential to be of much greater public health significance than lead paint or other well-known harmful sources that are common around the world,” says Perry Gottesfeld, executive director of Occupational Knowledge International.
Recent surveys of lead exposure in Africa and Asia have suggested that blood lead levels have remained stubbornly elevated despite the ban on lead in petrol in most of the world. “The presence of lead in food cooked in these pots may be one contributing factor to the ongoing lead poisoning epidemic,” Gottesfeld says.
Study author Jeffrey Weidenhamer, professor of chemistry at Ashland University, says lead and cadmium exposure from regular use of these pots will significantly reduce IQ and school performance in children, and contribute to millions of deaths due to cardiovascular disease.
Other studies have documented the presence of lead in similar concentrations in cookware from other countries.
“On this basis, we suggested that our results might indicate a much larger global problem with inexpensive, non-anodised aluminium cookware as a previously unrecognised source of lead poisoning,” the researchers say in their report in the journal Science of the Total Environment.
SOLVE THE PROBLEM BY COATING THE POTS
One way to minimise harmful metal exposures from the use of inexpensive aluminium cookware would be to regulate or screen the source materials used in production. But efforts to prohibit the use of scrap metal for this purpose would be difﬁcult to enforce, and could result in smaller manufacturers shifting their operations to more clandestine locations.
“Our results suggest that corrosion-resistant coatings may be effective in reducing metal leaching from this type of cookware,” the study says.
“There are a number of possible alternative coatings that require additional investigation including ﬂuoropolymer materials as well as anodisation and enamel coatings.”
The report says improving the corrosion resistance of this cookware with a post-production coating treatment appears to be a more feasible option than regulating or screening material inputs used by small producers.
“Research is urgently needed to identify safe and effective corrosion- resistant coatings that could improve the safety of this cookware,” the study says.
“The present study … suggests that exposure to metals including lead through corrosion of such cookware is a major public health problem.”