The Vice of Spice: Confronting Lead-Tainted Turmeric (Wudan Yan)
By Aaron Gertler 🔸 @ 2023-09-03T19:11 (+26)
This is a linkpost to https://undark.org/2023/07/19/the-vice-of-spice-confronting-lead-tainted-turmeric/
I'm a sucker for any article that shows the public health world springing into action. This is grade-A stuff, covering every step of the process, and I wish I could see it as a Hollywood, Bollywood, or Dhallywood thriller. (Are you busy, R. Balki?)
Excerpts
For most of his turmeric trading career, Sheikh engaged in an open secret: While processing raw turmeric to powder, he added a chemical called lead chromate to get the tubers to glow yellow. Sheikh and the locals refer to the compound as peuri — and nearly all the farmers and traders at the market are familiar with it. Lead chromate is a chemical used in paints to, for instance, make school buses yellow, and it can enhance the radiance of turmeric roots, making them more attractive to buyers.
For decades, Sheikh didn’t know the exact harm that peuri could cause. That changed in the fall of 2019, when researchers from the nonprofit International Center for Diarrheal Disease Research, Bangladesh, or ICDDR,B, traveled to Ataikula and adjacent districts in the northwest to meet with Sheikh and others in the turmeric business. The researchers warned them that consuming lead chromate could lead to kidney and brain damage or cause developmental delays in children. By that point, the spice had made its way out of the country: The problem had already gone global.
Eskandar Molla, a farmer from northwest Bangladesh, has been growing turmeric for over 50 years. He sells his fresh turmeric fingers at nearby Hazir Hat, an open air market. There, he gets paid a market rate for what he sells: In March of this year, it was around 1,400 taka (about $13 USD) for a 88-pound satchel. Middlemen, who have the facilities to boil and dry the root, buy it from him and other farmers.
Getting the moisture out is critical for the root to be pulsed into powder. Traders lay out a single layer of turmeric fingers in vast, sunny, open fields for a month. Workers manually go through and inspect for roots that are either too long, too fat, or too skinny.
Once dried, the turmeric fingers are polished. Here, they are dumped into large “drums,” which are turned by hand or motorized. This continual physical agitation removes the outer skin of the turmeric to reveal the true color of the root. It’s in this step that lead chromate would be used to enhance color.
For years, the only food in which the FDA had established a maximum level of lead was candy: 0.1 parts per million for small children. It took the agency about 16 years to announce another update, outlining guidelines for other foods commonly consumed by babies and young children. Fruits, the agency said, should not exceed 10 parts per billion in lead, and root vegetables and dried cereals should not exceed 20 parts per billion. This guideline did not discuss spices, and no maximum limits for lead are noted for adults.
Many of the lead levels detected in turmeric have ranged from 28 to 146 parts per million, magnitudes more than the FDA’s established acceptable levels for other foods. (The FDA said in a statement that even though it monitors levels of lead in food, and knows about the turmeric recalls owing to high lead levels, it has not yet set a limit for lead in spices.)
Tom Tarantelli, the New York Department of Agriculture and Market’s former senior food chemist, has estimated that children in families that use turmeric regularly could be consuming 3 to 4 grams a day of that spice alone, suggesting that these kids are consuming far more spice than, say, candy.
The first half-hour of the movie:
In a rural part of the country, pregnant women and children had high levels of lead in their blood. There were none of the usual suspects of lead exposure. There were no nearby battery recycling plants and families didn’t paint their homes. How could this be?
Forsyth and her Bangladeshi colleagues had a slew of hypotheses. Maybe the lead was coming from jewelry or food storage containers. Or perhaps it came from clay, soil, or ash that the mothers were exposed to during pregnancy. Rice was another possibility, as the staple crop could have absorbed lead from the soil. Forsyth and her colleagues sampled and tested all of these. She vividly remembers the first summer of her Ph.D., as she baked and ground rice into a pulp to test for lead in a sweltering laboratory in rural Bangladesh. But there was no obvious red flag.
The climactic action sequence into a feel-good ending (hopefully we avoid any sequels):
Authorities also raided Shyambazar using a machine called an X-ray fluorescence analyzer which can quickly detect lead in spices. Nearly 2,000 pounds of turmeric was seized in the raid and two wholesalers were fined 800,000 taka, more than $9,000 USD.
A few months later, the team went back again to collect samples to see how their intervention had fared. Only about 5 percent of 157 samples were found to be adulterated with lead chromate, down from nearly 50 percent before. When the researchers conducted a sampling spree again in 2021, they found that the use of lead chromate had practically disappeared.
[...]
The crackdown on turmeric in 2019 may, in part, explain why the use of lead chromate in polishing turmeric has since decreased. It was a punishable crime, and although there was only one raid, people now know there’s a risk of getting caught.
[...]
But government officials and researchers say that enforcement and surveillance must be maintained. “A one-time conviction is not sufficient,” wrote Jahan, who has since moved on from the Bangladesh Food Safety Authority. Follow-up is required as she has “seen such criminals go back to doing what they did even after facing consequences.”
Monzur Morshed Ahmed, a member of BFSA, says that the agency is in the process of procuring handheld X-ray fluorescence analyzers to distribute to districts around Bangladesh so local authorities can continue monitoring the use of lead chromate themselves.