Lead pigment in turmeric is the culprit in a global poisoning mystery (2024)

I immediately tested the 5 year old Sadaf tumeric in my kitchen cabinet using a 3M lead testing kit I happened to have in my house. Thankfully it came out negative!

That doesn't sound technically plausible to me—there aren't any inexpensive tests. Do you mean something like this 3M product[0], that's intended for paint not food, and is documented as "LeadCheck™ Swabs reliabily detect lead in paints at 0.5% (5,000 ppm). 3M™ LeadCheck™ Swabs may indicate lead in some paint films as low as 0.06% (600ppm)."? If so, those aren't remotely suited for this purpose—those detection lower-bounds represent astronomically high amounts of lead, for a food item.

The highest end of Pb contamination in turmeric in Bangladesh (as in OP) is, from a cursory search, maybe 483 ppm [1]. Regulatory limits in the US are in the low parts-per-billion [2]. This metal bioaccumulates over a lifetime.

[0] (.pdf) https://multimedia.3m.com/mws/media/1581338O/3m-leadcheck-in...

[1] https://pubmed.ncbi.nlm.nih.gov/25214856/ ("Contaminated turmeric is a potential source of lead exposure for children in rural Bangladesh" / "Results: Lead concentrations in many turmeric samples were elevated, with lead concentrations as high as 483 ppm")

[2] https://www.consumerreports.org/babies-kids/baby-food/fda-pr...

Those 3M lead testing kits are designed to detect lead at concentrations on the order of, I don't know, what, like, a million times the limits set in food safety standards?

https://www.epa.gov/sites/default/files/documents/3M-leadche...

There is a much easier and reliable way to test it -> https://eatrightindia.gov.in/dart/#:~:text=Test%2014%20%3A%2...

Thanks for this heads up. This will be useful information for other people with the same idea I had.

I don't see any method for lead chromate in turmeric powder, unless I'm missing something.

Yes indeed. Here's also an instruction video for it:

https://www.youtube.com/watch?v=tXWPf0HQd5U

It's used for coloring, because it makes it apparently gives it the same color as good real tumeric

OK, so the method given for artificial coloring on that page. I'm curious if that works for lead chromate. It seems so simple that it must have been tried in this case? Regardless I'll file it away to at least try on stuff to avoid what colors it can detect.

It's the one below the one ashwinsundar linked, "detection of artificial colour in turmeric powder".

The test is: when you add the powdered turmeric to water, natural turmeric will give the water a "light" yellow color, while adulterated turmeric will give it a "strong" yellow color.

This is not a test that I'd characterize as "easy" or "reliable".

> Lead Chromate apparently has an extremely low solubility in water, so how does this work?

A lab such as https://aihlabs.com/ may be able to test food