Related;

https://news.ycombinator.com/item?id=36481693 -- Turmeric’s unexpected link to lead poisoning in Bangladesh (9 months ago)

https://news.ycombinator.com/item?id=38139011 -- How to stop adulterated turmeric from killing people (5 months ago)

https://news.ycombinator.com/item?id=29375003 -- Herbs and Spices Might Contain Arsenic, Cadmium, and Lead (2021)

Is there any particular reason spices would be more of a concern than produce that are consumed fresh and in much higher quantities?

I assume it's a lot easier to misrepresent a dried and pulverized product than a whole food product. A whole bunch of information about anatomical structure, texture, moisture content, color, etc. is lost when turning a fresh herb into a jar of powder.

Seeds accumulate heavy metals. Many spices are made from seeds. But there is also heavy metals in sunflower seeds, pumpkin seeds, etc.

The grinding apparatus often contaminates the product. Lead gears were used to increase reliability by the British and these spice fields still use machinery they left behind because it saves transport costs to compact on site.

Yes, some spices like cinnamon were cut with chemicals which look like cinnamon.

https://www.fda.gov/food/alerts-advisories-safety-informatio...

Adulteration is one reason. Accidental contamination another.

But also some plants tend to accumulate certain compounds. Possibly to 100...1000x the levels from the soil it grows in. Eg. rice is known to accumulate arsenic occuring in soils naturally. And some soils just happen to be rich in, or polluted with <insert undesired substance here>.

Farmers may not even know. Or care...

Fresh product has a lot of pure water and is less prone to be adulterated with dyes that can be toxic at middle or long-term.

Is also normally unfalsifiable and cheaper, so there is less incentives into manipulating it.

Easier to adulterate. Classic example is lead chromate in Turmeric, but perhaps Chrome Orange in saffron is possible too.

Exactly. Metal salts add bright color and also weight.

> spices would be more of a concern than produce

It looks like they were looking at ground spices?

Are there brands which are certified as free of these contaminants (and have proof)?

(2021)