Hazy recollections ahead. Lead, arsenic and mercury are explicit ingredients in ashes (bhasmam) form. Their claimed material properties are they are non toxic and reach the sick tissues faster than anything else. Concerns about heavy metal poisoning are raised in India when the west reports them about exported medicines. The modern medicine body IMA also complains. But even recently we got an arsenic based homeo medicine for covid.

I disagree adulterated turmeric being the lead source.