Mustard oil is adulterated with argemone seeds which are obtained from Mexicans poppy (a yellow flowered poppy plant, with bluish silver-veined leaves). The seeds closely resemble mustard seeds in appearance, although their surface is rough and uneven. The only difference is that argemone seeds have a little tail at the end.
Argemone seeds have proved to be dangerously toxic in the form of oil and seeds. Regular consumption of this oil gives rise to epidemic dropsy (resembling wet beriberi). Watery fluid is collected in the tissues of the . body causing swelling, it starts with gastro intestinal disturbances, irregular fever with rashes on exposed parts. Swelling of feet and legs follow leading to oedema of thighs, hand and face. As the disease progresses, glaucoma leads to blindness, enlargement of the liver, and even lead to cancer and respiratory diseases. It may even be fatal due to cardiac – arrest.