Fossil fuel combustion is the largest source of air pollution by Vanadium. You may recall that coal and oil are among the richest sources of Vanadium. You said Ramashanker was suffering from Vanadium toxicity and you said that this occurred because he was working as a boiler cleaner. Tarun, industries where exposure to Vanadium may occur are Vanadium pentoxide production, Vanadium metal production, and production of Vanadium catalyzers. But as I said earlier, the most dangerous profession still is probably boiler cleaning.
Skin is a minor route of absorption in man.
Absorbed Vanadium accumulates in mainly in bone, and to some extent in the liver, muscle and kidney. The whole Vanadium content of a normal human weighing about 70 kg has been estimated to be between 17 and 43 mg. You said that Ramashanker is suffering from Vanadium toxicity. Yet there is an interesting test by which I can prove my theory. In Vanadium toxicity, the cystine content of fingernails is supposed to decrease.