Indian traffic policeman Surendar Singh waved away clouds of dust and smoke and unbuttoned his shirt to show a small box bulging out of his chest.
"It literally keeps me alive," said Singh, 48, as he showed the implanted cardiac defibrillator device that detects when his heart rhythm goes dangerously awry and delivers a shock to restore it to normal.
"It's the price you pay for working in this madness," he said, gesturing to a clogged intersection in the northern city of Bhiwadi, found to be the most polluted in the world.