A WHO (World Health Organization) reports says diesel fumes are more carcenogenic than secondhand cigarette smoke. It says diesel exhaust may be a possible cause of bladder cancer.

Diesel exhaust is now in W.H.O.’s Group 1 carcinogen group: Along with smoking, asbestos, ultraviolet radiation, alcohol and other elements that pose cancer risks.

So, how afraid should we be? In their defense, auto makers say that the studies were done on older diesel engines and that 'modern diesel engines used in wealthy countries burn low sulfur fuel, thus emitting 98 percent less particulates than old ones did and 99 percent less nitrogen oxide, which adds to ozone buildup. How about diesel engines in Indian cars?