India’s notorious traffic pollution is no longer an urban malaise, its impact is now being felt 4,000 metres above sea level, in the Himalayas. Geologists have found high levels of sulphur from diesel emissions along the Manali-Leh highway that snakes through the northwestern Himalayas. Soil samples from four sites along the 480 km highway were tested for 10 heavy metals and sulphur among other chemicals. While the good news is that heavy metal contamination was found to be low, the soil had significantly high levels of sulphur (490–2033 ppm), which the scientists attribute to diesel exhaust from heavy traffic on this mountainous road. Indian diesel contains some of the highest concentrations of sulphur in the world and an estimated 70% of automobiles running on Indian roads use diesel,
— source thehindu.com