Hyderabad produces around 4,500 tonnes of solid waste daily, which is transported from collection units in Imlibun, Yousufguda and Lower Tank Bund to the dumpsite in Jawaharnagar. Disposal is managed by the Integrated Solid Waste Management project which was started by the GHMC in 2010. Rapid urbanisation and increased economic activity has also led to increased industrial waste, air, noise and water pollution, which is regulated by the Telangana Pollution Control Board (TPCB). The contribution of different sources to air pollution in 2006 was: 20–50% from vehicles, 40–70% from a combination of vehicle discharge and road dust, 10–30% from industrial discharges and 3–10% from the burning of household rubbish. Deaths resulting from atmospheric particulate matter are estimated at 1,700–3,000 each year. Ground water around Hyderabad, which has a hardness of up to 1000 ppm, around three times higher than is desirable, is the main source of drinking water but the increasing population and consequent increase in demand has led to a decline in not only ground water but also river and lake levels. This shortage is further exacerbated by inadequately treated effluent discharged from industrial treatment plants polluting the water sources of the city.
Try to answer this question if possible (otherwise reply "unanswerable"): What percentage of the air pollution in Hyderabad comes solely from vehicles?
20–50%