Hundreds of cars drove over a combination of used syringes, gauze and other dry medical waste on Green Valley road yesterday, before emergency responders arrived and clean the hazardous mess. A driver for the Pomona based company “Wastestream” was unaware that his rear doors had opened, and some contents spilled out. Both southbound lanes and one northbound lane of Green Valley road had to be closed for two hours while crews cleared the road of the bio-medical waste. The company responsible for transporting the waste will pay for the clean-up. The spill has been ruled an accident.