When turning on the engine in the car without turning on the A/C we put our and the passenger’s health in danger. This happens when the car is left outside and the windows are closed it can accumulate 2000-4000 mg of benzene which is 40 times more than the permitted level. When people sit in the car with closed windows, they inhale benzene without being aware of the toxin affecting the kidneys, the liver and the bone tissue. It also takes a lot of time and effort for the organism to eliminate it. The windows should be open before turning on the A/C.
This is the medical explanation: Before it starts to cool the air, the air conditioner ejects all the heated air out along with benzene (a toxic which causes cancer), so when you sit in the car open the windows for couple of minutes even if you don’t notice any smell of a heated plastic and then turn on the A/C. Also, when you turn on the car, leave the windows open for couple of more minutes.