Why we shouldn't switch on the car aircon right away

Got this tip via email.  It’s not advisable to turn on the aircon immediately after boarding the car as the heated plastic smell in the car is carcinogenic - a toxin called Benzene. Prolonged exposure may cause leukemia.  It’s recommended to open the windows first to release the toxin. Acceptable Benzene level indoors is 50 mg per sq. ft.  and a car parked indoors with the windows closed will contain 400-800 mg of Benzene. If parked outdoors (under the sun at a temperature above 60 degrees F), the Benzene level goes up to 2000-4000 mg, 40 times the acceptable level!  With the heat in the Philippines, we must have inhaled a lot of Benzene already!  Tsk...tsk...