Defogger problems of the 2000 Toyota 4Runner

Vetilation system is emitting some type of odor which gives the passanger in the front seat a headache and causes dizziness. Dealer has said that it is from a chemical reaction in the plastic in combination with the haet and the chemicals used air conditioner. The dealer says that the vents should be sprayed with some type of freshener they use on a weekly basis to eliminate the odors. I believe this problem could cause serious health problems and the manufacturer should be contacting us so they can change the material used in the vents to eliminate this problem all together.