Driving a work vehicle with exhaust leak?

I am worried Im being exposed to the exhaust. The small van that I drive for work had the muffler stolen and the mechanic told my boss that a straight pipe would work. Since I got the van a couple months ago I've been smelling exhaust. Everyday all day. The person that had the van before me never said anythibg about it. When I asked her, she said she used air freshner to get rid of the smell. I told my boss and they said they're working on it, but in meantime, I am worried I'm being exposed to exhaust everyday. I often feel very "dried out" after work and foggy, Which I could sum up to just a hard day at work. But now since after work yesterday the side of my eyeball has been red and feels dry/itchy. I know these are all symptoms of co2 exposure, but I don't know if I'm being extra. Is it possible to be poisoned by the exhaust inside the cabin? Thank you for any advice!