Ok need some legal advice here and NO you can not chare me

. Anywayz I work at a local grocery store and they have all these sexist rules. Let me list them
1. Girls can not do carts (bring them in)
2. Girls DO not have to tuck there shirts in
3. Guys can't do tags (price tags)
4. Guys can't do trash (only girls can)
Ok not lets get into the meat of this. There are many more girls then guys there. So even when girls WANT to do carts they will not let them and force me too. Now this would not bother me if I did not have ashma (sp?) and Photosensitivity. I mean I go out there and its horriable I itch like crazy and can harld breath. So I tell them and they say "well you the only one who can do it". Now mind you there is someone else who has a slight heart condition but they don't even let him do it. Just the other day I passed out cause they would not let me take a break and I could not breath. As soon as I woke up they put me back out. I was sick the rest of the day. Is this legel? its just seems that there are better ways to handle this.