I had a similar problem/situation at both the Marriott World Center and Las Vegas' Venetian. It was handled in two totally different ways. In both hotels, the person staying in the room next to me was smoking and it (the smoke/fumes) came over to my room. At the Venetian, I called and they said there was absolutely nothing they could do. and that was that. Even though it was a non-smoking floor, "people are going to do what they want." My clothes, and belongings, smelled like cigarette smoke all week. At the Marriott, I called and they understood and were concerned. She immediately offered several suggestions. (Perhaps it's coming through an open balcony door? Would you like air freshener? etc.) When I told her it was concentrated in the tub/toilet room, so the neighbor must be smoking in the bathroom, she said, "I'll call security immediately." One to two hours later, the smell was completely gone!
I also wanted to point out that the convention food here is unbelievable!!! The restaurant food was average, but the buffets they put out for large groups in the convention halls were phenomenal! I was so impressed I asked for the recipes for two of the side dishes and the chef gave them to me! I particularly enjoyed the pesto tortilloni and the scalloped sweet potatoes ! Amazing!