Tomatoes are self pollinating, don't depend on honeybees, just breezes (or shake the plant a little)
It is nitrogen, not oxygen they were mentioning as possibly causing the problems. As noted if you use too much high nitrogen fertilizer, you will get big leafy plants with few flowers. If that is the problem, quit fertilizing, flush the soil well with lots of water, and add some bone meal.
If you have lots of flowers, that is probably not the problem. Look at the sticky at the top of this section on blossom drop. If you hare having plenty of the little yellow flowers, but they drop off without setting fruit, that is blossom drop, which is a stress reaction. If the plant is stressed, it drops the blossoms to concentrate on survival. Then you have to figure out what is stressing it.