First, the air fresheners don't actually freshen, they just mask. With so many of our homes sealed up for climate control, we often don't have the old-fashioned option of opening our windows to bring in good clean air. Just because it smells good doesn't mean it's really fresh. If you have a problem with odors, the first thing you need to do is look to see if you can eliminate the source.
The other problem is that these products are made of dangerous chemicals. The EPA website points out that these products are generally made of four ingredients: four basic ingredients in air fresheners: formaldehyde, petroleum distillates, p-dichlorobenzene, and aerosol propellants. I don't know about you, but these really don't seem like things we should be dispersing into our air and inhaling.
If you're not able to open your windows to freshen your residence, try some more natural options. Put some essential oils (such as lemon or lavender) into a bottle with some water and spray it around your house. Try one of the reed-type diffusers (such as the one pictured) and use with some natural essential oil product made for diffusers. Burn a naturally-scented beeswax or soy candle. Or simmer some natural ingredients, such as rosemary, cinnamon sticks, or citrus, in a small pot of water on the stove. (Beware: Never leave candles or simmering pots unattended.) All of these options are natural, great smelling, and chemical-free.
Have a healthy week!