Holidays equals candles for lots of folks, but it turns out that your average candle is not as green as it could be.
Most candles are made from paraffin wax, paraffin is a by-product of crude oil. Crude oil...well you know the story. Even worse, the soot from paraffin wax is apparently no good for your lungs and can cause respiratory damage. There is also lead in the wicks of some candles! Apparently the best way to tell is to part the threads o the wick, and rub the metal core against paper, it it leaves a mark then it's lead. Which is just not cool.
Better to switch to unscented vegetable wax, beeswax or soy-wax candles. They burn cleaner and more evenly that paraffin candles, putting way less soot into the air.
I'm a big fan of 100% beeswax candles, the smell reminds me of Paris (the city not the Hilton). The Beeswax Candle Company has a huge range, starting from $1 each for their tealights.