Before you light that Christmas candle…

It’s certainly beginning to look a lot like Christmas here in Manhattan. I can see the lights twinkling in every direction when I look out my office window. But it turns out making it smell like Christmas could be a big problem if you’ve got allergies or asthma…

That’s right, all those candles and air fresheners that people love to have wafting through the air this time of year–the ones that smell like “Apple Cinnamon” or “Holiday Baking”–they contain harmful chemicals that can trigger allergy and asthma symptoms.

“This is a much bigger problem than people realize,” said Stanley Fineman, MD, the president of the American College of Allergy, Asthma and Immunology (ACAAI).

In fact, according to a report presented at the annual scientific meeting of the ACAAI in Boston last month, about 20 percent of the population–and 34 percent of people with asthma–report problems from these air fresheners.

Even small exposures increase risk of asthma in children, studies show. And high concentrations of these chemicals can trigger eye and respiratory tract irritation, headaches, dizziness, and even memory impairment.

Just take a quick glance at the labels–formaldehyde, petroleum distillates, alcohols–these are the ingredients that create those “homey” scents! In fact, one study of plug-in deodorizers pinpointed more than 20 different volatile chemicals–a third of which are classified as toxic or hazardous.

And to make matters worse, even some products labeled “organic” or “green” are still full of toxic chemicals.

Here’s a tip–if you want your house to smell like apples and cinnamon, go the truly natural route: Get out your paring knife, peel up and core some Granny Smiths, sprinkle them with cinnamon, and pop them in the oven for half an hour. Not only will your kitchen smell amazing, but you get something that no air freshener can hold a candle to (sorry, I couldn’t resist): The added perk of a delicious dessert to enjoy.