Your house can make you sick

(Money Magazine) -- You're sniffling and wheezing your way through another winter. A run of bad luck with germs? Sure, but it also may be the result of something more insidious: toxins.

Chemicals found in common home furnishings can cause asthma and flu-like symptoms, and your basement or bathroom may be harboring allergy-inducing mold. You could even be experiencing a reaction to a more dangerous substance that could cause kidney damage or cancer.

The problem of home toxins has increased in recent years, says Linda Kincaid, an industrial hygienist in San Jose. It's a nasty byproduct of the well-meaning drive to become more energy-efficient. "We used to live in houses that were not well insulated and allowed a lot of air to come in," says Kincaid. Now that homes are tightly sealed to prevent airflow from outside, chemicals can become more concentrated in your indoor space. That risk goes up in the winter, when your doors and windows generally remain shut.

Banishing toxins from your home isn't an exciting improvement, but it's a crucial one, since many states counsel home buyers to do environmental checks before closing on a home. Below you'll find five of the most dangerous and common toxins to watch for, along with the most wallet-friendly ways to nip them in the bud.

TOXIN RADON DANGER LEVEL: HIGH [4]

It's the second-leading cause of lung cancer behind smoking.

Who's at risk: Everyone. It's an odorless, colorless gas that comes from the soil and can leak into your home. It's been found in every type of house and in every state.

What to do: Radon test kits are available at most hardware stores for $10 to $20. Place one in your basement and leave it for two days. If the level of radon in your home is high, you'll need to spend about $1,200 to have a contractor who's an expert in radon removal put in a venting system, which will direct the gas away from the house. Unfortunately, your homeowners insurance probably won't cover the cost.

If you have recently installed granite countertops, you'll need to buy a second test kit for your kitchen too, since some granite that includes uranium can emit radon gas. It's not likely that your countertop will cause a high radon reading (it affects only about 5% to 10% of granite on the market), but if yours is affected, you'll have to either revamp your kitchen ventilation or replace your granite counter.

TOXIN ARSENIC DANGER LEVEL: HIGH [4]

The poison has been linked to various kinds of cancer and a range of unpleasant side effects, from nausea to blindness.

Who's at risk: Anyone who has a wooden deck, porch, fence, tree house or outdoor play furniture built before 2005. Arsenic is a preservative, and until four years ago, wood was treated with it to prevent rotting. The chemical can leach into surrounding soil (affecting plants growing in the ground nearby), and it's possible to touch arsenic-treated wood and come away with it on your hands. Young children are especially vulnerable, since they tend to put their fingers in their mouths.

What to do: No need to pony up for a new deck; just treat the wood every year with an oil-based stain so that when you touch the wood, you're touching the sealant, not the arsenic. It's best to do it in the spring, says Gary Ginsberg, Ph.D., author of "What's Toxic, What's Not," so your deck will be ready for the summer, when it's going to be used the most. You can find various weatherproofing stains for about $25 a gallon.

TOXIN LEAD DANGER LEVEL: MODERATE [3]

Lead can damage the central nervous system, kidneys and blood cells; even low levels in the blood can impair mental and physical development.

Who's at risk: Those living in homes that date back to the '70s.

What to do: Don't use home test kits for lead -- they aren't reliable. Instead, get recommendations for private labs from your state housing department. The test will cost you about $20 to $30; if it comes back positive, cover your walls with a coat of encapsulant (about $40 a gallon).

Unfortunately, the biggest problem probably isn't the paint on your walls -- it's the paint on your windowsills. "The window grinds it down to a fine powder and the breeze can blow it in," Ginsberg says. "It can contaminate the whole room." Your best bet is to replace the windows, including the woodwork and tracks. If there's a toddler in the house, consider replacing moldings and baseboards as well, since kids can chip off paint by chewing on it.

TOXIN FORMALDEHYDE DANGER LEVEL: MODERATE [3]

Formaldehyde and other volatile organic compounds (VOCs) can cause nausea, dizziness and allergy symptoms. Chronic exposure can damage your liver and central nervous system.

Who's at risk: Anyone who has recently added new floors, carpets or furniture; moved into a new home; or used common brands of paints or aerosol sprays. The adhesive used in carpeting and to hold together pressed-wood products contains formaldehyde, which releases that and other chemicals into the air. (That "new carpet" smell may be your Berber emitting chemicals.) Many paints, sealants and lacquers also release compounds.

What to do: If you've been in your home for a few years, relax. "The building has had a chance to outgas," says John Banta, an industrial hygienist and co-author of "Prescriptions for a Healthy House."

If you're refurbishing, one option is to opt for VOC-free building materials, but you'll pay a steep price: Formaldehyde-free bamboo flooring from EcoTimber, for instance, costs $5.79 to $6.49 a square foot, compared with $3.87 to $4.57 a square foot for bamboo wood flooring from Home Depot.

Can't afford to go totally VOC-free? Splurge on the bedroom; it's generally where you spend the majority of your indoor time, so you'll reap more benefit from the change. Alternatively, simply renovate and buy new furniture during warmer months, when you can leave your windows open. When you order a new carpet, ask the factory to let it air out for a couple of weeks in the warehouse before delivering it. Almost all VOC chemicals will dissipate into the air over time.

TOXIN MOLD DANGER LEVEL: LOW [2]

Mold doesn't present a severe health risk, but it may worsen asthma. If you're allergic to mold, it can also cause nasal congestion, irritated eyes or wheezing.

Who's at risk: If you've had a water problem, such as a roof or plumbing leak, and the area was wet for more than 48 hours.

What to do: Toxic black mold has gotten a lot of press in recent years, but regular mold spores "are everywhere," Ginsberg says, and the Centers for Disease Control and Prevention says they rarely cause adverse health conditions.

That said, if mold is unsightly or causing your sinuses to act up, you'll probably want to get rid of it. If it's a small area (less than three feet by three feet), remove it yourself with detergent and water. If it's a larger section, you'll want to bring in a professional to prevent spreading mold spores around your house.

Expect to pay $150 to $200 for a mold inspection and $500 and up for removal, depending on how widespread the problem is. Your homeowners insurance may cover it, but be warned: After insurers were slapped with lawsuits over black mold a few years back, they began excluding mold coverage and socking homeowners who reported water damage with higher premiums and deductibles.

Regardless, it's certainly worth spending $150 or so for a dehumidifier in your basement to draw extra water out of the air. Sometimes an ounce of prevention is the healthiest possible fix.