It’s much better to keep mold at bay in the first place by finding and fixing leaks and minimizing dampness. Often the problem is “a leaky roof or window, or a broken pipe,” Damon said. “But it can also be high humidity — use a dehumidifier to bring down that humidity level. And it’s important that you ventilate the more humid parts of your house, like the bathroom, laundry and cooking areas.” Flip on exhaust fans while showering, cooking or running the dishwasher, and make sure your clothes dryer vents outside.
This one’s the killer. Carbon monoxide, an odorless gas produced by burning fuel (including gasoline, wood and propane), can build up in your bloodstream, choking out oxygen in red blood cells. The gas sends more than 20,000 Americans to the E.R. every year. First, it causes nausea, dizziness and confusion, then without a quick infusion of fresh air, carbon monoxide will make you lose consciousness or worse. It can be fatal in just a few minutes with higher concentrations, and a few hours with lower ones.
Risks increase in the winter in colder climates. The biggest culprits are malfunctioning heating systems, such as furnaces, gas water heaters and gas dryers, Damon said. “You should have someone check your heating system — anything that burns gas, oil or coal — every year,” he advised. And don’t warm up your car inside an attached garage, even with the garage door open.
It’s important that you have at least one carbon monoxide detector installed near your bedroom, so it’ll wake you up if the gas builds up in your sleep. Check and replace the batteries at least twice a year. Do it now, while you’re thinking about it.
Volatile organic compounds (V.O.C.s)
A slew of different chemicals fall into the catchall term V.O.C.s (including formaldehyde and benzene), and because they’re found in thousands of different products, from paint to carpeting to furniture to glue, it’s likely that some are off-gassing into your home’s air right now. Short-term, inhaling high levels of them can cause eye and throat irritation, nausea, headaches and dizziness; long-term, it’s linked to cancer and damage to the nervous system, liver and kidneys.
One of the biggest sources of formaldehyde in particular is new building materials, said Dr. Arthur Chang, chief medical officer for the C.D.C.’s division of environmental health science and practice. New particleboard, plywood, adhesives, paints, varnishes and carpeting are all common offenders. If you’re not living in a brand-new house, you can still be exposed by painting or renovation projects, new furniture, and some household cleaners, disinfectants and cosmetics, among other things.
One of the best defenses is to keep levels low in the first place by looking for “low- or no-V.O.C.” or “low formaldehyde” labels when shopping for paint, couches, mattresses and wood products (also check ingredient lists for “urea,” and avoid those products). If a new purchase has that sickly chemical smell, put it in a garage or on a patio to let it off-gas for a few days; wash new drapes before hanging them. Some V.O.C.s are water soluble, so humid air will speed off-gassing; a dehumidifier can help tamp things down.