Spring may be just around the corner, but here in Washington that means lots of rain and time spent indoors. And the air you breathe inside your house or office may not be as healthy as you think. It’s likely polluted with chemicals and allergens, which can aggravate asthma, allergies and other conditions.

Most people associate pollution with outdoor air, but many studies have shown that indoor air can also be quite dirty. It may contain lead, formaldehyde, fire-retardants and other chemicals. You are also likely to find dust mites, mold, pet dander and pollen. Even if you don’t have pets, you may have pet dander that you pick up from your school or workplace or even a trip to the mall.

What are allergies? Allergies affect about 20 percent of Americans. People with allergies have an immune system that reacts to substances in the environment. Usually these substances are harmless to the general population. Symptoms include itchy, watery eyes, sneezing, runny nose, rashes, feeling tired or ill and hives.

What is asthma? Asthma is a chronic disease of the airways that makes breathing difficult. Inflammation of the air passages narrows the airways that carry oxygen to the lungs. Symptoms include coughing, wheezing, shortness of breath and chest tightness.

Asthma affects nearly 23 million Americans, including 7 million children, according to the American Lung Association.

Here are some ways to make sure the air in your house is healthy for you and your family:

Clean your floors

Chemicals and allergens can build up in carpets, behind furniture and other hidden spots. They get stirred up when people walk through a room. One of the most common allergens is dust mites. They are microscopic organisms that live in household dust and feed on the dead skin cells of humans and pets. Regular cleaning is the only way to reduce their presence. Vacuuming regularly – at least twice a week – can keep that dust at bay. Go over the carpet several times to make sure you get as much as you can.

A vacuum with a HEPA filter can reduce the concentrations of particles including lead in your home. That filter also will contain more of the dust. And while you have your vacuum out, clean the furniture, too. Don’t forget to wash the floors that don’t have carpet. Mopping can take care of the dust and particles left behind after vacuuming. New microfiber mops can trap more dust and don’t require chemicals, which can also irritate allergies.

Hair and dander on pets can also trigger allergies and asthma. Keep them out of sleeping areas and away from upholstered furniture if possible.

Trap those dust mites

Mites are found in pillows, blankets and other bedding. Wash bedding once a week in hot water. Use allergen-proof mattress and pillow covers. Keep stuffed animals off beds.

Trap the allergens before they get in. Floor mats help keep a lot of the dirt and chemicals outside.

Make sure you and your visitors wipe their feet and take off their shoes when coming into the house. In some parts of Pierce County, the soil contains higher-than-normal levels of lead and arsenic that is tracked in on shoes. Those chemicals can get into your lungs.

Control the humidity. Moisture breeds mold and dust mites. Try to keep your humidity around 30 to 50 percent. A dehumidifier can help. Also, don’t overwater your houseplants. Too much water can promote the growth of organisms that can affect people with allergies. Make sure you don’t have any leaking pipes or windows or other sources of water that can promote mold. Mold is usually found in damp areas such as basements or bathrooms.

Bring in fresh air. Open your windows regularly, even when it’s cold outside. That increases the outdoor ventilation and lowers the humidity. Crack a window when you are cooking, running the dishwasher or bathing.

No smoking please. Smoking isn’t good for you, but neither is breathing secondhand smoke. Cigarette smoke contains more than 4,000 chemicals and none of them is good for you. Research shows that breathing smoke can lead to ear and respiratory infections, asthma and cancer among other conditions.

Stay natural if possible. Synthetic fragrances in cleaning solutions and air fresheners can be irritating to people with allergies and asthma. Use mild cleaners that don’t include artificial fragrances. Lemons and baking soda can clean many surfaces and leave a fresh scent without chemicals.

Spending a little time making sure the air in your house is healthy could save you and your family from many lung-related health problems in the future.

Dr. Ronald Benveniste is an Ear, Nose and Throat physician for MultiCare Health System.