According to May, some ways to immediately reduce allergens is to have fewer carpets and rugs. Also, buying leather furniture or covering furniture you already have with an allergen-control cover will reduce allergens in the home.
But if you are not looking to remodel or refurnish your home, just cleaning the home at least once a week may be enough to keep the home healthy, said May.
"You don't need expensive products, as long as you're cleaning on a continual basis," he said, adding that simply wiping surfaces with a damp cloth will do the trick.
However, May recommends investing in a high efficiency particulate air, or HEPA, vacuum. HEPA is a type of filter that traps the dust or mold spores that regular vacuums may circulate back into the air.
Although the Food and Drug Administration regulates the safety and effectiveness of household cleaning products, it does not monitor the ingredients on the product's label, said Jess Lerner, environmental consultant and founder of greenontheinside.net.
"Most of the time, cleaning product labels will say 'do not swallow' or 'harmful if ingested,' but they don't list the ingredients and most of these chemicals are never tested to see how they interact with each other and affect us," Lerner said.
Dr. Michael Shannon, associate chief of the Pediatric Environmental Health Clinic at Children's Hospital Boston said cleaning products can have side effects including "headache, fatigue, nasal congestion, watery and itchy eyes, cough, sore throat and a worsening of asthma."
Shannon said ventilation is the most important aspect of cleaning.
"Try and not clean when children are in the house," he said.
Lerner recommended making homemade cleaners with everyday household products such as baking soda and vinegar. But if you're going to buy a commercial cleaner, she recommended looking at the label before throwing it in your shopping cart.
"Just like in food products, if there is a long name listed in the ingredients, be wary and find out what that chemical is before you use it," she said.
While air filters may improve indoor air, you may want to deal with some of the actual sources of indoor air pollution first.
"Of all of the ways to keep a healthy home, a portable filter is the least important on the list," said May.
Eliminating the source of allergens, such as rugs or pets, will prevent allergens from spreading and should be the first step before getting an air filter, he said.
"It's a hopeless attempt to clean the air without removing the source that's going to continue the spores from spreading," said May.
And, contrary to what some may think, pricier air filters may not necessarily mean better quality or protection. In fact, May said some filters that cost less than $200 are more effective than some of the more expensive types.
Fifty percent of the fire deaths that occur each year in the United States take place in the 5 percent of homes without smoke detectors, according to the Massachusetts Department of Fire Services. And excess smoke exposure can lead to long-term health problems.
According to Dr. Michael Aschner, professor of pediatrics and pharmacology at Vanderbilt University in Nashville, Tenn., carbon monoxide poisoning is one of the major concerns related to excess smoke exposure.