Members of my family suffer from allergies. My husband has had allergies for years and my children started showing to have symptoms when they were toddlers. It’s not easy trying to care for them when there are so many contributing factors. We try to eat healthy and exercise, avoid allergic foods, eliminate toxic chemicals, and air pollutants to reduce their symptoms. We use humidifiers in their rooms during winter and dehumidifiers in the basement in the summer. We’ve added electrostatic air cleaning filters in the whole house HVAC system — and when their allergies didn’t seem to get better, we tried several types of portable air cleaners in individual rooms.
Air pollution is one of the main allergy and asthma triggers. Unfortunately, our best efforts of using various air cleaning methods to control indoor pollution didn’t make a significant difference. After doing some research, I found out why.
WHERE DOES INDOOR AIR POLLUTION COME FROM?
According to Environmental Protection Agency (EPA), air pollution is among the top five causes for environmental health problems. Indoor air pollutants mainly consist of particulate matter – dust, smoke, animal dander, pollen (brought in from outside) particles generated from operating appliances like cooking stoves, HVAC units, ashes from fireplaces, dust mites, molds, bacteria and virus. Gaseous pollutants come from combustion of gas stoves, car exhaust (from attached garages), tobacco smoke, off gassing of toxic chemicals from furniture, upholstery or fabric, glue, paints, furniture finishes, cleaning products, and pesticides. Both types can be reduced to some degree by using air filters or purifiers but different types of removal methods have varying degrees of success, if at all.
- Mechanical air filters – remove particles by circulating the air in the room and by capturing the particles on the filter materials. High Efficiency Particulate Air (HEPA) filters are in this category. HEPA is commonly used in vacuum cleaners and whole house air filtration systems. The problems with any mechanical filters are that they may not be efficiently filtering the amount of polluted air.
- Electronic air cleaners – use electrostatic attraction to trap charged particles and then accumulate on their flat surface plates. These filters are usually installed in HVAC systems, but there are a few portable systems that use this technology. The problem with these units are that they use high voltage to penetrate ionized fields producing ozone, which is lung irritant.
- Gas-phase air filters – gaseous pollutants are usually filtered using absorbing elements like activated carbon. Although some gas-phase filters may remove specific pollutants from indoor air, none is expected to adequately remove all of the gaseous pollutants in a typical home. Carbon monoxide, for example, is not readily contained by absorption and furthermore, there is concern that saturated filters may release trapped pollutants back into the air. Most gaseous pollutant removal filters are elaborate and not used in residential systems.
- Ultraviolet Germicidal Irradiation Cleaners (UVGI) – use ultraviolet lamps to kill airborne biological pollutants or on the moist areas like HVAC surfaces. But typical UVGI cleaners used in homes have limited effectiveness in killing bacteria and molds. In order for this system to be effective, UV exposure needs to be much higher than what home unit provides. There are also concerns of growth of microorganisms on the system; the spreading of microorganisms can occur during filter change – mold spores on the filters can be released back to the airstream during sudden airstream change.
- Photocatalytic Oxidation Cleaners – manufacturers and vendors claim these filter systems eliminate particles, tobacco smoke, microorganisms and other indoor particles by converting them into harmless by-products. But the fact is, these pollutants are not removed from the environment. It actually creates ozone as a by-product, which is lung irritant. Ozone can can trigger asthma attacks, coughing, chest discomfort, irritation of the respiratory tract. The technology is still in its infancy for residential use for removing contaminants because available photocatalysis are ineffective. For it to be used effectively in a home setting, application issues like requiring large amount of energy, and complexity engineering design need to be resolved.
Importantly, air filters are not regulated by FDA. Vendors and manufacturers of air filtering units, portable or whole house, can describe the technology and spell out all the engineering specs, but they cannot prove health benefits.
HOW TO ACHIEVE CLEANER INDOOR AIR WITHOUT USING AIR FILTERS
According to EPA, the best way to minimize the risk of indoor air pollution is to control the source of the pollution. Some air cleaning methods might help in reducing some of the harmful pollutants, but EPA cautions: they many not help in decreasing adverse health effects.
How do you achieve cleaner indoor air? Here are a few steps.
- Ventilate and bring clean air in to replace the polluted indoor air.
- Do not wear shoes inside. Leave dust and chemicals outside the home.
- Encase the mattress and pillow in allergy proof cases to minimize dust mites.
- Vacuum and wet mop floors regularly. Large particles like animal dander and pollen are heavy and fall to the surface.
- Install wood floors instead of carpet which can trap particles.
- Wash linens and bedding regularly.
- Clean cat litter box regularly.
- Do not smoke.
- Do not burn food.
- Do not burn wood. Gas fireplaces are better, but check the chimney to make sure it’s well ventilated.
- Use low VOC paints, furniture with safe varnishes, non-toxic cleaners, upholstery furniture without flame retardants, and non-toxic personal care products
- Keep windows closed during high seasonal allergy season.
- Control moisture level to prevent mold.