Bedding and Pillows | Body Care (Personal Care) Products | Home Care Products | Home Filtration of Air and Water (Also for Cars) | Home Renovation, Decorating, and Construction | Indoor Plants as Air Filters | Nourishment: Food and Cooking | Reading Resources (Bibliography)
If you are living in a new house or planning to build one, invest in an electrostatic whole house filter such as the Newtron or Permastat or in a good pleated filter such as those made by the 3M Company. Since not all HVAC systems can accommodate the addition of an electrostatic filter, check with the manufacturer of your particular HVAC system. If you live in an older home with dirty air ducts, an electrostatic whole house filter will not be very beneficial. For older homes, portable air purifiers are the better option.

COEM can not recommend any specific brands or models of air purification systems due to rapidly changing technology. We are unable to determine if the manufacturer’s claims are valid. Therefore, we simply recommend that you look for room purifiers with three stages of filtration: particulate with a hospital grade HEPA, activated charcoal, and ultraviolet light which kills viruses and bacteria and helps to degrade chemical pollutants. Ozone producing purifiers should be avoided since ozone is a major pollutant that irritates lungs.

For room air purifiers that have been independently tested in real homes, check out the Allergy Buyers website This website cuts through the inflated claims of manufacturers and sells only those that really work.

Other product sources are: NEEDS, 800 634-1380; The Living Source, 254 776-4878; and E.L. Foust Co Inc, 800 353-6878.
Charcoal Air Masks – Surgical Style
3M Nuisance Level Organic Vapor Relief Mask Model Number 8247 R95. Available at COEM.
NEEDS has a variety of masks for inhalants and chemical odors.
Check the yellow pages for the headings of industrial equipment, industrial hygiene, and industrial safety products. Near COEM in North Charleston, there are Carolina Equipment and Safeco.
Check the Internet for additional products
Reprinted from Better Breathing Inside Your Car by Joseph D. Younger, AAA’s Go Magazine July-August 2007.

If you drive a vehicle made after the millennium, chances are it has cabin filtration as part of its heating, ventilation, and air conditioning (HVAC).

“About 30 million vehicles in North America currently have cabin air filters,” says Rich White, vice-president of the Automotive Industry Aftermarket Association.  “However, most people have never heard of a cabin air filter and don’t know whether their vehicle is equipped with one.” Knowing how the filter works and how to perform maintenance can help eliminate allergens and pollutants, shut out bad smells, and generally help you breathe better while driving.
Where to Find Your Filter
Nearly half of the new cars sold on the U.S. market come with cabin filtration systems. That compares to almost 90 percent in Europe and about 70 percent in Japan. A newer import is more likely to have one than a domestic model.

Check the owner’s manual.  Look under “cabin air filter,” “cabin filtration,” or “pollen filter.”

Can’t find a reference?
Ask your dealer’s service department whether your model has a cabin air filter and, if so, where it is.

On most cars, you’ll find the filter’s access panel on the passenger’s side, either under the dash, beneath the glove box, or in the glove box. You might need to look under the hood, on the passenger’s side, across the firewall from the glove box.

“Some cars actually have two filters, depending on the capacity of the HVAC system and the available space,” says Dave Lester, general manager of Micron/Air cabin air filtration, which supplies original-equipment cabin filters for two out of every three cars that have them. You’ll most likely find the second filter either right alongside the first or in a comparable location on the driver’s side.
Replacing & Upgrading
Carmakers recommend replacing the cabin air filter every year or every 15,000 miles. Unfortunately, many drivers never replace filters and some normal maintenance checklists don’t include cabin filter replacement.

A persistent bad odor might signal your filter needs replacing.

“One tell-tale sign is reduced airflow when you turn on the air conditioning or heat,” notes Lester. “That’s because the filter has trapped dust and other contaminants restricting airflow into the cabin.”

Some upscale cars include a warning light on the dash as a reminder.

Filters fall into two general categories. Particle filters remove dust, pollen and other microscopic specks suspended in the air.  Usually, they have at least one layer to trap coarse particles and an electrostatically charged layer to catch really tiny stuff. So-called combination filters add a layer of activated charcoal to trap odors and noxious gases.
Combination Filters
A combination filter makes a noticeable difference, especially in big-city, bumper-to-bumper traffic.

“Studies show that pollutants can collect inside the vehicle at concentrations ten times higher than the air outside,” notes Lester.

With the windows up and the A/C on, your car’s HVAC system sucks in exhaust from vehicles directly ahead and concentrates them inside the cabin.

A combination filter can trap most of those gases, including nitrogen oxides, sulfur dioxides and other smog-forming pollutants.  But even the best activated charcoal won’t filter out carbon monoxide or carbon dioxide, two common auto emissions.

If your current system uses only a particle filter, you can probably find an aftermarket combination filter to fit.

“Because combination filters have an extra layer with charcoal and the filtration media are somewhat thicker, you might experience a slight reduction in airflow,” explains Lester.
Comparative Shopping
The automotive industry doesn’t make comparison-shopping easy. Unlike home furnace filters, cabin air filters don’t have MERV ratings (Minimum Efficiency Report Value, a standard measuring the filter’s ability to trap particles as small as 3 microns).

However, Freudenberg Nonwovens, makers of Micron/Air filters, intends to include MERV ratings on its packaging.

In the absence of standards, you have to judge a filter by its material. Avoid inexpensive cellulose (paper) filters.
Good quality water is essential to good health. Unfortunately our tap water contains many contaminants including toxic chlorinated chemicals, heavy metals, and microorganisms.

In addition, water treatment plants generally disinfect with chlorine rather than purify the water, adding their contaminants to the water. Chlorine added to drinking water bonds to the naturally occurring organic matter such as tannins and forms toxic chlorinated hydrocarbons. This is why you should avoid drinking tea using chlorinated water.

Contaminants such as lead from solder leach into the water from pipes.

Distilled water is less desirable because all healthful minerals are removed. Distilling removes non-volatile chemicals well, but gives poor removal of volatile chemicals like pesticides, chlorine, and ammonia. Distillers that combine steam distillation plus replaceable post-distillation organic carbon filters are a better choice when distillation is desired. See for these types of distillers.  When mold buildup in other water filtration systems has been an ongoing problem, distillation may be a good option.

Boiled tap water results in removal of chlorine and pesticides, but is time consuming and releases these pollutants into indoor air.

The two options for drinking cleaner water that The Center most often encourages are: when possible, spring water in glass bottles, or filtration. Spring water can be delivered to your home in large, heavy glass bottles. Remember to insist on glass bottles. Plastic bottles should never be used long term because they contain plasticizers which have estrogen like properties.

Home water filters can treat water throughout your home or you can obtain a small filter that fits under the kitchen sink or on a kitchen countertop. Avoid filters that have inside plastic that will contaminate the water. A favorite water filter for many years has been the stainless steel Multi-Pure filter available for $400 at This filter has a solid carbon block filter which is more dense than charcoal so that it filters out volatile organic chemicals, pesticides, some heavy metals, and bacteria.  You can also connect this filter to your refrigerator ice maker.  We suggest that you replace the filter, which costs about $40, once every six months. The cost of a water filtering system can be deducted from income tax if prescribed by a doctor.

Other product sources are: NEEDS, 800 634-1380; The Living Source, 254 776-4878; and E.L. Foust Co Inc, 800 353-6878; Culligan, 800 culligan.

All material provided on the Center for Occupational & Environmental Medicine web site is for educational purposes only. Access to the web site does not create a doctor-patient relationship nor should the information contained on the web site be considered specific medical advice for any person, patient and/or medical condition. Consult a physician regarding the application of any opinions or recommendations from this website, for any symptom or medical condition. Dr. Lieberman specifically disclaims any liability, loss or risk, personal or otherwise, that is or may be incurred as a consequence, directly or indirectly, resulting from use or application pertaining to any of the information provided on the web site.