Is there a link between central air conditioning and chronic disease? A new study hints at one

Think air conditioning, and you're likely to connect this modern amenity with the comfort it provides on scorching summer days. "The Relationship of Housing and Population Health: A 30-Year Retrospective Analysis," in the April 2009 issue of Environmental Health Perspectives, makes a different connection, suggesting a link between central air conditioning and chronic disease. The study connects the dots between the National Health and Nutrition Examination Survey (NHANES) and the Census Bureau's American Housing Survey (AHS).

(Note: Acting Surgeon General Steven K. Galson, M.D., M.P.H., on June 9 released "The Surgeon General's Call to Action to Promote Healthy Homes." Download a PDF of the call to action: Surgeon General Call to Action Healthy Homes 6-9-09.)

One key housing trend identified in the AHS is the increase in central air conditioning; in 2002, nearly 60 percent of U.S. households had a central-air-conditioning system, up from approximately 15 percent in 1972. In that same 30-year time period, the NHANES reveals how asthma rates more than doubled, from 3.4 percent to 7.8 percent, and the average body mass index climbed from 24.9 to 27.7; a BMI of 25 and above is considered overweight; 30 and above, obese. (See the charts, right and below.)

The study authors acknowledge that various risk factors contribute to weight gain and respiratory problems as well as other health issues, but they make a good case that air conditioning and heating are at least partially to blame. For one thing, there's the lifestyle impact. "The increase in central air conditioning and its associated improved thermal comfort could provide an incentive for people to remain indoors and thus exercise less and/or to exert less energy through lower metabolic rates," they wrote.

As for indoor-air quality, the authors contend that central-air systems "increase air velocities and resuspension of particulate matter" and reduce fresh-air introduction, since "windows that would otherwise be open in the warm months are more likely to be kept closed in the presence of central air conditioning." They also observe that air conditioning and closed windows can help reduce pollen and dust mite-inducing humidity in some environments.

Any broad-stroke study such as this one will have its caveats and counterarguments. The study's authors point out that television and junk food also contribute to changes in health. But this analysis takes the discussion of housing and health relationships beyond lead-based paint and other familiar hazards, especially as they relate to disadvantaged groups. Do the study's findings mean you should jettison your air conditioning? Probably not. But they're a good reminder that you should:

Maintain your forced-air system. If you have central air, change the system filter when it's dirty, maybe about once a month or so, to prevent dust from accumulating on the evaporator fins and being dispersed throughout the house. If your home has window air conditioners, clean the filters once a month. And during heating season, replace furnace air filters monthly.

Ventilate adequately. Exhaust fans in the kitchen, bathroom, and laundry area are best at expelling combustion gases, odors, and excessive moisture, which can breed mold and other allergens. In a temperate climate, turning off the AC and opening the windows on cool days can also help ventilate, provided there's not a pollution or pollen advisory in effect. Install a whole-house fan to expel hot indoor air and bring in fresh, cooler outdoor air when the weather is mild.

Exercise regularly. Good cardiovascular health not only keeps weight down but can also help prevent several chronic diseases, including hypertension and type 2 diabetes. During summer months, limit outdoor activity to before 10 a.m. and after 4 p.m. Review these additional tips for staying safe in the sun and read our latest report on sunscreens (available to subscribers).—Daniel DiClerico | e-mail | Twitter | Forums | Facebook

Essential information: Read our latest report on air conditioning and cooling your home (available to subscribers), which includes ratings of 29 window air conditioners and brand reliability of 11 central-air-conditioner manufacturers. And learn more about air purifiers and indoor air.

Programmable thermostats are no longer part of the federal Energy Star program

The U.S. Environmental Protection Agency recently announced that it will suspend its Energy Star specification for programmable thermostats effective December 31, 2009. Any models manufactured after that date cannot bear the Energy Star label; manufacturers will have several months to update their Web sites and promotional material.

While that suspension might seem odd—using a programmable thermostat can help you cut your cooling and heating costs by up to 20 percent—it follows investigations by the EPA into concerns with programmable thermostats, including difficulties in using these devices. Indeed, as we found in our October 2007 report on programmable thermostats, the controls on these devices are sometimes so confusing that one could cause your energy costs to go up. The EPA administers Energy Star with the U.S. Department of Energy.

The EPA also questioned the lack of differentiation between Energy Star-qualified models and nonqualifying ones; the scant evidence showing that programmable thermostats conserve energy on a consistent, nationwide basis; and the fact that savings ultimately come down to consumer behavior—even the best programmable thermostat won't save energy if you doesn't use it properly. Programmable thermostats had been part of Energy Star since 1995.

The EPA will continue to educate the public about the savings associated lowering a thermostat in winter or raising it in summer, particularly when the home is unoccupied, a process that is automated with programmable thermostats. The agency will also work with manufacturers and other interested parties on a new Energy Star specification.

The EPA's decision doesn't mean you should abandon using a programmable thermostat. To find the right model for your home, read our buying advice and check out the ratings of more than two dozen models (available to subscribers).—Daniel DiClerico | e-mail | Twitter | Forums | Facebook

Essential information: Try these 25 ways to save energy. And for advice on energy-efficient ways to stay cool this summer, read our July 2009 report on air conditioning (available to subscribers).

How polluted is your air? American Lung Association report identifies the most polluted places in the U.S.

The American Lung Association's newly released "State of the Air 2009" report finds that six out of 10 Americans live in areas where air pollution levels endanger human life.

The 10th edition of the report ranks cities and counties affected by the three most common types of pollution: ozone, annual particle pollution, and 24-hour particle pollution. Three California cities—Los Angeles, Bakersfield, and Fresno—are in the top 10 list in all three categories. Cities with the cleanest skies include Cheyenne, Wyoming; Fargo, North Dakota; and Honolulu. (The map shows the most polluted U.S. cities by year-round particle pollution.)

"This should be a wake-up call. We know that air pollution is a major threat to human health," said Stephen J. Nolan, national board chairman of the American Lung Association. "When 60 percent of Americans are left breathing air [that's] dirty enough to send people to the emergency room, to shape how kids' lungs develop, and to kill, air pollution remains a serious problem."

While power plants, diesel engines, and ocean-going vessels are among the biggest sources of air pollution, house paint is also a source. "By far, people painting their houses is the largest source category of emissions under our regulatory jurisdiction," Naveen Berry, planning and rules manager at California's South Coast Air Quality Management District, said in our March 2009 report on interior paint, which covered levels of volatile organic compounds in finishes.

To curb pollution, the ALA recommends you drive less, lobby schools to use cleaner buses, and not burn wood and trash.—Daniel DiClerico | e-mail | Twitter

Essential information: Find out how to protect yourself from air pollution, and get the facts on air purifiers.

EPA responds to Consumer Reports article on low-VOC paint, vows action

Green paint has gone mainstream. Many major manufacturers have at least one line that's low in volatile organic compounds (VOCs), and several eco-friendly niche brands have joined the market. The Environmental Protection Agency's attention to low-VOC paints, however, has lagged, as we reported in our March 2009 report on interior paints.

Among the article's findings:
• Federal VOC limits are higher than those set by many regional and state agencies.
• The national test method for measuring VOCs is outdated.
• Limits should apply to tints, which are typically added to the can at the point of purchase, not just to base coats.
• The federal government should establish VOC standards for indoor-air pollutants.

Consumer Reports received a response to the article in a March 31, 2009, letter from the EPA, signed by Acting Assistant Administrator Elizabeth Craig. She noted that the EPA is working on an amendment to the current VOC rule that will lower federal VOC limits to 150 grams per liter (g/l) for nonflat finishes and 100 g/l for flat. The amendment will also call for a more accurate test method for VOCs. As for colorants, Craig wrote, "We are not aware of any state or local agency that has included colorants in the VOC emission calculation for architectural coatings." But, she added that the EPA will solicit public comment on the issue with an eye toward future action.

Craig did not address our concerns of indoor-air quality and VOCs since the EPA has no statutory authority to regulate VOC in the indoor environment. She noted that "the EPA's Indoor Environments Division is currently working to increase its public education efforts and the public's understanding of issues related to VOC in the indoor environment."

"We appreciate the timely response from the EPA acknowledging our concerns around VOC limits for paints and pigments and explaining their plans for upcoming regulatory actions to address," says Urvashi Rangan, Ph.D., director of technical policy at Consumers Union.

The EPA has said it will promulgate a new rule for stricter VOC regulation some time after December 2009. We'll continue to report on the agency's efforts.—Daniel DiClerico | e-mail | Twitter

Essential information: Read our buying advice for air purifiers and use these simple tips to improve the quality of your home.

The Toxic Avenger takes on New Jersey

My family and I caught a really good show last night, The Toxic Avenger, at the New World Stages theater complex in New York City. It's a pretty hysterical 90-minute musical comedy with a blazing rock score, but there's an underlying serious tone to the play, especially so for New Jersey residents like me. New Jersey is portrayed as more Garbage State than Garden State, with toxic dumps, befouled air, and other environmental atrocities.

The main character, Melvin Ferd III, lives in a fictional place called Tromaville, at the fake Exit 13B off the New Jersey Turnpike. The Good Earth Corporation, run by the town's highly corrupt, despicable mayor, has turned part of the town into a toxic dumping ground. When Melvin sets off to clean up Tromaville, he's dumped by a couple of goons into a vat of chemical sludge, then emerges as a disfigured superhero. I won't reveal too much of the play, but the photo shows some of the talented cast singing "It's a Brand New Day in New Jersey!" at the end of the show.

As much as my family and I laughed our heads off and enjoyed the show, when I drove home on the turnpike within a few miles of where Tromaville would be, I wondered whether all the fun-poking at New Jersey is merited.

I'm not naive about the environmental problems New Jersey faces. Four days a week on my way to and from work, I drive past a spot on the turnpike around Newark where the air takes on an odd stench (probably from some chemicals) and, I kid you not, there's now a billboard for The Toxic Avenger.

But when I checked out the state and city rankings of air pollution from the American Lung Association (latest figures are for 2007), there were plenty of metropolitan areas whose air quality was worse than New Jersey's. Don't get me wrong, New Jersey still gets some ignominious top-25 positions in the different air-quality categories. But many metro areas apparently are worse off than Jersey, including some in Utah and Oregon, which you might expect to have cleaner air.

I've still got some work to do on the brownfields/toxic sludge angle and will do research on the New Jersey Department of Environmental Protection's Site Remediation Program site. Already I'm concerned, based on this statistic my daughter showed me: "At any one time, the NJDEP oversees some 23,000 contaminated sites. An estimated 10,000 of these are potential brownfield sites."

Where's the Toxic Avenger when you need him?—Steven H. Saltzman | e-mail | Twitter

Essential information: If you're concerned about oil tanks or hazardous contamination at a property you own or plan to buy, read this post about Environmental Data Resources. And visit the Environmental Protection Agency site to get more details on waste and pollution and air quality. If you're concerned about the air inside your home, use our buyer's guide to air purifiers.

By the Numbers: Asthma is on the rise in the U.S.

23 million

Number of Americans with asthma, according to the U.S. Environmental Protection Agency. Almost 2 million emergency-room visits a year are attribute to asthma, says the EPA. February is National Care About Your Indoor Air Month, an event started in 2008 by Honeywell--no surprise--a maker of air purifiers. Learn more about indoor-air-quality issues and read our report on air purifiers.

Retooling Sharper Image reinvents itself

Companies like Coca-Cola, Nike, Google, and many other corporate A+-listers know the value of the brand. The Sharper Image, which declared bankruptcy in February 2008 and in June announced it was shuttering its retail stores, hopes that its once highly regarded brand can resuscitate its business.

The Sharper Image, whose Web site says "Welcome to a New Era: Quality, Innovation, Design," is now licensing products bearing its name and selling them through third-party retailers, according to a January 19 article in The New York Times. The story also noted that the company is working on "a new generation of its famous (or infamous) air purifier."

In recent years, our tests of several versions of the Sharper Image's air purifiers, including the largest Ionic Breeze models, consistently found that they did not do a good job at cleaning the air of dust and smoke. What's more, the units we tested emitted ozone as a by-product. While ozone in the upper atmosphere protects us from the sun's ultraviolet rays, ground-level ozone is an irritant that can aggravate asthma and decrease lung function. Over time, the Sharper Image's air purifiers emitted less ozone, but their cleaning performance remained lackluster. We're always interested in testing new air purifiers, including those from the Sharper Image.—Celia Kuperszmid Lehrman

Essential information: Remember, it's smarter to remove the sources of indoor-air pollutants or to ventilate your home than to rely on a device to remove the pollutants from indoor air. So before you buy an appliance to deal with indoor-air-quality problems, try these simple, inexpensive steps. Consumer Reports believes that air purifiers that emit even small amounts of ozone are not your best choice. To learn more about air purifiers, read our report and visit our product page.

New California regulation impacts ozone-generating air purifiers

Under a regulation that the California Air Resources Board finalized in the fall, manufacturers of room air purifiers that generate ozone to kill germs and remove other indoor-air pollutants have until October 18, 2010, to get their products tested, certified as emitting safe levels of ozone, and labeled, in accordance with the new regulation.

Ozone in the stratosphere protects us from some solar radiation. But ground-level ozone, even at relatively low levels, has been linked to decreased lung function and increased risks of throat irritation, coughing, chest pain, and lung-tissue inflammation. Studies have also shown that ozone reacts with scented cleaners, air fresheners, and other household products to produce potentially harmful substances like formaldehyde, a carcinogen; acrolein, a toxic irritant; and ultrafine particles.

Ozone generators have produced ozone at levels as high as 4,300 parts per billion in our tests. And the U.S. Environmental Protection Agency has warned against using such devices. After the October 2010 deadline, air purifiers that produce ozone levels greater than 50 ppb in any mode cannot be marketed or sold in California for personal use in occupied spaces such as homes, businesses, and schools.

The other two most common technologies used to purify air are:

• Mechanical filtration, which uses a fan to draw air through a filter, often a HEPA-quality filter. These models typically generate no ozone. (CARB requires these types of products to be certified to UL 507 and so labeled, and the manufacturer must submit design drawings to CARB to prove the model does not produce ozone and that it is only a mechanical filter.)

• Electrostatic precipitation, which produces levels of ozone that tend to be less than 50 ppb, the level CARB considers hazardous.

Whole-house ("in-duct") models, which attach to forced-air heating/cooling systems, are not restricted as part of the regulation; neither are devices made, sold, and used only for industrial use.

Eliminating allergens and ventilating spaces are more effective than any air purifier, according to the U.S. Environmental Protection Agency and the American Lung Association. But if you're considering buying an air purifier, read our ratings-based report, "Filtering the Claims."—Ed Perratore

Essential information: Learn about the different types of air purifiers.

In this neighbor dispute, air-purifier maker clears the air

They say good fences make good neighbors, but in one New York City apartment building, an air-filtration system was key to keeping the peace.

The dispute became known last winter after news stories reported that a couple, lawyers who live in an upscale Upper West Side apartment building, had sued a neighbor on their floor because cigarette smoke was wafting from her condominium into the common hallway. The plaintiffs have a young son whose health, they claimed, was being affected by the secondhand smoke.

New Yorkers love a good real-estate dispute, and this one had the makings of a reality-TV classic (the defendant had also been accused of having her dog urinate on a the plaintiffs’ stroller). But the parties settled the matter out of court, thanks in part to the third-party efforts of Aerus, which makes vacuums and air purifiers.

Shortly after the suit was filed, Aerus offered to install an air-filtration system for free in the defendant’s apartment to help capture the smoke from her cigarettes. In a New York Times article, Joseph P. Urso, chief executive of Aerus, said the filtering system was instrumental to reaching a settlement.

We’re currently working on a story on neighborly disputes, and would love to hear your stories about any nuisances you’ve had to deal with, including issues related to topics like noise, fences, trees, boundaries/property lines, safety, and esthetics.

If you have a compelling tale to tell, send us an e-mail with all the details. As always, we’ll respect your privacy—read our privacy policy—and will keep your information confidential. Please indicate if you’re willing to be contacted by a reporter working on this story.—Daniel DiClerico

Essential information: When you’re in the market for an air purifier, read our latest report on these devices and follow our advice to determine whether you need one and to choose the right model for your home. Ratings of room and whole-house models are available to subscribers.

Sharper Image to shutter its retail stores

Planning to shop at a Sharper Image store for a Father’s Day gift?

News flash: Under new ownership, the retailer has put $50 million worth of inventory at its remaining 86 stores on a closeout sale as it morphs into a company without any brick-and-mortar stores. All merchandise, the San Francisco-based company announced, is selling for 20 to 40 percent off the regular price. On Monday, June 9, the Sharper Image Web site had only a listing of retail locations, a link to send the company an e-mail, and this message: “Sorry to keep you in the dark. But, there’s something big coming. Soon. Stay tuned.”

Even with the price breaks, we don’t favor the Sharper Image Hybrid Germicidal Purifier SI724GRY electrostatic precipitator-type room air cleaner, $500. It rated only a fair in our latest review of room and whole-house air purifiers.

(Part of the financial hardship that led to the company’s February 2008 declaration of Chapter 11 bankruptcy and its May 2008 sale for $49 million grew out of a proposed settlement to a class-action suit filed on behalf of millions of consumers who purchased a Sharper Image Ionic Breeze Silent air purifier after April 1, 1999. Learn more about the legal issues in this January 2008 story from the Home & Garden blog.)

The company’s retail stores will accept all major credit cards, but all sales are final. Forget about discounts based on prior purchases or other discount offers; the company says it won’t accept them. And if you have any Sharper Image gift cards, read about the restrictions the company placed on the gift cards after it filed Chapter 11 bankruptcy in February and learn about the efforts by competitors to lure away chagrined customers.—Ed Perratore

Essential information: When you’re in the market for an air purifier, use our advice to determine whether you need one and learn how to choose the right model for your home. Ratings of room and whole-house models are available to subscribers. You'll find Father's Day gift ideas on our dads and grads page.