There seems to be no middle ground when it comes to cigarette smoke. In the United States and Canada, people have strong opinions over whether or not smoking should be allowed in public. And each side enjoys spewing facts and figures at the other side about how safe/unsafe secondhand smoke can be. At this point in time, nonsmokers seem to have the upper hand. They’ve successfully lobbied to have cigarette smoking banned from most office buildings and many public places, including restaurants. Smokers aren’t going quietly, though. They claim they’re enjoying a perfectly legal product and therefore, should be allowed to indulge in their habit wherever they choose.

Manufacturers say they’ve got the answer to the problem — better ventilation and filtration equipment that can allow smokers and non-smokers to get along just fine. Naturally, this is stirring some debate. Non-smokers say no equipment can totally protect a person from the harmful contaminants in cigarette smoke. Smokers say that the equipment can provide cleaner air than we breathe outside.

So who’s right? It depends on who you believe.

Figure 1. General description of how air-filtration equipment uses ions to clean air.

Statistics Galore

We’ve all been inundated with smoking statistics over the years. Until recently, these statistics usually centered around the increased health risks of the smokers themselves (lung cancer, emphysema, etc.). In 1993, however, the Environmental Protection Agency (EPA) became more concerned about the health effects of secondhand smoke.

Secondhand smoke is a mixture of the smoke given off by the burning end of a cigarette, pipe, or cigar, and the smoke exhaled from the lungs of smokers. This mixture contains more than 4,000 substances, more than 40 of which are known to cause cancer in humans or animals, says the EPA, and many of which are strong irritants. Secondhand smoke is also called environmental tobacco smoke (ETS); exposure to secondhand smoke is called involuntary smoking, or passive smoking.

EPA has classified secondhand smoke as a known cause of lung cancer in humans (Group A carcinogen). The agency estimates that passive smoking causes approximately 3,000 lung cancer deaths in nonsmokers each year. EPA also states:

  • Exposure to secondhand smoke causes irritation of the eye, nose, and throat.
  • Passive smoking can irritate the lungs, leading to coughing, excess phlegm, chest discomfort, and reduced lung function, And
  • Secondhand smoke may affect the cardiovascular system, and some studies have linked exposure to secondhand smoke with the onset of chest pain.

EPA maintains that it is widely accepted in the scientific and public health communities that secondhand smoke poses significant health risks to children and adults. For this reason, the agency urges policies to protect nonsmokers from involuntary exposure to tobacco smoke.

On the other side of the fence sit those who believe EPA has overstated the actual health hazards of secondhand smoke. As evidence, smoking groups point to a July 1998 decision by the U.S. Federal Court that effectively orders the EPA to remove ETS from the Class A carcinogen classification. In his decision, Federal Judge William Osteen wrote, “In conducting the ETS Risk Assessment, [EPA] disregarded information and made findings on selective information; did not disseminate significant epidemiologic information; deviated from its Risk Assessment Guidelines; failed to disclose important findings and reasoning; and left significant questions without answers. EPA’s conduct left substantial holes in the administrative record. While so doing, produced limited evidence, then claimed the weight of the Agency’s research evidence demonstrated ETS causes cancer.”

Gian Turci, P.E. (Genoa, Italy), chief executive officer of FORCES (Fight Ordinances and Restrictions to Control and Eliminate Smoking) International, adds that even though secondhand smoke contains all the combustion byproducts of organic materials, it is also true that:

  • The quantities of these components, even in so-called “high concentrations,” are infinitesimally small, often in the order of gram to the sixth/seventh negative power per cubic meter.
  • Once released by the cigarette tip, the byproducts undergo a natural process of thermochemical catalysis that radically alters the potentially harmful emissions (though already present in just tiny amounts). Since nobody ever stands 1 in. perpendicularly above the tip of a cigarette, the catalyzed compounds are what actually constitute ETS. And
  • Even in the absence of ventilation, the exposure to such low concentrations requires tens of thousands of hrs to reach an accumulation that is still within the ASHRAE standards.

“Secondhand smoke is not Uranium 238, nor is it Lawrencium 260. It is just something that may be unpleasant to some,” adds Turci.

Figure 2. An example of an air filtration unit, as installed on a ceiling, designed to reduce the amount of outside air needed in an indoor environment.

New Equipment Available

Since there is no doubt that cigarette smoke is unpleasant to some people, manufacturers have come up with equipment they think will help the situation. There are three acceptable ways of accomplishing contaminant removal in the hvac world: Remove the source, dilute the space with outside air, or filter the air. Some argue that removing the source — in this case, smokers — isn’t a good economic solution for restaurants, as they may see 25% to 30% of their clientele head to establishments in other cities that welcome smokers.

Some manufacturers state that diluting with outdoor air isn’t always a good option, because in order to work well, the outside air needs to be cleaner than the indoor air. In many metropolitan cities, that’s not the case. Also, it would be very expensive to heat or cool the vast amounts of outdoor air that would need to be brought in for sufficient dilution.

That leaves filtration, which Scott Roberts, national sales and marketing manager, Honeywell Inc. Commercial Air Products (Niceville, FL) says can work very well. He states that it’s not even necessary to separate smokers from nonsmokers with a physical wall in a restaurant — an air curtain will work just as well. “Consider a restaurant where to the left is no smoking and to the right is smoking. An aisle separates the two. I can put in an air cleaner on the righthand side that blows air right down in that aisle. The air goes to the right side, because that’s where the intake is. Then I can pump in 500 cfm but only return 400 cfm, because I’m exhausting 100 cfm. That makes the area have negative pressure,” says Roberts.

That negative pressure keeps the smoke from drifting into the non-smoking side of the restaurant. Roberts states that any smoke that is returned through the hvac system is then diluted with minimal amounts of outside air, so that smoke is not introduced into the nonsmoking section via the hvac system.

Brian Monk, P.E., vice president of sales and marketing, Circul-Aire (Montreal) agrees that the proper technology can work.

“The engineer needs to be smart about laying out a restaurant, so that the smoking area can be kept under a negative pressure. If the air is sweeping towards that area instead of leaving that area, the contaminants can be contained and will never get back to where the nonsmokers are sitting. The air from the smoking area then will be either exhausted outside or filtered with a multifaceted filtration system to address all the contaminants that are in the cigarette smoke.”

Monk says that his company’s gas phase filtration equipment can successfully trap both the particles and gases in cigarette smoke, so that there is little to no detectable odor. Monk cites an experiment he was involved in, in which two smokers were placed in a conference room. Before they started smoking, the air was tested and found to have a background concentration of particulates that measured 50,000 particles per liter (ppl).

“When the two people started smoking, the particle count in the room rose from 50,000 up to 525,000 ppl in that space. And that was just after a couple of minutes – it was dramatic. This is a very strong contaminant. We turned on our system, which removed all the impurities in the air, including the gases and the particles. After 15 to 20 minutes, we were able to bring the room concentration back down to baseline, which was 50,000 ppl,” says Monk.

Both Monk and Roberts can cite numerous cases in which their respective equipment was installed, and the restaurant employees, patrons, and even city officials agreed that the smoke was almost undetectable. However, the concern still exists that even a small exposure to secondhand smoke can cause problems. The difficulty is that no one has actually proven how much exposure is too much exposure.

According to Monk, there are threshold limit values on just about every kind of contaminant, from mercury to chlorine to carbon monoxide. However, those limit values haven’t been established for cigarette smoke. Roberts wonders why every other harmful airborne contaminant has an exposure limit, but cigarette smoke doesn’t. “Radiation has an exposure limit, yet cigarette smoke doesn’t. I’d rather sit around and smell uncontrolled smoke the rest of my life than think uncontrolled radiation is anywhere near me,” he says.

Figure 3. One school of thought about ventilation in the hospitality industry promotes creating an indoor environment where air travels from the nonsmoking section to the smoking section, then out of the building.

Still Not Convinced

David Bearg, P.E., CIH, Life Energy Associates (Concord, MA) is convinced that the only way to protect nonsmokers from smokers is to place the smokers in a smoking room that is physically isolated from the nonsmoking area. Then, he says, the smoking area must be exhausted to the outdoors in such a way as to maintain the smoking area at a negative pressure to the nonsmoking areas and the exhaust must be situated so as to prevent the re-entry of the smoking exhaust back into the building. He notes this doesn’t protect restaurant workers who are serving in the smoking area, though.

As backup, Bearg cites a 1994 ASHRAE paper entitled “Effectiveness of Ventilation in 23 Designated Smoking Areas in California Office Buildings.” In that study, the authors concluded that the most effective smoking area design is that of an enclosed smoking area with no air recirculation to nonsmoking areas, exhaust to the outside, and a negative air pressure relative to adjoining nonsmoking areas.

Furthermore, the authors concluded, enclosed smoking areas without an exhaust to the outside offer only moderate protection to nonsmokers in adjoining areas, whereas open, adjacent, and/or contiguous smoking/nonsmoking areas offer moderate to no protection at all to occupants of the nonsmoking sections. “I’m very cynical about the technology for a number of reasons,” says Bearg. “Tobacco smoke is uncontrolled combustion, so it generates not only very fine particulate, which can be very difficult to capture, but it also has gaseous and semi-volatile components. Even if you have very efficient filtration, what’s to prevent the semivolatile components that are captured to begin to give off odors over time as more and more gets collected?”

He notes that this fact is especially important, because of concerns about whether restaurant owners will perform the needed maintenance. After all, many restaurants are financially marginal operations, and there may not be the available funds for installing and maintaining such a system.

Elia Sterling, president, Theodor Sterling and Associates (Vancouver, BC, Canada) says that operation and maintenance definitely play a key role. “The hospitality industry has to understand operation and maintenance. Patrons have had bad experiences usually where the hospitality establishment has not been maintaining and operating their systems properly.”

He adds that several studies he’s conducted showed establishments helped eliminate their ETS issues by simply operating and maintaining their mechanical systems as they should be — not by putting in any significant investments into their systems.

Roberts says Honeywell has addressed those issues by providing restaurant owners with lease-to-own equipment. For a set amount each month (anywhere from $100 to $300, depending on the size of the restaurant), restaurant owners can have an independent Honeywell indoor air quality representative install and maintain the equipment. The owners then own the equipment at the end of the two- or three-year lease. The equipment is also easily dismantled, so if the owners move, they can take it with them.

“The key is that the product is now so simple that maintenance can be done by anyone from a maid to a dishwasher to a ceo. Or if they prefer a service contract, it’s very inexpensive and can be thrown into the price of the lease. Our independent representatives can then service or repair the equipment as necessary,” says Roberts.

Bearg still isn’t sure why manufacturers are catering to smokers at all, as they comprise such a small part of the North American population to begin with. And though he’s not opposed to the technology itself, it’s not something he would ever choose to specify for a customer. “There are other more interesting and creative ways for me to earn a living and help people than to let a few more smokers smoke. As far as I’m concerned, there aren’t enough smoke-free areas yet.”

James Repace, a former EPA policy analyst and physicist who is now a secondhand smoke consultant (Bowie, MD) is another who is skeptical about using filtration for cigarette smoke. “Even expensive particulate air cleaners cannot remove enough tar particles in room air to eliminate the cancer risk from environmental tobacco smoke. In general, filtration of indoor air to remove environmental tobacco smoke contaminants is futile — like trying to filter a lake to control water pollution,” he says.

Repace also quotes from a 1994 U.S. Occupational Safety and Health Administration (OSHA) proposed rule, which states that smoke cannot be removed from the air before reaching the breathing zone of nearby employees — even by air cleaning.

Sterling doesn’t buy this logic. He has published numerous studies that demonstrate engineering provides effective solutions to ETS problems through the use of dilution directional airflow and air cleaning. “Mechanical engineering prides itself on being able to achieve solutions. If they can’t solve the problem of environmental tobacco smoke, then how can they solve other problems? I really think it’s essential — it’s not an option — it’s essential that mechanical engineers weigh in on this issue and demonstrate effective engineering options.”

Skeptical Engineers

There’s no question that many engineers are unsure about specifying ventilation and filtration systems that claim to control cigarette smoke. Any new technology in the hvac world usually takes a while to catch on. Even Bearg admits this, stating that people are very reluctant to adopt new technologies. “They know what they know and do their best to get by with what they know. It can be very frustrating,” says Bearg.

To solve this problem, Roberts says that manufacturers need to provide better education and training for engineers. “Engineers are not educated adequately to understand the option of filtration,” he says. Roberts also notes that engineers are programmed to try and solve cigarette smoke problems with ventilation alone. Roberts is adamant in stating that the hvac system alone should not be relied upon to control cigarette smoke. “To use your hvac system to get rid of smoke isn’t going to work. If it did work, we wouldn’t have a problem today. People have been throwing hvac systems at smoke for 30 or 40 years, and guess what? We’ve still got a secondhand smoke problem,” says Roberts.

He adds that restaurants that don’t have a problem with their heating and air conditioning should leave those systems alone. In addition, the minimal filtration located on an hvac system is there to protect the hvac equipment — not remove particulates and odors. The answer, says Roberts, is to provide standalone air cleaning that addresses particles and gases.

Whichever side of the smoking debate you subscribe to, one thing’s for sure — the issue is not going away any time soon. ES

SIDEBAR Mesa Muddle

Engineers and restaurants owners alike are definitely cautious about investing in any new ventilation and filtration systems. And they may have good reason. Some cities haven’t yet decided whether to allow exceptions to the “no smoking” bans in restaurants utilizing better filtration.

One such city is Mesa, AZ, where the smoking issue has been generating heated debate for the last few years. Recently a TGI Friday’s in Mesa installed an upgraded ventilation system, and the Mesa City Council agreed that it was very difficult to detect smoke in the restaurant. Therefore, they allowed the restaurant to permit smoking.

After the system had been in operation for three months, the Mesa City Council has suggested that it will reverse itself and go back to a strict smoking ban that allows exemptions only to bars that don’t serve food and to restaurants that place smokers in separate, isolated rooms. This decision came after nonsmoking advocates, including the EPA’s James Repace, told the Council that there is no ventilation system that could keep smoke from drifting around an open area.

When TGI Friday’s initially won approval to allow smoking with the new system, several other restaurants in the area installed the same system. They now hope they’ll be exempt should the Council reverse itself. The saga continues.