Knowledge Building: In-Car Air Quality
While the topic of air quality is obsessed over in many Canadian homes and offices, it is almost forgotten when people jump into their cars–where they spend hours on end, and often experience the worst air quality of all.
The fact is that the air inside a car can be so polluted, we would be better off standing beside the highway at rush hour.
A study conducted in July 2000 by the International Center For Technology Assessment in Washington, D.C. starkly outlined the problem.
“The results of 23 separate scientific studies conducted during the 1980s and 1990s reveal that in-car air pollution levels frequently reach concentrations that may threaten human health,” reported the study. “The reports show that the air inside of cars typically contains more carbon monoxide, benzene, toluene, fine particulate matter, and nitrogen oxides than ambient air at nearby monitoring stations used to calculate government air-quality statistics. In-car pollution is often even worse than pollution in the air at the side of the road.
“Public health officials frequently issue warnings reported in local weather broadcasts when concentrations of auto pollutants exceed healthful levels in the ambient air,” it continued. “[However,] the air quality inside of cars is typically much worse. In-car benzene concentrations sometimes exceed concentrations in the roadside air by up to fourfold. Carbon monoxide concentrations may be more than 10 times higher inside of cars than at the side of the road. Elevated in-car pollution concentrations particularly endanger children, the elderly, and people with asthma and other respiratory conditions.”
The study summarized its findings with a rather chilling conclusion: “While it receives little attention, in-car air pollution may pose one of the greatest modern threats to human health.”
Though the study was published before the widespread use of more effective filtering systems for passenger compartment ventilation–the cabin air filters that are now on some 40% of new cars built in North America (versus 70% in Europe), according to a Freedonia Group study–the issue remains no less important.
With the time commuters spend in cars increasing annually–Canadian average 59 minutes just going to work and back, up nearly 10 minutes in the last decade–the fact that cars might have particulate filters, or the more sophisticated combination filters that also subdue some gaseous pollutants, means little if those filters remain in place long past their useful life of less than 20,000 km.
For most Canadians, that would mean a yearly replacement, but most Canadians–and this includes those working in service bays–seldom think about the hidden cabin air filter, never mind focus on its replacement.
This despite the fact that there is a raft of research–both specific to air quality in vehicles and air quality in general–to support the need to pay attention to air quality.
For example, studies by the World Health Organization and the American Academy of Paediatrics conducted two analyses in 2004 that concluded that significant harm could come to children due to air quality issues, particularly particulate pollution.
Among the conclusions were particle pollution, particularly traffic-related pollution, can result in both short- and long-term decreased lung function, can aggravate asthma, and can lead to a greater prevalence of bronchitis, coughs, and respiratory infections. And, when you combine the warnings about the dangers of living adjacent to high-traffic areas with the findings that the air inside the car may be worse, it should at the very least convince those who own cars equipped with air-quality filtration systems to maintain those systems.
The most highly effective type is the combination filter, which includes activated charcoal along with particle filtering media to reduce gaseous contamination and odours as well as particles of dust, pollen, and combustion by-products (among other sources). This type can reduce diesel odour by 80%, according to a 2006 paper published by Heinz Reinhardt and Ulrich Stahl, of filter manufacturer Freudenberg Vliesstoffe AG.
But it does have a limited life.
“To ensure that the air entering the passenger compartment through your vehicle’s heating, air conditioning and vent system is uncontaminated, your vehicle’s cabin air filter must be clean and functioning well,” says Ramon C. Nunez, director of filtration for Robert Bosch, LLC.
“In our daily travels, whether you realize it or not, we are affected by a number of different odours – from excessive air pollution to local oil refineries, landfills, and farms. In fact, the number one odour people dislike most is the smell of fish, which we often experience when driving near waterfronts,” says Alan Hirsch, M.D., a neurologist and psychiatrist at the Smell & Taste Research and Treatment Foundation in Chicago, in a press release from Honeywell, which supplies the Fram brand of filters.
Also known as Dr. Smell, Hirsch frequently lectures around the US and has served as an expert on smell and taste for CNN, Good Morning America, Dateline, 20/20 and The Oprah Winfrey Show.
“My studies over the last 20 years suggest that ambient odours are more than just unpleasant; they can actually produce various negative effects on human emotion, behaviour and physical health. Smells can affect mood faster than any other sense, and they can be very distracting, especially while driving.”
Dr. Hirsch suggests that preventing bad smells from entering the vehicle’s interior cabin, or having only good smells present, could increase learning speed and concentration.
“It’s easy to get distracted by foul or unpleasant odors. Research suggests that we can’t focus as well as when we are exposed to either pleasant odours or no odours at all,” says Hirsch.
So, in addition to the more dire consequences of poor air quality, can we also blame road rage and accidents on bad smells? Perhaps not, but it seems that they could be contributing factors to less than ideal driving conditions, which can’t be a good thing, for your customers or their cars.
According to Shiv Manjunathaiah, a leading filter engineer with Honeywell Int’l, the effect of lack of maintenance depends on how polluted the filter’s ambient environment is. There could be a reduction in airflow only, or worse. “You could be affecting your HVAC system with a lot of corrosion. That is really not known. People tend to live with it, and put it down to mileage.
“People are starting to get more sensitive about it,” he adds. “If you are in a real dusty environment, you can use up the filter quickly and block the airflow.
“That other part is the musty smell. That is because of all the mildew and fungus that grows on it. If you don’t change it, the filter gets wet and that musty smell comes into the cabin.
“That smell is actually mould, and for people with allergies, this is a very serious matter. It is a sensitive matter, just as it is in a home filtration system. There are stringent tests for stopping allergens, and regulatory agencies [of home systems].” -However, no similar standards exist for cabin air filter performance. “The automotive industry is a little scared of making those claims, even if there are some products that may have those benefits.”
Regardless of industry reluctance, what is more telling is the fact that few consumers even know their car has one, a point which must be laid squarely at the feet of the automotive industry.
While some sectors–notably the quick lubes–offer inspection and replacement of easy-to-reach models, most repair facilities have yet to take advantage of promotional tools designed to raise awareness, or make it part of their standard inspections.
With the rising incidence of the pollution hazard in the vehicle population, the attendant health and comfort benefits of proper filtration, and the high probability that virtually every car equ
ipped with a cabin air filter that you and your customers will encounter is overdue for replacement, it would be wise to consider adding it to the standard, routine maintenance offering.
What is particle pollution?
Particle pollution, also called particulate matter or PM, is a combination of fine solids and aerosols that are suspended in the air we breathe.
Particles are made up of different things. “A mixture of mixtures” is how the U.S. Environmental Protection Agency (EPA) describes them. PM can be solids, like dust, ash, or soot. PM can also comprise completely liquid aerosols, or solids suspended in liquid mixtures.Particles are different sizes. The ones of most concern are small enough to lodge deep in the lungs where they can do serious damage. They are measured in microns. The largest of concern are 10 microns in diameter (PM10). The group of most concern is 2.5 microns in diameter or smaller (PM2.5). Some of these are small enough to pass from the lung into the bloodstream, just like oxygen molecules. By comparison, the diameter of a human hair is huge at 70 microns.
Particles come from different sources.
Burning fuel is a major source of the smallest types of particle pollution-whether from woodstoves to diesel trucks and buses to coal-fired power plants. Larger particles also come from other sources, including agricultural practices or wind-blown soil and dust.
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