Why We Test


Understanding Vehicle Emissions

Motor vehicles are a necessity for Utah citizens and businesses alike; however, the emissions they emit create very real health and environmental concerns. When unregulated, motor vehicle emissions are contributors to respiratory and cardiovascular issues, are linked to asthma and lung cancers, and can detriment soil quality. We, here at the Davis County Air Quality Bureau (a body of the Health Department), are committed to doing our part in the State of Utah’s push for cleaner air and healthier lives through the effective identification and repair of gross polluting vehicles.

Internal combustion engines, both gasoline and diesel, emit harmful byproducts that cause adverse health effects in people. The primary emissions of motor vehicles are Hydrocarbons (HC), Carbon Monoxide (CO),Nitrogen Oxides (NOx) and Particulate Matter (PM). Even at controlled levels, these emissions can cause respiratory problems, such as childhood asthma and adult-onset asthma. At high levels, these individual chemicals are highly toxic and can cause cancer, birth defects and long-term damage to the respiratory, cardiovascular and nervous systems. In 2011, http://www.lung.org/  reported that the transportation sector significantly contributed to the presence of these emissions (numbers are approximates):
  • 13% of primary fine particliate matter (PM2.5)
  • 59% of Nitrogen Oxide (NOx)
  • 33% of Carbon Dioxide (CO2)
  • 46% of Volatile Organic Compounds (VOC)

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Respiratory Health and Vehicle Emissions

Strong evidence is emerging that suggests asthma cases increase in residential populations positioned closer to roadways. In 2010,the Health Effects Institute (HEI) published a review supporting the relationship between traffic-related air pollution and its adverse health effects on the respiratory and cardiovascular systems. The evidence concluded that traffic-related air pollution triggers asthma attacks in children, and may contribute to the onset of childhood asthma, impaired lung function, cardiovascular disease and premature death. The results of the 2010 HEI review compounded the growing number of studies and reviews linking traffic-generated air pollution to adverse respiratory health. The links below showcase these studies: The CDC reports that approximately 1 in 12 people in the United States suffer from asthma, including 1 in 10 children, and both of those numbers continue to rise annually. With substantial evidence linking traffic-related emissions and respiratory issues, particularly asthma, it is important that we approach emissions-control programs as critical elements in maintaining and improving air quality that reverse these trends. Vehicle inspections are a key component in this push for better air quality and healthier lives.

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Why Vehicle Inspection Programs Fail

Motor vehicle inspection programs undergo continued scrutiny regarding their effectiveness. The core question in the national exchange has been, “do they actually improve air quality?” The answer is, “not always.”

Many jurisdictions around the country implement vehicle inspection programs simply as a response to federal requirements. In order to protect federal investment in their state, these jurisdictions opt for program designs that inspect the bare minimum of their local fleets, which is ineffective in producing sustainable gains in air quality. Regardless of whether an emissions program actually cleans the air, it still requires public expenditures and investments to implement and manage the program. For those programs providing the bare minimum inspection models, these become wasted, public funds enabling government waste to persist, without a direct return for the citizens affected by the program. This model sacrifices public investment, public trust and good air quality for the receipt of more federal investment.

Ultimately, these low-return programs will face the court of public opinion and, per the ineffectiveness inherent in their very design, will be viewed skeptically and offered up for divestment and/or legislative repeal. While a few may view this as a political victory, ultimately everyone loses in these situations.

The divestment and repeal of vehicle emission programs means that dirty vehicles will no longer be removed from the roads we all use. Gross polluters are permitted to operate their vehicles, often at toxic levels and with an indicative level of smoke spewing from their engines. For all the pollution that can be seen piling out of a tailpipe, there is significantly more that cannot be seen. PM2.5, for instance, is a byproduct of internal combustion engines that is invisible to the naked eye, but is a lethal pollutant emitted en-masse from uncontrolled vehicles.

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Why Air Check Davis County Succeeds

AirCheck Davis County is at the forefront of restoring the integrity of these important programs that, when properly managed, effectively remove heavy-polluting vehicles from the roadways to create good, sustainable air quality moving forward. It is not enough for us to just meet the federal standards; we care about the health of our citizens and the quality of our environment. For this reason, we here at the Davis County Health Department selected a program design that does what it’s meant to do – keep our air clean!

Certain jurisdictions have provided the path for sustainable, air quality improvement measures. The Los Angeles Basin in California, a historical image of smoggy skies, today boasts the largest turnaround in air quality in the world. The area is subject to some of the most stringent and comprehensive vehicle testing in the world.

% Decrease in Ground Level Ozone (03) Concentrations (ppm), 1980 - 2010
South Coast (LA) Air Basin vs. National Average (8-hour Average)
Range (Years) National Average* South Coast (LA) Air Basin†
1980 – 2010 28% decrease 67% decrease
1990 – 2010 17% decrease 36% decrease
2000 – 201011% decrease 22% decrease
Sources: *EPA (graph/data) †AQMD (graph/data)

While the South Coast (LA) Air Basin is still above the national average, the area has made considerable gains against the national average due to the comprehensive and responsible emissions program California administers. These decreases in ground-level ozone are essential for local, state and regional health initiatives aimed at improving air quality and lessening the prevalence of respiratory and cardiovascular attacks. It is because of the gains seen in responsibly implemented programs and the forecasted growth in the Wasatch Front that Davis County opted for a program that provided measurable air quality control.

For 2012, the AirCheck Davis County Program inspects all on-road passenger vehicles and trucks, of all  fuel types. The inspections administered via the program identify vehicles that emit excessive levels of pollution.

By including nearly every vehicle registered in Davis County and not focusing on a myopic group of model year vehicles, the AirCheck Davis County Program is able to identify the grossest polluting vehicles and eliminate excessive pollution for the health of all Davis County residents and guests.

As the Wasatch Front area continues to grow and new businesses bring new neighbors, it is important that we remain vigilant in our missions to maintain the air quality that makes Utah a national model for better living. To ensure we achieve our clean air goals and protect public investment through a program that satisfies the federal standards and creates measurable gains in air quality, AirCheck Davis County implements the nation’s most dynamic inspection parameters to-date.

Returning to the core question, “do inspection programs actually improve air quality?” The answer is, “yes.”

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