Understanding how clean or hazardous your air is can protect your health because local air quality has an impact on how you live and breathe. A key tool in measuring our air is the Air Quality Index, or AQI by the EPA. The AQI reports daily air quality for four major air pollutants regulated by the Clean Air Act: ground-level ozone, particulate pollution, carbon monoxide, and sulfur dioxide. The AQI provides a guide to air quality and your health.
Eduardo Garcia Cancela
San Diego ranks 20 out of 25 nationwide in terms of short-term particle pollution and ranks 23 nationwide in year-round particle pollution, according to the American Lung Association’s State of the Air 2014 report.
The particles being measured by our air quality sensors are categorized as “fine particles.” These particles are 2.5 micrometers in diameter or smaller and are generally found in smoke or haze. They can be directly emitted from sources such as fires, as well as gases emitted from power plants and automobiles. The Environmental Protection Agency considers them to be dangerous because they are small enough to pass through the nose and throat. Once inhaled they can go into the lungs and can potentially cause long term heart or lung problems.
The amount of carbon monoxide in San Diego’s air is highest during the winter. This is because of the city’s proximity to the ocean as well as its year-round temperate climate, according to a September 2007 report by the City of San Diego. Rising hot air mixes with weaker cold air to clear out nighttime skies in most of the U.S. But San Diego’s cooler temperatures are augmented by persistent onshore winds blowing in from the Pacific Ocean. Those winds, along with the moisture-laden air form what is known to San Diegans as the “marine layer.” This layer is a band of tightly packed clouds that is commonly called “fog” by those living away from coastal regions. In the summer, warm air rising pushes the marine layer higher in the atmosphere. Since San Diego’s warmer months occur around the transition between summer and fall, the marine layer can completely disappear. Strong Santa Ana winds blow offshore, preventing any cooling from forming. But in the cool months of winter — often lasting through the spring — the layer sinks closer to the ground, trapping pollutants such as carbon monoxide underneath.
According to 2013 MIT Laboratory for Aviation and the Environment study, air pollution causes about 200,000 early deaths each year in the U.S. In addition, researchers found that California has about 21,000 early deaths annually from air pollution.
“Particle pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles, ” according to the EPA. Particles that are 10 micrometers in diameter or smaller generally pass through the throat and nose and enter the lungs, causing serious heart and lung problems, and other critical health issues.
San Ysidro is an air quality hotspot in the San Diego region, due in large part to the proximity of the U.S.-Mexico port of entry. Residents in the San Ysidro area living near the U.S.-Mexico border may be exposed to more air pollutants, according to a study published in the journal Atmospheric Environment. The study used rooftop air samples taken during six different time periods over a course of seven months in 2010. Earlier this month, a new air quality monitoring system was installed at the port of entry that was hailed by local officials.
Over 147 million Americans live in counties with unhealthy levels of ozone and particle pollution, and breathing in these pollutants puts them at risk of lung cancer and premature death, according to the American Lung Association.
In the effort to shield Americans from fine particulate pollution, the U.S. Environmental Protection Agency strengthened the annual health National Ambient Air Quality Standard for fine particles to 12.0 micrograms per cubic meter (µg/m3).
Studies from the U.S. Environmental Protection Agency have connected particle pollution, especially fine particles, which are particles that are smaller than 2.5 micrometers in diameter, to serious health hazards. These hazards include premature death for people with heart or lung disease, nonfatal heart attacks, irregular heartbeat, aggravated asthma, decreased lung function and irritation of airways that leads to coughing and difficulty breathing. This particle pollution can also cause coughing, wheezing and decreased lung function to children and adults who are otherwise healthy, according to the agency.
Our bodies’ natural defenses, like sneezing and coughing, are only effective against particles 10 microns or larger in diameter. Anything smaller can either get trapped in the lungs or pass through into the bloodstream. Vehicle exhaust is one such example of particulate pollution that can affect the health and lifespan of an individual.
Jennifer Alessandra Rocha Chiappini
Pollutant exposure may contribute to some adverse health outcomes in some individuals such as asthma, low birth rate and heart disease.