Thursday, August 9, 2018

Wildfires and Summer Can Impact Air Quality

Sixteen forest fires are burning across California with no end in sight. The state’s largest fire on record was last year’s Ventura County fire which burned 282,000 acres. In California they name fires- it was called the Thomas Fire. This year’s Mendocino Complex fire had already burned 283,000 acres and only hopes that firefighters will manage to control those fires this week. Air quality in California north of Yuba City is “Unhealthy” due to all the smoket and particulates in the air. Air quality in the Rogue Valley of southwestern Oregon has worsened to “Hazardous” after a change in wind direction pushed more wildfire smoke from California into the area. The wind is blowing northwest.

Poor air quality can hurt the very young, the elderly and the sick. When particulate pollution is high it is best to stay indoors. On hot summer days even in areas without wildfires, air quality can be impacted. Before you drive your kids out to soccer practice or a game, check the air quality. Long term exposure to particulate pollution can cause premature death in people with pre-existing cardiac or respiratory disease, but it is simply not healthy to send the kids out to exert themselves on poor air quality days.

Air pollution in the form of fine particles with diameters smaller than 2.5 microns, called PM 2.5, lodge in the lungs which can aggravate other conditions both immediately and long term –cutting months off of lives. This fine particulate matter can have immediate health impacts: itchy, watery eyes, increased respiratory symptoms such as irritation of the airways, coughing or difficulty breathing and aggravated asthma. Long term health effects can result from both short-term and long-term exposure to particulate pollution. Two major studies pne called the "Harvard Six Cities" and the other the American Cancer Society study, both outlined the connections between human health and exposure to fine particles.

PM 2.5 is either directly emitted or formed in the atmosphere. Directly-emitted particles come from a variety of sources such as cars, trucks, buses, industrial facilities, power plants, construction sites, tilled fields, unpaved roads, stone crushing, and burning of wood and the vast fires burning California now. Other particles are formed indirectly when gases produced by fossil fuel combustion react with sunlight and water vapor. Combustion from motor vehicles, power plants, and refineries emit particles directly and emit precursor pollutants that form secondary particulates. Ammonium nitrate and ammonium sulfate are the principal components of secondary particulates.

The U.S. Environmental Protection Agency, EPA, requires states to monitor air quality and ensure that it meets minimum air quality standards. The US EPA has established both annual and 24-hour PM2.5 air quality standards (as well as standards for other pollutants). The annual standard is now 12 ug/m3 (an AQI of 39). The 24-hr standard is 35 ug/m3 (an AQI of 99.

The reason I had been thinking about air quality was the fires burning in California. This will be the second year in a row that that California has recorded the state’s “largest fire in recorded history.” California’s expanding development into the chaparral and sagebrush, lack of proper management of their forested areas combined with longer droughts seems to have brought more fires. We need to plan for the future that is coming.

Just as I keep an eye on my water quality I also spot check the local air quality. The developing world is expanding their air pollution, the United States and most of the western developed world continues to reduce air pollution. Environmental and weather events like wildfires and inversion layers can impact our air quality. If you want to take a look at real time particulate pollution levels you can see what the monitors nearest your home are reporting. Recall that the levels are reported in AQI (0-50 AQI is good air quality and 51-99 is moderate air quality). Long Park in Haymarket Virginia was reporting an AQI level of 31 as I was finishing this article. Long Park is about 3 miles from my house down route 15.

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