Polluted Logan air is a risk to health
Utah State University’s Randy Martin, associate professor of environmental engineering, is leading research into substantial air pollution found throughout Cache Valley.
Cache Valley ranks number one in the state of Utah for PM 2.5, a pollutant consisting of fuel emissions and ammonia that can cause various health issues such as respiratory problems and lung dysfunction, Martin said.
Research has shown that PM 2.5 poses a great health risk to people; as a result, the Environmental Protection Agency has started to monitor PM 2.5 more closely, Martin said.
This particle is a health risk because of its small size. PM 2.5 is particulate matter less than two and one-half microns per diameter. It has the ability to get down into deep lung tissue and stay there for long periods of time, shutting down effective breathing, Martin said.
“The PM 2.5 is a newly regulated pollutant from the EPA and is particularly bad for people who already have compromised respiratory problems, such as people with asthma and young children whose lungs are not fully developed,” Martin said.
There are many ways to solve the problem, said Grant Koford, environmental health scientist for Bear River Health Department. The fact that USU switched to natural gas rather than coal for heating, and Logan City is now changing its generators from diesel to natural gas, will be a big help, Koford said.
In an effort to reduce PM 2.5, Logan City has restricted the number of wood stoves used during days with a lot of inversion. An inversion is when warm air is over the top of cool air and prohibits the diffusion of pollutants into the atmosphere.
However, based on USU’s study, wood stoves only account for about 10 percent of the particles that exist in the valley, Martin said.
In January, the regulations passed last year regarding wood stove use came into effect, Koford said. The regulations list three colors that code the days valley residents can use their wood burning stoves, Koford said. The color codes are red for restricted burning, yellow for caution and green for clear days for burning. Koford said residents of the valley can check their local newspapers, radio station and the Department of Environmental Quality Web site, www.deq.utah.gov/EQAMC/amc.htm, to determine what conditions are for that day.
“In addition to the restriction of wood burning stoves, Logan City has started to enforce a Utah code that has always been in effect about visible smoke on vehicles,” Koford said. “If a gas power vehicle is smoking, then they can be pulled over or reported to a hotline. They will be sent a letter saying that their car is smoking and must get it fixed. It’s kind of a warning before they get a ticket.”
Inversions are the primary cause of the increased amount of PM 2.5 in the winter, Martin said. Under these conditions, the valley’s particulate matter is trapped under the inversion cover.
“When inversion happens, it traps air pollution, and if the meteorological conditions are right, it will last for days,” Martin said. “In those situations, the pollution just builds up and builds up and builds up over days.”
Geography works against Cache Valley, Martin said. The three-sided valley with mountains to the south, east and west allows for very stagnant air. Low level inversions are a typical occurrence in the winter, Martin said.
“In the summertime, the stagnation periods don’t last as long. In the wintertime, it will be stagnant for five or six days,” Martin said. “In the summertime, there is just more dynamic atmospheric mixing.”
PM 2.5 is a problem in Cache Valley because of the high amount of ammonia from agriculture in the area, Martin said. Cache Valley ranks second in the nation for the highest amount of ammonia deposition concentration, Martin said. The high level of ammonia combined with emissions from automobiles, wood burning fireplaces, industry, oil and coal burning furnaces create PM 2.5, Martin said.
“Seventy-five thousand cows in the valley in the wintertime adds a lot to our biological waste burden and so that puts a lot of ammonia in the atmosphere,” Martin said. “Our ammonia-rich atmosphere combines with nitrates that are omitted from combustion sources, primarily automobiles in the valley, to form the various small particles.”
Koford said if Cache Valley exceeds the standard amount for three years in a row, then it is in violation. The EPA will then step in and tell the state to come up with a plan to reduce the amount of PM 2.5 in Cache County, Koford said. Items of action could range from emission tests to oxygenated fuels, and also the possible regulation of drive-through windows at banks and fast food restaurants.
“If we do exceed the limit, there isn’t much we can do about the weather,” Martin said. “What we will have to do is try to limit the sources from where these particles are coming from.”
In time, the city will most likely need to start looking very closely at vehicle inspection programs to ensure cars are not emitting a large amount of pollutants in the air, Martin said. Also, the city may need to make an effort to get more people to use the city’s transit system and promote more car pooling to limit the number of vehicles on the road, Martin said.
“There are not a lot of things we can do with the agriculture in the valley. Eventually, it will have to limit the number of cows in the valley, but that’s not practical at this point,” Martin said. “It is more practical to try to get people not to burn their wood stoves, to limit their automobiles and to increase the efficiency of traffic flow on Main Street.”
Last year, the city synchronized the traffic lights on Main Street. This should help reduce the amount of PM 2.5 during the winter because vehicles are not sitting idle as much downtown, Martin said. He added that there has been talk about a bypass west of Logan City that would allow traffic to go around town more efficiently and that could also reduce the amount of pollution.
The state has monitored Cache Valley from a regulatory standpoint for the past three years, Martin said. When it first started to monitor here, it was a very bad winter and the valley was 30 percent over the standard, Martin said.
The second winter, the valley experienced long periods of inversion and ended up with more than twice the standard, Martin said. However, last winter was a “make or break year,” and fortunately the winter was mild with little inversion, Martin said.
The state will take the last three years and average them together and this is how they will determine if the area has exceeded the limits, Martin said. Last year, Cache Valley only exceeded the standard once, so the three-year running average, which won’t be official until this December, looks like the valley will “dodge the bullet” with the average for the three years just below the standard, Martin said.
-dlalbiston@cc.usu.edu