Oklahoma is a state in the South Central region of the United States. It shares land borders with 6 other states; Texas, Kansas, Missouri, Arkansas, New Mexico and Colorado. It is the 28th most populous state in the US with a population of almost 4 million people, in 2020. Residents are fondly known as Oklahomans or "Okies". Its largest city is also its capital which is Oklahoma City.
It is a major producer of natural gas, oil and agricultural products and relies on the aviation, energy, telecommunications and biotechnology industries as its economic base.
Throughout most of 2020, Oklahoma City experienced 9 months when the air quality met the World Health Organisations (WHO) target figure of 10 µg/m³ or less. The month of June saw a slight rise up to 12.2 µg/m³ which is still classed as “Moderate” quality air with figures between 12.1 and 35.4 µg/m³. The remaining two months of April and July saw figures of between 10 and 12 µg/m³ which classified the air as being a “Good” quality.
Records from 2019 showed an average annual reading of 9.1 µg/m³, whereas 2020 showed figures of 9.5 µg/m³. On the whole, it can be looked at as being fairly consistent.
Industrial polluters are mostly the power generating companies and chemical manufacturing units that release smog-forming pollutants into the atmosphere. However, they are not the main source of air pollution in Oklahoma: that role is filled by the emissions produced by vehicles.
It has been decided that something needs to be done about the pollutive contribution from industry. The local government put together a plan which would see voluntary measures which were aimed at reducing emissions.
107 local businesses were asked to take part, but a disappointing number of just 20 gave a positive response.
Members of the public were also asked to change their driving habits but this in itself was not enough to make a noticeable difference. Local businesses need to get involved before changes could really be noticed.
The energy sector is the state’s major industrial polluter of both smog-forming compounds. Together, the energy and natural gas industries create at least 81 per cent of the nitrogen oxide pollution in the state.
Power generation creates almost 100,000 tons of nitrogen oxides on an annual basis which is almost 50 per cent of the total state emissions. The natural gas industry comes in second place with a 35 per cent emission rate.
Following these two main polluters came cement production, refineries and paperboard manufacturers.
The power generating companies are aware of their emissions but defend themselves by stating that they only produce enough power to satiate the demands of the consumer. If they demanded less, then the output would be reduced, pro-rata.
“Ozone season” can be thought of as the time of year when temperatures increase and with it, the increase in production of ozone. Generally thought of as being from the end of March until the end of September, though seasonal variations can, and do, occur.
Because ozone is one of the main air polluters in Oklahoma, it has almost become the standard by which air quality is measured.
The U.S. Environmental Protection Agency recently issued new stricter limits on ground-level ozone. The advice given for new ground-level ozone standards is 70 parts per billion. It was said that the lower proposed figure of 65 ppb would be unobtainable at the present time and would cause unnecessary worry for many people.
The 70 ppb limit should be acceptable for most of the counties in Oklahoma State. It is thought that monitoring sites in Oklahoma City and Tulsa will record the highest levels due to the larger volume of traffic on their road networks.
States like Oklahoma also can’t prevent ozone-causing compounds from blowing in from neighbouring sources such as Texas.
Vehicle emissions threaten Oklahoma's air quality with a range of pollutants, including carbon monoxide, ground-level ozone, nitrogen dioxide and dust and other particulates. Other sources include emissions from industrial processes.
It would appear that most of the air pollution in Oklahoma comes from ozone (O3) and fine particulate matter (PM2.5 and PM10), which is virtually the same as many other US states.
Particle pollution is caused directly by sources, such as construction sites, unpaved roads, fields, chimneys or fires. Particle pollution can also be emitted from power stations, industries and automobiles.
Ozone is produced by chemical reactions involving gases from pollution sources. Ozone production reactions primarily involve hydrocarbons and nitrogen oxide gases, as well as ozone itself, and all require sunlight for completion. The EPA states that ozone is most likely to reach unhealthy levels on hot sunny days in urban environments, but can still reach high levels during colder months.
During the last two years, Oklahoma City recorded a total of 19 days when air quality readings fell below acceptable EPA standards; the days were categorised as unhealthy for “sensitive” groups, which includes people with lung disease and asthma, and for senior citizens and children under the age of 14 years. That exceeded the total number of substandard air-quality days the city recorded in the four previous years combined.
Tulsa also witnessed an increase in poor air quality days last year, with alerts on 10 days that the air was “unhealthy for sensitive groups” and one day when the entire population was warned it was “unhealthy”. That was the most the city has seen since 2013.
However, it is generally agreed that, on the whole, the quality of air has improved over the past decade.
As early as 2011, air monitoring stations across the state recorded some of the highest levels in recent history on the Air Quality Index. The EPA uses those figures to rank each day, taking into account the most common air pollutants, which are ground-level ozone, fine particulate matter, carbon monoxide and sulphur dioxide.
Air quality is a measure of how clean or how polluted the air is. Monitoring air quality is important because polluted air can be bad for health and the health of the environment. Air quality is measured using the Air Quality Index, or AQI. The AQI works in a similar way to a thermometer that runs from 0 to 500 degrees.
However, instead of showing changes in the temperature, the AQI is a way of showing changes in the amount of pollution in the air. The higher the figure: the more polluted the air.
The Earth’s atmosphere mainly consists of just two gases, nitrogen and oxygen but because of air pollution, it also contains many other gases, most of which are detrimental to health. The AQI index monitors five of the major pollutants found in the ambient air. These are ground-level ozone, carbon monoxide, sulphur dioxide, nitrogen dioxide and airborne particles or aerosols.
The AQI is usually divided up into 6 sections, colour-coded for ease of use. Each section is in increments of 50 points, where 0-50 is classed as good quality air with no foreseen problems.
The producers of this information rely on ground-monitoring stations and also satellites. GOES-R Series satellites can provide particle pollution measurements approximately every five minutes of the day, whereas JPSS satellites can provide a higher resolution measurement of aerosols over the entire planet, but only once a day.
According to the latest report from the American Lung Association, Oklahoma City’s air quality is no longer on the list of cleanest cities. Levels of both ozone and particulate pollution have increased to unacceptable levels. Oklahoma City, in particular, fails to meet the acceptable standards for particulate pollution. This placed the health of 650,000 residents at risk, including those who are more vulnerable to the effects of air pollution such as senior citizens, children under the age of 14 years and those with pre-existing respiratory problems or lung disease.
Ozone and particulate pollution are two pollutants that are dangerous to public health and can increase the risk of premature death and other serious health effects. Asthma attacks, cardiovascular damage, and developmental and reproductive harm are known to increase when subject to air pollution. It can also cause lung cancer, and new research links air pollution to the development of serious diseases, such as asthma and dementia.
When compared to previous years’ figures, it can be seen to be on the increase. It is thought the warmer temperatures which have been experienced over the last few years has had an effect on ozone production. The pollution created through a higher level of particulate matter was also recorded as being noticeably higher than the figure from previous years.
These are particularly dangerous, because of their microscopic size they can easily bypass the body’s defences and pass deeply into the lungs. Once in the alveoli, they can pass into the bloodstream and travel anywhere in the body, eventually ending up in the heart or brain. They can trigger asthma attacks, heart attacks and strokes and cause lung cancer as well as premature deaths.