Qualité de l’air à Little Rock

What is the current level of air pollution in Little Rock, AR?

Little Rock is the capital and most populous city of the U.S. state of Arkansas. It can be found on the south bank of the Arkansas River. It took its name from a rock formation that was seen by the banks of the river. According to the census which was conducted in 2019, the population was estimated to be 198,000 people.

During the middle of 2021, Little Rock was enjoying a period of “Good” quality air with a US AQI reading of 46. This United States Air Quality Index number is an internationally used set of metrics supported by the World Health Organisation (WHO) and is used to compare the air quality in different cities throughout the world using comparable standards. It is calculated by using the levels of the six most commonly found pollutants. If figures are not all available, the figure is calculated using what information is available. For Little Rock, the only pollutant measured was PM2.5 which was 11.1 µg/m³. This figure is slightly above the target level as suggested by the World Health Organization (WHO).

With a level such as this, doors and windows can safely be opened to allow fresh air to enter the rooms. All types of outdoor activities can be enjoyed without fear.

Is the level of air pollution constant throughout the year in Little Rock?

Air pollution can be very volatile and, as such, can change very quickly depending on many variables, such as wind speed and direction and atmospheric conditions.

Looking back at the figures published by IQAir.com, it can be seen that the worst period of air quality was found during June when the recorded figure was 12.4 µg/m³. This was classified as being “Moderate” with figures between 12.1 and 35.4 µg/m³. The subsequent three months of July, August and September showed an improvement which put the quality into the “Good” bracket with readings of 10.7, 11 and 10.3 µg/m³. To be in this bracket, the figures need to be between 10-12 µg/m³. For the remaining eight months of the year, Little Rock achieved levels below the target figure suggested by the World Health Organization (WHO). This target figure is 10 µg/m³ or less.

The best month for quality was during February when the recorded level was 5.3 µg/m³. Historically, records for air pollution have been kept since 2017 when the figure was 9.6 µg/m³, and this figure almost remained constant for the next three years. 9.4, 9.1 and 9.1 µg/m³ again for last year. Due to the COVID-19 pandemic which swept across the world, levels of air pollution usually dropped due to many vehicles not being driven because their drivers were not required to go to work. Several factories and small processing units were also temporarily closed which again lowered emissions into the environment.

What is the main source of air pollution in Little Rock?

The American Lung Association’s 2020 “State of the Air” report found Little Rock had mixed rankings for the most widespread air pollutants which are ozone and particle pollution and both of them can be deadly.

Sources that discharge emissions include motor vehicles, coal power generation, concentrated industries and fires, whether controlled or wild.

They did report that Little Rock was found to have recorded more unhealthy ozone days when compared to last year.

Particle pollution comes from coal-fired power plants, vehicle emissions, wildfires and wood-burning devices. Also from any internal combustion engine that operates on fossil fuel, such as garden equipment and machines used in the leisure industry.

After the introduction of the “Clean Air Act” in 1970, the air quality has gradually been getting better. Year-round particle pollution levels have dropped lately thanks to the clean-up of coal-fired power plants and the replacement of old, dirty diesel engines.

Arkansas is one of the few states in the country that consistently meets all federal air quality standards for criteria pollutants such as sulfur dioxide, particulates, nitrogen oxides, carbon monoxide and lead.

Even the agricultural sector contributes to air pollution through windblown soil from erosion, fine particulates from diesel engines and controlled burning of biomass and methane emission from rearing livestock. Spreading fertilizer can also pollute the air as dust can easily be carried on the wind.

What can be done to improve the air quality in Little Rock?

Ozone Action Days (OAD) is a public awareness program supported by the Arkansas Department of Health. An Ozone Action Day is declared when weather conditions are predicted to combine with polluting emissions to form high levels of ozone, under the influence of ultraviolet light emitted by the sun. This often forms near the ground and may cause harmful health effects. People and business operators should take action to reduce emissions of ozone-causing pollutants. There are two levels of Ozone Action Days, one is color-coded orange for when those of a sensitive nature are likely to be adversely affected. The other level will be color-coded red which indicates that everyone will be affected by the predicted high ozone levels.

Some simple precautions can be taken by everybody, these include conserving electricity and setting your air conditioner to run at a higher temperature. Choose a cleaner way of commuting to work, such as sharing a ride to work or using public transportation. Cycle or walk when possible for short journeys. Try not to use lawn or garden machinery with gas-powered engines. You should also not refill your vehicle during the afternoon when the sun is at its strongest. The Ozone forecasting season is from 1^st May until 30^th September.

The local authorities have worked to develop a voluntary smoke management plan for Arkansas farmers to ensure that the practice of post-harvest crop residue burning is done in the most environmentally friendly way possible. They also actively encourage the use of solar panels especially on farms and in isolated rural communities.

Does the agricultural industry pollute the air around Little Rock?

About 3 percent of the population is employed in agriculture, which is one of the major industries in the state ranking in 13^th position in the whole country. The state of Arkansas is the country’s leader in the production of rice, turkeys, and broilers.

The poultry industry is a major cause of environmental degradation in the United States because of the sheer amount of waste products that are produced. The amount of animal waste produced in the U.S. is overwhelming. In chickens, for example, the daily production of wastes is essentially equal to the amount of feed used. This means for every truckload of feed that is brought onto the farm, a similar load of waste must be removed. Poultry manure contains large amounts of nitrogen, phosphorous, and potassium.

Factory poultry manure contains heavy metals. The 5,100 tons of poultry manure produced daily in Arkansas end up in the environment. This means that each day, 3,100 pounds of manganese, 3,300 pounds of iron, 540 pounds of copper, 3,600 pounds of zinc and 300 pounds of arsenic are created daily and need to be disposed of somehow. Arsenic is a known carcinogenic agent that when inhaled can cause cancer in humans, particularly lung cancer. Airborne contaminants in poultry confinement units include the mixture of agents comprising organic poultry dust, skin debris, broken feather barbules, insect parts, aerosolized feed and poultry excreta.

What detrimental effects on human health does the air in Little Rock have?

The main effects of air pollution on health range from alterations in lung function, heart problems and other symptoms and complaints to an increase in the number of deaths, hospital admissions and visits to the doctor, especially due to respiratory and cardiovascular causes.

In recent years there has been an advance in the knowledge and understanding of the effects of air pollution on health provided by a large number of scientific research from around the world. These studies have highlighted the importance of air quality in the health of the population and have made it possible to identify the main mechanisms of action by which exposure to air pollution causes damage to health.

The Guidelines set for the first time a guideline value for particulate matter (PM). The goal is to keep concentrations as low as possible. As there is no known PM threshold below which harmful health effects disappear, the recommended value should represent an acceptable and achievable goal to minimize such effects based on local limitations, capacities and priorities in the matter of public health.

PM pollution affects more people than any other pollutant and its main components are sulfates, nitrates, ammonia, sodium chloride, coal, mineral dust and water. PM consists of a complex mixture of liquid and solid particles of organic and inorganic substances suspended in the air. Particles are classified according to their aerodynamic diameter into PM10 (particles with an aerodynamic diameter less than 10 microns) and PM2.5 (aerodynamic diameter less than 2.5 microns). The latter poses a greater danger because, when inhaled, they can reach the peripheral areas of the bronchioles and alter the pulmonary gas exchange. It is from here that they can also enter the bloodstream.

Chronic exposure to the particles increases the risk of cardiovascular and respiratory diseases, as well as lung cancer. Exposure to pollutants from solid fuel combustion in open fires and traditional indoor stoves increases the risk of acute lower respiratory infection and mortality from this cause in young children, it is also a major risk factor for chronic obstructive pulmonary disease and lung cancer among adults. Mortality in cities with high levels of pollution is between 15 percent and 20 percent higher than that registered in cleaner cities.

As an atmospheric pollutant, nitrogen dioxide can be correlated with several activities. In short-term concentrations greater than 200 µg/m³, it is a toxic gas that causes significant inflammation of the respiratory tract. It is the main source of nitrate aerosols, which constitute an important part of PM2.5 and, in the presence of ultraviolet light, ozone.

The major sources of nitrogen dioxide emissions are combustion processes using fossil fuels such as heating, electricity generation, and vehicle and ship engines.

Ground-level ozone which should not be confused with the ozone layer in the upper atmosphere is one of the main components of smog. It is formed by the reaction with sunlight (photochemical) of pollutants such as nitrogen oxides (NOx) from emissions from vehicles or industry and volatile organic compounds (VOCs) emitted by vehicles, solvents and industry. The highest ozone levels are recorded during periods of sunny weather, the highest level is attained during the early hours of the afternoon.

Excess ozone in the air can have serious adverse effects on human health. It can cause breathing problems such as asthma, reduce lung function and lead to lung disease. It is currently one of the atmospheric pollutants of greatest concern. Various studies have revealed that daily mortality and mortality from heart disease increase by 0.3 percent and 0.4 percent respectively with an increase of 10 µg/m³ in ozone concentration.

Even young, healthy people can experience negative health impacts due to polluted air including respiratory irritation or breathing difficulties during exercise or strenuous outdoor activities. The actual risk of adverse effects depends on the current health status, the pollutant type and concentration, and the length of exposure to the polluted air.

Those most susceptible to severe health problems from air pollution are individuals with pre-existing heart disease, coronary artery disease or congestive heart failure. Pregnant women, children under the age of 14 years, senior citizens and those whose job compels them to spend prolonged periods outdoors are also at a higher risk.

High levels of air pollution levels can cause immediate health problems such as aggravated cardiovascular and respiratory illnesses. It adds stress to the lungs and heart because they have to work harder to supply the body with the correct level of oxygen that it needs. Cells within the respiratory system can become irrevocably damaged.

Exposure to polluted air over prolonged periods of time presents its own permanent problems. These may include accelerated aging of the lungs, which leads to loss of capacity and a decrease in their functionality. Diseases such as asthma, bronchitis, emphysema, and possibly cancer develop more readily under these conditions. Ultimately, it can shorten the lifespan.