Qualité de l’air à Lincoln

Is Lincoln a highly polluted city right now?

Lincoln is the capital city of the U.S. state of Nebraska and the county seat of Lancaster County. According to a census which was conducted in 2019, Lincoln had an estimated population of 356,000 people. This ranks it as the second-most populous city in Nebraska.

In the middle of 2021, Lincoln was experiencing a period of “Moderate” air quality with a US AQI reading of 93. This United States Air Quality Index number is calculated using the levels of six of the most commonly found air pollutants, namely, nitrogen dioxide, sulfur dioxide, ozone, carbon monoxide and both sizes of particulate matter, being PM2.5 and PM10. It can be used as a standard when comparing air quality in other cities around the world. If data is unavailable for all 6 pollutants, a figure can still be calculated by using what figures there are. In the case of Lincoln, only PM2.5 was recorded which was 32.2 µg/m³. The World Health Organization (WHO) has a recommended level of 10 µg/m³, so with this figure, it can be seen that it is more than three times the suggested level.

Whilst not an extremely high level of pollution, the advice given would be to close all windows and doors to avoid the ingress of more polluted air into the rooms. Those of a sensitive disposition should avoid outdoor exercise until the air quality improves. The table published at the top of this page will help, as will the AirVisual app which can be downloaded onto your mobile so you can access the data in real-time.

Is the level of air pollution in Lincoln consistent throughout the year?

Looking back at the figures for 2020 published by IQAir, it can be seen that the month with the poorest air quality was April, even though the figure was 10.4 µg/m³, which classified it as being in the “Good” category. For the remaining eleven months of the year, Lincoln achieved the target figure as recommended by the World Health Organization (WHO) of 10 µg/m³ or less. The month with the best quality air was February when a figure of 5.4 µg/m³ was recorded. November coming a close second with 5.5 µg/m³.

Historically, records were kept since 2017 when the annual average was 11.4 µg/m³. In 2018 the reading was 7.5 µg/m³ followed by 8.8 µg/m³ in 2019. Both of the latter figures achieving the WHO target. The best figure was for 2020 when the air quality was recorded as being 7.3 µg/m³. This figure is not surprising because of the restrictions imposed by the COVID-19 situation. Many vehicles were temporarily unused as their drivers were not required to work from the office, instead they were given a temporary leave and allowed to work from home. This had the effect of drastically reducing pollution within the city center. Many small factories and non-essential production units were also closed which again lead to an improvement in air quality. We will have to wait until next year to see if the trend continues once the threat of COVID-19 had subsided.

What are the sources of this air pollution in Lincoln?

Atmospheric pollutants can be of natural origin (volcanic emissions, plants producing pollens, lightning, etc.), but also due to human activities such as transportation, industry emissions, heating of buildings by combustion, agriculture with the use of nitrogen fertilizers, pesticides and animal emissions and waste incineration.

Because air pollution is very volatile it can be affected by many variables such as the wind which is a good ally because it promotes the dispersion of pollutants, but sometimes by moving them, it just moves the problem. Rain leaches the air by dissolving the molecules of sulfur dioxide and nitrogen oxides in the water, however, the air is purified, but the rains turn acidic which is very harmful. The sun acts directly on pollution by transforming nitrogen oxides into ozone. It is photochemical pollution. Temperature: in summer, high temperatures can act on the formation of ozone. In winter, the temperature differences between night and day cause thermal inversions and pollution domes. In winter, buildings must also be heated and energy produced, which releases pollutants during the combustion of fossil fuels or biomass.

Greenhouse gas and atmospheric pollutants have an identical source: human activities (transport, housing, industry, agriculture). But unlike greenhouse gases, air pollution has a direct local effect on health and the environment. The main pollutants that pose a problem in the Lincoln region are nitrogen dioxide, particulate matter and ozone.

Can anything be done to improve air quality in Lincoln?

Particulate matter, nitrogen dioxide (NO₂) and ground-level ozone (O₃) are the pollutants that cause the most damage to human health and the environment in the USA. These pollutants are mainly emitted by road transport, residential heating, agriculture and industry. What all sources of air pollutants have in common is that they are deeply rooted in the fundamental systems of our societies for mobility, production and consumption of energy and food. These same systems are not only the main sources of air pollutants but also the root causes of the climate crisis and the rapid erosion of biodiversity. The way people move and goods are transported, the heat and power generation processes and the way we produce and consume food are, in many ways, the foundations of our current way of life. This is the reason why it is not easy to transform these systems. In many cases, this forces us to re-examine the way we build our societies and the way we live.

The relocation of industrial facilities, the modernization of domestic heaters and heaters, the use of cleaner fuels for heating, the transition to cleaner buses and trams, and the introduction of low-emission transport zones are some initiatives which could be introduced which would certainly help clean the air. These measures reduce local air pollution and, in many cases, noise, thus improving the quality of life of residents. In addition, these same measures reduce greenhouse gas emissions and, in many cases, save money.

What effect does traffic have on air quality in Lincoln?

The main source of pollution in urban agglomerations is automobile traffic: this is therefore where action must be taken. While more and more local authorities are seeking to introduce cleaner driving in the city, many cities have chosen to restrict car traffic in their city centers, or even to ban the most polluting vehicles there. Some cities have introduced Low Emission Zones where certain vehicles are prohibited from entering and others are required to pay a fee to enter. Usually, electric vehicles are exempt in order to encourage people to develop an interest in using them.

Transport is responsible for almost 30 percent of total carbon dioxide emissions. While other sectors have reduced their emissions since 1990, increased mobility has led to an increase in carbon dioxide emissions from transport.

Some say that electric vehicles are the answer to the city’s pollution problem, whilst others say that they merely move the source of pollution to where the electricity is generated. Electric cars are found to be cleaner than vehicles with combustion engines. In addition, electric cars will become greener in the future as the share of electricity produced from renewable energies will increase.

Heavy-duty vehicles usually use diesel as a form of fuel which produces a considerable amount of black carbon or soot.

Combustion of fuel produces more particulates in the exhaust in diesel engines than in gasoline engines. The older generation diesel vehicles thus emitted large quantities.

For their part, gasoline vehicles were traditionally very low emitters of particles. But the introduction of gasoline direct injection (IDE) technologies from 2007, aimed at reducing fuel consumption, has changed that.

These vehicles emit more fine particles, in particular when cold and during strong acceleration. However, in 2016, direct-injection gasoline vehicles represented 43 percent of gasoline vehicle sales in Europe, showing significant growth. And these models are spreading to gasoline ranges, an evolution that partly explains the increasing number of fine particles present in our atmosphere.

The abrasion of tires, brakes and the road also generates fine particles, regardless of the vehicle's propulsion technology.

All vehicles are concerned, including the electric vehicle, even if emissions linked to brake wear are reduced compared to a conventional vehicle thanks to energy recovery. The emissions of fine particles by a private vehicle linked to the phenomena of abrasion of tires, brakes and the road are of the order of 5 to 30 mg per kilometer traveled; levels higher than the levels of exhaust emissions of recent vehicles, gasoline as diesel.

Lincoln was named as one of the cleanest cities in the USA in 2019.

The American Lung Association’s 2019 “State of the Air” report disclosed that the Lincoln metropolitan area was one of the least polluted metropolitan areas in the country. It found that Lincoln was only one of six cities that had no unhealthy air quality days between 2015 and 2017.

Even though Lincoln is one of the cleanest cities as far as air quality is concerned, the residents are warned not to become complacent because unhealthy air quality days can happen as a result of high heat, power plant emissions and wildfires in the western U.S.

What are the detrimental effects of air pollution in Lincoln on our health?

Since 2013, particles in outdoor air have been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC). The toxicity of these particles derives from both their composition and their size. The finer the particles, the more they are able to penetrate deeply into the body and pass through the bloodstream to other organs.

Biological agents, such as pollens and molds, can also be responsible for health effects. In addition, there are several types of interactions between air pollutants and pollens since certain chemical air pollutants can promote the allergic reaction by lowering the threshold of bronchial reactivity and/or by accentuating the irritation of the nasal mucous membranes or oculars and can also act on pollen grains, for example by deforming or breaking the wall of the pollen grain, which then allows them to penetrate deeper into the respiratory system than whole pollen grains.

The effects of air pollution on health observed following exposure of a few hours to a few days (acute exposure, known as short-term) are as follows: eye or respiratory tract irritations, asthma attacks, exacerbation of cardiovascular and respiratory disorders which can lead to hospitalization, and in the most serious cases to death.

Every day, an adult inhales between 10,000 to 20,000 liters of air composed of an average of 99 percent oxygen and nitrogen. But this air can also contain various pollutants that can be the source of harmful effects on health.

People who breathe polluted air can have a variety of symptoms. These vary depending on each person's sensitivity to air pollution. In the short term, the main symptoms include eye irritation, wheezing or difficulty in breathing, irritation and inflammation of the respiratory tract which leads to coughing, and increased shortness of breath, especially during physical activity or exercise.

Breathing polluted air can also worsen symptoms in people who already have chronic illnesses, especially respiratory or heart disease. In rare cases, this can lead to hospitalization or premature death of the person.

Some groups of people are more susceptible than others. These would include people already suffering from angina, people who have had a heart attack, people with diabetes as their immune system is often lower than usual.

Pregnant women, babies and children under the age of 14 years and senior citizens are also at risk. Young children breathe more air relative to their body weight than people in other age groups. This means they breathe in more contaminants, making them more vulnerable to air pollution. Their pulmonary system and their body's defenses are not yet fully developed. As a result, young children cannot easily fight off diseases that can result from air pollution. Older adults may have weaker lungs, heart, and defense systems. They may also have undiagnosed lung or heart disease.

People who play sports or work hard outdoors breathe faster and more deeply than others. This allows more polluted air to enter the lungs.