Qualité de l’air à Vernon

What is the level of air pollution in Vernon city now?

Vernon is a city in the Okanagan region of the Southern Interior of British Columbia, Canada. It can be found 440 kilometers northeast of Vancouver. According to a census conducted in 2013, Vernon had an estimated population of approximately 40,000 people whilst its whole metropolitan region (known as Greater Vernon) had a population of 58,500 people. With a population of this size, Vernon is ranked as the largest city in the North Okanagan Regional District.

In July 2021, Vernon was experiencing a period of very poor air quality with a US AQI figure of 212 which classified it as being “Very Unhealthy”. This United States Air Quality Index figure is calculated using the levels of six of the most prolific air pollutants, namely, nitrogen dioxide, sulfur dioxide, ozone, carbon monoxide and both sizes of particulate matter, better known as 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. The only record available in July 2021 was PM2.5 which was 162 µg/m³. Bear in mind that the recommended level by the World Health Organization (WHO) is just 10 µg/m³, Vernon’s air quality was sixteen times higher than is deemed to be acceptable. Looking at figures recorded for the previous days and forecasted figures for the following days, this is not a unique figure but part of a series of poor quality days.

Does the level of pollution vary much in Vernon City?

Because air pollution is very volatile it can be affected by many variables such as the wind which can be a good ally because it helps to disperse the pollutants, but sometimes by moving them, it just moves the problem.

According to the figures published by IQAir for 2020, there were four months of the year when the air quality was “Good” with readings between 10 and 12 µg/m³. These were the months of January, February, September and November with figures of 10.3, 11.3, 11.9 and 11.3 µg/m³, respectively. The remaining eight months of the year achieved the target figure of being less than 10 µg/m³, as recommended by the World Health Organisation (WHO). It would appear that the best time of year for air quality are the months of May, June and July. These three months returned the lowest readings of 4, 3.7 and 4.7 µg/m³, respectively.

Historically, records were kept from 2019 when the average annual figure was recorded as being 9.1 µg/m³. The following year of 2020 showed a slight improvement with a figure of 7.8 µg/m³. This figure could be due to 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 furloughed and allowed to work from home. This had the effect of noticeably 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.

What are the sources of this air pollution in Vernon?

Atmospheric emissions of natural sources can originate from forest fires, bush fires or even volcanism can be the source of atmospheric emissions of pollutants.

Anthropogenic air emissions are emissions of human origin. The distinction is commonly made according to the nature of the emission sources (mobile or stationary sources) or the sector of activity. The majority of human activities are direct or indirect sources of pollution emissions.

Industry is a major source of air emissions. The use of electricity does not emit pollutants at the place of consumption, but it very often generates emissions at the place where this electricity is produced. Examples of pollutants emitted by this sector are sulfur dioxide (SO₂), dust, metals and volatile organic compounds (VOCs).

Transportation is also a major source of air pollution whether the mode of transport is air, sea or automobile, it contributes to atmospheric pollutant emissions. Examples of pollutants emitted by this sector are nitrogen oxides (NOx), particles in exhaust gases and carbon monoxide (CO).

Any combustion generates emissions because the burning of waste, whether by an individual or in a dedicated installation, is another source of pollution. Examples of pollutants emitted are metals, hydrochloric acid (HCl) and dioxins.

During the middle part of 2020, wildfires were the main source of air pollution in and around Vernon. In the north Okanagan near Vernon, British Columbia Fire Management Service BC Wildfire responds to another wildfire, known locally as the Becker Lake Fire. Currently, it is only 1 hectare in size as is mainly under control, but the smoke is thick enough to be seen from Vernon. It is only 3 to 5 kilometers away from the city. Evacuations of remote houses in the vicinity had already started.

BC Wildfire listed more than 250 active fires in the province, 84 of which had been discovered in the past two days. Almost 20 of these blazes were considered to be fires of interest because they were particularly visible or threatening to communities and infrastructure. One of these had already burned over 1,200 hectares and was under constant observation due to its voraciousness.

It was reported that about 40 percent of forest fires were caused by lightning.

Can anything be done to improve air quality in Vernon?

One in two forest fires is the result of human recklessness. A barbecue near the forest, a cigarette thrown on the ground, DIY work: all these behaviors can cause fires to start. A forest fire can be caused naturally by lightning but also by intentional or unintentional human action. Climate change, which contributes to the drying out of vegetation, increases the risk of forest fires.

It is generally thought that 90 percent of fires are of human origin, and half of forest fires are the result of carelessness. 80 percent of fires start within 50 meters of homes. It is estimated that more than 50 percent of fire starts could be avoided by applying the right actions on a daily basis. These include not making fires or lighting barbecue near forests and green open spaces. Observe the prohibitions issued by the fire department. Do not smoke cigarettes in the forest, or in the great outdoors in times of drought, and do not throw your butt on the ground or out of the moving car.

Even if it is not the only contributor to air pollution, the transport sector plays a major role, especially in highly urbanized areas. Contrary to popular belief, diesel vehicles are not the only emitters of fine particles leaving the exhaust; new direct-injection gasoline vehicles also contribute to these emissions. In fact, it is all vehicles, regardless of their propulsion system, which generates such particles; quite simply because a good part of it comes from the abrasion of tires and brakes. These thus represent almost half of the total emissions linked to road transport in urban areas.

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. But the introduction, from 2005, of particulate filter technology, a device generalized in 2009, has drastically reduced these emissions: diesel vehicles equipped with a filter now emit a few mg/km of particles whereas they previously emitted around 50 mg/km. Particulate matter emissions from the diesel fleet thus fell by 35% between 2004 and 2013, despite the increase in the number of vehicles in use.

The abrasion of tires, brakes and the road also generates fine particles, no matter what 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.

What might come as a surprise though is the emissions of fine particles by a private vehicle linked to the phenomena of abrasion of tires, brakes and the road are approximately 5 to 30 milligrams per kilometer traveled which are levels higher than the levels of exhaust emissions of recent vehicles, both gasoline as diesel. An informed driver knows that the life of his tires and brake pads depends heavily on his driving style, and the same goes for fine particles generated by wear.

How long does the wildfire season last in British Colombia?

Wildfires are getting longer, fiercer and more costly to contain. Wildfires have burned an average of 7 million U.S. acres every year since 2000. But from 1960 to 1999, wildfires consumed half that amount which was an average of 3.5 million acres a year. U.S. wildfire seasons now last an average of 76 days longer than in the 1970s and 1980s. Before 1986, a wildfire was contained on average in less than eight days. Since then, the average wildfire has burned for 37 days.

Fires themselves are also getting harder to fight with so much fuel on the landscape, they’re just higher intensity fires. They’re risky and difficult to control, which contributes to them burning for longer. Primarily due to climate change making the ground drier easier to ignite.

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

When the outdoor air quality is poor or a smog warning (yellowish haze made up of gases and particles) is in effect, it means that there is a high amount of pollutants in the air. The main pollutants are as follows: fine particles (PM 2.5). These are tiny particles that can penetrate deep into the respiratory system. The other main pollutants are ozone (O₃), sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and carbon monoxide (CO).

The pollutants we breathe can be harmful to our health. These side effects can be felt immediately or in the longer term. Long-term exposure to sources of pollution can have serious health consequences. Vulnerable or sensitive people are people who, because of their state of health or their age, will show symptoms more quickly or more strongly following exposure to air pollution, whether short or long term. Depending, of course, on the chemicals suspended within the air.

There are certain groups of people who are more susceptible to air pollution which include pregnant women, infants and children under the age of 8 years, senior citizens who are over 65 years old and people with pre-existing respiratory problems such as cardiovascular pathologies, cardiac or respiratory insufficiency and people with asthma.

The symptoms that can be felt during a pollution episode are generally less severe than the effects associated with long-term exposure to outdoor air pollution. These symptoms could be an increase in asthma attacks, throat irritation, dryness and soreness of the eyes and nose and coughing.

Regarding particles, air pollution monitoring (measurement and modeling stations) currently focuses on particles with an aerodynamic diameter of less than 10 micrometers (PM10) and particles with an aerodynamic diameter of less than 2.5 micrometers. (PM2.5). However, more and more scientific studies are interested in particles of even smaller size such as ultrafine particles also called nanoparticles (with a median aerodynamic diameter of less than 0.1 micrometers).

The impact of fine particles (PM2.5) on cardio-respiratory mortality and morbidity is now widely documented. Various chronic pathologies (cancer, cardiovascular and respiratory pathologies, etc.) develop after several years of exposure to particles, even at low concentration levels. Other effects are increasingly highlighted: possible effects on reproduction, risk of premature birth, damage to the neurological development of the child.

Particulate Matter is a complex mixture that may contain soot, smoke, metals, nitrates, sulfates, dust, water and tire rubber. It can be directly emitted, as in smoke from a fire, or it can form in the atmosphere from reactions of gases such as nitrogen oxides.

The size of particles is directly linked to their potential for causing health problems. Small particles (known as PM2.5 or fine particulate matter) pose the greatest problems because they bypass the body’s natural defenses and can get deep into the lungs and potentially the bloodstream. Exposure to such particles can affect both the lungs and the heart and other organs in the body.