Qualité de l’air à Ashland

Is Ashland a highly polluted city now?

Ashland is a city in Jackson County, Oregon. It is located about 26 kilometers north of the state border with California towards the southern end of the Rogue Valley. According to a census conducted in 2010, Ashland had an estimated population of approximately 21,000, this had grown to 22,000 over the next nine years.

At 23.00 on 10^th August 2021, Ashland was experiencing a period of air quality that was classed as being “Very unhealthy” with a US AQI figure of 276. This United States Air Quality Index number is calculated using the levels of six of the most prolific air pollutants, which are 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. For Ashford, only PM2.5 was available which was 225.9 µg/m³. The World Health Organization (WHO) has a recommended level of 10 µg/m³, so with this figure, it can be seen that the level in Ashford was over 22 times the recommended safe level, although no level of pollution is thought of as being safe.

With pollution at this level, the recommendations are to stay indoors and close all doors and windows to prevent the re-entry of more polluted air. An air purifier would be beneficial if one is available, which needs to be calibrated to re-circulate the air and not suck more in from outside. Avoid outdoor exercising until the air quality improves but if venturing outside is unavoidable, then wearing a good quality face mask is essential. The table that is published at the top of this page should help with that decision or download the AirVisual app for constant updates as to the state of the air in real-time.

Does the level of air pollution in Ashland remain the same throughout the year?

Looking back at the figures released by IQAir for 2020, it can be seen that the worst month for air quality was during September when the recorded figure was 78.4 µg/m³ which was classified as being “Unhealthy”. Any figure between 55.5 and 150.4 µg/m³ would be classified as such. October was seen to be the next worst with a figure of 16 µg/m³, which was quite a reduction from the previous month and placed it into the “Moderate” group. For the remainder of the year, Ashland achieved the target figure of 10 µg/m³ or less as recommended by the World Health Organization (WHO). The best quality being seen during June when it was 2.8 µg/m³. April and May also returned low figures of 3.3 and 3.0 µg/m³.

Historically, records pertaining to air quality have been kept since 2017 when the average figure was recorded as being 10.9 µg/m³, which would be classed as boing “Good”. The following year of 2018 saw a decline in quality when a figure of 14.8 µg/m³ was recorded. This would be from the “Moderate” air quality bracket. A noticeable improvement was registered in 2019 when the WHO target figure was attained. The actual figure was 6.4 µg/m³. A decline was seen in 2020 when the average figure was noted to be “Moderate” again with a reading of 12.4 µg/m³.

This figure came as a surprise because of the restrictions imposed by the COVID-19 pandemic. Many vehicles were temporarily unused as their drivers were not required to work from the office, instead they were furloughed and were encouraged to work from home. This had the effect of drastically reducing pollution within the city center, due to the reduced numbers of vehicles on the roads. Many small factories and non-essential production units were also closed which again lead to an improvement in air quality. Yet, for some reason, Ashland recorded the worst annual average figure since records began.

Where does all this polluted air in Ashland come from?

The majority of Oregon's air pollution originates from motor vehicles, a common trend across US cities. Other sources include fossil fuel-based energy production, wood-burning, construction, manufacturing, industry and wildfires. When wildfires are burning they create a huge spike in poor quality air but they are not prevalent throughout the year.

The main sources of air pollution linked to automobile traffic are from cars, trucks and buses. When an engine burns fuel, either gasoline or diesel, it releases pollutants into the air that can harm your health, such as nitrogen oxides, carbon monoxide, fine particles such as PM2.5 and PM10 and volatile organic compounds (VOCs). Additionally, the part of the gasoline used by the engine that evaporates without being burned and the wear of tires, brakes and the road surface also cause air pollution. Tons of microscopic particles of rubber are produced every year which find their way into the surrounding land and eventually can end up in the food chain. Emissions from automobile traffic also contribute to the formation of smog.

Almost half of everyone living in the United States which is estimated to be 150 million, live in areas that don’t meet federal air quality standards. Passenger vehicles and heavy-duty trucks are major sources of this pollution, which include ozone, particulate matter, and other smog-forming emissions.

It has been proved that passenger vehicles are a major pollution contributor, producing substantial amounts of nitrogen oxides, carbon monoxide and other pollutants. In 2013, the transportation industry as a whole contributed more than half of the carbon monoxide and nitrogen oxides, and almost a quarter of the hydrocarbons emitted into the environment.

What is the truth behind the wildfires which devastate the western states of the USA?

Dangerous brush fires burning in the northwestern United States threaten Indigenous lands already struck by one of the worst droughts in recent memory. About 60 fires have so far destroyed more than 4,000 square kilometers in a dozen western states, including Oregon and Washington.

In Oregon, the Bootleg Fire, which has so far incinerated at least 20 homes, continued to burn near the California border. At least 2,000 houses are threatened by the flames.

An official warned that the fire is doubling in size every day. The flames now cover 815 square kilometers, and firefighters have sometimes had to retreat to keep them safe, and the weather doesn't look like it will improve anytime soon. Wind speeds are increasing and fanning the flames.

Scientists warn that climate change is making the West hotter and drier, and the weather will become more unpredictable as the world warms.

Only a small percentage of wildfires are started by man’s careless actions, most are started by dry lightning strikes.

What can be done to alleviate the poor air quality in Ashland?

Cleaner vehicles and modern fuel technologies provide us with an affordable means of reducing transportation-related air pollution and climate change emissions. These vehicles are already rolling off the production line. These include fuel-efficient vehicles that use less oil; cleaner fuels that produce fewer emissions and electric cars and trucks that can entirely remove exhaust emissions.

Strong federal and state policies also help. Tougher vehicle emission standards have helped cut pollution from cars and trucks by about 90 percent since 1998, with further improvements coming from the introduction of the latest Tier 3 standards. Future emissions reductions from trucks and other heavy-duty freight carrying sources are essential for meeting air quality standards and helping to protect the health of those who live and work close to ports, rail yards and freight corridors.

Zero-emissions vehicles (ZEVs) or electric vehicles (EVs) eliminate exhaust emissions by replacing a gasoline or diesel engine with an electric motor. Removing the exhaust fumes results in zero carbon dioxide emissions from the vehicle and significantly reduces air pollution. However, they still produce some pollutants through the wear and tear on their tires, brake pads and abrasion of the road surface. These tiny particles of rubber accumulate around the road perimeters and eventually settle in the surrounding soil where they can then become part of the food chain as plants absorb them as they grow.

Low-emission zones are being slowly introduced in some larger cities where vehicles that produce standard emissions pay a fee to use them and enter. Electric vehicles would pay no such fee as it is based on emissions produced. This is an ideal way of operating clean zones within the city. Cycles and pedestrians are encouraged to make use of these areas too. The introduction of cycle paths and walkways are being installed to encourage more use. These areas make the ideal place for people to exercise because of the comparative lack of air pollutants that are usually inhaled. Usually, there will be areas where trees are planted as they are known to help clean the environment.

What effect does poor quality air have on human health?

Due to legislation, technology and the relinquishment of highly polluting fossil fuels in many countries, air quality in the US has been improving over the last decades. However, air pollution continues to negatively affect a wide range of the population, especially in cities. Because of its complexity, tackling air pollution requires coordinated action at multiple levels. To engage citizens, it is essential to provide them with up-to-date information in an accessible way. There are so many apps now that are downloaded to smart devices, it makes it much easier to monitor the situation in real-time.

According to the WHO, suspended particles (Particulate Matter) affect more people than any other pollutant. Its main components are sulfates, nitrates, ammonia, sodium chloride, coal, mineral dust and water. Particles are classified according to their diameter into PM10 (particles with an aerodynamic diameter less than 10 microns) and PM2.5 (aerodynamic diameter less than 2.5 microns). The latter is the most dangerous because when inhaled, they can reach the bronchioles and alter the pulmonary exchange of gases, causing respiratory diseases, and even cancer.

The health effects of PM2.5 and PM10 are produced by the levels of exposure to which most of the urban and rural population are subjected in both developed and developing countries, increasing the risk of cardiovascular and respiratory diseases, as well as lung cancer. But there are also other pollutants that are equally highly harmful to health, such as sulfur dioxide. Studies indicate that a percentage of people with asthma experience changes in lung function and respiratory symptoms after periods of exposure to sulfur dioxide of as little as 10 minutes.

Although carbon dioxide is perhaps the substance that contributes the most to global warming and climate change, the truth is that it is not the only one. Many other gaseous or particulate compounds, known as 'climate pollutants', influence the amount of solar energy (including heat) retained by the Earth.

Methane for example, is a very powerful climate pollutant, as well as an atmospheric pollutant associated with agricultural activities, closely associated with livestock production and meat consumption. Particulate matter affects both climate change and air quality. Depending on its composition, it can have a cooling or warming effect on the local and global climate. For example, black carbon or soot, which is one of the components of fine particulate matter and the result of incomplete combustion of fuels, absorbs solar and infrared radiation in the atmosphere and therefore causes a warming effect. It can often be seen at the side of the roads as it hangs onto the vegetation.

Air pollution is not the same everywhere. Different pollutants are released into the atmosphere from a wide variety of sources. Road transport, agriculture, power plants, industry and households are the largest emitters of air pollutants in the US, together with the seasonal spikes caused by wildfires. Once in the atmosphere, these pollutants can react with each other under the influence of ultra-violet light into new ones and spread. The design and implementation of policies to address this complexity are not simple tasks.

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