Qualité de l’air à Virginia

Does Virginia have polluted air?

Virginia is a state located in both the Mid-Atlantic and Southeastern regions of America, situated between the Appalachian Mountains and the Atlantic Coast. It is bordered by other states such as Washington, Maryland, North Carolina and Kentucky, and is home to an estimated 8.54 million people, as per a census conducted in 2019.

It has a climate that can be classed as ‘humid subtropical’, having highs of up to 30 degrees centigrade, all the way down to averages of minus 4 degrees in the winter months. It has made plans to close many of its coal powered plants by the mid 2020’s, and has seen success in reducing its haze and air pollution levels in the mountain regions since the closure of several of its coal plants, however despite these initiatives there are still many cities on record with less than optimal levels of pollution, with certain months of the year climbing up significantly in terms of their air pollution content.

Looking at some of the cities and their varying air qualities over the course of 2020, some of them stand out as having some less than appreciable levels of air cleanliness. One city in particular stands out, Centreville, which came in with a yearly PM2.5 average of 11.9 μg/m³. This placed it within the ‘good’ air quality ratings bracket, which requires a PM2.5 reading of anywhere between 12.1 to 35.4 μg/m³ to be classified as such. This reading placed it in 1^st place out of all cities ranked in Virginia (with the capital city of Richmond coming in at 8^th place with a reading of 8.8 μg/m³), as well as placing it in 1880^th place out of all cities ranked worldwide. Whilst Centreville’s reading was only 1.9 units shy of moving down a notch into the World Health Organizations (WHO's) target goal for the optimal quality of air at 10 μg/m³ or less, it still stands to reason that for a U.S city this is quite a high reading, and it’s ranking worldwide quite high and could thus do much to improve.

Other cities that came in with noteworthy readings of pollution were ones such as Vienna, with a PM2.5 reading of 11.4 μg/m³, and the City of Manassas at 10.3 μg/m³. Both of these cities also came in within the ‘good’ ratings bracket, making three cities in the state of Virginia come in with this rating, whilst the other 14 came in within the WHO's target goal. Whilst this demonstrates a better level of air cleanliness in other cities, when viewing their yearly readings, there are still many months where the pollution levels come in significantly higher, with the reasons as to why being discussed in short.

What are the main causes of air pollution in Virginia?

Much of the air pollution generated in Virginia comes from a small number of sources, that come together to form the larger readings of PM2.5 and other pollutants present in the air. PM2.5 refers to particulate matter that is 2.5 micrometers or less in diameter, with the ability to go down to sizes far smaller, such as 0.001 microns or less in diameter. Due to this incredibly small size as well as the large number of different materials that they are comprised of (usually a mixture of both organic and inorganic matter), they present a significant health risk when respired, and as such, they are used as a major component in the calculation of the overall AQI, or air quality index.

Some of the different sources of PM10, PM2.5 and the other various pollutants present in the air in Virginia would be ones such as pollution from the aforementioned power plants, particularly when they utilize fossil fuels such as coal or natural gas as their main energy sources. Coal is pulverized into a fine powder form in these facilities, then combusted in order to generate energy, which can lead to large emissions of harmful chemical compounds as well as dangerous particulate matter into the air. Factories can also lead to the dispersal of such pollutants into the air, although generally if they have good pollution preventing protocols in place the amount of industrial effluence can be lessened.

Other sources include vehicles and the exhaust fumes that they emit, which accounts for a very high amount of certain contaminants in the air, which will be touched on in short. Larger vehicles, or heavy duty ones as they are known (which include ones such as trucks or lorries, as well as buses) can also be a major source of pollution, particularly when large amounts of importation or exportation occurs in certain areas.

These vehicles often run on diesel fuel, and although there are many plans to reduce the number of these in use as well as phasing out a majority of diesel use altogether, they still remain prevalent on the roads and thus another source of pollution, along with the smaller personal vehicles. Even worn down tire treads can leak enormous amounts of microscopic rubber particles into the atmosphere, which can harm both human health and ecosystems.

Other sources include poorly paved roads or even road repair sites, as well as construction areas, mining sites and any other activity that assists in the dispersal of finely ground or coarse particles into the air such as dust or gravel. The formation of certain pollutants can also occur within the atmosphere during certain months of the year as well, usually as a byproduct of pollutants being exposed to large amounts of sunlight. These would be among the main causes of pollution that take place within Virginia.

What are some health problems associated with air pollution in Virginia?

Exposure to pollution can have a number of different health issues, with some variations based on individual disposition, as well as what type of pollution one is exposed to along with the length of exposure. Ailments that fall under the chronic obstructive pulmonary disease bracket (COPD) may present themselves, which includes pneumonia, bronchitis, emphysema and asthma. As well as this, scarring to the lung tissue can occur, which besides reducing full lung function and reducing life expectancy (as well as a reduction in quality of life), can also make one more predisposed to the previously mentioned respiratory diseases. Other serious conditions would be ones such as ischemic heart disease, heart attacks and even strokes, showing the seriousness that high exposure to pollution carries with it, and the growing need to reduce it.

When is the air quality at its worst in Virginia?

Observing the data collected over the course of 2020, Virginia displayed some periods of time where the PM2.5 count was higher than other months of the year. These were divided into two distinct periods, which were namely the end of the year pollution rises (which can be seen to have carried on into the early months of the following year, which is even present on the 2020 data itself), and the other time period being in the middle of the year.

As the temperature drops significantly during the winter months towards the end of the year, power plants are often pushed into working considerably harder due to the larger demand for power to heat both homes and businesses. As well as this, some people will turn to the use of firewood or charcoal to use in fireplaces in their homes, which as well as providing heat, also generates its own pollutive problems, particularly when carried out by a large number of people. The rise of PM2.5 seen in the hotter months (namely July and August) may be as a result of the formation of ozone (O₃), which as mentioned previously, can be formed due to exhaust fumes and other pollution accumulations being subject to large amounts of sunlight.

In closing, the months of November and December presented with some of the highest readings of PM2.5, with many months across various cities coming in with readings that hit either the ‘moderate’ pollution bracket (12 to 35.4 μg/m³ required) or the ‘good’ ratings bracket (10 to 12 μg/m³). However, the month of July also saw some severe rises in pollution, with the city of Centreville having a very high reading of 19.3 μg/m³, the highest seen throughout the entire year in the whole state of Virginia. Many other cities also displayed readings well above their yearly average in the month of July.

What are some types of pollution found in Virginia’s air?

Some of the main pollutants in the air would include ones that typically see emanation from combustion sources, as well as varying types of fine particulate matter. For the latter, finely ground silica dust can be thrown out by construction sites or road repair areas (along with poorly paved roads that see use from cars). Black carbon is another pollutant that falls into the tiny particle category, and along with silica dust, has potent carcinogenic effects when inhaled.

Nitrogen dioxide (NO₂) and sulfur dioxide (SO₂) are also released in large amounts by vehicles, as well as ozone (O₃) as a secondary pollutant in the atmosphere. Both nitrogen and sulfur dioxide can aid in the formation of acid rain clouds, which besides causing damage to the environment as well as buildings, can cause inflammation and irritation to the lining of the lungs, afflicting those who live near busy roads or other areas where these chemical compounds linger in the atmosphere.

Black carbon is formed alongside volatile organic compounds (VOC's) when the incomplete combustion of both fossil fuels or organic matter takes place. Some examples of prominent VOC's include ones such as benzene, toluene, xylene and methylene chloride, as well as formaldehyde (which is also found in many household products).