جودة الهواء في Shasta County

Is there air pollution present in Shasta?

Shasta is currently experiencing a high bout of polluted air, with the whole month of August 2021 coming in with sizeable elevations in its US AQI and PM2.5 readings. Both of these are measurement units of air pollution, with PM2.5 being ultrafine particle pollution. Both will be discussed in further detail following the explanation of the air pollution situation present in Shasta.

As mentioned, August saw some fairly severe levels of pollution present, indicating that the air was permeated with smoke, haze, smog and clouds of harmful fine particles. US AQI readings are a number aggregated from the various main pollutants found in the air, which include coarse and ultrafine particles (PM2.5 and PM10). In late August of 2021, a US AQI reading of 164 was recorded, placing Shasta into the 'unhealthy' air quality rating bracket, color-coded as red and requiring a US AQI reading of 151 to 200 to be classified as such. the PM2.5 count was also found to be 8 times higher than the WHO's exposure recommendation, indicating that the air at the time in which these readings were taken would be harmful to the entire population’s health, and even more so to vulnerable individuals.

Other US AQI readings present over the month of August were ones such as 237 and 252, which would have placed Shasta into the very unhealthy air quality rating bracket. Absolute highs of 335 and 356 were also recorded, placing Shasta into the ‘hazardous’ air quality rating bracket, the highest possible one that can be achieved at a US AQI reading of 301 and beyond. As the name indicates, the air pollution level would be extremely dangerous and the chance of adverse effects occurring considerably higher, even more so than the above mentioned 'unhealthy' air quality reading, which would still present many health risks to those living in the surrounding area.

Why is Shasta experiencing polluted air?

Apart from the previously mentioned forest fires contributing heavily to the extremely elevated levels of pollution, there are many other sources of air pollution present in Shasta that can assist in bringing up the ambient pollution levels. When any amount of anthropogenic or industrial activity takes place, many related sources of pollution come with them, due to processes such as the combustion of fuels occurring in the many factories throughout the state and around Shasta, as well as car engines, power plant boilers and other similar industrial processes that rely on combustion all contributing to the overall pollution level, giving off their unique types of chemical pollutants and fine particles into the atmosphere.

As touched upon, vehicles are a relatively large contributing factor to consistently rising air pollution levels in Shasta and throughout much of the state of California. A multitude of these vehicles are in use, which includes among them ones such as cars, motorbikes and heavier freight vehicles, often used for the transportation of industrial materials, goods and other items or produce. These are vehicles such as trucks and lorries.

A large number of vehicles in particular areas throughout the state of California utilize diesel as their primary source of fuel, and as such can give out significantly more pollutants, typically those that come from the combustion of fossil fuels.

Vehicles also release many tons of ultrafine rubber particles, due to the residual degrading of tire treads over a long period causing this to happen. These microscopic rubber particles enter into the air and can cause a plethora of health problems when inhaled. Furthermore, they can settle on the soil, bodies of water and other areas where they can cause ecological and environmental damage, entering into the food chain which can bring with it many problems for future generations.

As was also mentioned earlier, smoke from fires is the largest contributor to severe elevations in air pollution levels. The PM2.5 readings that were recorded throughout 2020, as well as the US AQI readings currently occurring in mid-2021, are indicative that they can cause hazardous bouts of air pollution to take occur, carrying with them far more health risks, environmental damage and elevations to the overall pollution readings than any other source of air pollution present in both Shasta and the whole of the United States, due to the large clouds of smoke and particle pollution that they can release.

The geography in the state of California can also assist in keeping the pollution levels high. With the presence of several different forest fires currently taking place, along with ones from years past, (referring in particular to the 2020 forest fires ravaging much of the state in mid to late 2020), California is subject to higher than normal pollution levels, reaching dangerous PM2.5 and US AQI figures, particularly when all of the correct meteorological and industrial/anthropogenic conditions are met.

What are ultrafine particles and what health risks do they pose in Shasta?

PM2.5 refers to particulate matter that is 2.5 micrometers or less in diameter, making it roughly thirty times smaller than that of a human hair, in diameter. Due to this minute size, as well as being able to go down to sizes many microns smaller, it can penetrate deep into the tissue of the lungs upon breathing, causing many health issues to occur.

Additionally, it can also cross into the bloodstream due to its size, making it one of the most dangerous pollutants that can be found in Shasta and throughout the rest of the world. The small air sacs or alveoli that are transport oxygen into the bloodstream instead allow these tiny particles to pass through the blood barrier, allowing them to travel to the furthest reaches of the body.

PM2.5 can be made up of materials such as nitrates and sulfates, dust and soot, various metals, along with other ultrafine materials such as silica and gravel dust. Water and other liquid vapors can also fall under the PM2.5 bracket, along with mold spores and fungi, bacteria, and other dangerous inorganic materials or microorganisms. These all make up the PM2.5 classification, with any material under the 2.5-micrometer size being classed as such, with the more harmful ones being of greater importance in reducing their level in the air.

What further health issues can arise from pollution exposure in Shasta?

Aside from the high PM2.5 readings on record from times past in Shasta, there are still other times of the year where the air quality sees improvements. Whilst there are readings from times past that have fallen within the World Health Organization's (WHO's) target goal for the best level of air quality, it is still always possible for air pollution to occur within localized areas, with air quality levels falling based on the human activity taking place, in combination with meteorological conditions.

Though pollution has a potent ability to affect all members of the population, there are many groups of people that are far more vulnerable to exposure. These sensitive or at-risk groups include people who are far more likely to succumb to the many illnesses brought on from excessive breathing of chemical compounds in the air, as well as the ultrafine particles and other air contaminants adding to their health issue risk.

These groups are people such as young children and babies, as well as the elderly. The elderly can be particularly vulnerable when it comes to health issues from breathing pollutants. Respiratory infections or mild coughs or colds can develop into more life-threatening illnesses, with this possibility rising alongside the pollution levels, hence why bouts of extreme pollution caused by fires are such a risk to this demographic. Others that are considered to be at-risk groups are those who have a poor level of health, which can be made worse by being sedentary or smoking.

Others include those that have pre-existing health conditions or compromised immune systems. Certain individuals may exhibit hypersensitive reactions when exposed to the many different air contaminants or fine particulate matter in the atmosphere, causing skin rashes and possibly respiratory distress.

Besides at-risk individuals being the ones that need to take extra care during bouts of heightened pollution levels, it is of importance to note that no groups are safe from pollution exposure, and this includes any levels of pollution. Even small levels of certain pollutants in the air have a chance to cause adverse effects and trigger off certain pre-existing conditions.

Regarding health issues and illnesses, the first to appear will generally be ones such as dry coughs, chest pains and infections, as well as irritation of the respiratory tract. These will generally abate, or decrease in severity when exposure to pollution is halted. Regarding fine particles once again, when they enter into the bloodstream, they can cause many serious conditions.

A vast number of these PM2.5 materials (such as the variety mentioned above in the PM2.5 question) are linked to elevated cancer rates, due to them possessing carcinogenic properties (with ones such as soot being a known carcinogen). This is released in large amounts from fires, along with factories and industrial processes. Car engines also release these from the combustion process that takes place in their engines, putting them into the atmosphere via their exhaust pipes. Because of the large amount of its release from wildfires, black carbon presents a major hazard to the health of those living in Shasta whilst wildfires are taking place.

Regarding skin conditions related to pollution exposure, ones such as acne, atopic dermatitis, psoriasis as well as other rashes such as eczema can also present themselves during periods of high pollution levels, due largely to ultrafine particles clogging the pores of the skin, as well as irritation to the skin being caused by certain chemical compounds.

Chronic obstructive pulmonary disease (COPD) is prevalent amongst people affected by high levels of pollution, particularly if it takes place over a longer period, being common amongst those who smoke or have a career whereby they are exposed to large amounts of fine particles or other harmful. COPD is an umbrella term that refers to several different respiratory conditions.

These include bronchitis, pneumonia, asthma, as well as emphysema and any illness or condition that decreases the lung’s ability to take in air. In the longer-term or chronic cases, an individual that is exposed to pollution over many months or years (common amongst those with the aforementioned careers or those that live near to busy roads or industrial sites), conditions such as ischemic heart disease start to present themselves, especially so amongst the more vulnerable members of the population. Ischemic heart disease takes place when the tissue of the heart fails to receive enough oxygen. Rates of heart attacks will also rise alongside the aforementioned cardiovascular issue, along with the chance of strokes, arrhythmias, nausea and headaches, as well as death in more severe cases. Many instances of premature death are directly linked to higher levels of pollution exposure.

Because of this, during periods of elevated pollution levels, preventative measures should be utilized so that individuals may avoid any possible damage to their health. These precautions include avoiding outdoor activities and exercise, in particular outdoor ones such as jogging, which raises the heart rate, increasing respiration along and therefore the number of pollutants taken into the lungs.

Wearing fine particle filtering masks is also recommended, especially when outdoor movement cannot be avoided. Doors and windows should be closed to prevent indoor air pollution levels from rising. Air purifiers can also be run, if available, as they have a prominent effect on reducing indoor air pollution build-ups, which can decrease any adverse health effects that can arise from excessive pollution exposure.

When is the pollution level at its highest in Shasta?

Observing the levels of air pollution on record from 2020, it can be seen that Shasta also had some highs of PM2.5 readings, due once again to the occurrence of forest fires making their way through the state of California.

The months that had the highest readings were August through to December. Also of note is that the months of January and February also came in with somewhat elevated readings, showing that Shasta can have poorer levels of air quality not directly influenced by forest fires. August through to the end of the year presented with readings of 30.2 μg/m³, 61.4 μg/m³, 30.8 μg/m³, 17.2 μg/m³ and 15.2 μg/m³ respectively. September was the month with the highest level of air pollution and was seen almost universally throughout the state of California, with a majority of cities seeing a huge spike in air pollution during this month, although the latter months of the year generally had their respective elevations, due to how large the forest fires were and how wide an area they covered.

January and February came in at 18.8 μg/m³ and 17.1 μg/m³, placing them into the 'moderate' air quality rating bracket, which requires a PM2.5 reading of 12.1 to 35.4 μg/m³ to be classed as such. As such, the air quality during these first two months was also less than perfect, although they paled in comparison to the pollution levels seen in September.

When is Shasta cleanest in regards to its air quality?

Whilst many months recorded over 2020 came in with less than perfect PM2.5 readings, there was a period of time in which the air cleanliness improved significantly. This took place between March through to July, all of which had PM2.5 readings that fell within the WHO's target goal of 10 μg/m³ or less, for the most optimal level of air quality.

Their readings were 9.9 μg/m³, 5.7 μg/m³, 3 μg/m³, 3.4 μg/m³ and 7.8 μg/m³ respectively. This placed May and June into the cleanest months of the year position, with 3 μg/m³ and 3.4 μg/m³ being a very respectable level of air quality, significantly freer from clouds of smoke, haze, and hazardous particulate matter contaminating the air, especially when compared to the months in which wildfires took place.