Qualité de l’air à Mammoth Lakes

How badly polluted is the air in Mammoth Lakes?

Mammoth Lakes of California is a city that has come in with some very high levels of air pollution in recent times. Throughout 2020, Mammoth Lakes presented with an extremely high yearly average reading of PM2.5, one of the most dangerous pollutants found in the air.

Air quality throughout Mammoth Lakes and the state of California is measured in US AQI, as well as PM2.5 being a prominent measure of air pollution, particularly when regarding the yearly averages. The US AQI figure itself, or the United States Air Quality Index, is a figure aggregated from several main pollutants found in the air. These include ones such as ozone (O₃), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), as well as the two main forms of particle pollution, PM10 and PM2.5.

In 2020, Mammoth Lakes presented with a PM2.5 reading of 25.6 μg/m³. This placed it in the 'moderate' rating bracket for air quality, which requires a PM2.5 reading of anywhere between 12.1 to 35.4 μg/m³ to be classified as such. This is color-coded as yellow, much the same as the US AQI rating, with the PM2.5 reading instead being taken in micrograms per cubic meter (whilst the US AQI reading is calculated from the volumes of the main pollutants in the air as mentioned above).

This reading also placed Mammoth Lakes in 539^th place out of all cities ranked worldwide for 2020, as well as 7^th place out of all cities ranked in the USA for the same year. This is a very high ranking on the global scale, being one of the top ten most polluted cities in the United States and having several months of the year whereby the air pollution levels rose to dangerous levels, with their numbers and the resulting health issues being discussed later on in the article.

These were caused predominantly by the fires that swept through much of California in the latter period of 2020, causing the most polluted cities in America to be dominated by ones with close proximity to the fires occurring in California and the Bay Area. Whilst the city was hit heavily by these sources of pollution, it also had other months whereby the pollution levels were significantly lower, indicating that the air quality was considerably freer from smoke, haze and contaminating clouds of particle pollution.

Looking at the US AQI levels in July of 2021, Mammoth Lakes came in with a reading of 31, placing it into the 'good' air quality rating bracket. This requires a US AQI reading of anywhere between 0 to 50 to be classified as such, making it one of the most optimal levels of air quality. Those with pre-existing health conditions or sensitive dispositions towards chemical and particle-based pollutants would be able to go about their day without having to worry about any aggravation of respiratory conditions. The general public would remain unaffected as well, making times such as these the best to conduct outdoor activities or exercise.

Referring back to particulate matter and why it is so dangerous (and hence its prominence as a measure of air quality), PM10, the larger and coarser of the two, generally consists of material such as dust, smoke, bacteria, mold spores and pollen. These larger ones can aggravate the mucous membranes and cause discomfort or allergic reactions but lack the inherent danger that smaller particles have. PM2.5 generally consists of ultrafine metals, sulfates, soot, water and other liquid vapors, along with silica dust. This minute size allows it to penetrate deep into the tissues of the lungs, causing a myriad of health issues.

In observing the overall level of air pollution present in Mammoth Lakes, it can be seen that whilst the air quality took a heavy blow in the latter months of 2020, the city generally maintains a fairly respectable level of air quality, with some months even having very appreciable readings of both US AQI and PM2.5.

To safeguard one’s health from future potential catastrophic polluting events, air quality forecasts can be followed, with updates coming in on an hourly basis. Such forecasts are available on this page, as well as via the AirVisual app. When pollution levels start to elevate for whatever reason (with factors such as meteorological conditions often causing pollution accumulations, with a lack of strong winds or rain leading to buildups of chemical compounds or fine particles), certain preventative measures can be taken.

These include ones such as avoiding outdoor activity, particularly of the strenuous variety. Fine particle filtering masks can also be worn (available for purchase on-site), and doors and windows should be sealed to prevent the ingress of pollution into your household or place of business. Indoor air purifiers can also be run, if available, which can aid greatly in keeping the air quality at more optimal levels.

What are some of the most prominent causes of air pollution in Mammoth Lakes?

As mentioned in the prior question, Mammoth Lakes was subject to severe levels of air pollution due to the fires that blazed through large portions of California. However, there also remain other polluting elements that aid in raising the year-round ambient pollution levels, causing higher numbers of PM2.5 even in the absence of fires and other such events.

One of these would be the issue of vehicular fumes and emissions. With vehicle ownership constantly on the rise throughout the United States as well as the rest of the world, vehicular pollution remains one of the more consistent sources of air pollution, releasing a variety of different chemical compounds and particles into the atmosphere as a result of the combustion process that takes place within the engine. Heavier freight vehicles such as lorries, trucks and buses would also be in use, transporting people in and out of the city, along with industrial goods and other products.

Many of these larger vehicles utilize diesel fuel, which can give out far larger amounts of pollution than smaller, more sustainable motors would. Furthermore, the eventual wear and tear of tire treads over long periods of time can lead to many tons of microscopic rubber particles entering into the atmosphere, as well as contaminating bodies of water and the topsoil. Besides being extremely harmful to the health of individuals who inhale such particles, they can also make their way into the food chain, causing damage to ecosystems, vegetation and the environment.

Further pollution sources include ones such as construction sites, road repairs, demolition sites and other similar activities that disturb large amounts of earth, gravel or sand. Whilst it is a largely unknown source of pollution, poorly maintained construction sites and finely ground materials can add heavily to the pollution levels present in the air of any given location, with excessive exposure to some of the more ultrafine particles having many long term consequences for those that live close to such areas.

When is the air quality at its worst in Mammoth Lakes?

Whilst there only exists concise data for Mammoth Lakes from 2020 onwards, a true picture of the city’s pollution levels cannot yet be ascertained. However, utilizing the air quality data that was recorded throughout 2020, the months with the highest levels of air pollution can still be discussed, along with their consequences.

The month of August is when the air quality in Mammoth Lakes started to take a turn for the worst in 2020, with the preceding month of July coming in with a very respectable reading of 5.3 μg/m³, placing it within the World Health Organization's (WHO's) target goal for the best level of air quality at 10 μg/m³ or less. The following month jumped up to 16 μg/m³, and then went up by an extreme amount to 143.5 μg/m³ in September, followed by 109.4 μg/m³ in October.

August's reading of 16 placed it into the 'moderate' air quality rating bracket, whilst September came in in the absolute higher end of the 'unhealthy' air quality rating bracket. This is color-coded as red (with the most polluted air quality ratings having red, purple and maroon as their warning colors), and requires a PM2.5 reading of anywhere between 55.5 to 150.4 μg/m³ to be classified as such. As the name indicates, the air pollution at this level would cause a large number of ill health effects, with large clouds of smoke, haze, smog and hazardous particulate matter permeating the atmosphere.

Whilst September and October had extreme levels of pollution due to the fires in the state, it can also be seen that the later months of the year, as well as the first month of the year, had slightly elevated levels of PM2.5. November and December both came in with readings of 15.3 μg/m³ and 13.9 μg/m³ respectively, and whilst these may have been inflated somewhat by residual pollution leftover from the fires, the reading of 10.9 μg/m³ in January could indicate a pattern whereby pollution levels will tend to rise towards the end of the year, following on into the early months of the next year before returning to more respectable levels.

As such, Mammoth Lakes may still see elevations in its pollution levels towards the second half of the year, although many times less than the PM2.5 readings that were seen at the end of 2020. January's reading of 10.9 μg/m³ placed it into the 'good' air quality rating bracket, which requires a PM2.5 reading of anywhere between 10 to 12 to be classified as such, indicating a wide range of air quality ratings. Future years that lack the fierce fires and subsequent smoke clouds may have a considerably less disparity between their readings, with the most polluted reading of 2020 being over 100 times greater than that of the year's cleanest reading.

What are some pollutants found in Mammoth Lakes air?

Besides the main air pollutants that make up the US AQI aggregate, Mammoth Lakes would also have many other contaminants present in the air. The combustion of fossil fuels and organic matter alike can release black carbon (the main component in soot) and volatile organic compounds (VOCs) out into the atmosphere.

VOCs are known as such due to their ability to maintain a gaseous state even at lower temperatures, hence their volatile nature. They include cancer-causing agents such as benzene, as well as many other ones including styrene, toluene, methylene chloride, xylene, formaldehyde and tetrachloroethylene. VOCs also happen to be the number one offender when it comes to indoor pollution, in a large number of households. Many different products that include varnished surfaces, glue, paint, along with toiletries such as scented lotions, aerosols, cleansers and disinfectants and certain candles all releasing VOCs over time (or when set alight, in the case of candles).

Other contaminating materials that may be found in areas that have high concentrations of smoke from wood or organic matter being burnt, as well as industrial areas or construction sites include wood tars, dioxins, furans, mercury, lead, cadmium and polycyclic aromatic hydrocarbons.

Hydrocarbons are compounds that consist of carbon and hydrogen atoms and can result from the incomplete combustion of hydrocarbon fuels. Petroleum, gasoline, coal and kerosene are but a few examples, and as such their prevalence as a form of pollution is high in any place that sees large amounts of anthropogenic, industrial or natural disasters take place.

What health issues can arise as a result of pollution exposure in Mammoth Lakes?

Whilst health problems can present themselves at any level of pollution exposure (with the chances of ill effects occurring as the PM2.5 count goes above the WHO's target goal of 10 μg/m³), the months that had the extreme highs of air pollution in 2020 would bring with them many adverse conditions.

These include ones such as dry coughs, chest pain, as well as inflammation of the lungs and airways, with particulate matter entering various organs throughout the body and causing systemic inflammation (due to their small size allowing them to travel throughout the body via the bloodstream). The migration of toxic materials through the body can result in conditions such as cancer, ischemic heart disease, strokes, arrhythmias, heart attacks and death.