Air quality in Ketchum

Is Ketchum a polluted city?

Ketchum is a city located in the central region of Idaho, part of Blaine County. This county is home to some 21,300 inhabitants, and Ketchum itself having an estimated 2,800 people living there as of 2019, making it a small-sized city. Regarding its air quality levels, it has come in with a variety of readings, ranging from extremely clean (coming in with a very respectable yearly average of PM2.5 readings over 2020) up to more dangerous levels of pollution, due in part to fires taking place throughout the state of Idaho.

Whilst the main causes of air pollution in Ketchum will be discussed in further detail in the following questions, wildfires that affect vast swathes of land can affect cities many miles away from their initial source. Hazardous clouds of smoke, haze and fine particles can drift great distances, settling over cities and causing their US AQI reading to go up rapidly. The US AQI reading is a figure aggregated from the volume of main air pollutants typically found in the atmosphere in Ketchum, as well as throughout the rest of the USA. It refers to the United States Air Quality Index, one that is used prevalently due to its highly stringent rules in place, being far stricter regarding the level of air pollution than measurements that are used in other countries.

The US AQI figure is calculated from pollutants such as sulfur dioxide (SO₂), nitrogen dioxide (NO₂), ozone (O₃), carbon monoxide (CO) and the two main forms of particle pollution, PM10 and PM2.5.

Out of the two forms of particulate matter, PM2.5 is the far more deadly of the two, being 2.5 micrometers or less in diameter, roughly 30 times smaller than the width of a human hair. It consists of ultrafine materials such as metals, sulfates, soot, water droplets and other forms of vapor, along with dust or finely ground silica. The yearly average of any given city or location is usually taken in PM2.5, which is recorded in micrograms per cubic meter (μg/m³). High quantities of PM2.5 are associated with a large number of health conditions, which can include ones such as systemic inflammation, cancer, alteration to the nervous system and scarring of the lung tissue and a reduction in its full capacity to take in oxygen.

In July of 2021, a US AQI reading of 115 was recorded, placing Ketchum into the 'unhealthy for sensitive groups' bracket on the particular day and time in which the measurement was taken. This rating bracket requires a US AQI reading of anywhere between 101 to 150 to be classified as such, and is color-coded as orange, in use throughout the air quality maps, graphs and forecasts on this page and throughout the IQAir website, for ease of reference and navigation. As the level of air pollution increases, the color gets darker accordingly, with red, purple and maroon being used to indicate the most dangerous levels of air pollution.

When this reading of 115 was recorded, the PM2.5 count was also found to be four times above what the World Health Organization's (WHO's) exposure recommendation was set out as. This would bring with it a large number of health issues, and as the name of this group rating indicates, those who belong to sensitive, unhealthy or at-risk groups would be most susceptible to the damage caused by particle exposure. This includes members of the population such as young children, babies and pregnant mothers.

Children who are still undergoing their vital formative years are highly susceptible to the damaging effects that extended or acute pollution exposure can bring. Alterations to the nervous system or various organs throughout the body can manifest itself in the form of cognitive impairment or slowed development, both physically and mentally. Furthermore, many skin conditions or respiratory issues may present themselves, which can rapidly turn into prolonged or even lifelong conditions if exposure is not ceased entirely or at least lessened. Due to the pervasive nature of ultrafine particles and their ability to enter into the bloodstream via the alveoli in the lungs, unborn children can also be affected by their introduction to the mother’s body (along with the other damaging effects that chemical pollutants can bring). This can lead to instances of miscarriage, premature births or babies born with low birth weight, raising the infant mortality rate as well as leaving them with potential afflictions to their health.

Other vulnerable groups in Ketchum that should take extra care to safeguard themselves from higher pollution levels are the elderly (who are also highly at-risk from even mild respiratory conditions bringing with them complications that could result in terminal illnesses), along with those with pre-existing health conditions, compromised immune systems, as well as those with a hypersensitive disposition towards fine particles or chemical pollutants.

Whilst a high level of US AQI was recorded in July of 2021, it must be noted that Ketchum has also maintained a very good level of air quality over the last few years, consistently coming in with yearly averages that have placed it amongst some of the cleanest cities both in the United States and worldwide. This means that whilst Ketchum would usually see a great quality of air, it may be subject to sudden elevations due to polluting events such as wildfires. Other ambient sources of air pollution present will be discussed, coming mainly from anthropogenic and industrial activities.

During bouts of high pollution, which were present in mid-2021 (with other US AQI readings coming in at 92, 119 and 125), preventative measures such as wearing fine particle filtering masks, avoiding outdoor activity along with strenuous activities, exercise or sports, as well as closing doors and windows can all go a long way in keeping pollution exposure levels to a minimum. Indoor air purifiers can also be run if they are available, and hourly updates can be followed either via the air quality map present on this page or on the AirVisual app.

In closing, Ketchum is a city that maintains a very good quality of air throughout the majority of the year but may be subject to sudden elevations in its pollution level, and as such a level of vigilance should be employed to take the appropriate measures when such polluting events do occur.

Why does Ketchum have higher pollution levels?

As mentioned, wildfires can have a highly polluting effect on many cities throughout the state, even if they do not occur in direct proximity to any given location. The burning of vast amounts of organic material can release many pollutants into the air, along with damaging particles.

Other sources of air pollution would be emissions and fumes released from vehicles, along with factories, power plants, construction and demolition sites all adding to the amount of pollution present in the air, with both cars and industrial sites giving out pollutants related to the combustion of fuel, or fossil fuels in many cases, along with construction sites leaking large amounts of particle pollution into the air.

What types of pollution is found in the air in Ketchum?

Besides the main pollutants that are used to calculate the US AQI figure, several other pollutants can be found in the air throughout Ketchum, often having higher volumes in certain areas, with locations such as busy roads or intersections (or any road that sees rush hour traffic or many vehicles passing through it) as well as industrial areas or factories often having higher levels of certain pollutants in their direct vicinity.

Other pollutants would include ones such as volatile organic compounds (VOCs) and black carbon. Both of these are emitted in high quantities from the use of fossil fuels, as well as the incomplete combustion of organic material (with the forest areas being burnt in the fires releasing both of these in abundance). Black carbon is the main component of soot and can be highly carcinogenic when inhaled, as well as having climate-changing properties. Black carbon can absorb solar radiation and release it directly as heat, causing a warming effect on the surrounding environment and climate.

Some examples of VOCs include benzene, another highly dangerous and carcinogenic compound, along with toluene, methylene, styrene, formaldehyde and xylene. Due to their volatile nature, they can maintain a gaseous state even in lower temperatures, thus making them easier to breathe. They also constitute one of the main forms of indoor pollution, being given off from a variety of household items such as wood varnishes, paints, certain types of glue, as well as scented candles, aerosols (air fresheners or deodorants) and even cosmetic products releasing them into the surrounding environment. As such, the running of air purifiers can assist greatly in reducing their prevalence, as well as being conscious of what items are used within the household, as well as other factors such as poor ventilation also playing a part in their accumulation.

Other pollutants that are problematic in certain areas include the aforementioned ozone. This heavy molecule is created when the various oxides of nitrogen (NOx) are exposed to higher levels of solar radiation, forcing a chemical reaction to take place whereby ozone is created, making it a secondary pollutant that is significant in many areas throughout the USA, due to often forming on roads and other areas where NOx or other gases can cause its creation.

When is the air at its most heavily polluted in Ketchum?

Observing the pollution levels that were recorded for 2020, it can be seen that Ketchum maintained a great level of air quality throughout the year. Many months came well within the World Health Organization's (WHO's) target goal of 10 μg/m³ or less, for the best quality of air.

However, there were two months present that were significantly higher than the rest of the year, once again with polluting events such as fires (as well as the pre-existing ambient pollution levels) compounding the PM2.5 figure on record. Both August and September came in with readings of 13.6 μg/m³ and 13.9 μg/m³ respectively. This placed them in the 'moderate' rating bracket, which requires a PM2.5 reading of anywhere between 12.1 to 35.4 μg/m³ to be classified as such.

These were the only two months of the year to move outside of the WHO's target bracket and up into the 'moderate' one, making them considerably more polluted than the rest of the year, having PM2.5 figures that were over four times higher than the cleanest month of the year. It is at times like these when the previously mentioned preventative measures should be utilized in order to minimize pollution exposure. Although they were not overtly bad by international standards, it is of note that any level of air pollution has the chance to cause adverse health effects. As such, when the pollution count rises, so too do the chances of health conditions occurring, as well as their severity. Caution should be practiced when these pollution spells do occur.

When does the air quality start to improve in Ketchum?

Looking at the PM2.5 figures on record once again for the year 2020, it can be seen that Ketchum came in with a yearly average of 6.3 μg/m³. This was an extremely respectable reading and would have been even more so had it not been skewed by the sudden spikes in pollution seen in August and September, and to a lesser extent October.

This reading placed Ketchum into the WHO's target bracket once again, and looking at years prior, it can be seen that Ketchum maintained decent levels from 2017 all the way through to 2020. 2017 came in with a reading of 6.3 μg/m³, 2018 with a reading of 5 μg/m³, 2019 at 4.3 μg/m³, and then a slight elevation up to 6.3 μg/m³ in 2020, giving it the same reading as 2017.

2020’s reading placed Ketchum in 4276^th place out of all cities ranked worldwide, a respectable placing. In regards to its cleanest months, February through to July had the lowest readings of PM2.5 on record in 2020, making it a period in which the air was significantly freer from smoke, haze, smog and hazardous clouds of fine particles. April had the cleanest reading of the year at a very low 2.8 μg/m³, making it the most optimal month of the year in regards to air quality.