Qualité de l’air à Shadegan

Is the air quality in Shadgan polluted?

Shadgan is a city that has some high levels of air pollution present throughout the year, with certain months rising to even greater heights. When such spikes in air pollution occur, those who are vulnerable or belong to at-risk demographics may wish to take preventative measures in order to safeguard their health. Some of the more polluted months that were recorded over the course of 2020 will be mentioned later in the article, as well as the US AQI readings collected in mid-2021.

US AQI is itself an aggregated number formed from several main air pollutants, with their individual volumes calculated together to form the overall US AQI number. Observing the US AQI number that came in during late May of 2021, it can be seen that a figure of 76 was recorded, putting Shadgan into the higher end of the ‘moderate’ air pollution ratings bracket.

In order to be classified as such, as per the US AQI ratings system, a reading of anywhere between 51 to 100 must be present. The moderate rating of pollution is color coded as yellow, on both air quality graphs and maps on the IQAir website. Those who have a sensitive disposition towards chemical pollutants or fine particles may find themselves experiencing mild symptoms, however the general public will remain largely unaffected by such levels.

According to the US Environmental Protection Agency (EPA), any reading on the US AQI scale between 0 to 150 is deemed as acceptable. However, on the higher end of this scale, the air quality may start to cause aggravated symptoms amongst the aforementioned vulnerable groups, whilst the general public may also start to experience some form of respiratory irritation. Other readings of US AQI that came in over the month of May in Shadgan were higher ones such as 118 and 146, coming in within the ‘unhealthy for sensitive groups’ bracket (101 to 150 required), color coded as orange.

Higher US AQI readings recorded over May came in at 152 and 154, both of which fell into the ‘unhealthy’ ratings bracket, color coded as red and indicating a level of air pollution that comes with an increased chance of detrimental effects amongst those who are exposed, exacerbating both pulmonary and cardiac conditions amongst those who may be suffering from them.

Other groups that may fall foul to the ill health effects of high levels of pollution include young children, babies and pregnant mothers. The elderly are also particularly susceptible to respiratory ailments or infections, along with those who have pre-existing health conditions (as mentioned particularly those of the lungs or heart), compromised immune systems and a hypersensitivity towards chemical pollutants and particulate matter.

What are some of the main sources of air pollution in Shadgan?

Before moving to the main sources of air pollution present in Shadgan, it should be mentioned that in 2020, the city came in with a PM2.5 average reading of 30.3 μg/m³ over the course of the year, placing it in the higher end of the ‘moderate’ pollution ratings bracket. When taking into account the PM2.5 ratings system, a reading of anywhere between 12.1 to 35.4 μg/m³ is required for classification. This placed Shadgan in 9^th place out of all cities ranked in Iran, as well as 386^th place out of all cities ranked worldwide in 2020.

In order to hit such a high pollution level, there would be numerous sources of air pollution present that combine to form these elevated readings. The main ones would be the heavy use of vehicles, particularly cars and motorbikes, as well as larger freight vehicles such as trucks and lorries. Many of these would be of the aged variety, thus giving out far more noxious forms of pollution, also leaking oil vapor and hazardous particles (as well as often running on leaded fuels, adding to the pollutive issue).

Other significant sources include emissions from power plants and factories (also burning coal and natural gas for their energy source), along with oil refineries, construction sites and poorly paved roads. In closing, vehicles account for a majority of the air pollution in Shadgan and indeed much of Iran, whilst industrial come in as the second biggest offenders.

What are some of the pollutants that are found in Shadgan?

Some of the main types of pollution that one would find permeating the atmosphere in Shadgan would be those that are typically released from combustion sources, as touched on earlier, along with any activity, either human based or meteorological in nature, disturbing large amounts of sand, dust or earth.

Some of the pollutants that arise as a result of these activities include the ones that go into forming the US AQI aggregate. These are nitrogen dioxide (NO₂), ozone (O₃), sulfur dioxide (SO₃), as well as both PM2.5 and PM10. Others include black carbon, a material that is the main component in soot and falls into the PM2.5 category, indicating that it is an extremely dangerous form of pollution with both carcinogenic and climate changing properties.

Along with black carbon, the incomplete or poor combustion of both fossil fuels and organic material can lead to the creation of volatile organic compounds (VOCs), which include chemicals such as benzene, xylene, toluene, methylene chloride and formaldehyde.

Other dangerous pollutants that can be found from the fallout of burning low quality coal and other materials includes heavy metals such as lead and mercury, along with dioxins, furans, polycyclic aromatic hydrocarbons, all of which can have devastating effects on both human health and the environment, affecting ecosystems and vegetation alike.

When does Shadgan experience the highest levels of air pollution?

Observing the air quality data as collected over 2020, it can be seen that Shadgan had its most polluted PM2.5 readings over the months of July, and September through to November, all of which came in within the ‘unhealthy for sensitive groups’ bracket (35.5 to 55.4 μg/m³ required).

Their readings respectively were 36 μg/m³, 39.1 μg/m³, 41.2 μg/m³ and 35.7 μg/m³, making October the most polluted month of the year with its PM2.5 reading of 41.2 μg/m³.

Does Shadgan have a cleaner period of air quality during the year?

Whilst the majority of the year in Shadgan has elevated ambient levels of air pollution, with no significant drops in the PM2.5 level, it can be seen that on a relative level, the months of January through to June, along with August and December all had ‘moderate’ readings of air pollution, indicating that the air would be somewhat cleaner than the months previously mentioned above.

Out of all of these, April came in with the cleanest level of air quality, with a PM2.5 reading of 20.7 μg/m³.