Air Quality Index
The air quality index (AQI) is used for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The AQI focuses on the health effects that may experience within a few hours or days after breathing polluted air. The AQI is based on five major air pollutants regulated by ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide.
The index runs from 0 to 500; the higher the number, the greater the level of air pollution. If it’s registering a number that is less than 100, then air pollution is below the level known to cause adverse health effects. When the index hits 101 or above, the outdoor air remains safe for many, but older adults and children are at increased risk. Those with heart and lung disease may also be at greater risk. A number above 200 is considered “very unhealthy.” The index is also divided into six color-coded categories, with green and yellow representing the best conditions, and orange, red, purple, and maroon indicating levels that are progressively worse. Wildfires are a common cause of extended periods of unhealthy air.
Considering the closure of industries and restrictions on community activities, including inter-city transportation and mobility, it is expected that these measures will have significant effects on the number of air pollutants from industries and vehicles, especially in large cities. Important environmental pollutants include particulate matter (different combinations of solid, liquid, and vapor particles), which are mainly in two types of particles with an aerodynamic diameter < 2.5 µm (PM2.5) and < 10 µm (PM10), tropospheric ozone [O3], nitrogen dioxide [NO2], sulfur dioxide [SO2], carbon monoxide (CO). Nitrogen oxides are caused by the combustion of fossil fuels, which is a good indicator of vehicle-related air pollution. It has been shown that more than 50% and 23% of the total nitrogen oxides (NOX) in developed and developing countries are related to transportation. This pollutant can also react with volatile organic compounds and the sun’s ultraviolet rays to produce tropospheric ozone, which poses a severe health threat such as inducing airway inflammation and increasing airway hyperreactivity.
Even if the level of daily air quality is not listed as dangerous, some experts say that you may still feel negative effects. The effects of air pollution can be mild, like eye and throat irritation, or serious, including heart and respiratory issues. They can also linger even after the air has cleared, as pollution can cause inflammation of the lung tissue and increase the vulnerability to infections.
In recent years, large amounts of polluted air streams and frequent environmental pollution problems have affected human health and reduced average life expectancy. Therefore, ecological awareness and the demand for a healthy environment are also increasing. A World Health Organization (WHO) report states that in 2012, seven million deaths were caused by air pollution worldwide (WHO, 2014). Studies have shown that fine particulate pollution (PM2.5) is highly correlated with population mortality and morbidity. Sulfur dioxide in the atmosphere can affect the respiratory system and lung function and can stimulate the respiratory tract, thereby aggravating asthma and chronic bronchitis in humans, and making people more vulnerable to diseases such as respiratory infections. O3 pollution, which has become increasingly prominent in recent years, can also cause respiratory diseases and increase the possibility of lung infections. Therefore, the risk of death in patients with heart and lung diseases is also greater. In recent years, various diseases caused by air pollution have been on the rise. It is estimated that 2.5 million deaths are caused by indoor and outdoor air pollution each year.
• How to protect when air quality becomes poor
• Stay indoors if you can, with the windows and doors closed.
• If you have air conditioning, run it continuously, not on the auto cycle. It’s also helpful to close the
fresh air intake so that smoke doesn’t get inside the house.
• Portable air cleaners can also reduce indoor particulate matter in smaller spaces.
• Avoid frying food, which can increase indoor smoke.
• Avoid strenuous outdoor activities like exercising or mowing the lawn.
• Don’t smoke cigarettes.
• And though exercising outdoors can be a great way to stay healthy, the 101-150 range on the Air Quality
Index is probably the highest level at which it remains safe to do so.