PM2.5 Monitoring
Air Quality Index : AQI
It is a report on air quality information in a format that is easy for the general public to understand. To disseminate information to the public about the level of air pollution in each area Does it affect health? One air quality index is used to represent the concentration of 6 air pollutants as follows
- Dust with a diameter of not more than 2.5 microns (PM2.5)Â is a dust with a diameter of not more than 2.5 microns caused by combustion from vehicles. Burning agricultural materials, forest fires, and industrial processes can reach the air sacs in the lungs As a result, it can cause diseases in the respiratory system. and various lung diseases If given in large quantities or for a long time, it will accumulate in the lung tissue. causing the lung function to deteriorate due to bronchitis asthma
- Particulate matter less than 10 microns (PM10)Â is dust with a diameter of not more than 10 microns caused by fuel combustion. Open fire Industrial processes, grinding, milling or powdering of construction affect health because inhaling it can accumulate in the respiratory tract.
- Ozone gas (O3)Â is a colorless or light blue gas with a pungent odor. Slightly soluble in water. Occur both at high levels of the atmosphere from the earth’s surface and the level of the Earth’s atmosphere near the ground. Ozone gas is an air pollutant is ozone gas in the Earth’s atmosphere caused by the reaction between nitrogen oxides and volatile organic compounds with sunlight as a catalyst. If affects health by causing the irritation to eyes, the respiratory system, and mucous membranes. It decreased lung capacity whiel tired quickly, especially in children, the elderly, and people with chronic lung disease.
- Carbon monoxide (CO)Â is a colorless, odorless and tasteless gas produced by the incomplete combustion of carbon-containing fuels. This gas can accumulate in the body where it combines with hemoglobin in red blood cells about 200-250 times better than oxygen. When inhaled, this gas will compete for hemoglobin in the blood. This results in carboxyhemoglobin (CoHb) which facilitates the reduced transport of oxygen to cells of the body. As a result, the body becomes weak, and the heart works harder.
- Nitrogen dioxide (NO2) is a colorless and odorless gas which slightly soluble common in nature , or caused by human actions such as burning various fuels, some industries, and etc. This gas affects the visual system and people with asthma or respiratory diseases.
- Sulfur dioxide (SO2)Â is a colorless gas, or may have a light yellow color. It has a high concentration of flavor and smell caused by nature and burning fuels with sulfur as a component. It is good at water solubility and combine with other pollutants to form fine dust particles. This gas has a direct impact on health. It causes irritation to conjunctiva, skin and the respiratory system. If taken for a long time, it can cause chronic bronchitis.
Thailand’s air quality index is divided into 5 levels, ranging from 0 to 201 and above, with each level using colors to symbolize the level of health impacts (Table 1) The air quality index of 100 is equivalent to the general atmospheric air quality standard. If the air quality index is higher than 100, the air pollution concentration value is above the standard and the air quality on that day will begin to affect public health.
Table 1 Criteria of Thailand Air Quality Index
I = Air quality sub-index
X = Concentration of air pollutants from the measurement
Xi , Xj = The minimum, maximum value of the pollutant concentration range with the value X.
Ii , Ij = The minimum, maximum value of the air quality index range corresponding to the concentration range X from the calculated subindex.
Which air pollutant has the highest index? It will be used as the Air Quality Index (AQI) at that time.
Table 2 Air Pollution Concentration Equivalent to Air Quality Index
Average interval and the air pollutant unit used in the calculation
- PM2.5 24 hours continuous average : micrograms per cubic meter or µg./m3
- PM10 24 hours continuous average : micrograms per cubic meter or µg./m3
- O3 8 hours continuous hours average : parts per billion or ppb or 1/1,000,000,000
- CO 8 hour continuous average : parts per million or ppm or 1/1,000,000
- NO2 1 hour average : parts per billion or ppb or 1/1,000,000,000
- SO2 1 hour average : parts per billion or ppb or 1/1,000,000,000
Frequently asked questions
The standard value of the 24 hour average should not exceed 37.5 micrograms per cubic meter. The standard value of the annual average should not exceed 15 micrograms per cubic meter.
The Air Quality Index or AQI (AQI: Air Quality Index) is the process of converting air quality data into health impact levels. Use colors as a symbol of severity. Note that the AQI value does not have units, but values represent the amount of pollutants. There are units of concentration of substances such as micrograms per cubic meter, etc.
Thailand’s air quality index shows 5 color levels, blue, green, and yellow, showing the level of air pollution that is still within the standard where yellow is close to the standard value. May affect people who are especially sensitive to air pollution. And when it exceeds the standard, it will be orange and red, which will affect the general public in a wide range.
When converted to AQI color scale at the same amount of pollution it is found that Thai and foreign colors are used differenly. However, the difference lies only in the representation of the colors. Asking the public to understand the level of health warnings you Will find that the health warnings in Thailand and abroad are the same.
Pollution Control Department It is accelerating development to expand its measurement network. In the period that there is no information in your area Citizens can use information from nearby stations. and have activities similar to their own area The area is divided into, for example, an urban area. industrial area agricultural areas, etc., if the air pollution exceeds the standard People will be able to perceive pollution by themselves, such as unpleasant odors. uncomfortable breathing irritation, etc. should contact the Office of Natural Resources and the Environment in your province. or contact the Pollution Control Department, hotline 1650
and ‘General public’, meaning people other than People who need special health care
