The air quality in Tunisia noticeably improved in September 2021, compared to August of the same year, according to the monthly report on “the concentration of environmental pollutants at ground level in Tunisia in September 2021”, released by the National Institute of Meteorology of Tunis (INM) Wednesday.
According to the report, the results of monthly averages for this month, compared to that of August 2021, showed a decrease in sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3), which are polluting gases caused mainly by human activities, by 22%, 25%, 16% and 2% respectively, with the use of the Sentinel-5P satellite measurements analysed and developed at INM.
A decrease in the concentration of sulfur dioxide (SO2) was recorded in Tunisian regions between August and September 2021, and the average monthly concentration of this went down from 2.22 μg/m3 to 1.74 μg/m3.
The highest concentration was recorded in Greater Tunis (6.28 μg/m3 in August 2021 and 4.91 μg/m3 in September 2021) and the lowest in Mahdia (0.72 μg/m3 in August and September 2021).
Regarding the concentration of nitrogen dioxide (NO2), the Tunisian regions also experienced a decrease between August and September 2021.
The average monthly concentration decreased from 3.42 μg/m3 to 2.58 μg/m3.
The maximum concentration was reported in Greater Tunis (20.15 μg/m3 in August and 13.61 μg/m3 in September) and the minimum in Kebili (0.4 μg/m3 in August and 0.32 μg/m3 in September).
A slight decline was also noted in the concentration of ozone (O3), whose average monthly concentration decreased from 58.30 μg/m3 in August 2021 to 57.21 μg/m3 in September 2021.
The maximum concentration was recorded on the island of Djerba or 74.46 μg/m3 in August and 75.71 μg/m3 in September and the minimum in Greater Tunis (33.94 μg/m3 in August and 39.35 μg/m3 in September).
As for the concentration of carbon monoxide (CO), the INM report also showed a decrease between the months of August and September 2021. The average monthly concentration of this gas fell from 159.68 μg/m3 in August to 134.45 μg/m3 in September. Greater Tunis experienced the maximum concentration (343.67 μg/m3 in August and 251.11 μg/m3 in September). The minimum concentration was recorded in El Borma (128.55 μg/m3 in August and 115.74 μg/m3 in September).
The INM report further highlights a decrease in the average monthly emission of nitrogen dioxide (NO2) and sulfur dioxide (SO2) and a slight increase in the emission of carbon monoxide (CO) in August and September 2021 compared to the same period in 2020.
As for ozone (O3), its average concentration decreased in August 2021 compared to August 2020 and slightly increased in September 2021 compared to September 2020.
Source: Tap News Agency