Hyderabad city has experienced a significant rise in aerosols over the past two decades, according to a study conducted by researchers from NIT Tiruchirappalli. Aerosols are tiny particles suspended in the atmosphere that can potentially contribute to pollution. The study, led by Aneesh Mathew, Nandan AK, and Padala Raja Shekar from the institute’s civil engineering department, focused on analyzing the concentration of Aerosol Optical Depth (AOD) between 2002 and 2021.
AOD measures the amount of solar radiation scattered or absorbed by aerosols in the atmosphere before reaching the ground. These aerosols are formed when particulate matter (PM) 2.5 and 10, along with water vapor and other particles, combine. The researchers estimated the concentration of these aerosols using AOD.
The data revealed that AOD levels have increased significantly over the years. In 2002, the average AOD level was less than 0.40, but by 2021, it had risen to 0.70. The years with the highest AOD severity were 2018 and 2021, with daily AOD levels exceeding 1 for 42 and 52 days respectively, indicating severe concentration levels.
Further analysis showed that AOD levels increased across all seasons over the 20-year period. Winter saw the highest increase at 48.7%, followed by autumn at 46.96% and summer at 44.6%. The increase during the monsoon season was comparatively lower at 38.3%. The researchers attributed the higher AOD levels in summer to forest fires, which are common in the forests of Telangana during that season.
However, they noted that vehicle pollutants also play a significant role, as AOD values during other seasons are not substantially lower than those in summer. The study underscores the importance of understanding the sources and patterns of aerosol pollution in urban environments to implement effective measures for air quality improvement.
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