GUWAHATI, June 22 � The Pollution Control Board, Assam (PCBA) has worked out an Air Quality Index (AQI) for measuring the air quality of State capital Guwahati, and as per the first AQI ratings, the city�s air quality during 2014 has been �Satisfactory.�
The AQI rates the air quality in six categories � Good (AQI 0-50), Satisfactory (AQI 51-100), Moderate (AQI 101-200), Poor (AQI 201-300), Very Poor (AQI 201-300), and Severe (401 and above).
However, the disturbing thing is that during the months January, February, March and April, the AQI borders on �Poor�, with a count of more than 199.
�AQI which is a tool for effective communication of air quality status to people in terms that is easy to understand. It transforms complex air quality data of various pollutants into a single number (index value), nomenclature and colour � following the same method as adopted by the Central Pollution Control Board,� RM Dubey, PCBA Chairman told The Assam Tribune.
The pollutant parameters taken into account for calculating AQI are SO2, NO2 & PM10.
The mean monthly and mean annual AQI for Guwahati for 2014 was worked out based on results for six NAMP stations located at Bamunimaidam, Gopinath Nagar, Khanapara, Santipur, Gauhati University and Boragaon.
The results show that the mean annual AQI for Guwahati for 2014 is 87 which falls under the �Satisfactory� category.
�The pattern of AQI round the year changes from month to month. During the year 2014, the AQI for the months January, February, March and April is found to be more than 199 and, therefore, during the months the air of the city fall under the �Moderate� category,� Dubey said.
During the remaining eight months of the year 2014 � i.e. May to December � the AQI was found to be in the range of 46 to 73, while for July and September, the AQI showed the best quality categorization i.e. �Good.� For the remaining six months the AQI has been of the second best category i.e. �Satisfactory.�
Dubey said that by and large the same pattern was reflected for almost all the years.
The PCBA will soon release the AQI for January to May 2015.
