There seems to be a positive side to the nationwide lockdown in the State, which has just entered the third week, with air quality improving perceptibly.
The pollution levels are “dropping dramatically”and consequently, the State has slipped into the first category of Air Quality Index (AQI) — good.
In all, there are four Continuous Ambient Air Quality Stations (CAAQMSs) in the State in Vijayawada, Visakhapatnam, Tirumala and Rajahmundry. According to information, of the 24 records, eight fell under the good category and the rest under the satisfactory category.
In Vijayawada, the air quality is recorded at 52 on April 4 and it came down to 39 on April 6. Visakhapatnam, a highly industrialised city, registered 45 on April 6 against 76 on April 1. Except pharmaceuticals, no other industry in Visakhapatnam is functioning. It has also contributed to the drop in air pollution.
Similarly, at Tirumala the air quality has been less than 50, which is good. Rajahmundry also recorded less than 50 during the last two days. In comparison, of the total four stations covered for calculation of AQI during March, 55 records fell under the good category, 62 under the satisfactory category and seven under the moderate category.
Eight pollutants
“Our data (Andhra Pradesh Pollution Control Board (APPCB)) show that air pollution has significantly come down,” says a senior functionary of the board, who did not want to be quoted.
Air Quality Index is a tool for effective presentation of air quality status to the people and decision makers. It transforms complex air quality data of various pollutants into a single number (Index Value), nomenclature and colour. The AQI is calculated taking eight pollutants — nitrogen oxide, sulphur dioxide, PM 2.5, PM 10, ozone, carbon monoxide, ammonia and lead content — in into account. The index scale has 0-50, 51-100, 101-200, 201-300, 301-400, 401-500. Now, the records are moving towards the good category. The first category, ‘good,’ has ‘minimal impact’ on people, but, it is a “temporary relief ” only.
The last two weeks has seen lakhs of people staying indoors, and consequently normal life, including movement of vehicles, has come down dramatically. The pollution levels will increase change once the lockdown was lifted, the official says.
