The Air Quality Index (AQI) at Plamoodu in Thiruvananthapuram and Vyttila in Ernakulam was ‘very unhealthy’ and ‘unhealthy’ respectively from May to November last year, according to a study by the Kerala State Pollution Control Board (PCB).
A considerable reduction was detected in the AQI at the nine real-time air quality monitoring stations set up by the board in six districts following the lockdown in May last year. The air quality went up from ‘moderate’ (100) to ‘good’ (50) in seven stations, except for Plamoodu and Vyttila, it said. However, the AQI at Plamoodu showed an upward trend from August 26 to September 6. The peak concentration was 320 (very unhealthy/hazardous) on September 1, it said.
The air quality study was held from January to December last year, covering nine real-time monitoring stations that include Plamoodu, Karyavattom (Thiruvananthapuram); Polayathodu (Kollam); MG Road, Vyttila and Eloor (Ernakulam); Corporation stadium (Thrissur); Palayam (Kozhikode); and Thavakkara (Kannur).
The AQI at Vyttila showed an increasing trend in May and June, while the peak concentration was 198 (unhealthy) on June 5. The air quality in the area showed a reading above 100 (unhealthy for sensitive group) from mid-January to the end of June. It was around 100 at MG Road till March.
Eloor, a major industrial hub, had an AQI around 50 (good) almost all the days, except on a few occasions when the average concentration was 62, according to the study.
‘Satisfactory’ level
The AQI was above 150 (unhealthy) in all stations from mid-January to mid-February. Though the concentration averaged 100-150 up to April in Kollam, it showed a uniform AQI range of 100 for the rest of the days, except for the period from May to June in which the air quality was ‘good’.
The air quality pattern of the State was found within the level of ‘satisfactory.’ It went beyond ‘very unhealthy’ on very rare occasions. The AQI within the State was also showing a slight increase from the middle of December, which might be due to seasonal changes as the rainy season has a significant effect in the reduction of AQI levels, it said.
