Measurements of Inhalable Particles < 10 μm (PM₁₀) and Total Suspended Particulates (TSP) Concentrations along the North–South Corridor, in Kolkata, India

The 24-hour concentrations of total suspended particulate matter (TSP) and respirable suspended particulates (PM₁₀) were monitored during March 2003 to February 2004 from a network of 15 sampling stations along a populated urban corridor of Kolkata City in India. The air samplers were placed at a distance 20–200 m from roadways and their height from ground level was within 3 to 5 m. It was also insured that from any obstacle to the airflow was at least 30 cm away. Over the study area, the monthly average concentrations of TSP and PM₁₀ were found to be 200.3 ± 93.1 μg/m³ and 95.8 ± 67.5 μg/m³, respectively, while the 24-hour average concentrations were in the range of 17–456 μg/m³ and 15–291 μg/m³, respectively. The higher average values at particular stations reflected the closeness of those to heavy road traffic. With regards to the temporal variations, higher concentrations were observed during winter and lower concentrations during monsoon. Statistical analysis of the sampling data was conducted to obtain general characteristics of the particulate pollution and to investigate the effects of traffic volume and meteorological factors on the pollution level. TSP and PM₁₀ concentrations were found to be highly correlated with each other at all the sampling stations. There were clear associations between TSP and PM₁₀ data set at all the measured 15 stations and on average, PM₁₀ was 52% of the total TSP concentration.

Key Words:

• Ambient air quality
• Suspended particulate matter
• PM₁₀
• Meteorological factors
• Statistical analysis.

ACKNOWLEDGMENTS

The authors are very thankful to the management and staff of West Bengal Pollution Control Board, Kolkata, India for providing cooperation and support for carrying out above research work. The suggestions on this research work by Prof. A.K. Dikshit, CESE, IIT Bombay is also acknowledged.

Notes

*Road gradient in flat.

**Correlation is significant at the 0.01 level.

*Correlation is significant at the 0.05 level.