Recent scenario of airborne pollens of Lucknow, India with special reference to intra- and interannual, diurnal, and vertical variation

Correspondence: Praveen C Verma CPMB, National Botanical Research Institute, (CSIR), Rana Pratap Marg, Lucknow – 226 001 (UP), India Tel +91 522 229 7922 ext 944 Fax +91 522 220 5836 Email praveencverma@yahoo.com Abstract: Biomonitoring of airborne pollen in Lucknow, India was conducted for 2 consecutive years (August 2005–July 2007) with the objective of assessing the recent status of airborne pollen of the city and analyzing the intraand interannual variations. Determination of total incidence of airborne pollen with subsequent contributions of individual components was carried out by measuring diurnal and vertical gradients. The Pearson correlation test was conducted to analyze pollen counts for 2 successive years. Principal component analysis was also carried out to examine the relative distribution of major pollen samples according to their dominance in the particular environment for 2 consecutive years. A total of 6089 pollen grains were caught in 2005–2006, which included 77 types against 4335 pollen grains comprising 61 types registered in 2006–2007. Two major pollen seasons, ie, spring and autumn, were confirmed. During 2005–2006, the highest airborne pollen concentration was found in February (154.67/m), while the spring pollen peak was shifted to March (133.7/m) in the consecutive year. The second pollen peak in both years was in August, which included mostly grass pollen. The highest airborne pollen contributor of 2005–2006 was grass, accounting for 25% of total pollen, while in the subsequent year Holoptelea dominated with 47% of total pollen. The diurnal analysis showed that the highest pollen concentration in 2005–2006 was around 2 pm due to abundant flowering of Morus, while in 2006–2007, the maximum concentration was reported at 10 am due to Holoptelea pollen. Inter-annual species variation in climate was also considered as an important factor involved in inter-annual variation in pollen incidence. In general, a positive correlation was observed with temperature, particularly average temperature. During each period, peak pollen counts occurred when the average temperature fell within the range of 22°C–23°C.