ORIGINAL PAPER Statistical evaluation of PM 10 and distribution of PM 1 , PM 2.5 , and PM 10 in ambient air due to extreme fireworks episodes (Deepawali festivals) in megacity Delhi S. Tiwari • D. M. Chate • M. K. Srivastava • P. D. Safai • A. K. Srivastava • D. S. Bisht • B. Padmanabhamurty Received: 29 September 2010 / Accepted: 9 August 2011 / Published online: 27 August 2011 Ó Springer Science+Business Media B.V. 2011 Abstract Temporal variation of PM 10 using 2-year data (January, 2007–December, 2008) of Delhi is presented. PM 10 varied from 42 to 200 lgm -3 over January to December, with an average 114.1 ± 81.1 lgm -3 . They are comparable with the data collected by Central Pol- lution Control Board (National Agency which monitors data over the entire country in India) and are lower than National Ambient Air Quality (NAAQ) standard during monsoon, close to NAAQ during summer but higher in winter. Among CO, NO 2 , SO 2 , rainfall, temperature, and wind speed, PM 10 shows good correlation with CO. Also, PM 10 , PM 2.5, and PM 1 levels on Deepawali days when fireworks were displayed are presented. In these festive days, PM 10 , PM 2.5 , and PM 1 levels were 723, 588, and 536 lgm -3 in 2007 and 501, 389, and 346 lgm -3 in 2008. PM 10 , PM 2.5 , and PM 1 levels in 2008 were 1.5 times lower than those in 2007 probably due to higher mixing height (446 m), temperature (23.8°C), and winds (0.36 ms -1 ). Keywords Hazardous particles Á Fireworks Á Mixing height Á Air quality Á Vehicular pollution 1 Introduction Ambient aerosols with mass median aerodynamic diameter less than 10 lm (PM 10 ), 2.5 lm (PM 2.5 ), and 1 lm (PM 1 ) are of interest owing to their effects on human health, visibility, and climate (Watson 2002; Pope and Dockery 2006; IPCC 2007; Pope et al. 1995, 2004; Chate 2011). Increasing particulate matter has already adversely affected human health in megacities ( [ 10 million people; Madronich 2006). In megacities, main S. Tiwari (&) Á D. M. Chate Á P. D. Safai Á A. K. Srivastava Á D. S. Bisht Indian Institute of Tropical Meteorology, Pune 411 008, India e-mail: chate@tropmet.res.in M. K. Srivastava Department of Geophysics, Banaras Hindu University, Varanasi 221005, India B. Padmanabhamurty B-3B/8C, Janakpuri, New Delhi, India 123 Nat Hazards (2012) 61:521–531 DOI 10.1007/s11069-011-9931-4