Prasad P.M.N.; Shyam Sundar E.; Hanuman Reddy V.; Chenna Krishna Reddy R.; Rami Reddy Y.V. Comparative Studies on Arsenic, Nickel & Lead Levels in Ambient Air Repairable Suspended Particulate Matter (p.M10) in and Around Tirupati. Int. J. Res. Pharm. Sci. 2013, 4, 118-122.