Evaluation of Status of Cadmium, Lead, and Nickel Levels in Biological Samples of Normal and Night Blindness Children of Age Groups 3–7 and 8–12 Years Hassan Imran Afridi & Tasneem Gul Kazi & Naveed Kazi & Sirajuddin & Ghulam Abbas Kandhro & Jameel Ahmed Baig & Abdul Qadir Shah & Sham Kumar Wadhwa & Sumaira Khan & Nida Fatima Kolachi & Faheem Shah & Mohammad Khan Jamali & Mohammad Balal Arain Received: 26 July 2010 / Accepted: 28 July 2010 / Published online: 12 August 2010 # Springer Science+Business Media, LLC 2010 Abstract The causes of night blindness in children are multifactorial, and particular consideration has been given to childhood trace metals toxicity, which is the most common problem found in underdeveloped countries. This study was designed to compare the levels of cadmium (Cd), lead (Pb), and nickel (Ni) in scalp hair, blood, and urine of night blindness children age ranged 3–7 and 8–12 years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure was developed as a sample pretreatment, for the determination of Cd, Pb, and Ni in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood, and urine. The Biol Trace Elem Res (2011) 142:350–361 DOI 10.1007/s12011-010-8796-9 H. I. Afridi : T. G. Kazi : Sirajuddin : G. A. Kandhro : J. A. Baig : A. Q. Shah : S. K. Wadhwa : S. Khan : N. F. Kolachi : F. Shah : M. K. Jamali : M. B. Arain National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan T. G. Kazi e-mail: tgkazi@yahoo.com J. A. Baig F. Shah M. K. Jamali e-mail: mkhanjamali@yahoo.com M. B. Arain H. I. Afridi (*) Mechanical and Manufacturing Engineering, Dublin City University, Dublin, Ireland e-mail: hassanimranafridi@yahoo.com N. Kazi Liaquat University of Medical and Health Sciences, Jamshoro 76080, Pakistan e-mail: tgkazi@yahoo.com e-mail: jab_mughal@yahoo.com e-mail: shah_ceac@yahoo.com e-mail: bilal_ku2004@yahoo.com