This book is penned on the basis of Ph.D. research work. It contains the concentration profile of persistent orgnaochlorines viz. HCH isomers and DDT metabolites in different environmental samples collected from two Sub-Himalayan states i.e. Uttarakhand and Himachal Pradesh of India. The work embodied in this book will be helpful to understand the role of air and temperature in persistence of HCH and DDT in sub temperate and temperate conditions. This book will also pay a way to understand the theory of global distillation and cold condensation of organochlorines in colder regions. The author attempted to cover most of the aspects during the research work and results are based on the conditions prevailing during the research period. The present scenario may change but hypothesis of global distillation and cold condensation may exist.