ABSTRACT
This chapter discusses the nature of vapours and gases and highlights the health effects from exposure, air monitoring techniques and analytical methods. It provides an overview of specific gases and vapours, with an emphasis on commonly found contaminants such as asphyxiants, irritants, toxic gases and vapours. Airborne chemical contaminants such as gases and vapours have unique characteristics that impact on the risk they present from exposure. Gases are essentially fluids that expand to occupy the space or volume in which they are confined. Many gases and vapours have a handy characteristic that is useful in recognising the hazard —an odour. Skin absorption of chemical contaminants typically occurs where a substance is splashed onto the skin or the skin is immersed directly into the substance. The movement of gases and vapours in the body is influenced by their partial pressure. Hydrogen and helium are the two simplest elements and occupy the first and second places in the periodic table.
