Lecture 10 19/12/2010 13:23:00
Criteria Air Contaminants
•SO2 – Sulphur Dioxide – mostly from burning coal smells like rotten egg. Can
react with water vapour to create sulphuric acid
•NO2 – Nitrous Oxide – highly reactive, mostly from cars, also contributes to
•Particulate Matter – small particles like dust and soot that can be suspended
in the atmosphere. Bad for respiratory issues.
•Volatile Organic Compounds (VOC’s) – organic compound related to usage of
household chemicals, car engines. Cancer causing.
•Carbon Monoxides – from incomplete combustion, inhibits oxygen absorption.
•Ammonia – mostly from livestock waste, bad odor, can form particulate
•Tropospheric Ozone – this ozone in the troposphere can be formed by
pollutants reacting with light to make smog.
Persistent Organic Pollutants (POP’s)
•They last for a long time, most are volatile so they can travel long distances.
•Can enter food chain, detrimental effects at low concentration.
•Principle sources are human activity (PCB’s, DDT), incomplete combustion
•Pivotal to environmental movement in the 1970’s
•Mercury and lead
•Can be transported long distances in atmosphere, bioaccumulate in food
chain, cause health issues. Stay in in environment for long time.
•Long range of atmospheric pollutants.
•Mercury: number of different forms, different toxicity, “natural occurrences in
environment exacerbate situation, bioaccumulative, fish are a major source.
Sources both natural and from humans.
•Lead: Similar effects to mercury, industrial metal smelting big source. Leaded
•Most common in air quality problem
•Can have industrial smog, from burning of fossil fuels.
•Photochemical smog are widespread.
•Light-driven reactions form ground-level ozone > brown air.