Civil Engineering Reference
In-Depth Information
Figure 2.1: The concentration of carbon dioxide in the atmosphere from 1750 until 1988. Source:
Mathisen 1990
Substances that form photochemical oxidizing agents,
low ozone
Photochemical oxidizing agents are generally very corrosive and are described as
smog. They are formed when a mixture of nitrogen oxides from fossil fuels, dust
and a few volatile organic compounds like turpentine, are subjected to sunlight.
The potential of a product to produce low ozone is referred to as its 'photo-
chemical ozone creation potential' (POCP).
Eutrophicating substances
Over-fertilization and the resulting overgrowth of weeds caused by these sub-
stances in water systems is known as 'chemical oxygen depletion' (COD). In the
building industry the most critical emission of nitrogen is in the form of nitric
oxides from combustion processes. Artificial fertilizers used when producing
plant substances can also cause problems. It is important to realize that the effects
of eutrophicating substances are dependent upon their location and the type of
earth in which they are placed.
Electromagnetic radiation
This includes radioactive radiation and radiation at lower frequencies, which can
affect life-processes. Building materials contribute to radioactive pollution
through the amount of nuclear powered energy used in their production. During
the use of the building some materials can emit small amounts of radioactive
Search WWH ::




Custom Search