Contamination of the marine environment from land-based sources
Marine Pollution Bulletin, Volume 25, Issues 1-4, 1992, Pages 32-36
H.L. Windom
Seven major categories of contaminants from land have perceived and/or real adverse effects on the coastal marine environment. Heavy metals, although perceived by the public to be a major contaminant of the marine environment, pose little threat on a global scale. Although sewage discharges, litter and oil spills constitute significant threats to the marine environment, their sources, fates and environmental effects are understood well enough to develop management strategies. Problems exist regarding those contaminants where management strategies have not been implemented. In the case of anthropogenically mobilized sediments, synthetic organic compounds, and nutrients, there is insufficient scientific information on the interrelationship between sources, transport, fates and effects to allow for development of management strategies for these contaminants, short of total source control.
Based on trends in world population growth, and global production and use of pesticides and fertilizers, it is concluded that nutrients, synthetic organic compounds and sewage pose the greatest present and future threat to the marine environment.
credit: ScienceDirect.com
Classification of Organic compounds is as follows. It has two parts: natural and synthetic compounds.
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The compounds which are prepared by reaction of other compounds are said to be "synthetic". They can be either compounds which are found in plants or animals or those that do not occur naturally.
Most polymers including all plastics and rubbers are termed as synthetic organic compounds.
Synthetic Organic Compound: Plastic
Plastics are typically polymers of high molecular mass, and may contain other substances for improving performance and to reduce costs.
The word plastic came from the Greek word plastikos which means capable of being shaped or molded, and also from plastos meaning molded.
There are mainly two types of plastics: thermoplastics and thermosetting polymers. Thermoplastics are the plastics which soften and melt if sufficient heat is applied. Examples of thermoplastics are polyethylene, polystyrene, polyvinyl chloride and poly tetrafluoroethylene (PTFE). Thermosetting plastics are the plastics which can melt and take shape once; once they are solidified, they cannot be melted.
The raw materials which take part in making most plastics are derived from petroleum and natural gas.
Synthetic Organic Compound: Rubber
Natural rubber is an elastic hydrocarbon polymer which was originally derived from latex. Latex is a milky colloid which is found in the sap of some plants. The plants in which an incision is made into the bark of the tree and the latex sap is collected and refined into a usable rubber. The most purified form of natural rubber is the chemical polyisoprene, It can also be produced synthetically. Natural rubber is used extensively in many applications and products, generally as synthetic rubber.
Credit of comment above: http://www.tutorvista.com/chemistry/synthetic-organic-compounds
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