Maize field grown in one of the 15 communities known to be contaminated by genetic pollution spread over 3 states of Mexico. From Greenpeace.org
The seemingly innocent concept of gene flow, the movement of alleles from one population to another, has become a bit of a hot topic in environmental circles since the author Jeremy Rifkin used the term 'Genetic Pollution' in 1998 to describe undesirable gene flow into wild populations. Although this often refers to the flow from genetically modified organisms to wild populations, conservation biologists have also used it to describe the undesirable flow of genes from any captive population to wild populations (eg from salmon in fish farms to local salmon populations).
Greenpeace, for example, have a page specifically about genetic pollution. Yet some people question the use of this term
"If you take a term used quite frequently these days, the term “genetic pollution,” otherwise referred to as genetic contamination, it is a propaganda term, not a technical or scientific term. Pollution and contamination are both value judgments. By using the word “genetic” it gives the public the impression that they are talking about something scientific or technical--as if there were such a thing as genes that amount to pollution.
They use it in terms of GM and in their anti-salmon farming and anti-aquaculture campaigns. If, for example, a fish escapes from a farm and interbreeds with a wild fish of the same species, they call that genetic pollution. They don’t realize that what they are saying in terms of science would be the same thing as saying that if a white person married a Chinese person, that would be genetic pollution."
What's Wrong with the Environmental Movement: an interview with Patrick Moore Competitive Enterprise Institute staff, Environment News 2004 published by The Heartland Institute.
It's an interesting discussion that makes you think about the way that words are used and abused.