Since the mid-1970s, genetic engineering and the possibility of accidental or deliberate environmental release of modified micro-organisms has been the centre of debates concerning the consequences of altering the ordinary course of nature. For a sound discussion on risks, it is of essence to separate substantive scientific and technical issues from non-informed perceptions of the general public. This chapter advocates this question to be framed on the already extensive history and wealth of data on the design, performance and risk studies made since the early 1980s on genetically modified organisms and more specifically, on available records on genetically engineered micro-organisms (GEMs) designed for non-contained applications as in situ bioremediation agents. Existing information provides a suitable background for tackling the uncertainties raised by newly engineered agents, including those that may stem from synthetic biology.

Bioremediation involves the application of micro-organisms for the removal of contaminants from the environment. Bioremediation competes effectively with other remediation approaches, such as thermal desorption and incineration. Further innovation of this technology involves the development of geneticically engineered strains with enhanced biodegradability capabilities. At present, however, there have been very few reported examples where genetically engineered micro-organisms have been released into commercial bioremediations. The main reasons for this include the lack of knowledge of the environmental risks and benefits of releasing genetically modified organisms into a contaminated area. In addition, non-specialist stakeholder support is often overlooked and remains a crucial area for improvement if sustainable remediation is to continue to develop. This chapter focuses on the application and risks associated with bioremediation.