This doctoral thesis analyses the concept of risk and how it functions as an organizing principle of discourse, paying close attention to actual linguistic practice. Article 1 analyses the concepts of risk, safety and security and their relations based on corpus data. Lexical, grammatical and semantic contexts of the nouns risk, safety and security, and the adjectives risky, safe and secure are analysed and compared. Similarities and differences are observed, suggesting partial synonymy between safety and security and semantic opposition to (...) risk. The findings both support and contrast theoretical assumptions about these concepts in the literature. Article 2 analyses the concepts of risk and danger and their relation based on corpus data. Frame semantics is used to explore the assumptions of the sociologist Niklas Luhmann that the risk concept presupposes decision-making, while the concept of danger does not. Findings partly support and partly contradict this assumption. Article 3 analyses how newspapers represent risk and causality. Two theories are used: media framing and the philosopher John Mackie’s account of causality. A central finding of the study is that risks are “framed” with respect to causality in several ways. Furthermore, newspaper reporting on risk and causality vary in complexity. In some articles, risks are presented without causal explanations, while in other articles, risks are presented as results from complex causal conditions. Considering newspaper reporting on an aggregated overall level, complex schemas of causal explanations emerge. Article 4 analyses how phenomena referred to by the term nano are represented as risks in Swedish newspaper reporting. Theoretically, the relational theory of risk and frame semantics are used. Five main groups of nano-risks are identified based on the risk object of the article: nanotechnology; nanotechnology and its artefacts ; nanoparticles, without referring to nanotechnology; non-nanotechnological nanoparticles ; and nanotechnology and nanorobots. Various patterns are explored within each group, concerning, for example, what is considered to be at stake in relation to these risk objects, and under what conditions. It is concluded that Swedish patterns of newspaper reporting on nano-risks follow international trends, influenced by scientific assessment, as well as science fiction. Article 5 analyses the construction and negotiation of risk in the Swedish controversy over the use of antibacterial silver in health care and consumer products. The controversy involves several actors: print and television news media, Government and parliament, governmental agencies, municipalities, non-government organisations, and companies. In the controversy, antibacterial silver is claimed to be a risk object that negatively affects health, the environment, and sewage treatment industry. In contrast, such claims are denied. Antibacterial silver is even associated with the benefit of mitigating risk objects that threaten health and the environment. In other words, both sides of the controversy invoke health and the environment as objects at risk. Three strategies organising risk communication are identified: representation of silver as a risk to health and the environment; denial of such representations; and benefit association, where silver is construed to mitigate risks to health and the environment. (shrink)