Scientific Nonknowledge and Its Political Dynamics: The Cases of Agri-Biotechnology and Mobile Phoning

While in the beginning of the environmental debate, conflicts over environmental and technological issues had primarily been understood in terms of "risk", over the past two decades the relevance of ignorance, or nonknowledge, was emphasized. Referring to this shift of attention to nonknowledge the article presents two main findings: first, that in debates on what is not known and how to appraise it different and partly conflicting epistemic cultures of nonknowledge can be discerned and, second, that drawing attention to nonknowledge in technology conflicts results in significant institutional effects and new constellations of actors in public debates. To illustrate and substantiate this political dynamics of nonknowledge we draw upon examples from the areas of agri-biotechnology and mobile phoning. In a first step, we develop in greater detail the concept of scientific cultures of nonknowledge and identify three such cultures involved in the social conflicts within the two areas. Subsequently, we analyze the specific dynamics of the politicisation of nonknowledge looking at the variety of actors involved and the pluralisation of perceptions and evaluations of what is not known. Then, we point out some of the institutional reactions to the political and cultural dynamics of scientific nonknowledge. We argue that the equal recognition of the diverse cultures of nonknowledge is a key prerequisite for socially legitimate and "robust" decision-making under conditions of politicised scientific nonknowledge. © The Author(s) 2010

Interlaboratory comparison for quantitative chlorine analysis in cement pastes with laser induced breakdown spectroscopy

International audienceConcrete structures experience severe damage during service, such as pitting corrosion of rebars caused by the ingress of chlorine (Cl) into the porous concrete structure. The ingress can be monitored using laser-induced breakdown spectroscopy (LIBS), a promising civil engineering technique used to detect Cl in concrete structures in addition to conventional wet chemistry methods. The key advantages of LIBS are high spatial resolution, which is important when analyzing heterogeneous concrete samples, as well as the almost complete absence of sample preparation. To assess LIBS as a reliable analytical method, its accuracy and robustness must be carefully tested. This paper presents the results of an interlaboratory comparison on the analysis of Cl in cement paste samples conducted by 12 laboratories in 10 countries. Two sets of samples were prepared with Cl content ranging from 0.06-1.95 wt.% in the training set and 0.23-1.51 wt.% in the test set, with additional variations in the type of cement and Cl source (salt type). The overall result shows that LIBS is suitable for the quantification of the studied samples: the average relative error was generally below 15 %. The results demonstrate the true status quo of the LIBS method for this type of analysis, given that the laboratories were not instructed on how to perform the analysis or how to process the data