With 100 days to go until the Olympic Games, and with concerns about the water quality in the Seine river -- where a handful of Olympic events are due to take place, microbiologist Françoise Lucas, a keen observer of France's ambitious bathing plan, points out that "European regulations are based on thresholds that are not zero risk" but "an acceptable risk" of contamination. Despite the infrastructures put in place, the fate of the Olympic events will depend on the weather, she insists. IMAGES AND SOUNDBITES