Consider a massive nuclear power plant, closely guarded and surrounded by barbed wire. Compare this with an innocuous solar panel perched on a roof, cheerfully and silently gathering sunlight. Is there any question in your mind which of the two energy systems is more dangerous to human health and safety? If the answer were a resounding "No", the matter could end there, and the editors would be left with a rather unsightly blank space in their journal. But research has shown that the answer should be a less dramatic but perhaps more accurate "maybe".