* Nearly half a century before the accident, scientists at the Brookhaven National Laboratory irradiated a forest of oaks and pines with cesium-137. They must have had a blank check; they blasted that place for two years. Do you remember Mr. Shigihara’s 95.1 microsieverts an hour? The experimenters would have been unimpressed. A tenfold increase over that dose—which is to say a full millisievert per hour—was where they first began to notice environmental degradation. Where the measured exposure remained near zero, there was, as might be expected, no perceptible biological effect on insects and vegetation; then the curve of radiation versus damage began to rise, shallowly at first. One to 2.5 millis stunted plant growth and diminished animal diversity. Pines suffered before oaks, which “persisted at rather high dose levels” (10 to 20 millis per hour). In the ring where the oaks had absorbed 2.5 millis, aphids infested them in populations more than 200 times greater than where oaks were left to themselves. Closer to the cesium source, at a dose of more than 50 millis, only fungivorous, xylophagous and saprophagous insects persisted in significant numbers; above 150 or 200 millis an hour, the insects were described as “occasional transients.” At 50 millis the oaks had already given way to huckleberries and blueberries; at 100 millis only sedges hung on; but not until somewhere beyond a horrific 250 millisieverts an hour did the diagram read: HIGHER PLANTS DEAD.