The overpressure decreases inversely as the cube of the radius, while the area of destruction increases with the square of the radius. An overpressure of 20 psi will produce a maximum wind velocity of 502 mph. When the shock wave reflects from hitting the earth's surface and recombines with the original shock wave it is called the Mach Stem. The overpressure is now approximately double due to this effect. Most blast injuries and fatalities occur because of indirect effects.
Objects become missiles.
The overpressure for a 1-Kt ground burst is 10 p.s.i. at 1100 feet. The thermal effects outweigh the blast effects slightly. Yes, enough thermal radiation is present to ignite the newspaper. It can cause tumors, leukemia and other related blood disorders. Cesium 137 behaves like potassium in the body.