As the title indicates, free-lance journalists Griffiths and Ballantine are not prone to understatement. Silent Slaughter, an intemperate account of the dangers of low-level radiation, is frankly calculated to scare the hell out of you. It's bad enough that the AEC (the regulatory agency) has a vested interest in promoting the use of nuclear energy and National Council of Radiation Protection (NCRP) estimates on permissible doses of radiation are probably too high. But Griffiths and Ballantine tell you more -- that TV sets, x-ray machines and luminous watches are emitting lethal doses of radiation; that everyone, especially young children and the unborn, is menaced. A pelvic x-ray given to a pregnant woman increases the chances of her child dying of leukemia or being born with mongolism or a hairlip; in 1967 GE sold 93,000 defective color TV sets unshielded and leaking the stuff right at your kid. And if you're still not quaking, consider the seepage from nuclear wastes, shipments of cobalt and plutonium lost in transit (31 in 1969 alone according to the AEC), fallout from underground testing, emissions from nuclear subs that sank, poor reactor design, etc., etc. Of course if you read quite carefully you'll find that most of their evidence re genetic damage is inferential; that scientific and medical evidence is sketchy and controversial; that the TV hazards can be avoided by sitting eight feet from the set, and that on balance x-rays and radiation treatments have saved vast numbers of lives. But the disclaimers are parenthetical while DANGER is blasted in shrill, histrionic tones which belie the assertion that ""the authors aren't trying to start a national panic."" Really?