Value chain · CLM-1328
In plain terms
Studies of radar and microwave workers up to 1972 found small lens changes but no clear cases of cataract below about ten times the US limit. The reviewers saw no harm at the limit but said nobody had shown that years of low-level exposure were harmless.
The claim as recorded
The same 1972 review judges that human data do not conclusively show that microwaves cause cataracts in people. A records study of 2,946 veterans treated for cataract against 2,164 without found no added risk from military radar work. A survey of 736 microwave workers against 559 controls found higher scores for minor lens defects, mainly posterior polar defects rising with duration and degree of exposure, but no cataracts or loss of sight, and suggested an ageing effect on the lens; a second survey of 475 exposed and 359 controls found a similar slight difference. Clinically significant cataracts had generally been linked to exposures of at least 100 mW/cm2, which the review calls a factor of 10 above the US maximum permissible exposure. Some workers had also been exposed to X-rays from high-voltage tubes, which can cause the same kind of cataract. The review states the US limit of 10 mW/cm2, based on the lens as the most sensitive organ, and the Soviet limit of 0.01 mW/cm2, 1000 times smaller, based on neurological and psychological effects not seen in the US. It finds no Western evidence of injury at 10 mW/cm2 and no evidence that there is no long-term low-dose effect, and recommends keeping 10 mW/cm2 rather than changing it without data.
Evidence behind this: T2, a peer-reviewed journal review summarising worker surveys and case reports; it permits "the review judged Y", not that the surveys are sound.
Scope and limits
Worker exposures were rarely measured, often at mixed frequencies, and the 0-3 lens scoring is called insensitive by the review. Retrospective designs. The Soviet and Polish surveys are judged of little value by the review on statistical grounds. The limits are as the review states them in 1972; the Soviet value is for continuous exposure.
What it assumes
The surveys' own exposure scores, which the review says were rough and in one case not entirely valid.
Where it comes from
PDF p.6 / printed 72: "The human data in itself does not even provide very conclusive evidence that microwave radiation causes cataracts in humans." PDF pp.6-7 / printed 72-73: dose levels "point to a threshold of at least 100 mW/cm2, a factor of 10 larger than the present maximum permissible exposure". PDF p.7 / printed 73: "The Soviet standard is 1000 times smaller at 0.01 mW/cm2"; "There is not now in the western literature any evidence of injury occurring at the 10 mW/cm2 level. Neither is there evidence to demonstrate that there is no long term low dose effect." PDF pp.5-6 / printed 71-72: the 2,946, 2,164, 736, 559, 475 and 359 counts.
Basis: mW/cm2; counts of exposed and control workers
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-1328
CLM-1328, Energy Aperture, as of 1972-01.
Connected records
Other published records linked to this one. A list, not a judgement.