RF Safe

Medical considerations of exposure to microwaves (radar)

JAMA · 1958 · No effect · Low evidence

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No effectLow evidencePaper 6705

In an initial comparison of 88 nonexposed persons with 226 radar-exposed employees (some with up to 13 years of radar work), the study reports no acute, transient, or cumulative physiological or pathological changes attributable to microwaves among people wor…

Study snapshot

PublicationJAMA · 1958
Study typecohort
Reported directionNo effect
Evidence ratingLow

Abstract

Apprehension over the possibility of injury to man by microwaves is based largely on the fact that sufficiently intense and prolonged radiation of this frequency has caused severe injuries to experimental animals. Several hundred workers who have been occupied about radar installations or have been exposed to radar beams have therefore been observed in a comprehensive medical surveillance program. This has been in progress for four years. The initial study was a comparison of 88 nonexposed persons with 226 radar-exposed employees, some of whom had worked with radar as long as 13 years. No acute, transient, or cumulative physiological or pathological changes attributable to microwaves have been revealed by this study in people working with highpower radar transmitters and frequently exposed to their output. These subjects are free to heed the warning sensation of heat and are advised to avoid exposure to any firing beam when in a zone defined by a minimum power density of 0.0131 watts per square centimeter. Since the development of increasingly high-powered transmitters is to be anticipated, the need for more precise and refined statements of human tolerance is evident.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typecohort
Effect directionno_effect
PopulationWorkers occupied about radar installations / radar-exposed employees; comparison group of nonexposed persons
Sample size314
Exposuremicrowave · medical surveillance program in progress for four years; some exposed workers up to 13 years
Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In an initial comparison of 88 nonexposed persons with 226 radar-exposed employees (some with up to 13 years of radar work), the study reports no acute, transient, or cumulative physiological or pathological changes attributable to microwaves among people working with high-power radar transmitters and frequently exposed to their output. The program advised avoiding exposure to any firing beam when in a zone defined by a minimum power density of 0.0131 W/cm^2.

Outcomes measured

  • Acute physiological changes
  • Transient physiological changes
  • Cumulative physiological changes
  • Pathological changes
  • Heat sensation (warning sensation)

Limitations

  • Frequency not specified
  • Exposure metrics largely not quantified beyond a stated minimum power density zone
  • Observational design; details of surveillance methods and specific endpoints not provided in abstract
View raw extracted JSON
{
  "study_type": "cohort",
  "exposure": {
    "band": "microwave",
    "source": "radar (occupational)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "medical surveillance program in progress for four years; some exposed workers up to 13 years"
  },
  "population": "Workers occupied about radar installations / radar-exposed employees; comparison group of nonexposed persons",
  "sample_size": 314,
  "outcomes": [
    "Acute physiological changes",
    "Transient physiological changes",
    "Cumulative physiological changes",
    "Pathological changes",
    "Heat sensation (warning sensation)"
  ],
  "main_findings": "In an initial comparison of 88 nonexposed persons with 226 radar-exposed employees (some with up to 13 years of radar work), the study reports no acute, transient, or cumulative physiological or pathological changes attributable to microwaves among people working with high-power radar transmitters and frequently exposed to their output. The program advised avoiding exposure to any firing beam when in a zone defined by a minimum power density of 0.0131 W/cm^2.",
  "effect_direction": "no_effect",
  "limitations": [
    "Frequency not specified",
    "Exposure metrics largely not quantified beyond a stated minimum power density zone",
    "Observational design; details of surveillance methods and specific endpoints not provided in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "microwaves",
    "radar",
    "occupational exposure",
    "medical surveillance",
    "power density",
    "human tolerance"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.9,
      "reason": "Study concerns workers exposed to radar installations/beams in an occupational setting."
    }
  ]
}
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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1001/jama.1958.03000090024006
PubMed: 13587196

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