TABLE 14: RFR AND OCULAR CHANGES
| Authors | Effects Sought or Examined | Exposure Modality | Effects Reported | Notes & Comments | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Cleary et al. (1965) | Analyzed were hospital cases of cataracts in U.S. WW II and Korean War veterans for a possible relationship to RFR-exposure. | Hospital cases with military occupational specialties (MOSs) related to radar were considered to have been RFR-exposed. | In the radar group, there were only 19 persons with cataracts and 2,625 persons without cataracts. In the nonradar group, there were only 21 persons with cataracts and 1,935 without cataracts. Those small percentages yielded no basis for an association between RFR-exposure and cataract causation. | Controls were veterans with non-radar MOSs concurrently hospitalized for ailments other than cataracts.
| Cleary and Pasternack (1966)
| Ocular effects of exposure at microwave installations based on the responses to a questionnaire.
| Controls were selected from the responses of personnel in non-RFR occupations at the same places. The authors derived exposure scores from the equipments used, average powers, RFR frequencies, and exposure durations.
| Regression lines were drawn for mean eye score versus age for both groups. The slope of the line for the exposed group was significantly higher than for the control group; the lines crossed at 20 years of age, perhaps indicating an acceleration of aging of lens tissue. However, no detrimental effects on vision were found.
| The exposed and control groups were examined with a slit-lens and graded for subcataractous lens changes on a 0-3 scale.
| Open to question were the use of a subjective scoring scale and a significant difference in age distribution between the groups and the age-related lens changes in both. Aurell and Tengroth (1973)
| RFR-ocular effects in 63 Swedish personnel who tested industrial radar equipment, measured RFR levels from klystrons, or worked in experimental laboratories. The controls were 30 unexposed people from the same industry.
| Unspecified microwave frequencies, levels, exposure durations.
| Both groups were examined independently by two eye specialists for visual acuity, opacities, and retinal lesions. No opacities were seen in those younger than 26 years in either group, but for each 5-year age span above 26 years, the percentages of opacities in the exposed group were higher than in the controls. Retinal lesions resembling scars after inflamatory reactions were seen in 19 of the 68 exposed persons versus only 1 of the 30 control persons.
| The authors speculated that the higher incidence of retinal lesions in the exposed group may have been due to RFR-leakages from equipment or carelessness among that group.
| Appleton and McCrossan (1972)
| Initial ocular survey of 91 persons at Fort Monmouth, NJ, where various communication, detection, guidance, and weather equipment were being developed, tested, and used. The controls were 135 Post employees who had never worked with or were near microwave equipment.
| Specific exposure data were not given, but all personnel with histories of working with lasers, microwave equipment, welding, xenon arcs, or ultraviolet were asked to participate.
| The participating persons were given eye examinations without any foreknowledge of their histories. Only those with histories of working directly with microwaves were designated as the exposed group. Scored were the numbers and locations of opacities and vacuoles, and if posterior subcapsular iridescence (PSCI) was seen. Results were presented for the 10-year age spans 20-29 through 60-69. For corresponding experimental and control age subgroups, there were several higher percentages, several lower percentages, and several with no difference.
| The lack of any statistical treatment of the data rendered it difficult to assess the findings for significance, and for possible linkage to RFR-exposure.
| Appleton (1973)
| Ocular survey extended by adding the data for personnel at 4 other Army bases, which yielded pooled totals of 605 exposed and 493 control personnel.
| See Appleton and McCrossen (1972).
| The findings for the larger data base were basically similar to those of the previous survey.
| The author elaborated on the use of opacities, vacuoles, and posterior subcapsular iridescence (PSCI) as easily recognized diagnostic criteria of possible subclinical eye damage, and noted that one or more of these signs are seen more often in people as they age and in younger persons who are developing cataracts.
| Appleton et al. (1975b)
| Final results of the ocular survey at the 5 Army bases, which encompassed totals of 1542 exposed and 801 control subjects.
| See Appleton and McCrossen (1972).
| As in the earlier surveys, for each 10-year age span, some percentages for the exposed groups were higher than for the control groups and some were lower. The authors concluded that lens damage due to microwave radiation from military equipment had not occurred.
| As before, the credibility of that conclusion is diminished by the lack of a statistical treatment of the data.
| Shacklett et al. (1975)
| Ocular surveys of 447 microwave personnel at 8 Air Force bases and of 340 age-matched controls.
| Exposures based on histories of working around microwave-generating equipment.
| High percentages of opacities, vacuoles, and posterior subcapsular iridescence (criteria the same as those used by Appleton and coworkers) were found in both the exposed and control groups, related primarily to aging and not associated with RFR-exposure.
| Work histories, the microwave equipment types involved, and the times spent working around each type were obtained. Also studied were medical histories of the subjects and families, in a search for evidence of various ocular diseases.
| Frey (1985)
| This author took issue with the findings of Appleton and McCrossan (1972). He remarked that the exposure group likely included persons who were not RFR-exposed and the control group included RFR-exposed persons. He also criticized the lack of a statistical analysis.
| See Appleton and McCrossen (1972).
| Frey statistically analyzed the Appleton and McCrossan (1972) data, and indicated that the opacity incidences and the age differences were not related, from which he concluded that the exposed group as a whole had significantly more opacities than the whole control group.
| He compared the percentages of opacities in Appleton and McCrossen's control group with the percentages of cataracts in men published by the National Center for Health Statistics (NCHS), and concluded that the study was biased. Not clear was why Frey (1985) chose to analyze the earlier Appleton and McCrossen (1972) study rather than the results of the larger Appleton et al. (1975b), which he dismissed as "also flawed". A similar comparison between the NCHS survey and the larger study shows that Frey's contention is specious.
| Wike and Martin (1985)
| These authors took issue with Frey's criticisms of Appleton and McCrossan (1972).
| See Appleton and McCrossen (1972) and Frey (1985).
| Wike and Martin's treatment of both the Appleton and McCrossen (1972) and the Appleton et al. (1975b) studies yielded the same conclusions: The occurrence of opacities was significantly associated with age and not with groups, rendering Frey's conclusion erroneous.
| Wike and Martin remarked that Frey's comparison of opacity percentages with NCHS cataract percentages was inappropriate because the two endpoints are not identical. For various reasons, they also regarded Frey's statistical treatment as inappropriate.
| Zaret (1974)
| Cataract in a patient, with exposure to a microwave oven as the suspected cause.
| Measurements of that oven yielded maximum leakage of 2 mW/cm² during operation and 40 mW/cm² on opening its door. The author estimated that the patient had used the oven for a total of about 850 hours and had opened its door about 8,500 times.
| The patient's ophthalmologist reported finding extensive posterior subcapsular opacities and a few anterior subcapsular opacities and vacuoles in both lenses, which were more advanced in the right eye. Cataract extraction from the right eye was done subsequently.
| Zaret (1974) indicated that microwave cataracts have a distinctive appearance.
| Appended to the paper were letters of comments, mostly critical of Zaret's findings, and a response by the author. Hollows and Douglas (1984a)
| Ocular effects in 53 radiolinemen exposed occupationally to RFR in Australia.
| The results of lens examination of the 53 subjects were compared with those for 39 non-radiolinemen matched in age from the same Australian states. The RFR frequencies ranged from 558 kHz to 527 MHz, primarily from radio and TV towers. The power densities near work areas ranged from 0.08 to 4,000 mW/cm².
| "Posterior subcapsular cataract" (PSC) was found in one or both eyes of 11 of the 53 radiolinemen (21%) versus in 3 of the 39 controls (8%), a nonsignificant difference (p=0.086). Alternatively, PSC was found in 19 of the 106 eyes (18%) of the radiolinemen versus in 6 of the 78 control eyes (8%), a barely significant difference (p=0.043).
| The contribution of RFR to the difference in PSC incidence is not clear because nuclear sclerosis was seen in some of the radiolinemen.
| Hocking (1984) & Harding (1984)
| Disputed some aspects of the Hollows and Douglas (1984a) study.
| See Hollows and Douglas (1984a)
| Hollows and Douglas (1984b) responded with explanations about how the subjects were selected, and that the frequencies and power-density measurements had been provided by Dr. Hocking's organization.
| At issue were how the 53 subjects were selected from 223 linesmen (comprising only 23%) and the accuracy of the exposure levels.
| Hocking et al. (1988)
| Effects of exposure of 9 radio linemen to an open waveguide that had been inadvertently activated.
| All 9 men were given medical examinations, their eyes were examined periodically for 9 months, and samples of blood and semen were evaluated. Two of the 9 men had been exposed to 4.1-GHz RFR at 4.6 mW/cm² for up to 90 minutes (the "high-exposure" group). The range of SARs in their lenses was calculated to be 1.2-1.5 W/kg. The other 7 (the "low-exposure" group) were exposed at less than 0.15 mW/cm².
| Various eye abnormalities were found in both groups in the first post-exposure ophthalmic examination, but vision was normal in all of the men. In the second examination, eye changes were found in both groups, but the third examination showed no further changes.
| One man of each group had a significant rise in creatine phosphokinase. Those in the high-exposure group showed no other significant biochemical or hematologic abnormalities. Three of the low-exposure men showed mild abnormalities in liver function, ascribed to alcohol consumption. The authors concluded that the slight abnormalities observed in both the high-exposure and low-exposure groups were inconsistent and unlikely due to the RFR-exposure.
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