Table 1.
Characteristics of 59 experimental studies of the effects of exposure to low-level radiofrequency electromagnetic fields.
| Source of funding
|
||||
|---|---|---|---|---|
| Study characteristic | Industry (n = 12) | Public or charity (n = 11) | Mixed (n = 14) | Not reported (n = 22) |
| Study design [no. (%)] | ||||
| Crossover trial | 10 (83.3) | 7 (63.6) | 12 (85.7) | 11 (50) |
| Parallel group trial | 0 (0) | 2 (18.2) | 1 (7.1) | 2 (9.1) |
| Other, unclear | 2 (16.7) | 2 (18.2) | 1 (7.1) | 9 (40.9) |
| Exposure [no. (%)] | ||||
| Location of antenna | ||||
| Next to ear | 4 (33.3) | 8 (72.7) | 11 (78.6) | 14 (63.6) |
| Other/unclear | 8 (66.7) | 3 (27.3) | 3 (21.4) | 8 (36.4) |
| Frequency banda | ||||
| 900 MHz | 11 (91.7) | 8 (72.7) | 13 (92.9) | 14 (63.6) |
| Other frequencies | 2 (16.7) | 7 (63.6) | 0 (0) | 5 (22.7) |
| Unclear | 0 (0) | 0 (0) | 1 (7.1) | 5 (22.7) |
| Median duration of exposure (range) | 180 (3–480) | 20 (5–35) | 45 (30–240) | 30 (4–480) |
| Outcomes assessed [no. (%)]a | ||||
| Electroencephalogram | 7 (58.3) | 5 (45.5) | 8 (57.1) | 12 (54.5) |
| Cognitive function tests | 0 (0) | 3 (27.3) | 8 (57.1) | 8 (36.4) |
| Hormone levels | 5 (41.7) | 0 (0) | 0 (0) | 2 (9.1) |
| Cardiovascular function | 2 (16.7) | 1 (9.1) | 0 (0) | 2 (9.1) |
| Well-being or symptoms | 1 (8.3) | 1 (9.1) | 1 (7.1) | 0 (0) |
| Other | 4 (33.3) | 3 (27.3) | 1 (7.1) | 3 (13.6) |
| Study quality [no. (%)]a | ||||
| Randomization adequate | 10 (83.3) | 7 (63.6) | 13 (92.9) | 9 (40.9) |
| Participants and assessors blinded | 1 (8.3) | 3 (27.3) | 8 (57.1) | 3 (13.6) |
| SAR determined | 4 (33.3) | 4 (36.4) | 8 (57.1) | 2 (9.1) |
| Statistical analysis adequate | 3 (25) | 3 (27.3) | 7 (50) | 1 (4.5) |
| Median study size (range) | 21 (8–38) | 24 (13–100) | 20 (13–96) | 20 (8–78) |
Percentages are column percentages.
a
The same study could be listed in more than one category.