Table 1: General description of studies.

Study	Study design, types of cancer outcome and type of exposure	Confounders	No. of Subjects/population	Source of data
Baumgardt-Elms [56]	Case control, morbidity, testicular, occupational	Matched by age and region	1066	Clinical and pathology departments in 5 regions in Germany, Interviews
Berg [57]	Case control brain tumors, occupational	Age, gender (matched), socioeconomic status, urban vs. rural area, ionizing radiation, smoking, cell phone, demographic characteristics, transmitters and ham radio, smoking and medical histories, occupational exposure to EMF	2241	Interviews, questionnaire. Four neurological clinics in Germany, population registries
Calle [58] Letter	Proportional mortality ratio, leukemia, occupational	Adjusted for age and year of death	6 radio and telegraph operators (observed)	Wisconsin Department of Health and Social Services
Cantor [46]	Case control, mortality, breast cancer, occupational	Adjusted for age and socio economic status	108,989 white women, 16,033 black women	National Cancer Institute, the National Institute for Occupational Safety and Health (NIOSH) and the National Center for Health Statistics
Chung –Yi [41]	Ecological morbidity, all site cancers, leukemia and brain tumors, environmental	Age, gender, ELF, calendar year of diagnosis, urbanization level of township	2606 including 939 leukemia and 394 brain cancer	National health Insurance Research Database, Taiwan National Communication Council
Coleman [59] Letter	Proportional registration ratio(PRR), leukemia, occupational	5-year age group, adjusted for age	8 cases of telegraph/radio operators	South-East England, South Thames Cancer Registry
Cooper [60] Letter	Ecological, morbidity, leukemia, environmental	Stratified by 5-year age bands, gender and socioeconomic status	20 leukemia cases	West Midlands Cancer Intelligence Unit database (Birmingham, England)
Degrave [35]	Cohort mortality, all types, occupational	Age	7349	Military, Belgian National Registry, Belgian National Cancer Registry
Davis [61]	Cohort, morbidity, testicular, occupational	Testes disease or trauma, family history of testicular cancer, occupational exposure to pesticides and herbicides	340 police officers	Interviews, SEER 1981 registry rates. Pathology slides
Demers [62]	Case control, morbidity, breast cancer, occupational	Age, work history, a broad range of risk factors (not detailed), education	527 total, 12 communication and broadcasting exposure, males	Cancer registries and National Cancer Institute, Interviews
Dode [31]	Ecological mortality, all site cancers, environmental	Age, gender	7191	Health Department of the city Belo Horizonte in Brazil, Brazilian Telecommunication Agency, Brazilian Institute of Geography and Statistics
Dolk [63]	Ecological, morbidity, all types, environmental	Age, socioeconomic class	408,000 males and females	National Statistics office UK, cancer registry, British Broadcasting Corporation. Population and cases were located via postcode of residence
Dolk [64]	Ecological, morbidity, leukemia, melanoma, bladder, childhood leukemia and brain, environmental	Age, socioeconomic status	3.39 million males and females	National Statistics office UK, cancer registry, British Broadcasting Corporation. Population and cases were located via postcode of residence
Eger [16]	Case control morbidity, all types, environmental	Age, gender	1000	Medical records
Elliot [65]	Case control, Brain and CNS, leukemia, non Hodgkin's and all cancers, environmental	Gender, date of birth, education, deprivation measure, population density, population mixing	6985 children	All the registered cases of cancer in children aged 0-4 in Great Britain in 1999-2001. Four national mobile phone operators provided data
Finkelstein [66]	Cohort morbidity all types, occupational	Age, calendar year	12 leukemia cases, 41 melanoma cases	Ontario cancer registry, 83 Ontario police departments
Goldsmith [47] analysis of Lilienfeld 1978	Cohort mortality, all site cancers, leukemia, breast, brain, occupational	Not stated		Lilienfeld 1978
Goldsmith [36] analysis of Robinette 1980	Cohort mortality all types, occupational	Year of birth	40,000 Korean war Naval personnel	Navy and Veterans Administration records
Goldsmith [47] analysis of Anderson 1986	Ecological morbidity, All site cancers and leukemia, environmental	Age	1143 cases of all site cancers in males and females 26 leukemia cases in males and females	Honolulu Cancer Registry, EPA radiation measurements
Grayson [67]	Nested case control, morbidity brain tumors, occupational	Age, race, military rank as a surrogate for socioeconomic status. Cases and controlled were matched	1150 males	US Air Force personnel records
Groves [68]	Cohort mortality, all types, occupational	Age	40,581 total 20,021 high exposure, males	Department of Veterans Affairs. Job classification from US Navy Veteran cohort, industrial hygienists
Ha [45]	Ecological, morbidity, all site cancers, breast, leukemia, lymphoma, brain cancer, environmental	Age	3152 -126,523 people per area	Clinical and pathology departments in 5 regions in Germany, Interviews
Ha [42]	Case control morbidity, leukemia and brain tumors, environmental	Matched on age, gender and year of diagnosis. Residential location, population density and socioeconomic status, industrialized environmental pollution	5966 children (up to 15 years old)	South Korean Medical Insurance Data system, National Cancer Registry
Hardell [69]	Case control, testicular, occupational	Selection of the closest subjects in birth registration number (born in the same year)	462 total 5 radar workers	Swedish Cancer Registry
Hayes [70]	Case control, morbidity, testicular, occupational	Age, radioisotopes, radioactive materials or nuclear materials, pesticides, polycyclic aromatic hydrocarbons	530 males	Three collaborating medical institutions in Washington DC area, two of the study hospitals were military hospitals
Hocking [71]	Ecological, morbidity and mortality, children and adults, leukemia and brain tumors, environmental	Age, gender, calendar period, area	585,000 males and females	New South Wales Cancer Registry (Australia), Commonwealth Department of Communication and Arts
Hocking [39]	Survival ecological, leukemia, environmental	Age, gender and year of diagnosis	160 children	New South Wales (Australia) cancer registry
Holly [72]	Case control, morbidity Uveal melanoma, occupational	Demographic characteristics, occupational history, and exposure to chemicals. Excluded home microwave ovens	668 males	Ocular Oncology Unity at the University of California San Francisco, interviews
Karipidis [73]	Case control, morbidity non Hodgkin's lymphoma, occupational	Matched on age, gender and area of residence. Occupational exposure, risk factors of NHL, ionizing radiation, chemicals	1388 males and females	New South Wales Central Cancer Registry, Australia. New South Wales and Austrian Capital Territory electoral polls
Karipidis [74]	Case control, Morbidity Glioma, occupational	Age, gender, postcode of residence. Occupational exposure, education. Job exposure matrix included exposures to ELF, RF, UV and ionizing radiation	838	14 Melbourne hospitals, Victoria Cancer Registy, major population centers in the state of Victoria, Australia. Questionnaires and interviews
Kliukiene [75]	Nested case control within a cohort, morbidity breast cancer, occupational	Job histories, Match on year of birth, exposures	495 within a cohort of 2619	National cancer registry of Norway
Lagorio [30]	Cohort mortality, all site cancers, leukemia, brain, Digestive, liver, lung, breast, occupational	Age, gender, calendar period – specific regional mortality rates to the person years at risk	481 females	Registry Office of the municipalities
Maskarinec [76]	Case control morbidity, leukemia, environmental	Age, gender, medical history, exposure to metals, smoking in the home, X rays, proximity to oil drums, parents occupational history and exposure to metals, chemicals. Case and controls were matched on gender and age	60 cases and controls, children	Hawaii Tumor Registry, Interviews
Mcdowall [27] Letter	Proportional mortality ratio (PMR), leukemia, occupational	-	6 telegraph radio operators (no. of cases)	Office of population censuses and surveys, England and Wales electrical occupations
McKenzie [77]	Ecological, leukemia morbidity, environmental	Age and socioeconomic status	216 children	New South Wales Central Cancer Registry
Merzenich [78]	Case control morbidity, leukemia, environmental	Age, gender and transmitter area (matching), population density	7807	German childhood cancer registry (1984- 2003)
Michelozzi [79]	Ecological, mortality, morbidity, childhood and adult leukemia, environmental	Age, gender, socioeconomic class	49,656 adults and children	Lazio Region Geographic information mortality system, Italian Cancer Registries, main hospitals in Rome, Residence data: local population register, and census tract
Milham [29] Letter	Proportionate mortality ratio (PMR), leukemia, occupational	Standardized by age and year of death	5 radio and telegraph operators, 5 TV and radio repairman, no. of observed	All deaths of Washington State. Washington State department of Social and Health Services
Milham [80]	Proportionate Mortality Ratio (PMR), leukemia, lymphoma, lung, brain, pancreas, occupational	Age, year of death	486,000 males total	Records of male deaths filed in Washington State
Milham [81] Letter	Proportionate mortality ratio (PMR), leukemia occupational	Age	1691 male deaths. Of them 24 with leukemia	Washington State and California, radio operators monthly magazine that lists deaths on monthly basis
Milham [82]	Cohort mortality, all types, occupational	Age	67,829 amateur radio operators	US Federal Communications Commission Amateur Radio Station and/or Operator License file from the National Technical Information Services
Milham [26]	Cohort, mortality, Hematologic, lymphatic and brain cancer, occupational	Age	67,829 amateur radio operators	US Federal Communications Commission Amateur Radio Station and/or Operator License file from the National Technical Information Services
Morgan [83]	Cohort, mortality, brain, lymphatic/hematopoietic, Hodgkin's, melanoma, respiratory system, stomach, breast, occupational	Age, gender, race	195,775 total 24,621 exposed	National Death Index, Social Security Administration, archived personnel files
Pearce [84]	Case control morbidity, leukemia, occupational	Matched on Age and year of registration	6 radio/TV repair, males	New Zealand cancer registry
Pearce [85]	Case control, morbidity, leukemia, occupational	Age	12 radio/TV repair, males	New Zealand Cancer Registry
Szmigielski [37]	Cohort, morbidity, all types, occupational	Age, diagnosis date	128,000 total 3,700 exposed, males	Military's health departments, hospitals, medical board, safety groups operating as health hygienic service
Szmigielski [38]	Cohort morbidity all types, occupational	Age	124,500 total, about 3500-4500 exposed males	Polish army, service records listing of exposures
Thomas [86]	Case control, mortality, brain tumor, occupational	Educational level, match on age at death, year of death and area of residence. Risk factors of brain tumor	821death certificates, males	Northern New Jersey, Philadelphia, PA, and southern Louisiana. Brain tumors verified through a hospital record review
Tynes [87]	Cohort morbidity, all types, occupational	Sea related lifestyle factors: A diet rich in fat, artificial light, disturbances in the geomagnetic field, alcohol	2619 females	National Cancer Registry of Norway
Wolf [17]	Cohort morbidity all sites, environmental	Socioeconomic class employment status, demographic heterogeneity due to differences in age gender and ethnicity	1844	Medical clinics, national and city incidence rate
Wright [28] Letter	Proportional Incidence Ratio (PIR) leukemia, occupational	Specific for age, gender and race	1 no. of cases (TV and radio repair)	Cancer Surveillance Program information on Los Angeles County