Epidemiological study (observational study)

Use of cellular telephones and brain tumour risk in urban and rural areas epidem.

By: Hardell L, Carlberg M, Hansson Mild K

Published in: Occup Environ Med 2005; 62 (6): 390-394

Aim of study (acc. to author)

In this study, further analyses were performed on the database of a Swedish case-control study (see publication 9105) on the use of cellular telephones and cordless telephones and the risk of brain tumors in urban and rural areas.

Further details

Furthermore, there are additional analyses of the database of the same case-control study (publication 9105) in publications 9520, 9361 and 12393.
The subjects were grouped into 6 categories (H1 - H6) depending on the population density according to the classification of the Statistics Sweden. The groups H1 and H2 include the largest cities Stockholm, Göteborg, and Malmö/Lund where as the lowest density group H6 consists of municipalities with less than 27,000 inhabitants within a radius of 30 km from the centre. The groups H1 - H3 are classified as urban, the groups H4 - H6 as rural.

Endpoint/type of risk estimation

brain tumor

Type of risk estimation:

incidence

(odds ratio (OR))

Exposure

- mobile communications
- analog mobile phone
- digital mobile phone
- GSM
- NMT
- cordless phone
- personal

Assessment

questionnaire: mean number and minutes of daily calls, use in car with fixed external antenna or hands-free device, ear most frequently used during calls)
interview: supplementing data
calculation: cumulative use in hours

Exposure groups

Group	Description
Reference group 1	unexposed
Group 2	H1-H6, analog, > 1 year latency
Group 3	H1-H3, analog, > 1 year latency
Group 4	H4-H6, analog, > 1 year latency
Group 5	H1-H6, analog, > 5 years latency
Group 6	H1-H3, analog, > 5 years latency
Group 7	H4-H6, analog, > 5 years latency
Group 8	H1-H6, analog, > 10 years latency
Group 9	H1-H3, analog, > 10 years latency
Group 10	H4-H6, analog, > 10 years latency
Group 11	H1-H6, digital, > 1 year latency
Group 12	H1-H3, digital, > 1 year latency
Group 13	H4-H6, digital, > 1 year latency
Group 14	H1-H6, digital, > 5 years latency
Group 15	H1-H3, digital, > 5 years latency
Group 16	H4-H6, digital, > 5 years latency
Group 17	H1-H6, cordless, > 1 year latency
Group 18	H1-H3, cordless, > 1 year latency
Group 19	H4-H6, cordless, > 1 year latency
Group 20	H1-H6, cordless, > 5 years latency
Group 21	H1-H3, cordless, > 5 years latency
Group 22	H4-H6, cordless, > 5 years latency
Group 23	H1-H6, cordless, > 10 years latency
Group 24	H1-H3, cordless, > 10 years latency
Group 25	H4-H6, cordless, > 10 years latency

Population

Group:
- men
- women
Age: 20–80 years
Observation period: January 1997 - June 2000
Study location: Sweden (Uppsala/Örebro, Stockholm, Linköping and Göteborg regions)

Case group

Characteristics: brain tumor, histopathologically verified
Data source: Cancer Registry
Exclusion criteria: deceased

Control group

Selection:
- population-based
Matching:
- sex
- area
- 5-years age group
- case:control = 1:1

Study size

	Cases	Controls
Eligible	1,617	-
Contacted	1,617	1,617
Participants	1,429	1,470
Participation rate	88 %	91 %

Statistical analysis method:

unconditional logistic regression

(adjustment:

age
sex
socioeconomic status

)

Results (acc. to author)

No effect of place of residence was found for analog cellular and cordless telephones. An increased risk for brain tumor was found among users of digital cellular telephones in rural areas compared to urban areas .

Limitations (acc. to author)

The results are based on low numbers und must be interpreted with caution.

Study funded by

Cancer och Allergifonden (Cancer and Allergy Foundation), Sweden
Nyckelfonden, Sweden
Örebro Cancer Fund, Sweden

Leitgeb N (2015): Synoptic Analysis of Epidemiologic Evidence of Glioma Risk from Mobile Phones
Leitgeb N (2014): Synoptic Analysis of Epidemiologic Evidence of Brain Cancer Risks from Mobile Communication
Hardell L et al. (2009): Mobile phones, cordless phones and the risk for brain tumours
Klaeboe L et al. (2007): Use of mobile phones in Norway and risk of intracranial tumours
Lahkola A et al. (2007): Mobile phone use and risk of glioma in 5 North European countries
Hardell L et al. (2006): Pooled analysis of two case-control studies on the use of cellular and cordless telephones and the risk of benign brain tumours diagnosed during 1997-2003
Takebayashi T et al. (2006): Mobile phone use and acoustic neuroma risk in Japan
Lönn S et al. (2006): Mobile phone use and risk of parotid gland tumor
Hardell L et al. (2006): Pooled analysis of two case-control studies on use of cellular and cordless telephones and the risk for malignant brain tumours diagnosed in 1997-2003
Schüz J et al. (2006): Cellular phones, cordless phones, and the risks of glioma and meningioma (Interphone Study Group, Germany)
Hepworth SJ et al. (2006): Mobile phone use and risk of glioma in adults: case-control study
Hardell L et al. (2006): Case-control study of the association between the use of cellular and cordless telephones and malignant brain tumors diagnosed during 2000-2003
Hardell L et al. (2005): Case-Control Study on Cellular and Cordless Telephones and the Risk for Acoustic Neuroma or Meningioma in Patients Diagnosed 2000-2003
Christensen HC et al. (2005): Cellular telephones and risk for brain tumors: a population-based, incident case-control study
Lönn S et al. (2005): Long-term mobile phone use and brain tumor risk
Lönn S et al. (2004): Mobile Phone Use and the Risk of Acoustic Neuroma
Hardell L et al. (2003): Further aspects on cellular and cordless telephones and brain tumours
Hardell L et al. (2002): Case-control study on the use of cellular and cordless phones and the risk for malignant brain tumours
Auvinen A et al. (2002): Brain tumors and salivary gland cancers among cellular telephone users
Hardell L et al. (2001): Ionizing radiation, cellular telephones and the risk for brain tumours
Inskip PD et al. (2001): Cellular-telephone use and brain tumors
Muscat JE et al. (2000): Handheld cellular telephone use and risk of brain cancer
Hardell L et al. (2000): Case-control study on radiology work, medical x-ray investigations, and use of cellular telephones as risk factors for brain tumors
Hardell L et al. (1999): Use of cellular telephones and the risk for brain tumours: A case-control study