Tore Tynes

Publications of Tore Tynes

• Predictors and overestimation of recalled mobile phone use among children and adolescents.

  Authors: Denis Aydin, Maria Feychting, Joachim Schüz, Tina Veje Andersen, Aslak Harbo Poulsen, Michaela Prochazka, Lars Klæboe, Claudia E Kuehni, Tore Tynes, Martin Röösli

  Progress in biophysics and molecular biology. 09/2011; 107(3):356-61.

  A growing body of literature addresses possible health effects of mobile phone use in children and adolescents by relying on the study participants' retrospective reconstruction of mobile phone use.A growing body of literature addresses possible health effects of mobile phone use in children and adolescents by relying on the study participants' retrospective reconstruction of mobile phone use. In this study, we used data from the international case-control study CEFALO to compare self-reported with objectively operator-recorded mobile phone use. The aim of the study was to assess predictors of level of mobile phone use as well as factors that are associated with overestimating own mobile phone use. For cumulative number and duration of calls as well as for time since first subscription we calculated the ratio of self-reported to operator-recorded mobile phone use. We used multiple linear regression models to assess possible predictors of the average number and duration of calls per day and logistic regression models to assess possible predictors of overestimation. The cumulative number and duration of calls as well as the time since first subscription of mobile phones were overestimated on average by the study participants. Likelihood to overestimate number and duration of calls was not significantly different for controls compared to cases (OR=1.1, 95%-CI: 0.5 to 2.5 and OR=1.9, 95%-CI: 0.85 to 4.3, respectively). However, likelihood to overestimate was associated with other health related factors such as age and sex. As a consequence, such factors act as confounders in studies relying solely on self-reported mobile phone use and have to be considered in the analysis.

• Mobile phone use and brain tumors in children and adolescents: a multicenter case-control study.

  Authors: Denis Aydin, Maria Feychting, Joachim Schüz, Tore Tynes, Tina Veje Andersen, Lisbeth Samsø Schmidt, Aslak Harbo Poulsen, Christoffer Johansen, Michaela Prochazka, Birgitta Lannering, Lars Klæboe, Tone Eggen, Daniela Jenni, Michael Grotzer, Nicolas Von der Weid, Claudia E Kuehni, Martin Röösli

  Journal of the National Cancer Institute. 08/2011; 103(16):1264-76.

  It has been hypothesized that children and adolescents might be more vulnerable to possible health effects from mobile phone exposure than adults. We investigated whether mobile phone use isIt has been hypothesized that children and adolescents might be more vulnerable to possible health effects from mobile phone exposure than adults. We investigated whether mobile phone use is associated with brain tumor risk among children and adolescents. CEFALO is a multicenter case-control study conducted in Denmark, Sweden, Norway, and Switzerland that includes all children and adolescents aged 7-19 years who were diagnosed with a brain tumor between 2004 and 2008. We conducted interviews, in person, with 352 case patients (participation rate: 83%) and 646 control subjects (participation rate: 71%) and their parents. Control subjects were randomly selected from population registries and matched by age, sex, and geographical region. We asked about mobile phone use and included mobile phone operator records when available. Odds ratios (ORs) for brain tumor risk and 95% confidence intervals (CIs) were calculated using conditional logistic regression models. Regular users of mobile phones were not statistically significantly more likely to have been diagnosed with brain tumors compared with nonusers (OR = 1.36; 95% CI = 0.92 to 2.02). Children who started to use mobile phones at least 5 years ago were not at increased risk compared with those who had never regularly used mobile phones (OR = 1.26, 95% CI = 0.70 to 2.28). In a subset of study participants for whom operator recorded data were available, brain tumor risk was related to the time elapsed since the mobile phone subscription was started but not to amount of use. No increased risk of brain tumors was observed for brain areas receiving the highest amount of exposure. The absence of an exposure-response relationship either in terms of the amount of mobile phone use or by localization of the brain tumor argues against a causal association.

• Location of gliomas in relation to mobile telephone use: a case-case and case-specular analysis.

  Authors: Suvi Larjavaara, Joachim Schüz, Anthony Swerdlow, Maria Feychting, Christoffer Johansen, Susanna Lagorio, Tore Tynes, Lars Klaeboe, Sven Reidar Tonjer, Maria Blettner [......] Anders Ahlbom, Olof Flodmark, Anders Lilja, Stefano Martini, Emanuela Rastelli, Antonello Vidiri, Veikko Kähärä, Jani Raitanen, Sirpa Heinävaara, Anssi Auvinen

  American journal of epidemiology. 07/2011; 174(1):2-11.

  The energy absorbed from the radio-frequency fields of mobile telephones depends strongly on distance from the source. The authors' objective in this study was to evaluate whether gliomas occurThe energy absorbed from the radio-frequency fields of mobile telephones depends strongly on distance from the source. The authors' objective in this study was to evaluate whether gliomas occur preferentially in the areas of the brain having the highest radio-frequency exposure. The authors used 2 approaches: In a case-case analysis, tumor locations were compared with varying exposure levels; in a case-specular analysis, a hypothetical reference location was assigned for each glioma, and the distances from the actual and specular locations to the handset were compared. The study included 888 gliomas from 7 European countries (2000-2004), with tumor midpoints defined on a 3-dimensional grid based on radiologic images. The case-case analyses were carried out using unconditional logistic regression, whereas in the case-specular analysis, conditional logistic regression was used. In the case-case analyses, tumors were located closest to the source of exposure among never-regular and contralateral users, but not statistically significantly. In the case-specular analysis, the mean distances between exposure source and location were similar for cases and speculars. These results do not suggest that gliomas in mobile phone users are preferentially located in the parts of the brain with the highest radio-frequency fields from mobile phones.

• Impact of random and systematic recall errors and selection bias in case--control studies on mobile phone use and brain tumors in adolescents (CEFALO study).

  Authors: Denis Aydin, Maria Feychting, Joachim Schüz, Tina Veje Andersen, Aslak Harbo Poulsen, Michaela Prochazka, Lars Klaeboe, Claudia E Kuehni, Tore Tynes, Martin Röösli

  Bioelectromagnetics. 02/2011; 32(5):396-407.

  Whether the use of mobile phones is a risk factor for brain tumors in adolescents is currently being studied. Case--control studies investigating this possible relationship are prone to recall errorWhether the use of mobile phones is a risk factor for brain tumors in adolescents is currently being studied. Case--control studies investigating this possible relationship are prone to recall error and selection bias. We assessed the potential impact of random and systematic recall error and selection bias on odds ratios (ORs) by performing simulations based on real data from an ongoing case--control study of mobile phones and brain tumor risk in children and adolescents (CEFALO study). Simulations were conducted for two mobile phone exposure categories: regular and heavy use. Our choice of levels of recall error was guided by a validation study that compared objective network operator data with the self-reported amount of mobile phone use in CEFALO. In our validation study, cases overestimated their number of calls by 9% on average and controls by 34%. Cases also overestimated their duration of calls by 52% on average and controls by 163%. The participation rates in CEFALO were 83% for cases and 71% for controls. In a variety of scenarios, the combined impact of recall error and selection bias on the estimated ORs was complex. These simulations are useful for the interpretation of previous case-control studies on brain tumor and mobile phone use in adults as well as for the interpretation of future studies on adolescents.

• Quantifying the Impact of Selection Bias Caused by Nonparticipation in a Case-Control Study of Mobile Phone Use.

  Authors: Martine Vrijheid, Lesley Richardson, Bruce K Armstrong, Anssi Auvinen, Gabriele Berg, Matthew Carroll, Angela Chetrit, Isabelle Deltour, Maria Feychting, Graham G Giles [......] Siegal Sadetzki, Tina Salminen, Marie Sanchez, Birgitte Schlehofer, Joachim Schüz, Jack Siemiatycki, Tore Tynes, Alistair Woodward, Naohito Yamaguchi, Elisabeth Cardis

  Annals of epidemiology. 02/2009; 19(1):33-41.e1.

  PURPOSE: To quantitatively assess the impact of selection bias caused by nonparticipation in a multinational case-control study of mobile phone use and brain tumor. METHODS: Non-responsePURPOSE: To quantitatively assess the impact of selection bias caused by nonparticipation in a multinational case-control study of mobile phone use and brain tumor. METHODS: Non-response questionnaires (NRQ) were completed by a sub-set of nonparticipants. Selection bias factors were calculated based on the prevalence of mobile phone use reported by nonparticipants with NRQ data, and on scenarios of hypothetical exposure prevalence for other nonparticipants. RESULTS: Regular mobile phone use was reported less frequently by controls and cases who completed the NRQ (controls, 56%; cases, 50%) than by those who completed the full interview (controls, 69%; cases, 66%). This relationship was consistent across study centers, sex, and age groups. Lower education and more recent start of mobile phone use were associated with refusal to participate. Bias factors varied between 0.87 and 0.92 in the most plausible scenarios. CONCLUSIONS: Refusal to participate in brain tumor case-control studies seems to be related to less prevalent use of mobile phones, and this could result in a downward bias of around 10% in odds ratios for regular mobile phone use. The use of simple selection bias estimation methods in case-control studies can give important insights into the extent of any bias, even when nonparticipant information is incomplete.

• Reproductive Factors and Risk of Meningioma and Glioma.

  Authors: Annette Wigertz, Stefan Lönn, Per Hall, Anssi Auvinen, Helle Collatz Christensen, Christoffer Johansen, Lars Klæboe, Tiina Salminen, Minouk J Schoemaker, Anthony J Swerdlow, Tore Tynes, Maria Feychting

  Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology. 10/2008; 17(10):2663-2670.

  Female sex hormones have previously been suggested as possible risk factors for brain tumors, but published studies have reported conflicting results. We conducted a population-based case-controlFemale sex hormones have previously been suggested as possible risk factors for brain tumors, but published studies have reported conflicting results. We conducted a population-based case-control study of glioma (n = 626) and meningioma (n = 906) cases and randomly selected controls stratified on age and geographic region (n = 1,774) in Denmark, Finland, Norway, Sweden, and the United Kingdom. Unconditional logistic regression was used to estimate odds ratios (OR) for glioma and meningioma in relation to reproductive factors. A decreased glioma risk was associated with ever-pregnancy compared with never-pregnancy [OR, 0.8; 95% confidence interval (95% CI), 0.6-1.0]. Meningioma risk among women ages <50 years was increased in relation to number of pregnancies leading to a live birth (OR, 1.8; 95% CI: 1.1-2.8 for giving birth to 3 children compared with nulliparous women; P(trend) among parous women = 0.01). This relation was not found for older women. Breast-feeding among parous women increased the glioma risk (OR, 2.2; 95% CI, 1.3-3.9 for breast-feeding 36 months or more compared with breast-feeding 3 months or less). Menopausal status and age at menopause were not associated with meningioma or glioma risk. Our findings imply that reproductive hormones may influence the occurrence of meningioma and glioma. (Cancer Epidemiol Biomarkers Prev 2008;17(10):2663-70).

• Ionizing radiation exposure and cancer risk among Norwegian nurses.

  Authors: Jenny-Anne S Lie, Kristina Kjaerheim, Tore Tynes

  European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP). 09/2008; 17(4):369-75.

  The influence of occupational exposure to ionizing radiation on risk of radiation-related cancers was studied among Norwegian nurses. A cohort of 43 316 nurses who graduated between 1914 and 1984,The influence of occupational exposure to ionizing radiation on risk of radiation-related cancers was studied among Norwegian nurses. A cohort of 43 316 nurses who graduated between 1914 and 1984, and were registered by the Norwegian Board of Health's registry of nurses, was followed up from 1953 through 2002 by linkage to the Norwegian Cancer Registry by unique personal identification numbers. Indicators of radiation exposure were developed from data on work history. Internal analyses were performed with Poisson regression, according to time since first potential radiation exposure, duration of exposure, and period of first exposure, using unexposed nurses as reference group. No clear association was found between exposure to ionizing radiation and cancers of the breast, thyroid, ovary, or leukemia, malignant melanoma or other skin cancer. Increased risk of lung cancer was found in the subgroups of nurses first exposed after 1950 (rate ratio=1.47, 95% confidence interval: 0.97-2.23, 26 cases), and in nurses with less than 20 years since first exposure (rate ratio=3.41, 95% confidence interval: 1.67-6.99, 9 cases), but the most likely explanation was confounding by smoking.No firm evidence that nurses potentially exposed to ionizing radiation had increased risk of radiation-related cancer was found.

• Allergic conditions and brain tumor risk.

  Authors: Annette Wigertz, Stefan Lönn, Judith Schwartzbaum, Per Hall, Anssi Auvinen, Helle Collatz Christensen, Christoffer Johansen, Lars Klaeboe, Tiina Salminen, Minouk J Schoemaker, Anthony J Swerdlow, Tore Tynes, Maria Feychting

  American journal of epidemiology. 11/2007; 166(8):941-50.

  An inverse association between allergic conditions and glioma risk has been reported previously. In this large population-based case-control study, the authors identified cases diagnosed with gliomaAn inverse association between allergic conditions and glioma risk has been reported previously. In this large population-based case-control study, the authors identified cases diagnosed with glioma or meningioma in Denmark, Norway, Finland, Sweden, and southeast England between 2000 and 2004. Detailed information on self-reported physician-diagnosed allergic conditions was collected from 1,527 glioma cases, 1,210 meningioma cases, and 3,309 randomly selected controls. Logistic regression showed an odds ratio of 0.70 (95% confidence interval: 0.61, 0.80) for glioma associated with a diagnosis of any of asthma, hay fever, eczema, or other type of allergy. The risk estimates for glioma were around 0.65 for each allergic condition (asthma, eczema, hay fever, and food allergy), and the 95% confidence intervals were equally consistent, at around 0.55, 0.80. The reduced risks of glioma related to eczema, hay fever, and allergy overall, but not asthma, were confined to current rather than past conditions. Meningioma risk was not associated with allergic conditions, except for eczema (odds ratio = 0.74, 95% confidence interval: 0.60, 0.91). Our results show a reduced risk for glioma associated primarily with current allergic conditions. If this is etiologic, it has implications for the understanding of how allergic conditions might reduce the tumor risk.

• Mobile phone use and risk of glioma in 5 North European countries.

  Authors: Anna Lahkola, Anssi Auvinen, Jani Raitanen, Minouk J Schoemaker, Helle C Christensen, Maria Feychting, Christoffer Johansen, Lars Klaeboe, Stefan Lönn, Anthony J Swerdlow, Tore Tynes, Tiina Salminen

  International journal of cancer. Journal international du cancer. 05/2007; 120(8):1769-75.

  Public concern has been expressed about the possible adverse health effects of mobile telephones, mainly related to intracranial tumors. We conducted a population-based case-control study toPublic concern has been expressed about the possible adverse health effects of mobile telephones, mainly related to intracranial tumors. We conducted a population-based case-control study to investigate the relationship between mobile phone use and risk of glioma among 1,522 glioma patients and 3,301 controls. We found no evidence of increased risk of glioma related to regular mobile phone use (odds ratio, OR = 0.78, 95% confidence interval, CI: 0.68, 0.91). No significant association was found across categories with duration of use, years since first use, cumulative number of calls or cumulative hours of use. When the linear trend was examined, the OR for cumulative hours of mobile phone use was 1.006 (1.002, 1.010) per 100 hr, but no such relationship was found for the years of use or the number of calls. We found no increased risks when analogue and digital phones were analyzed separately. For more than 10 years of mobile phone use reported on the side of the head where the tumor was located, an increased OR of borderline statistical significance (OR = 1.39, 95% CI 1.01, 1.92, p trend 0.04) was found, whereas similar use on the opposite side of the head resulted in an OR of 0.98 (95% CI 0.71, 1.37). Although our results overall do not indicate an increased risk of glioma in relation to mobile phone use, the possible risk in the most heavily exposed part of the brain with long-term use needs to be explored further before firm conclusions can be drawn.

• Use of mobile phones in Norway and risk of intracranial tumours.

  Authors: Lars Klaeboe, Karl Gerhard Blaasaas, Tore Tynes

  European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP). 05/2007; 16(2):158-64.

  To test the hypothesis that exposure to radio-frequency electromagnetic fields from mobile phones increases the incidence of gliomas, meningiomas and acoustic neuromas in adults. The incident casesTo test the hypothesis that exposure to radio-frequency electromagnetic fields from mobile phones increases the incidence of gliomas, meningiomas and acoustic neuromas in adults. The incident cases were of patients aged 19-69 years who were diagnosed during 2001-2002 in Southern Norway. Population controls were selected and frequency-matched for age, sex, and residential area. Detailed information about mobile phone use was collected from 289 glioma (response rate 77%), 207 meningioma patients (71%), and 45 acoustic neuroma patients (68%) and from 358 (69%) controls. For regular mobile phone use, defined as use on average at least once a week or more for at least 6 months, the odds ratio was 0.6 (95% confidence interval 0.4-0.9) for gliomas, 0.8 (95% confidence interval 0.5-1.1) for meningiomas and 0.5 (95% confidence interval 0.2-1.0) for acoustic neuromas. Similar results were found with mobile phone use for 6 years or more for gliomas and acoustic neuromas. An exception was meningiomas, where the odds ratio was 1.2 (95% confidence interval 0.6-2.2). Furthermore, no increasing trend was observed for gliomas or acoustic neuromas by increasing duration of regular use, the time since first regular use or cumulative use of mobile phones. The results from the present study indicate that use of mobile phones is not associated with an increased risk of gliomas, meningiomas or acoustic neuromas.

• Mortality in the Sami population of North Norway, 1970-98.

  Authors: Tore Tynes, Tor Haldorsen

  Scandinavian journal of public health. 02/2007; 35(3):306-12.

  AIMS: The pattern of mortality among many groups of indigenous people has been shown to be disadvantageous in comparison with the general population. Knowledge regarding causes of death among theAIMS: The pattern of mortality among many groups of indigenous people has been shown to be disadvantageous in comparison with the general population. Knowledge regarding causes of death among the Sami population in the northern part of Norway is limited. The Sami constitute an ethnic minority whose lifestyle diverges from that of the rest of the population. METHODS: A cohort of 19,801 persons of Sami origin was followed up to evaluate specific causes of mortality during the period 1970-98. Standardized mortality rates (SMR) were calculated using the rural population of the three Norwegian counties included in the study as a reference population. RESULTS: Among Sami, 5,955 total deaths were observed, as opposed to 5,537 expected (SMR = 1.08). For both Sami women and men a significantly higher SMR for cerebrovascular diseases was found, which was more pronounced for women. For Sami men, an excess SMR for violent death was observed (SMR 1.32, 95% confidence interval (CI) 1.20-1.46); this was highest among Sami men living in a reindeer-breeding family. For both genders, mortality from all malignant neoplasms combined was lower than in the reference population. SMRs were 0.86 (95% CI 0.79-0.94) and 0.89 (95% CI 0.80-0.99) for men and women, respectively. Low SMRs were also observed for chronic liver diseases, 0.18 (95% CI 0.02-0.63) and 0.12 (95% CI 0.00-0.68) for Sami men and women, respectively. To be a member of a reindeer breeding household appeared to offer protection from mortality caused by circulatory system diseases in men, especially mortality from ischaemic heart disease. CONCLUSIONS: The total mortality in the North Norway Sami population, an ethnic minority in Norway, was slightly higher when compared with a regional reference population. The differences observed when evaluating mortality by diagnosis might be due to lifestyle, diet, psychosocial, and/or genetic factors.

• The INTERPHONE study: design, epidemiological methods, and description of the study population.

  Authors: Elisabeth Cardis, Lesley Richardson, Isabelle Deltour, Bruce Armstrong, Maria Feychting, Christoffer Johansen, Monique Kilkenny, Patricia McKinney, Baruch Modan, Siegal Sadetzki [......] Brigitte Schlehofer, Jack Siemiatycki, Masao Taki, Toru Takebayashi, Tore Tynes, Martie van Tongeren, Paolo Vecchia, Joe Wiart, Alistair Woodward, Naohito Yamaguchi

  European journal of epidemiology. 02/2007; 22(9):647-64.

  The very rapid worldwide increase in mobile phone use in the last decade has generated considerable interest in the possible health effects of exposure to radio frequency (RF) fields. A multinationalThe very rapid worldwide increase in mobile phone use in the last decade has generated considerable interest in the possible health effects of exposure to radio frequency (RF) fields. A multinational case-control study, INTERPHONE, was set-up to investigate whether mobile phone use increases the risk of cancer and, more specifically, whether the RF fields emitted by mobile phones are carcinogenic. The study focused on tumours arising in the tissues most exposed to RF fields from mobile phones: glioma, meningioma, acoustic neurinoma and parotid gland tumours. In addition to a detailed history of mobile phone use, information was collected on a number of known and potential risk factors for these tumours. The study was conducted in 13 countries. Australia, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, New Zealand, Norway, Sweden, and the UK using a common core protocol. This paper describes the study design and methods and the main characteristics of the study population. INTERPHONE is the largest case-control study to date investigating risks related to mobile phone use and to other potential risk factors for the tumours of interest and includes 2,765 glioma, 2,425 meningioma, 1,121 acoustic neurinoma, 109 malignant parotid gland tumour cases and 7,658 controls. Particular attention was paid to estimating the amount and direction of potential recall and participation biases and their impact on the study results.

• Paternal occupational exposure to radiofrequency electromagnetic fields and risk of adverse pregnancy outcome.

  Authors: Geir Mjøen, Dag Ottar Saetre, Rolv T Lie, Tore Tynes, Karl Gerhard Blaasaas, Merete Hannevik, Lorentz M Irgens

  European journal of epidemiology. 02/2006; 21(7):529-35.

  BACKGROUND: During the last decades, public concern that radiofrequency radiation (RFR) may be related to adverse reproductive outcomes has been emerging. Our objective was to assess associationsBACKGROUND: During the last decades, public concern that radiofrequency radiation (RFR) may be related to adverse reproductive outcomes has been emerging. Our objective was to assess associations between paternal occupational exposure to RFR and adverse pregnancy outcomes including birth defects using population-based data from Norway. METHODS: Data on reproductive outcomes derived from the Medical Birth Registry of Norway were linked with data on paternal occupation derived from the general population censuses. An expert panel categorized occupations according to exposure. Using logistic regression, we analyzed 24 categories of birth defects as well as other adverse outcomes. RESULTS: In the offspring of fathers most likely to have been exposed, increased risk was observed for preterm birth (odds ratio (OR): 1.08, 95% confidence interval (CI): 1.03, 1.15). In this group we also observed a decreased risk of cleft lip (OR: 0.63, 95% CI: 0.41, 0.97). In the medium exposed group, we observed increased risk for a category of "other defects" (OR: 2.40, 95% CI: 1.22, 4.70), and a decreased risk for a category of "other syndromes" (OR: 0.75, 95% CI: 0.56, 0.99) and upper gastrointestinal defects (OR: 0.61, 95% CI: 0.40, 0.93). CONCLUSION: The study is partly reassuring for occupationally exposed fathers.

• Incidence of intracranial meningiomas in Denmark, Finland, Norway and Sweden, 1968-1997.

  Authors: Lars Klaeboe, Stefan Lonn, David Scheie, Anssi Auvinen, Helle C Christensen, Maria Feychting, Christoffer Johansen, Tiina Salminen, Tore Tynes

  International journal of cancer. Journal international du cancer. 01/2006; 117(6):996-1001.

  It has been reported that the incidence of meningioma increased in several industrialized countries in the late 1970s and early 1980s. The aim of this study was to evaluate the time trends inIt has been reported that the incidence of meningioma increased in several industrialized countries in the late 1970s and early 1980s. The aim of this study was to evaluate the time trends in incidence of meningiomas in Denmark, Finland, Norway and Sweden, with emphasis on the age distribution and sex ratio. Information about cases of meningiomas in people aged 15-84 years was obtained from the cancer registries of these Nordic countries for the years 1968-1997, and estimates of person-years at risk were calculated from information provided by the national population registries. Age-specific incidence rates per 100,000 and incidence rate ratios were calculated for 3-year periods. The female:male ratios were also evaluated. The combined incidence among men increased from 1.4 to 1.9 per 100,000 during the follow-up period, the corresponding rates for women were 2.6 and 4.5. The female:male ratio increased over time for several age groups and was as high as 3.5:1 in the group aged 40-44 years in the latest follow-up period (1993-1997). In summary, our results provide some support for the idea that the introduction of computed tomography in the late 1970s has had an impact on the detection of cases in people aged 60 and over. The decrease in the rate or detection postmortem has affected the incidence time trend, but it also coincides with widespread use of new imaging technologies. The increasing trend shown for the female:male ratio in the group aged 35-59 years is consistent with the possibility that increasing use of hormones may affect the incidence of meningiomas in women.

• Residential and occupational exposure to 50-Hz magnetic fields and brain tumours in Norway: a population-based study.

  Authors: Lars Klaeboe, Karl Gerhard Blaasaas, Tor Haldorsen, Tore Tynes

  International journal of cancer. Journal international du cancer. 06/2005; 115(1):137-41.

  Our case-control study was conducted to investigate whether residential and occupational exposure to magnetic fields increased the risk for brain tumours in adults. Data from an occupational exposureOur case-control study was conducted to investigate whether residential and occupational exposure to magnetic fields increased the risk for brain tumours in adults. Data from an occupational exposure matrix was also evaluated. The study population in this nested case-control study was made up of subjects aged 16 years and older who had resided in a broad corridor around a high-voltage power line in 1980 or during one of the years from 1986-1996. The cases were incident cases diagnosed during 1980-96. Two controls were matched to each case by year of birth, sex, municipality and first year entering the cohort. The time-weighted average exposure to residential magnetic fields generated by the power lines was calculated for the exposure follow-up from 1 January 1967 to diagnosis. In addition, job titles and branches of industry were classified as categories of hours per week in a magnetic field above background level (0.1 microT). Exposures were cumulated over occupationally active years for the exposure follow-up from 1 January 1955 to diagnosis. When residential magnetic fields are evaluated, the 2 upper residential, time-weighted, average magnetic field categories showed elevated odds ratios (ORs) for all brain tumours (OR = 1.6; 95% confidence interval [95%CI] 0.9-2.7 and OR = 1.3; 95% CI 0.7-2.3). Occupational exposure showed no association to exposure for any site. We found an elevated risk for residential exposure to magnetic fields and brain tumours, although the risk was not significant, and no clear exposure-response pattern was found. The findings for the occupational exposure groups showed an inverse association.

• Residential and occupational exposures to 50-Hz magnetic fields and breast cancer in women: a population-based study.

  Authors: Jolanta Kliukiene, Tore Tynes, Aage Andersen

  American journal of epidemiology. 06/2004; 159(9):852-61.

  A case-control study was conducted to investigate whether residential and occupational exposures to magnetic fields increased the risk for breast cancer among women. Cases of breast cancer diagnosedA case-control study was conducted to investigate whether residential and occupational exposures to magnetic fields increased the risk for breast cancer among women. Cases of breast cancer diagnosed during 1980-1996 were identified in a cohort of women living near a high-voltage power line in Norway in 1980 or between 1986 and 1996. Each case was matched by year of birth, municipality, and first year of entry into the cohort with two randomly selected controls without cancer. Residential exposure to magnetic fields was calculated as that generated by the lines before diagnosis, and occupational exposure was based on exposure matrix data. Women with residential exposure had an odds ratio of 1.58 (95% confidence interval (CI): 1.30, 1.92) when compared with unexposed women. The odds ratios for exposed women versus unexposed women with estrogen receptor (ER)-positive and ER-negative breast cancer were 1.33 (95% CI: 0.93, 1.90) and 1.40 (95% CI: 0.78, 2.50), respectively (ER status was available for 44% of the cases). Women with the highest occupational exposure had an odds ratio of 1.13 (95% CI: 0.91, 1.40) when compared with those unexposed at work. The findings suggest an association between exposure to magnetic fields and breast cancer in women.

• Incidence trends of adult primary intracerebral tumors in four Nordic countries.

  Authors: Stefan Lönn, Lars Klaeboe, Per Hall, Tiit Mathiesen, Anssi Auvinen, Helle C Christensen, Christoffer Johansen, Tiina Salminen, Tore Tynes, Maria Feychting

  International journal of cancer. Journal international du cancer. 02/2004; 108(3):450-5.

  Brain tumors are some of the most lethal adult cancers and there is a concern that the incidence is increasing. It has been suggested that the reported increased incidence can be explained byBrain tumors are some of the most lethal adult cancers and there is a concern that the incidence is increasing. It has been suggested that the reported increased incidence can be explained by improvements in diagnostic procedures, although this has not been totally resolved. The aim of our study was to describe the incidence trends of adult primary intracerebral tumors in four Nordic countries during a period with introduction of new diagnostic procedures and increasing prevalence of mobile phone users. Information about benign and malignant primary intracerebral tumor cases 20-79 years of age was obtained from the national cancer registries in Denmark, Finland, Norway and Sweden for the years 1969-98 and estimates of person-years at risk were calculated from the information obtained from national population registries. Annual age standardized incidence rates per 100,000 person-years were calculated and time trends analyses were carried out using Poisson regression. The overall incidence of all intracerebral tumors ranged from 8.4-11.8 for men and 5.8-9.3 for women, corresponding to an average annual increase of 0.6% for men (95% confidence interval [CI] = 0.4, 0.7) and 0.9% for women (95% CI = 0.7, 1.0). The increase in the incidence was confined to the late 1970s and early 1980s and coinciding with introduction of improved diagnostic methods. This increase was largely confined to the oldest age group. After 1983 and during the period with increasing prevalence of mobile phone users, the incidence has remained relatively stable for both men and women.

• Residence near power lines and the risk of birth defects.

  Authors: Karl Gerhard Blaasaas, Tore Tynes, Rolv Terje Lie

  Epidemiology (Cambridge, Mass.). 02/2003; 14(1):95-8.

  BACKGROUND: There has been some concern that exposure to electromagnetic fields may cause birth defects. We studied risks of birth defects by residential exposure to 50-Hz magnetic fields from powerBACKGROUND: There has been some concern that exposure to electromagnetic fields may cause birth defects. We studied risks of birth defects by residential exposure to 50-Hz magnetic fields from power lines. METHODS: We estimated the distance between residence and power lines for 161,844 Norwegian residences, and their corresponding magnetic fields in the period 1980 to 1997. Risks of 24 categories of birth defects were compared across exposure levels, adjusting for social and demographic variables. RESULTS: Among those living near power lines, the greatest reductions in risk were for cardiac defects (odds ratio = 0.5; 95% confidence interval = 0.3-0.9) and respiratory defects (0.4; 0.2-0.9). The largest increase in risk was for esophageal defects (2.5; 1.0-5.9). Other associations were weaker and had wide confidence intervals. CONCLUSIONS: There was little evidence that residence near power lines affected the risk of birth defects. The observed decreased risks of cardiac and respiratory defects and the increased risk of esophageal defects should be interpreted with caution given the number of endpoints, the imprecision in the calculations of the distance from the residence to the power line, and the limited information on pregnant women's change of residence.

• Comparison of three different ways of measuring distances between residences and high voltage power lines.

  Authors: Karl Gerhard Blaasaas, Tore Tynes

  Bioelectromagnetics. 06/2002; 23(4):288-91.

  The aim of this study was to evaluate whether distance data based on calculations by use of digitalized geographical information systems (GIS) and distance data based on measurements on 1:5000 mapsThe aim of this study was to evaluate whether distance data based on calculations by use of digitalized geographical information systems (GIS) and distance data based on measurements on 1:5000 maps agree sufficiently with on site distance measurements to be used as input to magnetic field calculations in epidemiological studies. The analysis were performed by use of weighted kappa (kappa(w)) statistical method described by Bland and Altman for comparison of measures of agreement. Map measurements showed better agreement with on site measurements than GIS calculations did. However, we consider both methods appropriate for use in larger epidemiological studies if the results are interpreted with caution. GIS calculations have the advantage of being both time and cost saving.