| 1. |
- Hardell, Lennart, et al.
(author)
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Increased concentrations of certain persistent organic pollutants in subjects with self-reported electromagnetic hypersensitivity : a pilot study
- 2008
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In: Electromagnetic Biology and Medicine. - : Informa UK Limited. - 1536-8378 .- 1536-8386. ; 27:2, s. 197-203
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Journal article (peer-reviewed)abstract
- Electromagnetic hypersensitivity (EHS) is used for a variety of subjective symptoms related to exposure to electromagnetic fields (EMF). The aim of this pilot study was to analyze the concentrations of certain persistent organic pollutants (POPs) in subjects with self-reported EHS. In total, 13 EHS subjects and 21 controls were included, all female. The concentration of several POPs was higher in EHS subjects than in controls. Lower concentrations were found for hexachlorobenzene and two types of chlordanes. The only significantly increased odds ratios (ORs) were found for polybrominated diphenyl ether (PBDE) #47 yielding OR=11.7, 95% confidence interval (CI)=1.45-94.7 and the chlordane metabolite MC6 with OR=11.2, 95% CI=1.18-106. The results were based on low numbers and must be interpreted with caution. This hypothesis generating study indicates the necessity of a larger investigation on this issue.
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| 2. |
- Hardell, Lennart, et al.
(author)
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Long-term use of cellular phones and brain tumours : increased risk associated with use for ≥10 years
- 2007
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In: Occupational and Environmental Medicine. - London : BMJ Publishing Group. - 1351-0711 .- 1470-7926. ; 64, s. 626-632
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Journal article (peer-reviewed)abstract
- AIM: To evaluate brain tumour risk among long-term users of cellular telephones. METHODS: Two cohort studies and 16 case-control studies on this topic were identified. Data were scrutinised for use of mobile phone for > or =10 years and ipsilateral exposure if presented. RESULTS: The cohort study was of limited value due to methodological shortcomings in the study. Of the 16 case-control studies, 11 gave results for > or =10 years' use or latency period. Most of these results were based on low numbers. An association with acoustic neuroma was found in four studies in the group with at least 10 years' use of a mobile phone. No risk was found in one study, but the tumour size was significantly larger among users. Six studies gave results for malignant brain tumours in that latency group. All gave increased odd ratios (OR), especially for ipsilateral exposure. In a meta-analysis, ipsilateral cell phone use for acoustic neuroma was OR = 2.4 (95% CI 1.1 to 5.3) and OR = 2.0, (1.2 to 3.4) for glioma using a tumour latency period of > or =10 years. CONCLUSIONS: Results from present studies on use of mobile phones for > or =10 years give a consistent pattern of increased risk for acoustic neuroma and glioma. The risk is highest for ipsilateral exposure.
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| 3. |
- Hardell, Lennart, et al.
(author)
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Meta-analysis of long-term mobile phone use and the association with brain tumours
- 2008
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In: International Journal of Oncology. - 1019-6439 .- 1791-2423. ; 32:5, s. 1097-1103
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Journal article (peer-reviewed)abstract
- We evaluated long-term use of mobile phones and the risk for brain tumours in case-control studies published so far on this issue. We identified ten studies on glioma and meta-analysis yielded OR = 0.9, 95% CI = 0.8-1.1. Latency period of > or =10-years gave OR = 1.2, 95% CI = 0.8-1.9 based on six studies, for ipsilateral use (same side as tumour) OR = 2.0, 95% CI = 1.2-3.4 (four studies), but contralateral use did not increase the risk significantly, OR = 1.1, 95% CI = 0.6-2.0. Meta-analysis of nine studies on acoustic neuroma gave OR = 0.9, 95% CI = 0.7-1.1 increasing to OR = 1.3, 95% CI = 0.6-2.8 using > or =10-years latency period (four studies). Ipsilateral use gave OR = 2.4, 95% CI = 1.1-5.3 and contra-lateral OR = 1.2, 95% CI = 0.7-2.2 in the > or =10-years latency period group (three studies). Seven studies gave results for meningioma yielding overall OR = 0.8, 95% CI = 0.7-0.99. Using > or =10-years latency period OR = 1.3, 95% CI = 0.9-1.8 was calculated (four studies) increasing to OR = 1.7, 95% CI = 0.99-3.1 for ipsilateral use and OR = 1.0, 95% CI = 0.3-3.1 for contralateral use (two studies). We conclude that this meta-analysis gave a consistent pattern of an association between mobile phone use and ipsilateral glioma and acoustic neuroma using > or =10-years latency period.
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| 4. |
- Hardell, Lennart, et al.
(author)
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Tumour risk associated with use of cellular telephones or cordless desktop telephones
- 2006
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In: World Journal of Surgical Oncology. - : Springer Science and Business Media LLC. - 1477-7819. ; 4:74
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Journal article (peer-reviewed)abstract
- BACKGROUND: The use of cellular and cordless telephones has increased dramatically during the last decade. There is concern of health problems such as malignant diseases due to microwave exposure during the use of these devices. The brain is the main target organ. METHODS: Since the second part of the 1990's we have performed six case-control studies on this topic encompassing use of both cellular and cordless phones as well as other exposures. Three of the studies concerned brain tumours, one salivary gland tumours, one non-Hodgkin lymphoma (NHL) and one testicular cancer. Exposure was assessed by self-administered questionnaires. RESULTS: Regarding acoustic neuroma analogue cellular phones yielded odds ratio (OR) = 2.9, 95 % confidence interval (CI) = 2.0-4.3, digital cellular phones OR = 1.5, 95 % CI = 1.1-2.1 and cordless phones OR = 1.5, 95 % CI = 1.04-2.0. The corresponding results were for astrocytoma grade III-IV OR = 1.7, 95 % CI = 1.3-2.3; OR = 1.5, 95 % CI = 1.2-1.9 and OR = 1.5, 95 % CI = 1.1-1.9, respectively. The ORs increased with latency period with highest estimates using > 10 years time period from first use of these phone types. Lower ORs were calculated for astrocytoma grade I-II. No association was found with salivary gland tumours, NHL or testicular cancer although an association with NHL of T-cell type could not be ruled out. CONCLUSION: We found for all studied phone types an increased risk for brain tumours, mainly acoustic neuroma and malignant brain tumours. OR increased with latency period, especially for astrocytoma grade III-IV. No consistent pattern of an increased risk was found for salivary gland tumours, NHL, or testicular cancer.
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| 5. |
- Söderqvist, Fredrik, et al.
(author)
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Exposure to an 890-MHz mobile phone-like signal and serum levels of S100B and transthyretin in volunteers
- 2009
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In: Toxicology Letters. - : Elsevier. - 0378-4274 .- 1879-3169. ; 189:1, s. 63-66
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Journal article (peer-reviewed)abstract
- Whether low-intensity non-thermal microwave radiation alters the integrity of the blood-brain barrier has been debated since the late 1970s, yet no experimental study has been carried out on humans. The aim of this study was to test, using peripheral markers, whether exposure to a mobile phone-like signal alters the integrity of the human blood-brain and blood-cerebrospinal fluid barriers. A provocation study was carried out that exposed 41 volunteers to a 30 min GSM 890 MHz signal with an average specific energy absorption rate distribution of 1.0 W/kg in the temporal area of the head as measured over any 1g of contiguous tissue. The outcome was assessed by changes in serum concentrations of two putative markers of brain barrier integrity, S100B and transthyretin. Repeated blood sampling before and after the provocation showed no statistically significant increase in the serum levels of S100B, while for transthyretin a statistically significant increase was seen in the final blood sample 60 min after the end of the provocation as compared to the prior sample taken immediately after provocation (p=0.02). The clinical significance of this finding, if any, is unknown. Further randomized studies with use of additional more brain specific markers are needed.
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| 6. |
- Söderqvist, Fredrik
(author)
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Health symptoms and potential effects on the blood-brain and blood-cerebrospinal fluid barriers associated with use of wireless telephones
- 2009
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Doctoral thesis (other academic/artistic)abstract
- Recent years have seen a rapid increase in the use of wireless telephones, yet little systematic data exist on the actual use of such devices in the general population. Mobile and cordless telephones emit radiofrequency fields (RF) raising concern about possible adverse health effects. As children and teenagers might be more vulnerable and have longer expected lifetime exposures to RF from these devices than adults, who started to use them later in life, they are a group of special concern. The aims of papers I and II in this thesis were to increase our knowledge of use of wireless telephones in the age group of 7-19 years, to study what factors could explain such use; and furthermore, whether the use among the 15-19 year group was associated with self-reported health symptoms and well-being. For collection of data a posted questionnaire was used. Among the 7-14 group (n=1423) nearly all had access to a mobile telephone, a cordless telephone or both, although the percentage of regular users was rather low, totally. Use of wireless telephones increased with age and was more common among girls than boys, especially among the 15-19 year group (n=1269). Relatively few regular users of mobile telephones reported to use a handsfree. Besides age and gender the probability of using either a mobile or cordless telephone was associated mainly with watching TV extensively and below average household income. Regular users more often had health symptoms and reported poorer perceived health than did non-regular users. However, the latter should be interpreted with caution since bias and chance findings due to multiple testing might have influenced the results. Methodologically more sophisticated studies are needed to confirm these results and also investigate directions of possible associations. The aim of papers III-V was to investigate the potential effects of wireless telephone emissions on the integrity of the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB) using biomarkers. In paper III – an observational study on adults (n=314) – use of mobile and cordless telephones combined was not associated with serum levels of S100B as a marker of BBB disruption. Analyzing the different telephone types separately yielded a weak association of decreasing concentrations with minutes since last use of cordless telephone on the day of leaving blood and a statistically significant association of higher concentrations the more years since first use of a 3G-telephone. However, the latter is probably a result of chance or confounding. Paper IV comprised the same data set as in paper III using serum transthyretin (TTR) as a marker of BCSFB dysfunction. The main finding was that the number of years since first use of mobile and cordless telephones combined was statistically significantly associated with higher serum levels of TTR regardless of how much each telephone type had been used. However, extra-cerebral sources of TTR might have confounded the results, if associated with exposure. Paper V was an experimental study investigating a possible short-term effect of an 890-megahertz mobile phone-like exposure on the BBB and the BCSFB of 41 volunteers. Repeated blood sampling before and after the provocation showed no statistically significant increase in the serum levels of S100B, while for TTR a small but statistically significant increase was seen in the final blood sample 60 minutes after the end of the provocation as compared to the prior sample taken immediately after provocation. The possible clinical significance of this finding is unknown. Larger randomized studies that employ use of additional more brain-specific markers and multiple exposure conditions are needed.
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| 7. |
- Söderqvist, Fredrik, et al.
(author)
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Mobile and cordless telephones, serum transthyretin and the blood-cerebrospinal fluid barrier : a cross-sectional study
- 2009
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In: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 8, s. 19-
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Journal article (peer-reviewed)abstract
- BACKGROUND: Whether low-intensity radiofrequency radiation damages the blood-brain barrier has long been debated, but little or no consideration has been given to the blood-cerebrospinal fluid barrier. In this cross-sectional study we tested whether long-term and/or short-term use of wireless telephones was associated with changes in the serum transthyretin level, indicating altered transthyretin concentration in the cerebrospinal fluid, possibly reflecting an effect of radiation. METHODS: One thousand subjects, 500 of each sex aged 18-65 years, were randomly recruited using the population registry. Data on wireless telephone use were assessed by a postal questionnaire and blood samples were analyzed for serum transthyretin concentrations determined by standard immunonephelometric techniques on a BN Prospec instrument. RESULTS: The response rate was 31.4%. Logistic regression of dichotomized TTR serum levels with a cut-point of 0.31 g/l on wireless telephone use yielded increased odds ratios that were statistically not significant. Linear regression of time since first use overall and on the day that blood was withdrawn gave different results for males and females: for men significantly higher serum concentrations of TTR were seen the longer an analogue telephone or a mobile and cordless desktop telephone combined had been used, and in contrast, significantly lower serum levels were seen the longer an UMTS telephone had been used. Adjustment for fractions of use of the different telephone types did not modify the effect for cumulative use or years since first use for mobile telephone and DECT, combined. For women, linear regression gave a significant association for short-term use of mobile and cordless telephones combined, indicating that the sooner blood was withdrawn after the most recent telephone call, the higher the expected transthyretin concentration. CONCLUSION: In this hypothesis-generating descriptive study time since first use of mobile telephones and DECT combined was significantly associated with higher TTR levels regardless of how much each telephone type had been used. Regarding short-term use, significantly higher TTR concentrations were seen in women the sooner blood was withdrawn after the most recent telephone call on that day.
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| 8. |
- Söderqvist, Fredrik, et al.
(author)
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Ownership and use of wireless telephones : a population-based study of Swedish children aged 7-14 years
- 2007
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In: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 7, s. 105-
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Journal article (peer-reviewed)abstract
- BACKGROUND: Recent years have seen a rapid increase in the use of mobile phones and other sources of microwave radiation, raising concerns about possible adverse health effects. As children have longer expected lifetime exposures to microwaves from these devices than adults, who started to use them later in life, they are a group of special interest. METHODS: We performed a population-based study to assess ownership and use of mobile phones and cordless phones among children aged 7-14 years. A questionnaire comprising 24 questions was sent to 2000 persons selected from the Swedish population registry using a stratified sampling scheme. RESULTS: The response rate was 71.2%. Overall, 79.1% of the respondents reported mobile phone access, and 26.7% of them talked for 2 minutes or more per day. Of those who reported mobile phone access, only 5.9% reported use of hands-free equipment. Use of cordless phones was reported by 83.8% of the respondents and 38.5% of them talked for 5 minutes or more per day. Girls generally reported more frequent use than boys. CONCLUSION: This study showed that most children had access to and used mobile and cordless phones early in life and that there was a rapid increase in use with age. It also showed very low use of hands-free equipment among children with mobile phone access, and finally that girls talked significantly more minutes per day using mobile and cordless phones than boys did.
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| 9. |
- Söderqvist, Fredrik, et al.
(author)
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Use of wireless telephones and self-reported health symptoms : a population-based study among Swedish adolescents aged 15-19 years
- 2008
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In: Environmental Health. - 1476-069X. ; 7:1, s. 1-10
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Journal article (peer-reviewed)abstract
- BACKGROUND: Despite the last years of rapid increase in use of wireless phones little data on the use of these devices has been systematically assessed among young persons. The aim of this descriptive cross-sectional study was to assess use of wireless phones and to study such use in relation to explanatory factors and self-reported health symptoms. METHODS: A postal questionnaire comprising 8 pages of 27 questions with 75 items in total was sent to 2000 Swedish adolescents aged 15-19 years and selected from the population registry using a stratified sampling scheme. RESULTS: The questionnaire was answered by 63.5% of the study subjects. Most participants reported access to a mobile phone (99.6%) and use increased with age; 55.6% of the 15-year-olds and 82.2% of the 19-year-olds were regular users. Girls generally reported more frequent use than boys. Use of wired hands-free equipment 'anytime' was reported by 17.4%. Cordless phones were used by 81.9%, and 67.3% were regular users. Watching TV increased the odds ratio for use of wireless phones, adjusted for age and gender. Some of the most frequently reported health complaints were tiredness, stress, headache, anxiety, concentration difficulties and sleep disturbances. Regular users of wireless phones had health symptoms more often and reported poorer perceived health than less frequent users. CONCLUSION: Almost all adolescence in this study used a wireless phone, girls more than boys. The most frequent use was seen among the older adolescents, and those who watched TV extensively. The study further showed that perceived health and certain health symptoms seemed to be related to the use of wireless phones. However, this part of the investigation was explorative and should therefore be interpreted with caution since bias and chance findings due to multiple testing might have influenced the results. Potentially this study will stimulate more sophisticated studies that may also investigate directions of associations and whether, or to what degree, any mediation factors are involved.
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| 10. |
- Söderqvist, Fredrik, et al.
(author)
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Use of wireless telephones and serum S100B levels : a descriptive cross-sectional study among healthy Swedish adults aged 18-65 years
- 2009
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In: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 407:2, s. 798-805
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Journal article (peer-reviewed)abstract
- BACKGROUND: Since the late 1970s, experimental animal studies have been carried out on the possible effects of low-intensive radiofrequency fields on the blood-brain barrier (BBB), but no epidemiological study has been published to date. OBJECTIVE: Using serum S100B as a putative marker of BBB dysfunction we performed a descriptive cross-sectional study to investigate whether protein levels were higher among frequent than non-frequent users of mobile and cordless desktop phones. METHOD: One thousand subjects, 500 of each sex aged 18-65 years, were randomly recruited using the population registry. Data on wireless phone use were assessed by a postal questionnaire and blood samples were analyzed for S100B. RESULTS: The response rate was 31.4%. The results from logistic and linear regression analyses were statistically insignificant, with one exception: the linear regression analysis of latency for UMTS use, which after stratifying on gender remained significant only for men (p = 0.01; n = 31). A low p-value (0.052) was obtained for use of cordless phone (n = 98) prior to giving the blood samples indicating a weak negative association. Total use of mobile and cordless phones over time yielded odds ratio (OR) 0.8 and 95% confidence interval (CI) 0.3-2.0 and use on the same day as giving blood yielded OR=1.1, CI=0.4-2.8. CONCLUSIONS: This study failed to show that long- or short-term use of wireless telephones was associated with elevated levels of serum S100B as a marker of BBB integrity. The finding regarding latency of UMTS use may be interesting but it is based on small numbers. Generally, S100B levels were low and to determine whether this association - if causal - is clinically relevant, larger studies with sufficient follow-up are needed.
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