Risk Of Acoustic Neuroma Research Articles

Occupational and Environmental Noise Exposure and Extra-Auditory Effects on Humans: A Systematic Literature Review.

Noise is a common harmful factor in our work and the environment. Most studies have investigated the auditory effects of noise exposure; however, few studies have focused on the extra-auditory effects of exposure to occupational or environmental noise. This study aimed to systematically review published studies on the extra-auditory effects of noise exposure. We reviewed literature from PubMed and Google Scholar databases up to July 2022, using the Patient, Intervention, Comparison, and Outcome criteria and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies that reported extra-auditory effects of occupational or environmental noise exposure. Studies were evaluated utilizing validated reporting tools (CONSORT, STROBE) appropriate to study design. A total of 263 articles were identified, of which 36 were finally selected and reviewed. Upon conducting a review of the articles, exposure to noise can elicit a variety of extra-auditory effects on humans. These effects include circulatory effects linked to higher risk of cardiovascular disease and decreased endothelial function, nervous system effects correlated with sleep disturbance, cognitive impairment, and mental health problems, immunological and endocrinal effects connected to increased physiological stress response and metabolic disorders, oncological and respiratory effects associated with an elevated risk of acoustic neuroma and respiratory disorders, gastrointestinal effects linked to an increased risk of gastric or duodenal ulcer, and obstetric effects connected to the risk of preterm birth. Our review suggests that there are numerous extra-auditory effects of noise exposure on human, and further investigations are needed to fully understand these effects.

Eczema as a protective factor for brain cancer: a meta-analysis

BackgroundBrain cancer is one of the most aggressive cancer types owing to poor treatment effects. Epidemiological studies have demonstrated that allergies may increase the disease risk. Therefore, this study evaluated the association between eczema and the risk of various brain cancers.MethodsWe systematically searched the PubMed and Embase databases from their inception until June 23, 2022. Two reviewers independently reviewed and screened the articles, extracted data, assessed the study quality, and pooled the results. Stata software was used to generate pooled odds ratios and 95% confidence intervals (CIs).ResultsWe included 20 studies comprising 5,117,222 patients that investigated the relationship between eczema and brain cancer. Eczema was significantly inversely associated with the risk of brain cancer (odds ratio [OR], 0.82; 95% CI, 0.77–0.87), glioma (OR, 0.53; 95% CI, 0.14–2.02), meningioma (OR, 0.74; 95% CI, 0.66–0.84), and acoustic neuroma (OR, 0.60; 95% CI, 0.41–0.88). Interesting, The strong correlation between eczema and the reduced risk of brain cancer was observed in people over 16 years old (OR, 0.79; 95% CI, 0.71–0.88), but not in those under 16 years old (OR, 0.94; 95% CI, 0.79–1.11). In addition, subgroup analyses found that eczema significantly decreased the glioma risk in Europeans (OR, 0.73; 95% CI, 0.65–0.82) but not Australians (OR, 0.53; 95% CI, 0.14–2.02) or Americans (OR, 1.01; 95% CI, 0.69–1.46).ConclusionEczema may be considered as a potential protective factor of brain cancer in population aged over 16 years. However, this relationship requires verification using large-scale clinical data.

Association of allergic diseases and epilepsy with risk of glioma, meningioma and acoustic neuroma: results from the INTERPHONE international case-control study.

We investigated the association of allergic diseases and epilepsy with risk of brain tumours, in Interphone, a 13-country case-control study. Data were obtained from 2693 glioma cases, 2396 meningioma cases, and 1102 acoustic neuroma cases and their 6321 controls. Conditional logistic regression models were used to estimate pooled odds ratios (ORs) and their respective 95% confidence intervals (CIs), adjusted for education and time at interview. Reduced ORs were observed for glioma in relation to physician-diagnosed asthma (OR = 0.73; CI 0.58-0.92), hay fever (OR 0.72; CI 0.61-0.86), and eczema (OR 0.78, CI 0.64-0.94), but not for meningioma or acoustic neuroma. Previous diagnosis of epilepsy was associated with an increased OR for glioma (2.94; CI 1.87-4.63) and for meningioma (2.12; CI 1.27-3.56), but not for acoustic neuroma. This large-scale case-control study adds to the growing evidence that people with allergies have a lower risk of developing glioma, but not meningioma or acoustic neuroma. It also supports clinical observations of epilepsy prior to the diagnosis of glioma and meningioma.

Diagnostic radiological examinations and risk of intracranial tumours in adults-findings from the Interphone Study.

BackgroundExposure to high doses of ionizing radiation is among the few well-established brain tumour risk factors. We used data from the Interphone study to evaluate the effects of exposure to low-dose radiation from diagnostic radiological examinations on glioma, meningioma and acoustic neuroma risk.MethodsBrain tumour cases (2644 gliomas, 2236 meningiomas, 1083 neuromas) diagnosed in 2000–02 were identified through hospitals in 13 countries, and 6068 controls (population-based controls in most centres) were included in the analysis. Participation across all centres was 64% for glioma cases, 78% for meningioma cases, 82% for acoustic neuroma cases and 53% for controls. Information on previous diagnostic radiological examinations was obtained by interviews, including the frequency, timing and indication for the examinations. Typical brain doses per type of examination were estimated based on the literature. Examinations within the 5 years before the index date were excluded from the dose estimation. Adjusted odds ratios were estimated using conditional logistic regression.ResultsNo materially or consistently increased odds ratios for glioma, meningioma or acoustic neuroma were found for any specific type of examination, including computed tomography of the head and cerebral angiography. The only indication of an elevated risk was an increasing trend in risk of meningioma with the number of isotope scans, but no such trends for other examinations were observed. No gradient was found in risk with estimated brain dose. Age at exposure did not substantially modify the findings. Sensitivity analyses gave results consistent with the main analysis.ConclusionsThere was no consistent evidence for increased risks of brain tumours with X-ray examinations, although error from selection and recall bias cannot be completely excluded. A cautious interpretation is warranted for the observed association between isotope scans and meningioma.

Case-control study on occupational exposure to extremely low-frequency electromagnetic fields and the association with acoustic neuroma

Exposure to extremely low-frequency electromagnetic fields (ELF-EMF) was in 2002 classified as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer at WHO based on an increased risk for childhood leukemia. In case-control studies on brain and head tumours during 1997–2003 and 2007–2009 we assessed life-time occupations in addition to exposure to different agents. The INTEROCC ELF-EMF Job-Exposure Matrix was used for associating occupations with ELF-EMF exposure (μT) with acoustic neuroma. Cumulative exposure (μT-years), average exposure (μT) and maximum exposed job (μT) were calculated. No increased risk for acoustic neuroma was found in any category. For cumulative exposure in the highest exposure category 8.52+ μT years odds ratio (OR) = 1.2, 95% confidence interval (CI) = 0.8–2.0, p linear trend = 0.37 was calculated. No statistically significant risks were found in the time windows 1–14 years, and 15+ years, respectively. In conclusion occupational ELF-EMF was not associated with an increased risk for acoustic neuroma.

Radiofrequency radiation from nearby mobile phone base stations-a case comparison of one low and one high exposure apartment.

Radiofrequency (RF) radiation in the frequency range of 30–300 GHz has, since 2011, been classified as a ‘possible’ human carcinogen by Group 2B, International Agency for Research on Cancer (IARC) at WHO. This was based on a number of human epidemiology studies on increased risk for glioma and acoustic neuroma. Based on further human epidemiology studies and animal studies, the evidence on RF radiation carcinogenesis has increased since 2011. In previous measurement studies, it has been indicated that high environmental RF radiation levels are present in certain areas of Stockholm Sweden, including in one apartment. Field spatial distribution measurements were performed in the previously measured apartment in Stockholm, which exhibited high RF radiation from nearby base stations. Based on the RF broadband analyzer spot measurements, the maximum indoor E-field topped at 3 V m−1 in the bedroom at the 7th floor. The maximum outdoor exposure level of 6 V m−1 was encountered at the 8th floor balcony, located at the same elevation and only 6.16 m away from the base station antennas. For comparison, a measurement was made in a low exposure apartment in Stockholm. Here, the maximum indoor field 0.52 V m−1 was measured at the corner window, with direct line of sight to the neighboring house with mobile phone base station antennas. The maximum outdoor field of 0.75 V m−1 was measured at the balcony facing the same next-door building with mobile phone base station antennas. The minimum field of 0.10 V m−1 was registered on the apartment area closest to the center of the building, demonstrating the shielding effects of the indoor walls. Good mobile phone reception was achieved in both apartments. Therefore, installation of base stations to risky places cannot be justified using the good reception requirement argument.

Impact of Cell-phone on Human Health: A Systematic Review of Literatures

The growth of communication technology in the last two decades has given the world a new look.With the blessings of digital technology, we can now communicate to any parts of the world with just a touch over the screen of our smart phone. Mobile phone hasnow become an indispensable part of our life.But, biological effects of radio-frequency electromagnetic fields (EMF) transmitted by mobile phones are still a matter of public and scientific debate. Countries accross the world are now getting concerned about the impact of mobiles on human health and environment.Radiofrequency waves generated from mobile phones cause potential public health problems. Short-term effects like changes in sleep, heart rate, and blood pressure, and long-term effects like carcinoma (particularly glioma) are well-documented. International Agency for Research on Cancer (IARC) published cancer risks from Radiofrequency(RF) radiation. Human epidemiological studies gave evidence of increased risk for glioma and acoustic neuroma. Further epidemiological, animal and mechanistic studies have strengthened the association. Besides, the carcinogenic effect of non-ionizing radiation emitted from cordless digital devices, numerous health effects have already been claimed to occur. Faced with this context, scientific community and legislative bodies are raising voice for the reduction of RF-EMF exposure to the safe limit for human health and environment. The RF exposure restriction guideline used by many agencies was established in 1998 by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and was based only on established short-term thermal (heating) effects from RF radiation neglecting non-thermal biological effects. The present study is, therefore, intended to review the literatures relating mobile phone and Wi-fito human health in order to make the scientific community updated on the association between mobile phone use and human health.
 Ibrahim Card Med J 2018; 8 (1&2): 53-65

Validation of self-reported occupational noise exposure in participants of a French case-control study on acoustic neuroma.

To validate self-reported occupational loud noise exposure against expert evaluation of noise levels in a French case-control study on acoustic neuroma and to estimate the impact of exposure misclassification on risk estimation. Noise levels were evaluated in 1006 jobs held by 111 cases and 217 population controls by an expert. Case-control differences in self-reporting were analyzed with logistic models. Sensitivity, specificity, positive and negative predictive values, and observed agreement of the self-reports were computed relative to the expert evaluation. They were used to calibrate the odds ratio (OR) between lifetime ever occupational loud noise exposure and the risk of acoustic neuroma, without adjustment for measurement error of the expert assessments. Cases reported noise levels in individual jobs closer to the expert assessment than controls, but the case-control difference was small for lifetime exposures. For expert-rated exposure of 80dB(A), reporting of individual jobs by cases was more sensitive (54% in cases, 37% in controls), whereas specificity (91% in cases, 93% in controls) and observed agreement (82% in cases, 81% in controls) were similar. When lifetime exposure was considered, sensitivity increased (76% in cases, 65% in controls), while cases specificity decreased (84%). When these values were used to calibrate self-reports for exposure misclassification compared to expert evaluation at 80dB(A), the crude OR of 1.7 was reduced to 1.3. Despite the relatively accurate reporting of loud noise, the impact of the calibration on the OR was non-negligible.

Environmental radiofrequency radiation at the Järntorget Square in Stockholm Old Town, Sweden in May, 2018 compared with results on brain and heart tumour risks in rats exposed to 1.8 GHz base station environmental emissions

Radiofrequency (RF) radiation in the frequency range 30 kHz to 300 GHz was evaluated in 2011 by the International Agency for Research on Cancer (IARC) at WHO to be a 'possible human carcinogen' Group 2B. The conclusion was based on human epidemiological studies on an increased risk of glioma and acoustic neuroma. In previous measurement studies, we found high environmental RF radiation levels at certain public places and also in an apartment in Stockholm, Sweden. One such place was the Järntorget square in the Stockholm Old Town. The EME Spy exposimeter was used for these studies. We have now conducted a field spatial distribution measurement with a radiofrequency broadband analyser. The maximum E-field topped at 11.6 V/m at the centre of the square, where the antenna was focused. Järntorget's mean value was 5.2 V/m, median 5.0 V/m, range 1.2-11.6 V/m. Of interest is that this level can be compared to a lifespan carcinogenicity study on rats exposed to 1.8 GHz GSM environmental radiation performed at the Ramazzini Institute (RI) in Italy. A statistically significant increase in the incidence of malignant schwannoma in the heart was found in male rats at the highest dose, 50 V/m. In treated female rats at the highest dose, the incidence of malignant glial tumours was increased, although this was not statistically significant. On the whole, the findings of this study showed that RF radiation levels at one square, Järntorget, in Sweden, were only one order of magnitude lower than those showing an increased incidence of tumours in the RI animal study. An increased cancer risk cannot be excluded for those working in the proximity of Järntorget for longer time periods.

Occurrence of primary brain tumors in cochlear implant patients in Sweden between 1989 and 2014.

PurposeCochlear implants are widely used for hearing rehabilitation of deaf children with congenital deafness or adults with acquired severe-to-profound hearing loss. The sound processor antenna creates a radio frequency-electromagnetic field transmitting the sound signal to the implant, similar to that in a mobile phone. A recent case report suggested a relationship between cochlear implants and malignant glioma, and some epidemiological studies have suggested an increased glioma and acoustic neuroma risk associated with long hours of mobile phone use. An epidemiological study is warranted to evaluate such a relationship in patients with cochlear implants.Patients and methodsTo examine whether this chronic radio frequency-electromagnetic field signaling is associated with an increased brain tumor risk, a population-based cohort study was performed examining all 2,748 patients receiving a cochlear implant in Sweden during the years 1989–2014. In all, 3,169 surgeries were performed in the total cohort. The expected occurrence of glioma, meningioma, and acoustic neuroma in the patient cohort was calculated using specific national incidence rates in the Swedish population.ResultsFour patients were diagnosed with a brain tumor during follow-up, three of them having meningioma compared with 0.95 expected (standardized incidence ratio =3.16, 95% CI 0.65–9.24), and one had glioma compared with 1.34 expected (standardized incidence ratio =0.75, 95% CI 0.02–4.15). No case of acoustic neuroma was observed compared with 0.09 expected.ConclusionIn this study, we did not find support for concerns raised in a previous case report regarding a potentially higher risk of glioma. The number of brain tumors observed was well within the numbers expected from national incidence figures. Although this was a relatively small cohort with a limited follow-up time, it is the largest epidemiological study to date to address this concern.

Fatal collision? Are wireless headsets a risk in treating patients?

ABSTRACTWireless-enabled headsets that connect to the internet can provide remote transcribing of patient examination notes. Audio and video can be captured and transmitted by wireless signals sent from the computer screen in the frame of the glasses. But using wireless glass-type devices can expose the user to a specific absorption rates (SAR) of 1.11–1.46 W/kg of radiofrequency radiation. That RF intensity is as high as or higher than RF emissions of some cell phones. Prolonged use of cell phones used ipsilaterally at the head has been associated with statistically significant increased risk of glioma and acoustic neuroma. Using wireless glasses for extended periods to teach, to perform surgery, or conduct patient exams will expose the medical professional to similar RF exposures which may impair brain performance, cognition and judgment, concentration and attention and increase the risk for brain tumors. The quality of medical care may be compromised by extended use of wireless-embedded devices in health care settings. Both medical professionals and their patients should know the risks of such devices and have a choice about allowing their use during patient exams. Transmission of sensitive patient data over wireless networks may increase the risk of hacking and security breaches leading to losses of private patient medical and financial data that are strictly protected under HIPPA health information privacy laws.

World Health Organization, radiofrequency radiation and health - a hard nut to crack (Review).

In May 2011 the International Agency for Research on Cancer (IARC) evaluated cancer risks from radiofrequency (RF) radiation. Human epidemiological studies gave evidence of increased risk for glioma and acoustic neuroma. RF radiation was classified as Group 2B, a possible human carcinogen. Further epidemiological, animal and mechanistic studies have strengthened the association. In spite of this, in most countries little or nothing has been done to reduce exposure and educate people on health hazards from RF radiation. On the contrary ambient levels have increased. In 2014 the WHO launched a draft of a Monograph on RF fields and health for public comments. It turned out that five of the six members of the Core Group in charge of the draft are affiliated with International Commission on Non-Ionizing Radiation Protection (ICNIRP), an industry loyal NGO, and thus have a serious conflict of interest. Just as by ICNIRP, evaluation of non-thermal biological effects from RF radiation are dismissed as scientific evidence of adverse health effects in the Monograph. This has provoked many comments sent to the WHO. However, at a meeting on March 3, 2017 at the WHO Geneva office it was stated that the WHO has no intention to change the Core Group.

Probabilistic Multiple-Bias Modeling Applied to the Canadian Data From the Interphone Study of Mobile Phone Use and Risk of Glioma, Meningioma, Acoustic Neuroma, and Parotid Gland Tumors.

We undertook a re-analysis of the Canadian data from the 13-country case-control Interphone Study (2001-2004), in which researchers evaluated the associations of mobile phone use with the risks of brain, acoustic neuroma, and parotid gland tumors. In the main publication of the multinational Interphone Study, investigators concluded that biases and errors prevented a causal interpretation. We applied a probabilistic multiple-bias model to address possible biases simultaneously, using validation data from billing records and nonparticipant questionnaires as information on recall error and selective participation. In our modeling, we sought to adjust for these sources of uncertainty and to facilitate interpretation. For glioma, when comparing those in the highest quartile of use (>558 lifetime hours) to those who were not regular users, the odds ratio was 2.0 (95% confidence interval: 1.2, 3.4). After adjustment for selection and recall biases, the odds ratio was 2.2 (95% limits: 1.3, 4.1). There was little evidence of an increase in the risk of meningioma, acoustic neuroma, or parotid gland tumors in relation to mobile phone use. Adjustments for selection and recall biases did not materially affect interpretation in our results from Canadian data.

Socioeconomic position and the risk of brain tumour: a Swedish national population-based cohort study

BackgroundThe aim was to investigate associations between different measures of socioeconomic position (SEP) and incidence of brain tumours (glioma, meningioma and acoustic neuroma) in a nationwide population-based cohort.MethodsWe included 4...

Risk Factors of Acoustic Neuroma: Systematic Review and Meta-Analysis.

PurposeMany epidemiological studies have investigated environmental risk factors for the development of acoustic neuroma. However, these results are controversial. We conducted a meta-analysis of case-control studies to identify any potential relationship between history of noise exposure, smoking, allergic diseases, and risk of acoustic neuroma.Materials and MethodsWe searched PubMed to identify relevant articles. Two researchers evaluated the eligibility and extracted the data independently.ResultsEleven case-control studies were included in our meta-analysis. Acoustic neuroma was found to be associated with leisure noise exposure [odds ratio (OR)=1.33, 95% confidence interval (CI): 1.05–1.68], but not with occupational noise exposure and ever noise exposure (OR=1.20, 95% CI: 0.84–1.72 and OR=1.15, 95% CI: 0.80–1.65). The OR of acoustic neuroma for ever (versus never) smoking was 0.53 (95% CI: 0.30–0.94), while the subgroup analysis indicated ORs of 0.95 (95% CI: 0.81–1.10) and 0.49 (95% CI: 0.41–0.59) for ex-smoker and current smoker respectively. The ORs for asthma, eczema, and seasonal rhinitis were 0.98 (95% CI: 0.80–1.18), 0.91 (95% CI: 0.76–1.09), and 1.52 (95% CI: 0.90–2.54), respectively.ConclusionOur meta-analysis is suggestive of an elevated risk of acoustic neuroma among individuals who were ever exposed to leisure noise, but not to occupational noise. Our study also indicated a lower acoustic neuroma risk among ever and current cigarette smokers than never smokers, while there was no significant relationship for ex-smokers. No significant associations were found between acoustic neuroma and history of any allergic diseases, such as asthma, eczema, and seasonal rhinitis.

Validation of self-reported start year of mobile phone use in a Swedish case-control study on radiofrequency fields and acoustic neuroma risk.

The possible effect of radiofrequency exposure from mobile phones on tumor risk has been studied since the late 1990s. Yet, empirical information about recall of the start of mobile phone use among adult cases and controls has never been reported. Limited knowledge about recall errors hampers interpretations of the epidemiological evidence. We used network operator data to validate the self-reported start year of mobile phone use in a case-control study of mobile phone use and acoustic neuroma risk. The answers of 96 (29%) cases and 111 (22%) controls could be included in the validation. The larger proportion of cases reflects a more complete and detailed reporting of subscription history. Misclassification was substantial, with large random errors, small systematic errors, and no significant differences between cases and controls. The average difference between self-reported and operator start year was -0.62 (95% confidence interval: -1.42, 0.17) years for cases and -0.71 (-1.50, 0.07) years for controls, standard deviations were 3.92 and 4.17 years, respectively. Agreement between self-reported and operator-recorded data categorized into short, intermediate and long-term use was moderate (kappa statistic: 0.42). Should an association exist, dilution of risk estimates and distortion of exposure-response patterns for time since first mobile phone use could result from the large random errors in self-reported start year. Retrospective collection of operator data likely leads to a selection of "good reporters", with a higher proportion of cases. Thus, differential recall cannot be entirely excluded.

Carcinogenicity of implanted synthetic grafts and devices

Cancer in women is a common cause of morbidity and death,and the aetiology is frequently unknown. Potential carcino-genic agents are all around us: in the air we breathe, the foodand fluids we digest, and in the background radiation thatsurroundsus.Also,diagnosticandtherapeuticagentshavethepotential to induce cancer in some patients under some cir-cumstances: X-ray investigations, radiation treatment, drugsand hormones with oestrogen are well-known examples. Toprove these associations and calculate risk is always a longand arduous scientific process, but what can be even moredifficultistoprovethatthereisnoriskorassociationbetweenvarious environmental factors or medical treatments and can-cer. There will always be an inherent risk of cancer occurringin any individual, but is this increased, and if so by howmuch? A recent example is the reported association betweenmobilephoneuse,low-level exposuretoradiofrequencyelec-tromagnetic fields and brain tumours. The evidence to datefrom multiple studies is that there is no increased risk ofacoustic neuroma [1] or brain tumours [2], but larger andlonger-term studies are needed.Implantable devices and grafts also have the potential toinduce cancer; thus, it is an important matter that is discussedby Ostergard and Azadi [3] in this issue of our journal. Theauthorsraisetheissueofthecarcinogenicityofpolypropylene(PPL) in animals and humans. Despite extensively searchingthe literature on PPL they found little evidence of carcinoge-nicity in humans, with only two cases in patients with poly-ester mesh grafts who had chronic infection and developed asquamous cell carcinoma 6 and 24 years following insertion[4]. As stated by Ostergard and Azadi [3], chronic inflamma-tionoflongdurationisaknowncauseofcancer.Themeshdidcontribute to the infection and inflammation, but is it in itselfcarcinogenic?By 3 months after implantation, PPL mesh is surroundedbymature connectivetissueand only rarely becomes infectedunless inappropriately situated, for instance, protruding intothe bowel, bladder or vagina. Synthetic mesh, including PPL,has been used in urogynaecological surgery since the 1960s[5, 6], and even more widely in other forms of reconstructivesurgery, such as hernia repair. Despite the millions of patientsworldwide who have had PPL implanted, the authors couldfind no evidence of an association with cancer, or any casereports.Thisshouldgiveourpatientsconsiderableconfidencethat their PPL implants will not cause cancer. However, thereare risks associated with graft and mesh usage; these do needto be carefully weighed against the potential benefits whenused in reconstructive surgery.WehavebalancedtheOstergardandAzadiarticlewithtwoother contributions written by experts in urogynaecology andPPL mesh and biomaterials [7, 8]. We hope that open discus-sionleads to a better understanding of thissensitive issue,notonlybyclinicians,butalso,justasimportantly,bythebroadercommunity, who can be reassured that even the most difficultissues will be scientifically assessed and discussed.References

Mobile phone use and its risk on hearing

ObjectivesThe aim of this study was to assess the potential changes in human hearing function as a consequence of exposure to electromagnetic fields produced by mobile phones through a review of in-vivo and in-vitro published studies.Data sourcesMedline databases (PubMed, Medscape, ScienceDirect and EMF-Portal) and all materials available in the internet from 2003 to 2012.Study selectionThe initial search presented 170 articles, of which 44 met the inclusion criteria. The articles studied the relation between mobile phones, the auditory system and genotoxicity.Data extractionIf the studies did not fulfill the inclusion criteria, they were excluded. Study quality assessment included whether ethical approval was obtained, whether the eligibility criteria were specified, and whether appropriate controls, adequate information and defined assessment measures were included.Data synthesisComparisons were made by a structured review with the results tabulated.FindingsIn total, 44 potentially relevant publications were included: 32 were human and 12 were animal studies. The studies do not indicate an association between any problem related to the auditory system and short-term exposure of mobile phone radiations, whereas long-term use of mobile phones may lead to high-frequency hearing loss. Studies concerning mobile phone radiation and the risk of acoustic neuroma have controversial results. Some authors did not notice evidences of a higher risk of tumour development in mobile phone users, whereas others report that usage of analog cellular phones for 10 or more years increases the risk of developing the tumour.ConclusionWe found no overall increased risk of hearing problems among short-term cellular phone users, whereas long-term use of mobile phones may lead to high-frequency hearing loss and an increased risk of acoustic neuroma after 10 years of mobile phone use. The potential elevated risk of brain tumours after long-term cellular phone use awaits confirmation by future studies

Long-term Mobile Phone Use and Acoustic Neuroma Risk

There is concern about potential effects of radiofrequency fields generated by mobile phones on cancer risk. Most previous studies have found no association between mobile phone use and acoustic neuroma, although information about long-term use is limited. We conducted a population-based, nation-wide, case-control study of acoustic neuroma in Sweden. Eligible cases were persons aged 20 to 69 years, who were diagnosed between 2002 and 2007. Controls were randomly selected from the population registry, matched on age, sex, and residential area. Postal questionnaires were completed by 451 cases (83%) and 710 controls (65%). Ever having used mobile phones regularly (defined as weekly use for at least 6 months) was associated with an odds ratio (OR) of 1.18 (95% confidence interval = 0.88 to 1.59). The association was weaker for the longest induction time (≥10 years) (1.11 [0.76 to 1.61]) and for regular use on the tumor side (0.98 [0.68 to 1.43]). The OR for the highest quartile of cumulative calling time (≥680 hours) was 1.46 (0.98 to 2.17). Restricting analyses to histologically confirmed cases reduced all ORs; the OR for ≥680 hours was 1.14 (0.63 to 2.07). A similar pattern was seen for cordless land-line phones, although with slightly higher ORs. Analyses of the complete history of laterality of mobile phone revealed considerable bias in laterality analyses. The findings do not support the hypothesis that long-term mobile phone use increases the risk of acoustic neuroma. The study suggests that phone use might increase the likelihood that an acoustic neuroma case is detected and that there could be bias in the laterality analyses performed in previous studies.

Mobile phone use and risk of intracranial tumors: A consistency analysis

A meta-analysis of studies on intracranial tumors and mobile phone use published by the end of 2012 was performed to evaluate the overall consistency of findings, assess the sensitivity of results to changes in the dataset, and try to detect the sources of between-study heterogeneity. Twenty-nine papers met our inclusion criteria. These papers reported on 47 eligible studies (17 on glioma, 15 on meningioma, 15 on acoustic neuroma), consisting of either primary investigations or pooled analyses. Five combinations of non-overlapping studies per outcome were identified. The combined relative risks (cRRs) in long-term mobile phone users (≥10 years) ranged between 0.98 (0.75-1.28) and 1.11 (0.86-1.44) for meningioma, with little heterogeneity across studies. High heterogeneity was detected across estimates of glioma and acoustic neuroma risk in long term users, with cRRs ranging between 1.19 (95% CI 0.86-1.64) and 1.40 (0.96-2.04), and from 1.14 (0.65-1.99) to 1.33 (0.65-2.73), respectively. A meta-regression of primary studies showed that the methodological differences embedded in the variable "study-group" explained most of the overall heterogeneity in results. Summary risk estimates based on heterogeneous findings should not be over-interpreted. Overall, the results of our study detract from the hypothesis that mobile phone use affects the occurrence of intracranial tumors. However, reproducibility (or lack of) is just one clue in the critical appraisal of epidemiological evidence. Based on other considerations, such as the limited knowledge currently available on risk beyond 15 years from first exposure, or following mobile phone use started in childhood, the pursuance of epidemiological surveillance is warranted.