Impact of Radiofrequency Exposure from Mobile Phones on the Risk of Developing Brain Tumors in Korean and Japanese Adolescents: A MOBI-Kids Case-Control Study

Abstract

Impact of Radiofrequency Exposure from Mobile Phones on the Risk of Developing Brain Tumors in Korean and Japanese Adolescents: A MOBI-Kids Case-Control Study My Note: Although not statistically significant (possibly due to poor statistical power), the odds ratios for all brain tumors increased with increasing quartiles of cumulative call time (from 1.10 to 1.61) and tumor RF energy (from 1.14 to 1.33) (see Table 4 for confidence intervals and tests of trend). Kojimahara N, Lee Y-H, Kyoung Lee A-K, Bae S, Jang Kwon H-J, Ha M, Sato Y, Taki M, Wiart J, Langer CE, Cardis E. Impact of Radiofrequency Exposure from Mobile Phones on the Risk of Developing Brain Tumors in Korean and Japanese Adolescents: A MOBI-Kids Case-Control Study. Journal of Epidemiology. Advance online publication June 17, 2023. doi: 10.2188/jea.JE20230005. Abstract Background: This study aimed to examine the association between risk of brain tumors and radiofrequency (RF) exposure from mobile phones among young people in Korea and Japan. Methods: This case-control study of brain tumors in young people was conducted in Korea and Japan under the framework of the international MOBI-Kids study. We included 118 patients diagnosed with brain tumors between 2011 and 2015 and 236 matched appendicitis controls aged 10–24 years. Information on mobile phone use was collected through face-to-face interviews. A detailed RF exposure algorithm, based on the MOBI-Kids algorithm and modified to account for the specificities of Japanese and Korean phones and networks, was used to calculate the odds ratios (ORs) for total cumulative specific energy using conditional logistic regression. Results: The adjusted ORs in the highest tertile of cumulative call time at 1 year before the reference date were 1.61 (95% confidence interval [CI], 0.72-3.60) for all brain tumors and 0.70 (95% CI, 0.16-3.03) for gliomas, with no indication of a trend with exposure. The ORs for glioma specifically, were below 1 in the lowest exposure category. Conclusions: This study provided no evidence of a causal association between mobile phone use and risk of brain tumors as a whole or glioma specifically. Further research will be required to evaluate the impact of newer technologies of communication in the future. Excerpts We also included brain tumors irrespective of their anatomical location, unlike the main MOBI-Kids analyses which excluded tumors in the mid-brain.... Regular mobile phone use was defined as use at least once a week for a period of 3 months or more in accordance with the international MOBI-Kids protocol. 15.... Personal Digital Cellular (PDC) as the second generation (2G) and personal handy-phone system (PHS) 18 were used in Japan mainly in the 1990's, where the third generation (3G) was adopted in Korea in the mid-2000s. The RF-EMF exposure levels from such networks was considerably higher than that from 3G and Long-Term Evolution (LTE). 19 .... In addition to the history of mobile phone use, the questionnaire collected detailed information on the history of using cordless Digital Enhanced Cordless Telecommunications (DECT) phones and Wi-Fi, occupational history, or daily use, including specific questions on exposure to EMF sources.23 However, the KJ study algorithm calculated RF exposure exclusively from mobile phone use, including 2G, 3G, LTE, and PHS communication systems.... Table 2 shows the baseline characteristics of the participants, including 52 from Korea, 66 from Japan, and 104 and 132 controls, respectively.... Of the 118 brain tumors, 46 were classified as gliomas, including 3 astrocytomas, 2 ependymomas, and 1 glioblastoma. Only five cases of meningioma were included in the study.... The mean duration of mobile phone use ranged from 3.10 years in the Japanese case group to 3.95 years in the Korean case group. The number of calls was approximately 10 times higher in the Korean case group and 3.5 times in the Korean control group, compared with that in the corresponding Japanese groups.... The OR in the highest tertile of cumulative call time (258.1 to 18,760 hours) for all brain tumors was 1.53 (95% CI, 0.69-3.40) compared with that of nonregular users. After adjustment for country and maternal education level, 25 the OR in the highest tertile was 1.61 (95% CI, 0.72-3.60). The OR by level of RF energy in the entire hemisphere of the tumor side, tumor, and at COG of the tumor were also slightly higher than 1, though.... In this study of Korean and Japanese young people, we observed a slight elevated risk of all brain tumor among the heaviest users of mobile phones. The confidence interval was large, however, and there was little evidence of a dose response relationship. ORs by level of RF energy were close to 1.0, again with no evidence of an association with dose.... ... exposure from extremely low frequency 26 and cordless phone use (DECT) were not included in the risk analysis because we determined that it was negligible.... This study is limited in that although 22 Korean and 36 Japanese brain tumor cases were included, which was more than that included in the international study. The generally low exposure levels compared with those observed in the INTERPHONE study, along with the skewed distribution, limited the statistical power of our study.... Conclusions Despite the aforementioned limitations such as the small study sample size, our findings suggested that mobile phone use does not greatly impact the development of brain tumors. However, because we combining evaluated young people in both Korea and Japan who were geographically and genetically similar, small numbers and large confidence intervals might preclude any clear conclusions. jstage.jst.go.jp

AI evidence extraction

Main findings

In this MOBI-Kids case-control analysis (118 brain tumor cases; 236 appendicitis controls), the adjusted OR for all brain tumors in the highest tertile of cumulative call time (1 year before reference date) was 1.61 (95% CI, 0.72–3.60), with no indication of a trend with exposure. For glioma, the adjusted OR in the highest tertile was 0.70 (95% CI, 0.16–3.03), and ORs in the lowest exposure category were below 1. ORs based on estimated RF energy in the tumor side/region were described as close to 1 with no evidence of dose association.

Outcomes measured

• Brain tumors (all)
• Glioma

Limitations

• Small sample size and limited statistical power; large confidence intervals
• Generally low exposure levels and skewed exposure distribution
• Exposure assessment relied on interview-based mobile phone use history (potential recall error)
• Risk analysis focused on RF exposure from mobile phone use only; other EMF sources (e.g., DECT, ELF) were not included in the risk analysis

Suggested hubs

• mobile-phones-brain-tumors (0.95)
  Case-control study of mobile phone RF exposure and brain tumor/glioma risk in adolescents/young adults.

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    "study_type": "case_control",
    "exposure": {
        "band": "RF",
        "source": "mobile phone",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "Cumulative call time assessed at 1 year before reference date; regular use defined as at least once/week for ≥3 months; mean duration of use ~3.10–3.95 years (by country/case status)"
    },
    "population": "Young people (adolescents/young adults) aged 10–24 years in Korea and Japan (2011–2015)",
    "sample_size": 354,
    "outcomes": [
        "Brain tumors (all)",
        "Glioma"
    ],
    "main_findings": "In this MOBI-Kids case-control analysis (118 brain tumor cases; 236 appendicitis controls), the adjusted OR for all brain tumors in the highest tertile of cumulative call time (1 year before reference date) was 1.61 (95% CI, 0.72–3.60), with no indication of a trend with exposure. For glioma, the adjusted OR in the highest tertile was 0.70 (95% CI, 0.16–3.03), and ORs in the lowest exposure category were below 1. ORs based on estimated RF energy in the tumor side/region were described as close to 1 with no evidence of dose association.",
    "effect_direction": "mixed",
    "limitations": [
        "Small sample size and limited statistical power; large confidence intervals",
        "Generally low exposure levels and skewed exposure distribution",
        "Exposure assessment relied on interview-based mobile phone use history (potential recall error)",
        "Risk analysis focused on RF exposure from mobile phone use only; other EMF sources (e.g., DECT, ELF) were not included in the risk analysis"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "MOBI-Kids",
        "case-control",
        "adolescents",
        "young adults",
        "mobile phone",
        "radiofrequency",
        "RF-EMF",
        "brain tumor",
        "glioma",
        "Korea",
        "Japan",
        "cumulative call time",
        "specific energy"
    ],
    "suggested_hubs": [
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