Environmental Factors and the Risk of Brain Tumours in Young People: A Systematic Review

2019 · Mixed · Insufficient evidence

← Research stream

MixedInsufficient evidencePaper 1715

Study snapshot

Publicationmanual · 2019

Study typesystematic_review

Reported directionMixed

Evidence ratingInsufficient

Abstract

Environmental Factors and the Risk of Brain Tumours in Young People: A Systematic Review Zumel-Marne A, Castano-Vinyals G, Kundi M, Alguacil J, Cardis E. Environmental Factors and the Risk of Brain Tumours in Young People: A Systematic Review. Neuroepidemiology. 2019 Jun 5:1-21. doi: 10.1159/000500601. Abstract BACKGROUND: Brain tumours (BT) are one of the most frequent tumour types in young people, although little is known about their risk factors. OBJECTIVE: The objective of the current work was to review and summarize the scientific literature concerning exposure to environmental factors and BT risk in young people (<25 years old). METHODS: PUBMED, Embase, Cochrane Library, Scopus, IME-Biomedina (bibliographic database of Consejo Superior de Investigaciones Científicas) and Web of science databases were searched. A score to assess the quality of the methodological information was created. RESULTS: Some possible associations between BT risk in young people were reported for cadmium, consumption of well water, presence of nitrate or nitrate-nitrogen in tap water, mother's passive smoking, air pollution, parental handling of pesticides at home and/or professional pesticide treatment within houses, living on a farm and/or with farm animals, some parental occupations and high amount of meat consumption. CONCLUSIONS: Although many of the studies reviewed suggest associations between the environmental exposures and BT in children and young adults, at present no reliable conclusion can be drawn as most results are based on small number of cases and exposure assessment is limited. Large-scale studies with better exposure assessment are needed to shed light on these possible associations, especially on exposure to heavy metals, tab water consumption, pesticides and parental smoking. Excerpt: Non-Ionizing Radiation Three articles [19, 42, 47] studied the association between extremely low frequency (ELF) exposure during pregnancy and BT risk. Regarding the exposure to electrically heated waterbeds during pregnancy, 2 articles found non-significantly reduced risks (1 for astrocytomas and the other for BT in general) based on small samples sizes [19, 47]. No significant association was found for PNET either [19]. Regarding exposure to ELF from electrical blankets during pregnancy, 3 articles found non-statistically significantly increased risk [19, 42, 47]. Two studies focused on childhood ELF exposure [39, 47] and BT risk. One [39] found a non-significantly reduced risk for electric blanket and waterbed use based on very small numbers of cases (n = 6 and 1, respectively). In the other study, the ORs were close to one. Two studies [48, 49] focused on radiofrequency (RF) exposures in childhood and BT were found. In the large multinational study [48], a non-significantly increased risk was found, with no evidence for an exposure response relationship between mobile phones use (which emits some ELF but mainly RF) and risk of BT. Use of mobile phones was low in this population, with an average duration of use of 2.7 years and lifetime cumulative time of use of only 35 h. Another study [49], which estimated average of exposure to RF from mobile phone base stations, found a non-statistically significant risk for exposure above the median, though the authors acknowledge several methodological limitations. Three studies focused on the exposure to magnetic fields (MF) [50-52] from high-current power lines, electric heating sources or electric appliances at home during childhood. One [50] found a significantly increased risk for ≥0.4µT of MF in the children's bedroom (OR 10.9 [1.05-113] based on 3 cases and 1 control). Two [51, 52] studies found a non-statistically significant increased risk for exposure at home to high MF compared to low ones. Open access paper: karger.com

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typesystematic_review

Effect directionmixed

PopulationYoung people (<25 years old); includes pregnancy exposures (maternal) and childhood exposures

Sample sizeNot supplied

ExposureELF/RF · pregnancy and childhood exposures; mobile phone use average duration 2.7 years and lifetime cumulative time 35 h (in one included study)

Evidence strengthInsufficientConfidence: 78% · Peer reviewed: yes

Main findings

The review identified a small number of studies on non-ionizing radiation and brain tumour risk in young people. For ELF exposure during pregnancy, electrically heated waterbeds were associated with non-significantly reduced risks in two studies, while electric blanket exposure showed non-statistically significant increased risks across three studies. For childhood RF exposures, one large multinational study reported a non-significantly increased risk for mobile phone use with no exposure-response relationship, and another study of RF from base stations found a non-statistically significant increased risk above the median exposure with noted methodological limitations. For childhood magnetic fields from power lines/heating/appliances, one study reported a significantly increased risk for ≥0.4 µT in the bedroom based on very small numbers, while two other studies found non-statistically significant increased risks at higher home MF exposure.

Outcomes measured

Brain tumours (BT) risk
Astrocytomas
PNET

Limitations

Authors conclude no reliable conclusions can be drawn overall due to small number of cases and limited exposure assessment
Non-ionizing radiation evidence based on few studies
Several reported associations were non-statistically significant
One significant MF finding was based on very small numbers (3 cases and 1 control)
Methodological limitations acknowledged in the base-station RF study
Low mobile phone use in the population in the large multinational study (average 2.7 years; 35 h lifetime cumulative use)

View raw extracted JSON

{
  "study_type": "systematic_review",
  "exposure": {
    "band": "ELF/RF",
    "source": "mobile phone; mobile phone base stations; power lines; electric blankets; electrically heated waterbeds; electric heating sources; electric appliances",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "pregnancy and childhood exposures; mobile phone use average duration 2.7 years and lifetime cumulative time 35 h (in one included study)"
  },
  "population": "Young people (<25 years old); includes pregnancy exposures (maternal) and childhood exposures",
  "sample_size": null,
  "outcomes": [
    "Brain tumours (BT) risk",
    "Astrocytomas",
    "PNET"
  ],
  "main_findings": "The review identified a small number of studies on non-ionizing radiation and brain tumour risk in young people. For ELF exposure during pregnancy, electrically heated waterbeds were associated with non-significantly reduced risks in two studies, while electric blanket exposure showed non-statistically significant increased risks across three studies. For childhood RF exposures, one large multinational study reported a non-significantly increased risk for mobile phone use with no exposure-response relationship, and another study of RF from base stations found a non-statistically significant increased risk above the median exposure with noted methodological limitations. For childhood magnetic fields from power lines/heating/appliances, one study reported a significantly increased risk for ≥0.4 µT in the bedroom based on very small numbers, while two other studies found non-statistically significant increased risks at higher home MF exposure.",
  "effect_direction": "mixed",
  "limitations": [
    "Authors conclude no reliable conclusions can be drawn overall due to small number of cases and limited exposure assessment",
    "Non-ionizing radiation evidence based on few studies",
    "Several reported associations were non-statistically significant",
    "One significant MF finding was based on very small numbers (3 cases and 1 control)",
    "Methodological limitations acknowledged in the base-station RF study",
    "Low mobile phone use in the population in the large multinational study (average 2.7 years; 35 h lifetime cumulative use)"
  ],
  "evidence_strength": "insufficient",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "brain tumours",
    "young people",
    "children",
    "systematic review",
    "non-ionizing radiation",
    "ELF",
    "radiofrequency",
    "mobile phones",
    "base stations",
    "magnetic fields",
    "electric blankets",
    "waterbeds",
    "power lines"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.2,
      "reason": "Review mentions some parental occupations as possible risk factors (not specific to EMF)."
    }
  ]
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1159/000500601
PubMed: Not supplied

Read the original paper →

Related papers

← Back to the Research Library