Evidence map›Paper›PMID 41660899›Full record

SynthesisAsian Pacific journal of cancer prevention : APJCP2026

Ambient Air Pollution and Risk of Brain Tumors: A Systematic Review and Meta-Analysis.

Ali Fadhil Hashim, Amirreza Karimi, Sanaz Ghanbari, Azizova Feruza, Nawras Abdel Abbas Esmaeel, Hussain Ali Rzoqy, Mozhgan Taebi, Soheyla Kalantari, Samad Karkhah, Azadeh Emami and 1 more

Abstract readSystematic ReviewMeta-Analysis
In one paragraph

Synthesis in Asian Pacific journal of cancer prevention : APJCP, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Ali Fadhil HashimDepartment of Pathology, College of Medicine, University of Karbala, Karbala, Iraq.
Amirreza KarimiSchool of Nursing and Midwifery, Mazandaran University of Medical Sciences, Sari, Iran.
Sanaz GhanbariFaculty of Nursing and Paramedicine, Mazandaran University of Medical Sciences, Amol, Iran.
Azizova FeruzaHead of the Department of Histology and Medical Biology, DSc, Tashkent State Medical University, Tashkent, Uzbekistan.
Nawras Abdel Abbas EsmaeelKarbala Technical Institute, AL-Furat al-Awsat technical University, Najaf, Iraq.
Hussain Ali RzoqyKarbala Technical Institute, AL-Furat al-Awsat technical University, Najaf, Iraq.
Mozhgan TaebiSchool of Allied Medical Sciences, Kerman University of Medical Sciences, Kerman, Iran.
Soheyla KalantariFaculty of Surgical Technology Department Paramedical School, Golestan University of Medical Sciences, Gorgan, Iran.
Samad KarkhahIndependent Researcher, Rasht, Iran.
Azadeh EmamiDepartment of Anesthesiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Reza SalehiDepartment of Anesthesiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe potential link between ambient air pollution and brain tumor incidence remains poorly understood, despite growing concern about environmental exposures and neurological health. While air pollutants are established carcinogens for several cancer types, their role in central nervous system (CNS) tumorigenesis has not been definitively established.

aimThis study aims to systematically evaluate and quantitatively synthesize the epidemiological evidence on the association between long-term exposure to ambient air pollution and the risk of brain tumors, including gliomas and meningiomas.

methodsA comprehensive literature search was conducted across PubMed, Embase, Scopus, Web of Science, and ProQuest (up to October 1, 2024), identifying observational studies assessing associations between air pollution and brain tumor incidence. Eligible studies were screened, data were extracted, and study quality was assessed using the Newcastle-Ottawa Scale. Random-effects meta-analyses were performed to estimate pooled relative risks (RR) for specific pollutants (PM2.5, NOx, NO2), and traffic proximity. Subgroup analyses and publication bias assessments were also conducted.

resultsEight studies met inclusion criteria, with five contributing to the meta-analysis. Pooled estimates indicated an association between long-term exposure to NO2 and brain tumors (RR = 1.06; 95% CI: 1.01-1.11). PM2.5 exposure showed a higher but more variable association (RR = 1.63; 95% CI: 1.04-2.55), while NOx (RR = 1.16; 95% CI: 0.93-1.45) and traffic proximity (RR = 1.07; 95% CI: 0.99-1.16) demonstrated weaker or borderline associations. Subgroup analyses suggested slightly stronger associations for meningioma than glioma. Significant heterogeneity was observed across studies, but no clear evidence of publication bias was detected.

conclusionsThis systematic review and meta-analysis provides suggestive evidence that long-term exposure to traffic-related air pollutants may be associated with a modestly increased risk of brain tumors. While results are not conclusive, the widespread exposure to these pollutants and the observed trends underscore the importance of further research using refined exposure assessments and tumor subtype-specific analyses.

Indexed as

Air PollutantsAir PollutionBrain NeoplasmsEnvironmental ExposureHumansIncidenceMeningiomaParticulate MatterRisk FactorsAir PollutantsParticulate MatterAir pollutionBrain tumorsenvironmental epidemiologyGliomameningioma

Identifiers

PMID41660899
PMCPMC13499623

What Socratic holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.