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A Meta-analysis of Traffic-related Air Pollution and Risk of Childhood Leukemia

Gong, Zeng-Hong, MD*; Li, Jian, MD; Wang, Xiao-Yong, MD*; Yu, Yan, MD*; Ren, Min-Min, MD*; Zhou, Jian, MD

Journal of Pediatric Hematology/Oncology: May 2019 - Volume 41 - Issue 4 - p 267–274
doi: 10.1097/MPH.0000000000001413
Original Articles

Background: Many studies have analyzed the association between traffic-related air pollution and risk of childhood leukemia, but the results are inconsistent. Therefore, we performed this meta-analysis to investigate the association between traffic-related air pollution and risk of childhood leukemia.

Methods: PubMed, Cochrane, and Embase databases were searched by the index words to identify eligible case-control studies, and relevant literature sources were also searched. The latest research was performed in September 2017. Odds ratio (OR) along with 95% confidence interval (95% CI) were used to analyzed the main outcomes.

Results: Twenty-one case-control studies were included in the meta-analysis. The results indicated that in the studies of overall traffic density (OR: 1.01, 95% CI: 0.98-1.04), high traffic density (OR: 1.04, 95% CI: 0.91-1.17), moderate exposure to NO2 (OR: 1.02, 95% CI: 0.93-1.10), and benzene (OR: 1.04, 95% CI: 0.71-1.37), the risks of childhood leukemia incidence were higher in the case group than the control group, but no significant difference was found. In other analysis, no significant difference was observed in the risk of childhood leukemia in the 2 groups.

Conclusions: Current evidence suggests that childhood leukemia is associated with traffic density, and moderate exposure to NO2 and benzene. However, more high-quality studies are required to confirm the conclusions.

Departments of *Hematology


Internal Medicine Center Laboratory, Dongtai People Hospital, Dongtai, Jiangsu Province, China

The authors declare no conflict of interest.

Reprints: Jian Zhou, MD, Department of Internal Medicine Center Laboratory, Dongtai People Hospital, No. 2 West Kangfu Road, Dongtai, Jiangsu Province 224200, China (e-mail:

Received June 23, 2018

Accepted December 13, 2018

Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.