Traffic related benzene exposure and childhood leukemia risk: a meta analysis

  Objective  To systematically evaluate the relationship between traffic related benzene exposure and childhood leukemia.

  Methods  The English databases of web of science and PubMed were searched with the key words of "childhood leukemia", "childhood ALL", "childhood AML", "benzene", "traffic density", "road density" or "vehicle density". The relevant literatures that met the requirements were searched and meta-analysis was performed by Stata 15.0 software.

  Results  A total of 579 literatures were screened and 21 case-control studies were included. There was moderate heterogeneity in 21 studies (I²=45%, P=0.014), so random effect model was used for statistical analysis. The results showed that the risk of childhood leukemia was not significantly associated to traffic related benzene exposure (pooled OR=1.03, 95% CI: 0.98-1.09, P=0.210). Further subgroup analysis showed that according to the NOS score, 12 studies with a score of ≥ 7 showed that traffic related benzene exposure had a statistically significant risk of childhood leukemia (pooled OR=1.04, 95% CI: 1.00-1.07, P=0.024). Funnel plot showed that there was no publication bias (Begg test, P=0.131).

  Conclusions  There may be no correlation between traffic related benzene exposure and childhood leukemia, and the results need further high-quality prospective study to verify.