Results of a prospective study linking data on cancer incidence collected as part of the American Cancer Society Cancer Prevention Study-II (ACS-CPSII) Cohort showed that exposure to ambient benzene was positively associated with development of myelodysplastic syndrome and T-cell lymphoma. This study was published online in the International Journal of Cancer and used estimates of low-level ambient benzene as calculated by the United States Environmental Protection Agency (EPA) National Ambient Toxics Assessment (NATA).
Exposure to high levels of benzene, a volatile organic compound, has been shown to increase the risk of developing acute myeloid leukemia, and there is also evidence to suggest that it may cause other hematologic malignancies.
The focus of this study is on evaluating potential cancer risks of ambient benzene exposure in the general population. This is important because the majority of previous studies investigating associations between benzene exposure and the risk of particular malignancies included only individuals exposed to benzene in an occupational setting.
The authors wrote that “to [their] knowledge this is the first nationwide cohort examination of the association between EPA’s modeled benzene estimates with individual level data and risk of hematologic malignancies in the United States.”
Of the 115,996 participants included in this analysis of the ACS-CPSII cohort, 2595 cases of hematologic cancer (1427 men and 1168 women) were reported between 1997 and June 2013, the date follow-up concluded.
In the overall cohort, ambient benzene exposure was positively associated with myelodysplastic syndrome (hazard ratio [HR]=1.16; 95% confidence interval [CI], 1.01-1.33 per µg/m3) and T-cell lymphoma (HR=1.29; 95% CI, 1.08-1.53 per µg/m3). In the cohort of men only, ambient benzene exposure, a positive association was also observed for ambient benzene exposure and any hematologic malignancy (hazard ratio=1.07; 95% CI, 1.01-1.15 per µg/m3) and follicular lymphoma (hazard ratio=1.28; 95% CI, 1.09-1.50 per µg/m3).
In conclusion, the authors wrote that “the results of this study suggest that ambient benzene increases risk of MDS and lymphoid malignancies, particularly follicular lymphoma, and T-cell lymphoma. Future studies with large numbers of cases of each subtype are needed to confirm these associations.”
- Teras LR, Diver WR, Deubler EL, et al. Residential ambient benzene exposure in the United States and subsequent risk of hematologic malignancies [published online February 9, 2019]. Int J Cancer. doi: 10.1002/ijc.32202