Occupational exposure to the industrial chemical styrene has been linked to an increased risk of developing acute myeloid leukaemia (AML), finds a new study in Epidemiology.
Previous research has suggested increased occurrence of leukemia and lymphoma among reinforced plastics workers exposed to high levels of styrene. This study investigated the exposure-response relationship between cumulative styrene exposure and rates of lymphohaematopoietic malignancies in 73,036 employees of 456 Danish reinforced plastics companies from 1968 to 2011.
A total 665 cases of 21 individual or combination lymphohaematopoietic malignancies were identified. Initial analyses suggested higher age, sex, and calendar year-adjusted incidence rate ratios (RRs) for AML, Hodgkin lymphoma and T-cell lymphoma with higher estimates of cumulative styrene exposure.
Accounting for time since exposure showed an exposure-response trend (P=.01). The risk of AML was doubled following estimated high versus low cumulative exposure during the prior 15-29 years (RR 2.4; 95% CI 1.2-4.6).
No increased risk following exposure during more recent years was observed and risk patterns were less consistent for Hodgkin lymphoma and T-cell lymphoma.