Wind turbines in Styria, Austria. Styrene is used in the manufacture of wind turbines.
A new study links styrene—a chemical used in the manufacture of plastics, rubber, and resins—to certain cancers.
The research showed that, contrary to previous suggestions, employees who have worked with styrene do not have an increased incidence of esophageal, pancreatic, lung, kidney, or bladder cancer.
On the other hand, they may have an increased risk of nasal and paranasal cancer, as well as myeloid leukemia and Hodgkin lymphoma (HL).
The research was published in Epidemiology.
“It is important to know for present and former workers exposed to styrene that they are unlikely to have become ill by doing their job if they have developed cancer of the esophagus, pancreas, lungs, kidneys, bladder, or a wide range of other types of cancer,” said study author Henrik A. Kolstad, MD, PhD, of Aarhus University in Denmark.
“This is also new and important knowledge in the USA, where styrene was added to the list of carcinogenic substances in 2011.”
In relation to the cancers for which the study shows a possible increased risk, Dr Kolstad emphasized that additional research is needed to determine if styrene is the actual cause of the employees’ disease.
For the current study, Dr Kolstad and his colleagues analyzed data on 72,292 employees who worked for 1 of 443 small and medium-sized companies in Denmark that used styrene for the production of wind turbines, pleasure boats, and other products from 1964 to 2007.
There were 8961 incident cases of cancer in this cohort from 1968 to 2012. The standardized incidence rate ratio (SIR) for all cancers was 1.04. When the researchers included a 10-year lag period, the SIR for all cancers was still 1.04.
As for hematologic malignancies, the researchers said they observed increased rate ratios associated with increased duration of employment for HL and myeloid leukemia.
For HL, the SIRs were 1.21 with no lag and 1.22 with a 10-year lag. For myeloid leukemia, the SIRs were 1.06 and 1.13, respectively.
The SIRs for non-Hodgkin lymphoma were 0.97 with no lag and 0.94 with a 10-year lag. The SIRs for multiple myeloma were 0.79 and 0.77, respectively.
For cancers of lymphatic and hematopoietic tissue, the SIRs were 0.97 with no lag and 0.96 with a 10-year lag. For lymphatic leukemia, the SIR was 0.96 for both time points.
The SIRs for monocytic leukemia were 0.77 with no lag and 0.56 with a 10-year lag. The SIRs for other and unspecified leukemias were 1.05 and 1.26, respectively.
The researchers noted that workers first employed in the 1960s had a higher risk of HL than workers first employed in subsequent years.
The SIRs were 2.12 for those first employed in 1964-1969, 0.82 for 1970-1979, 1.07 for 1980-1989, 1.52 for 1990-1999, and 1.10 for those first employed in 2000-2007.
There were no such associations for other cancer sites.
