PURPOSE: To investigate the risk of non-Hodgkin lymphoma (NHL) associated with residential carpet dust measurements of polycyclic aromatic hydrocarbons (PAHs).
METHODS: We evaluated the relationship between residential carpet dust PAH concentrations (benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, dibenz(a,h)anthracene, and indeno(1,2,3-c,d)pyrene, and their sum) and risk of NHL (676 cases, 511 controls) in the National Cancer Institute Surveillance Epidemiology and End Results multicenter case-control study. As a secondary aim, we investigated determinants of dust PAH concentrations. We computed odds ratios (OR) and 95 % confidence interval (CI) for associations between NHL and concentrations of individual and summed PAHs using unconditional logistic regression, adjusting for age, gender, and study center. Determinants of natural log-transformed PAHs were investigated using multivariate least-squares regression.
RESULTS: We observed some elevated risks for NHL overall and B cell lymphoma subtypes in association with quartiles or tertiles of PAH concentrations, but without a monotonic trend, and there was no association comparing the highest quartile or tertile to the lowest. In contrast, risk of T cell lymphoma was significantly increased among participants with the highest tertile of summed PAHs (OR = 3.04; 95 % CI, 1.09-8.47) and benzo(k)fluoranthene (OR = 3.20; 95 % CI, 1.13-9.11) compared with the lowest tertile. Predictors of PAH dust concentrations in homes included ambient air PAH concentrations and the proportion of developed land within 2 km of a residence. Older age, more years of education, and white race were also predictive of higher levels in homes.
CONCLUSION: Our results suggest a potential link between PAH exposure and risk of T cell lymphoma and demonstrate the importance of analyzing risk by NHL histologic type.