A study of benzene-exposed workers in China, conducted by investigators from the U.S. National Cancer Institute and the Chinese Academy of Preventive Medicine, is ongoing (15). To date, the primary NHL-related finding from the ∼74,000 observed workers is a 3-fold increase in NHL risk for benzene-exposed workers, increasing to a 4-fold excess in NHL risk for workers exposed to benzene for 10 or more years. For workers in the chemical industry in this cohort, the relative risk (RR) was even higher at 7.8. In a study of chemical industry workers in the United States, Wong (16) found that the RR for NHL mortality among white benzene-exposed workers was 8.6 (P = 0.02) compared with unexposed workers. For workers continuously exposed to benzene, the RR was 9.6 compared with unexposed workers. Cohort studies of workers in the chemical manufacturing industry are summarized in Supplementary Table S2.