Increased liver and lupus mortalities in 24-year follow-up of the Taiwanese people highly exposed to polychlorinated biphenyls and dibenzofurans

Background: A follow-up study was designed to compare the 24-year overall and disease-specific mortality in Yucheng people who were highly exposed to polychlorinated biphenyls/dibenzofurans (PCBs/PCDFs) to that in the background population in Taiwan. In 1979, the Yucheng (oil-disease in Chinese) incident occurred in central Taiwan involving approximately 2000 victims due to ingestion of rice oil contaminated with PCBs/PCDFs. Long-term follow-up of these people has been continued for 24 years. Methods: Standardized mortality ratios were calculated using the Taiwan population as comparison group. Overall and disease-specific mortality was compared between Yucheng and background populations. Results: Mortality from chronic liver disease and cirrhoses was increased in the Yucheng men, but not in women, in the early period after exposure. Cancer mortality was not increased in the Yucheng population up to 24 years after exposure. SLE in females was highly increased in the later period after PCB/PCDF exposure. Mortality from disease in any other organ system was not significantly different between Yucheng and background populations. Conclusions: The study provided a long-term mortality picture after the Taiwanese PCB/PCDF exposure incident. In addition to re-confirming the increase in liver mortality, we found high mortality of SLE among exposed population. This finding highlights the importance of further investigating the immunological effects associated with PCB/PCDF exposure.