Evaluation of background persistent organic pollutant levels in human from Taiwan: Polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls

This study was intended to determine the background levels of PCDD/PCDFs and PCBs in the Taiwanese population and to investigate factors potentially related to PCDD/PCDF and PCB levels. The levels of seventeen PCDD/PCDFs in the 251 serum samples collected from the general population in Taiwan ranged from 4.92 to 26.7 pg WHO1998-TEQ/g lipid (median: 11.5) and those of the twelve dioxin-like PCBs ranged between 1.74 and 21.6 pg WHO1998-TEQ/g lipid (median: 6.14). Five factors, age, gender, region of residence, dietary status, and smoking status, showed statistically significant association with the TEQ level of PCDD/PCDFs. The TEQ level of PCBs was statistically associated with age only, but not with the other four factors. The trends observed between age and the levels of PCDD/PCDFs and PCBs were not parallel in young subjects (< 30 years old) and old subjects (> 30 years old). The levels of PCDD/PCDFs and PCBs increased by 0.16 and 0.03 WHO1998-TEQ/g lipid per year for subjects above the age of 30, but there was no evidence of any association between age and the levels for subjects below the age of 30 years. These factors should be considered when investigating relationships between background serum levels of persistent organic pollutants and parameters associated with exposure sources or health outcomes.