To conduct proper biological monitoring of environmental exposure to bisphenol A (BPA), the variation in host susceptibility need to be investigated. For this purpose, we studied effects of genetic polymorphism in sulfotransferase (SULT) 1A1 on urinary BPA, a biomarker for BPA exposure, in 73 Koreans (male, 34; female, 39; age, 48.9 +/- 11.9 yrs). We used reverse phase-HPLC/FD for analysis of urinary BPA and obtained information from each subject on lifestyle, environment, and potential exposure to BPA via food. The HPLC/FD method showed good reproducibility (CVs < 0.1) and a relatively sensitive detection limit of 0.012 microg/L. These methods yielded a geometric mean of urinary BPA as 9.54 microg/L (8.91 microg/g creatinine), with a geometric standard deviation of 8.32 microg/L. Among potential routes for BPA exposure, only "vinyl wrapping of microwave heating" indicated a borderline positive association with urinary BPA level (p = 0.1). After PCR-RFLP, we found the allele frequencies of SULT1A1*1 and SULT1A1*2 were 0.89 and 0.11, respectively within the subjects. As the SULT1A1*1 allele of SULT1A1 is known to be a rapid sulfonylation-allele, the presence of SULT1A1*1 is suspected to rapidly dispose of environmental BPA. However resultant, urinary BPA levels were not significantly different between the SULT1A1*1/*1 identified subjects and the SULT1A1*1/*2 subjects. Therefore, to clarify host variability in urinary BPA level, different genetic polymorphisms in BPA metabolic enzymes other than SULT1A1 should be further studied.