# Risk Assessment of Bisphenol A in the Korean General Population
## 3 Exposure Level of BPA in Korea General Population
Urinary BPA concentrations for the general population above three years of age were obtained from the Korean National Environmental Health Survey (KoNEHS) Cycle 3 (2015 to 2017). The mean urinary BPA concentration (1.32 ng/mL, 1.38 \(\mu\)g/g creatinine) of the adult subjects (Table 3) was lower than that reported in other studies conducted in Malaysia (mean urinary BPA, 1.89 ng/mL), India (mean urinary BPA, 1.97 ng/mL), Japan (mean urinary BPA, 1.98 ng/mL), China (mean urinary BPA, 3.86 ng/mL), Vietnam (mean urinary BPA, 3.32 ng/mL), and Kuwait (mean urinary BPA, 4.10 ng/mL) [56]. Using the biomonitoring data from the Korean National Environmental Health Survey (KoNEHS) Cycle 3 (2015 to 2017), we calculated the extrapolated exposure amount. The calculation equation was suggested by the NIFDS in 2012 [16]. The total urinary BPA concentrations (\(\mu\)g/g creatinine) were adjusted for urinary creatinine concentration, multiplied by the age-specific estimated 24 h urinary creatinine output volume and divided by body weight. The equation for exposure estimates (\(\mu\)g/kg bw/day) based on PBPK modeling is as follows. \[ \begin{array}{l}\text{Estimated daily intake }(\text{EDI }(\mu\text{g/kgbw/day}))\\ =\frac{(\text{\it urinary BPA concentration }(\mu\text{g/g creatinine})+0.00001)\times\text{\it Urinary creatinine }\text{\it output }(\text{g/day})}{0.993\times\text{\it Body weight }(\text{kg})}\end{array}  \tag{1}\]  
Urine creatinine excretion volumes at each age were calculated according to [PERSON] et al. [57] and [PERSON] et al. [58]. The body weight of each age group used mean values from the data of the 2018-2020 Korea National Health and Nutrition Examination Survey (KNHANES). Using these assumptions, the biomonitoring-based mean exposure estimates are in the range of 0.017 \(\mu\)g/kg bw/day for adults and 0.042 \(\mu\)g/kg bw/day for children 3-6 years of age. The 95 th percentile exposure estimates were in the range of 0.104-0.201 \(\mu\)g/kg bw/day for all ages (Table 3). This is higher than EFSA's new TDI (0.04 ng/kg bw/day) but lower than Republic of Korea's TDI (0.02 mg/kg bw/day). Food is considered the main source of exposure in the general population (>95%), but in the adult group (19-79 years), food contributes 54.8%, and there may be other sources of exposure (Table 3). The results indicate that it is still necessary to evaluate additional exposure in the adult group. In the high-exposure biomonitoring group, with \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Exposure Method**} & \multicolumn{4}{c}{**Age Group (Years)**} \\ \cline{2-5}  & **3–6** & **7–12** & **13–18** & **19–79** \\ \hline Aggregated exposure amount & 0.045 & 0.028 & 0.021 & 0.023 \\ Dietary exposure amount & 0.040 & 0.030 & 0.018 & 0.017 \\ \hline Source: National Institute of Food and Drug Safety Evaluation (NIFDS), 2019–2020. & & & \\ \end{tabular}
\end{table} 
Table 2: Bisphenol A exposure assessment in Korean general population by age in 2018–2020 (\(\mu\)g/kg bw/day). -food contributing less than 20%, there may be additional sources of exposure (Table 3). One of the reasons for the low contribution of food in the high-exposure group may be the lack of information on the high intake of specific foods because the KHNAES is a dietary survey for the general population. BPA has been found primarily in canned foods and packaged foods and rarely or at very low concentrations in other foods. In the 2013-2016 KNHANES, the proportion of canned food consumers was very low at \(<\)18%. The KNHANES nutritional survey is conducted in one-day-24 h recall. Therefore, interpretation of the results is limited, and there were limitations in assessing the exact exposure for consumers who ate a lot of BPA-detected foods. In a probabilistic evaluation of canned food intake only, the total exposure level of the 75 th population and the exposure through canned food were estimated to be almost the same (Figure 1).