Department of Environmental Health Sciences, Jonathan and Karin Fielding School of Public Health, University of California Los Angeles, Los Angeles, CA 90095, United States.
State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, and Center for Environment and Health, Peking University, Beijing 100871, PR China.
Environ Int. 2020 Aug;141:105758. doi: 10.1016/j.envint.2020.105758. Epub 2020 May 8.
Recent studies suggested a significant downward trend in population's exposure to bisphenol A (BPA) in the United States. However, the temporal trend of BPA exposure remains unclear in China - a populous country with substantial industrial activities but less efforts made to phase out BPA in consumer products. In addition, it is unclear to what extent a visit from the United States to China could affect human exposure to BPA. In this natural experiment, we measured the concentration of total BPA in 418 urine samples repeatedly collected from 55 Los Angeles residents before, during, and after they spent 10 weeks in Beijing from 2012 to 2017. We found that traveling from Los Angeles to Beijing led to a 2.91-fold (95% CI: 2.43 to 3.50) increase in urinary BPA levels, which fully returned to baseline after study participants came back to Los Angeles. From 2012 to 2017, urinary BPA concentrations decreased in Los Angeles by 25.5% per year (95% CI: -30.8% to -19.8%; p < 0.001) but did not change in Beijing (p = 0.24). Consequently, the concentration ratio of urinary BPA between Beijing and Los Angeles increased from 1.23 (95% CI: 0.82 to 1.85) in 2012 to 4.05 (95% CI: 2.75 to 5.97) in 2017. These results indicate that BPA exposures may increase among international travelers to China. Additional efforts are needed to reduce population's exposure to BPA in China.
最近的研究表明，美国人群接触双酚 A（BPA）的水平呈显著下降趋势。然而，在中国这种人口众多且工业活动量大的国家，BPA 暴露的时间趋势尚不清楚，且在消费品中淘汰 BPA 的工作也做得较少。此外，美国人访华在何种程度上会影响人类接触 BPA 也尚不清楚。在这个自然实验中，我们测量了 2012 年至 2017 年期间，55 名洛杉矶居民在前往北京并逗留 10 周期间及前后，反复采集的 418 份尿液样本中的总 BPA 浓度。我们发现，从洛杉矶前往北京会导致尿液中 BPA 水平升高 2.91 倍（95%置信区间：2.43 至 3.50），而当研究参与者返回洛杉矶后，BPA 水平又完全恢复到基线。2012 年至 2017 年间，洛杉矶尿液中 BPA 浓度每年下降 25.5%（95%置信区间：-30.8%至-19.8%；p<0.001），但北京没有变化（p=0.24）。因此，2012 年北京和洛杉矶尿液中 BPA 的浓度比值为 1.23（95%置信区间：0.82 至 1.85），而到 2017 年则上升至 4.05（95%置信区间：2.75 至 5.97）。这些结果表明，国际旅行者前往中国可能会增加 BPA 暴露。中国需要进一步努力减少人群接触 BPA。
