The English translation of your question is: "Where does the lead content in baijiu (Chinese liquor) come from?"
To answer the question itself:
Lead in baijiu can originate from:
1. Raw materials: Contaminated grains or water used in fermentation.
2. Production equipment: Lead leaching from aging pots, pipelines, or storage containers (historically, lead-containing alloys were sometimes used).
（图片来源网络，侵删）
3. Environmental pollution: Soil or air contamination during cultivation or production.
Modern regulations and stainless-steel equipment have significantly reduced lead levels in most commercially produced baijiu.
（图片来源网络，侵删）
