Lettuce itself does not contain lead, the lead in lettuce is obtained from the environment during the growing process or during transportation and processing.
1. Growing process contaminated by lead: Farmland around mines, soil with long-term use of lead-containing fertilizers, and crops around chemical factories may all contaminate lettuce with lead during the growing process.
2. Transportation: Lead in containers during transportation is also an important source of lead contamination.
3. Processing: In the processing of lettuce, such as ceramic containers, metal utensils and long-term cooking may cause heavy metals to leach into the lettuce.
In fact, not only lettuce, but any crop can be contaminated with lead. If symptoms of lead poisoning such as gastrointestinal bleeding and toxic hepatitis occur, it is important to seek prompt medical attention and active treatment.