Which is more dangerous to human body, second-hand books or pirated books?

Pirated books are more harmful to human body. Pirated books have problems in spelling, grammar, translation and so on, and even omit or tamper with the original content, which leads to misunderstanding and misunderstanding of readers, thus affecting the reading effect and learning effect. In addition, pirated books use low-quality paper and ink and contain harmful chemicals, such as lead and mercury, which pose a potential threat to readers' health. In contrast, although second-hand books have been read and used many times, they are intact and will not cause harm to the human body. Moreover, the price of second-hand books is low, which can provide readers with an economical choice of buying books. So pirated books are more harmful to human body.