一些人喜欢用铅笔写东西,特别是小学生常用铅笔写作业。有的人有个坏习惯,就是每当思考时喜欢咬铅笔头或用舌头添铅笔尖。这样做既不卫生,又容易引起铅中毒。铅笔含毒量达25%,铅是重金属有毒物质。当你把铅笔一端放入口中时,便感到一种怪味,这就是铅的味道。这种习惯日积月累就容易引起铅中毒。铅中毒轻的易产生面色萎黄、头昏无力、精神萎靡、食欲 Some people like to write things with pencils, especially for primary school students who use pencils for writing. Some people have a bad habit, that is, whenever they like to bite the tip of a pencil or tongue tip pencil. It is neither hygienic nor prone to lead poisoning. Pencils toxic content of 25%, lead is a heavy metal toxic substances. When you put one end of a pencil into your mouth, you feel a strange smell, which is the taste of lead. This habit can lead to lead poisoning over time. Lead poisoning easy to produce pale complexion, dizziness, apathetic, appetite