In linguistics and grammar, a pronoun (abbreviated PRO) is a word that substitutes for a noun or noun phrase. It is a particular case of a pro-form.
Some of the most significant toxic effects associated with substances used or emitted in plastic production include: 13. 1  Benzene (PET, PVC, LDPE, PP): known human carcinogen, workplace exposure depresses the nervous system. 2  Chromium oxide (HDPE, LDPE): suspected carcinogen, damaging to the liver and nervous system.ome of the most significant toxic effects associated with substances used or emitted in plastic production include: 13. 1  Benzene (PET, PVC, LDPE, PP): known human carcinogen, workplace exposure depresses the nervous system. 2  Chromium oxide (HDPE, LDPE): suspected carcinogen, damaging to the liver and nervous system.
Benzene is released in the burning of above materials, so automobile exhaust, factory emissions contain them. Benzene is said to be carcinogenic, so exposure to high levels of benzene can cause cancer.