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.
Confidence votes 53. Not all polymers are bad. In fact humans are made up of polymers. But polymers from sources such as crude oil synthesized into plastics release toxins as they break down.When you burn plastics synthesized from crude oil feedstock, carbon dioxide and dioxins can be released into the air if smoke is not properly filtered as they are in high quality waste-to-energy incinerators.lthough natural polymers do not affect the environment, synthetic polymers do. Synthetic polymers are anythi â¦ ng that is manufactured or influenced by humans. Due to this, these types of polymers release reactants which are hazardous; both to humans and the environment.