Page 35 - Science Class 08
P. 35

v The lightweight nature of plas cs can also          gases as they burn. Besides, we need very high
                  be  a  problem  because  plas c  waste,  such     temperatures  in  incinera on  to  break  down
                  as  polythene  sheets,  can  be  blown  about     some of the pollu ng gases.
                  and  le   caught  in  trees,  bushes  and  in
                                                                    For  example,  most  of  the  plas cs  give  off
                  water bodies.
                                                                    Carbon  Monoxide  on  burning,  Polyurethane
              v Accumula on  of  plas cs  on  fields  blocks         gives  off  Hydrogen  Cyanide  (HCN)  and  PVC
                  the  soil  and  hinders  the  absorp on  of       gives off Hydrogen Chloride (HCI) on burning.
                  water by the soil.
                                                                    Burying
              v Some  animals,  especially,  ca le  eat  away
                  plas cs which can kill them.                      Plas c wastes can also be used for landfill. This
                                                                    is  a  quicker  method  but,  it  may  effect  the
              v Plas c  bags  can  also  contaminate  food          fer lity of the soil.
                  stuff  because  of  poisonous  dyes  ge ng
                  absorbed into food.                               Role  of  individuals  in  tackling  the  problems
                                                                    caused by plas cs:
              Disposal of Plas c Waste
                                                                    v People  should  use  bags  made  of  jute  or
              You already know about how plas c wastes are
                                                                        paper  in  place  of  polythene  bags  for
              causing  severe  damage  to  our  environment.
                                                                        shopping.
              Therefore, proper disposal of plas c wastes is
                                                                    v People should promote recycling schemes.
              very much important.
                                                                    v We  should  not  throw  plas cs  here  and
              Let’s know some processes:
                                                                        there or in the sewage system.
              Recycling
                                                                    v Plas c  wastes  should  be  collected  in  a
              This  is  the  best  way  to  get  rid  of  the  plas c
                                                                        separate dustbin.
              wastes.  In  this  method,  plas c  wastes  are
                                                                    v Plas cs  wastes  should  not  be  burnt  in
              collected,  sorted,  chopped,  melted  and  then
              removed. It means discarded plas cs are used              open.
              in industries to make fresh plas c products.



                                                                      1. Name  any  three  natural  and  man-made
                                                                         fibres.

                                                                      2. What  is  the  main  advantage  of  ar ficial
                                                                         fibres?
                                                                      3. What is synthe c material?

                                                                      4. Name any four natural polymers.
                                                                      5. What are the two types of plas cs?

                               Logo of Recycling                      6.  Write any five ar cles made up of plas cs.
              Incinera on                                             7. Why the containers made of plas cs are
                                                                         useful for storing food items?
              Burning  of  plas c  wastes  is  another  way  of
                                                                      8. Why  is  it  difficult  to  dispose  off  plas c
              their  disposal.  But,  this  method  causes  air
                                                                         wastes.
              pollu on.  Many  plas cs  produce  poisonous

              Science-8                                                                                          35
   30   31   32   33   34   35   36   37   38   39   40