Which one of the following is not a bioindicator of water pollution?
Sludge-worms
Blood-worms
Stone files
Stone files
C.
Stone files
Stoneflies (e.g., Perla sp.) belong to order Plecoptera of class insecta which has the terrestrial mandibulates.
Limit of BOD prescribed by Central Pollution Control Board for the discharge of industrial and municipal waste water into natural surface water, is:
< 3.0 ppm
< 10 ppm
< 100 ppm
< 100 ppm
Photochemical smog pollution does not contain
ozone
nitrogen dioxide
carbon dioxide
carbon dioxide
Which one of the following statements is not valid for aerosols?
They are harmful to human health
They alter rainfall and monsoon patterns
They cause increased agricultural productivity
They cause increased agricultural productivity
Montreal Protocol which calls for appropriate action to protect the ozone layer from human activities was passed in the year
1986
1987
1988
1988
