Question

list two major harmful effects of each of the following: (i)Rivers contaminated with sewage (ii)Too much gaseous exhausts containing CO2 and SO2 (iii)Pesticides such as DDT used in agriculture (iv)Prolonged noise such as the one produced by crackers

Answer 1

when rivers are contaminated with sewage the animals living in rivers will die due to harmful substances. when the contaminated water is supplied to agriculture the agriculture will get spoil.
when too much harmful gaseous are released into atmosphere it leads air pollution and people will get respiratory problems.
the use pesticides will cause a severe affect to agriculture
when a lot noise is released it causes noise pollition and people may suffer with haering problems.

Answer 2

river contaminated with sewage is a major problems for peoples who are living across the river side...
some problem are:
it is polluting the river water, which is harmful for boths humans and animals..
also, creating big problems for the society...