Question

Give reasons for the following statements.(i)Cloudy, dusty and humid nights are warmer than the clear, dust free, dry nights.(ii)Radiation kills the cancer cells.(iii)Thermal pollution of water is harmful for aquatic animals.(iv)Nitrite poisioning may be fatal in children.(v)Noise is also a pollutant.

Answer 1

(i) Clouds and dust particles can produce green house effect. This is the reason why cloudy, dusty and humid nights are warmer than the clear, dust-free and dry nights.
(ii) Radiation kills the cancer cells because cancer cells are of actively growing type and thus are destroyed by radiation.
(iii)Warm water can hold much less dissolved oxygen than cold water. Also, rise in temperature speeds up animal metabolism, increasing $O_2$ requirement thus further aggravating $O_2$ problem for. aquatic animals.
(iv) Nitrate pollutant in drinking water is reduced.
In the stomach to nitrite; the latter combines with hemoglobin and reduces its oxygen carrying capacity. In this way, nitrite poisoning may prove fatal in children.
(v) Unpleasant sound may impair power of hearing as well as general health of human.