1)pH in our digestive system
When our stomach has excess of acid it causes indigestion which produces pain and irritation .In order to cure indigestion, we can take bases called antacids which neutralizes the excess acid and reduces PH of stomach
2)pH change as the cause of tooth decay
If the Ph of our mouth falls below 5.5. This is because then the acid becomes strong enough to attack the enamel of our teeth and corrode it. This sets in tooth decay. The best way to prevent tooth decay is to clean the mouth thoroughly after eating food.
3)Plants and animals are sensitive to pH change
Most of the plants grow best when the pH of the soil is close to 7.If the soil is too acidic or basic, the plants grow badly or do not grow at all.