How are food and water shortage related to pollution

The water can be affected by point source pollution

water pollution is a huge problem especially when you're looking at areas that dont have good sewage system water pollution can be anything from oil to carcasses to chemical and lead to fecal matter
water pollution can involve food shortages. crop that grow food take water to grow. when water pollution takes hold that does not leave much water to irrigate crops. which means food does not grow which means their is no food which causes a food shortage

It was said to have happened by earthquakes, the shifts in the tectonic plates moved everything