Pollution and Effects

As an environmental health engineer, I think of pollution as anything not naturally found in water, air  or land that is present only as a result of human activity. 

Pollution may take any form (light, sound, odor, solids, liquids, gases, radiation, heat, etc).  Basically every single thing humans make from synthetic materials adds to the pollution of the planet unless all the ingredients are fully recycled.  (Almost everything sold in most stores is pollution, except water, plants, rocks and animals)

Nature also adds enormous quantities of pollution to Earth ecosystem annually, such as from volcanoes and wildfires.  

Some people would also count as pollution the introduction by humans of invasive species from one habitat into another, where that species "pollutes" the natural environment so badly that it decimates other species.
Pollution is derived from Latin word "polluere" which means to defile. Pollution is an undesirable change in the physical, chemical or biological characteristics of our air, land and water that can harmfully affect human life or that of other species, our industrial processes, living conditions and cultural assets. 
 In simple language, Any addition to air, water, soil or food & Noise that threatens the health and survival capabilities of humans or other living beings is known as pollution.

Pollution: n. adding poisonous chemicals to the environment in unnatural quantities which are harmful to lifeforms and this is frequently done by humans

The quantity of the pollution and the type of pollution should be considered when logically discussing pollution.

Some chemicals are only pollutants because there is too much of them around and they become threats to your health. An example is carbon dioxide which is a very reactive chemical. It does not pollute the environment because it quickly unites chemically with other substances and becomes inert or harmless. However, if you get too much of it or too great a QUANTITY into your lungs then you suffocate to death.

Government permitted pollution levels are frequently in parts per million in the air and parts per billion in the water and soil and this refers to the "safe" quantity limits of the pollutant.

Artificially created chemicals or drugs can be harmful to your health if they are not found somewhere in nature. The safest drugs are drugs extracted from plants or animals or those which are found in plants or animals and have been mass produced in the lab or factory. Because they are natural or part of nature there should be minimal fear but of course they can be unhealthy to your system if taken for too long or in too great a quantity. This is a reason why there are dosage limits and time limits for taking them.

If you are taking drugs not found in nature but those which are only produced artificially in the lab then you run the risk of ruining your metabolism in an unhealthy way either immediately with severe side effects or they can ruin your health in the long duration.

Artificial pesticides, herbicides, and fungicides made with chemicals not found in nature or those which don’t degrade in the soil or your stomach and intestines into harmless substances are true pollutants which should be outlawed.

GMO’s with bacterial genes inserted into them are unnatural pollutants with almost guaranteed long duration harm to your health. These kinds of genetically modified organisms can be successfully used in the mass production biologically of desired substances but they should never be a part of the food chain. Eating them will affect your present metabolism in a harmful way and even harm the genes of future generations of humans.

CONCLUSION:

Before you get paranoid about pollution remember to eat as much certified organic food as possible and if you occasionally ingest pesticides, herbicides, or meat gotten from growth hormones or antibiotics added to animal feed then you won’t immediately die and the effect on your long duration health and metabolism will be minimal.

Why are more humans dying of cancer than a hundred years ago? It doesn’t take much common sense to realize that the only significant thing which has changed is a polluted food and drink supply and the artificial prescription drugs which you are on!!!!!!

Source - Quara