Question: why are there bad things/chemicals in the world

Claire Bryer answered on 23 Jun 2015:

Many nasty chemicals can be formed as a product of reactions that are useful.
For example when we burn fuel (petrol) when driving a car, it produces nasty gases that actually warm up our planet and are harmful for our lungs. We still drive around because we need to go places.

But a lot of nasty chemicals already existed in the world, before we changed anything. We have co-evolved with the environment and we have developed special ways of getting rid of the bad stuff, so you shouldn’t worry too much!! Our body can cope with quite a lot. Our liver is the organ that removes all these chemicals so they do not harm us. You can limit your exposure to the horrible chemicals by not smoking, not drinking and living in a countryside environment (cities can be ‘smoky’, and so your life expectancy is actually slightly lower if you live in a city!)