Now to something most of us probably take for granted, thinking we live in a clean green part of the world and believing we are surrounded by fresh air.
But are we?
Dr Joel Rindelaub from the University of Auckland is an analytical chemist who specialises in air quality and environmental research.
From plastic particles to illicit drugs - he says many people would be surprised by what they're actually breathing in. Air pollution is the number one environmental threat to human health worldwide and he says New Zealand isn't exempt.