Smog. Im pretty sure smog is the only unhealthful air pollution on this list.
Why can’t you just write a paragraph?
There is an electrical gradient and there is a concentration gradient.
1.) Chemical gradient better known as concentration gradient is much more powerful and compelling than the electrical gradient.
2.) Water is a polar molecule, meaning one side it positively charged while the other is negatively charged. This polar charged molecule causes water to have a weaker electrical gradient, thus the water has to move on its concentration gradient.
