See these three samples of air filter that I use for cycling to work everyday. The lower two shown a baaadd pollution mark while the top one is freshly open from the plastic bag. I’ve tell you that pollution in Jakarta is worse than I thought, and this is one of the example. This is also the reason why I wear that funny looking pollution mask everyday. A friend of mine also suggest me to take a same amount of vitamin E and C everyday to help balance my body. Scary, imagine that toxic stays in your lunges!