You're using your personal experiences to validate a broad generalization regarding the effects of air pollution on rates of lung cancer for the population of an entire country; this is wrong. Your sample size is one and your argument is "I felt the fumes in my throat more when cycling then compared to when I was in a car; therefore it must be cancer". I appreciate that you actually had somewhat of a baseline, but your self experiment essentially tells you that exhaust fumes hurt your throat [full stop].