>> Air pollution

Depending on how long you are exposed,  air pollution it can make it
harder to breathe,Irritate your airways and lungs, 
Worsen chronic diseases
(heart disease, chronic bronchitis, emphysema and asthma)
Each person reacts differently to air pollution.
The best way to protect yourself is : 
1.Wear a mask
2.reduce your exposure to air pollution
3.Establish the correct value ,which means that use the gas transmitter
continuously monitor the air pollutant content 
of the atmosphere
(PM2.5, CO, CO2.and so on) keep your air quality in right value.