What are the effects of air pollution?
Respiratory System
Air pollution worsens or can even lead to asthma or chronic obstructive pulmonary disorder (COPD, which mainly consists of bronchitis and emphysema). Pollutants also inflame and damage lungs, causing people to cough and have irritated throats, and, in extreme cases, cancer.
Cardiovascular System
Air pollution contributes to ischemic heart diseases, which include heart attacks and heart failure. It also causes blood toxicity and blood coagulation abnormalities.
Nervous System
Studies have linked air pollution to decreased brain functions, autism, Alzheimer’s, suicidal thoughts, ADHD, and premature aging of the brain, especially in children. It also hurts the autonomic nervous system, which controls the heart.
Reproductive System
PM2.5 causes placental blood toxicity, which can harm a fetus. It can also cause intrauterine growth retardation and low birth weight of babies, especially when PM2.5 exposure happens in the first month of pregnancy.

What are the levels of air pollution?
Level AQI Meaning Activity
Good 0 to 50 Air quality is considered satisfactory. Air pollution poses little or no risk. All activities OK.
Moderate 51 to 100 Air quality is acceptable; however some pollutants may affect unusually sensitive groups. Sensitive groups should reduce exertion outside.
Unhealthy for Sensitive Groups 101 to 150 Sensitive groups may experience health effects; increasing likelihood of respiratory symptoms in sensitive individuals, aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly. The general public is not likely to be affected. All groups should reduce prolonged exertion outside. Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
Unhealthy 151 to 200 Everyone may begin to experience health effects; sensitive groups may experience more serious effects. Increased aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; increased respiratory effects in general population. Avoid prolonged exertion outside. Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion.
Very Unhealthy 201 to 300 Health warnings of emergency conditions. The entire population is more likely to be affected. Significant aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; significant increase in respiratory effects in general population. Avoid all outdoor activities. Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion.
Hazardous 301 to 500 Health alert; everyone may experience more serious effects. Serious aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; serious risk of respiratory effects in general population. Remain indoors. Everyone should avoid all outdoor exertion.