I recently read about air quality issues around the globe and became really concerned about the most polluted cities in the world. It seems like some places have dangerously high levels of PM2.5 and other pollutants. I am curious about which cities are the worst offenders and what causes their pollution. Is it mostly traffic, factories, or other factors? I am also interested in how the residents cope with this every day. Do they use masks, air purifiers, or try to stay indoors? I feel like this is a problem that needs more attention globally. 
Has anyone lived in or visited these cities and noticed the effects firsthand? Are there specific measures that have helped reduce pollution in these urban areas? I want to understand both the statistics and the real human experience. How does pollution affect daily life, health, and the environment? Any insights or stories would be really helpful.
From my experience, cities like Delhi and Beijing are often at the top of pollution lists. The main causes seem to be vehicle emissions, industrial activity, and sometimes weather patterns that trap pollutants. It is very noticeable when you are outside. Your eyes may water and breathing can feel heavy. People there often wear masks and use air purifiers at home to reduce exposure. I noticed that public awareness campaigns also play a role in helping people minimize health risks.
I lived in Jakarta for a few months and the smog was constant during certain seasons. The pollution comes mainly from traffic and nearby factories. Many people I met started wearing masks even when just walking to work. Indoor air purifiers are very common in apartments. I realized that even short walks outside can feel tiring due to the air quality. It is frightening how invisible pollutants can affect daily life.
Thank you, I will try to pay more attention to local air quality levels!
Mexico City is another example of a highly polluted urban area. I read that the government has introduced restrictions on vehicle use on certain days to reduce emissions. It helps somewhat, but during peak traffic hours, the air quality is still quite poor. People often carry portable air quality monitors to track PM2.5 levels. It is amazing how technology can help, but it does not fully solve the problem.
Air pollution is not only an Asian problem. Some cities in Eastern Europe and Africa also struggle. In cities like Krakow and Ulaanbaatar, coal burning for heating contributes heavily to smog in the winter months. I found that local authorities sometimes offer subsidies for cleaner fuels, but adoption is slow. Citizens have to be very proactive to protect their health.