I have been thinking about air pollution and I wonder how long it has been an issue for humans. I know it is a big problem today, but did it exist centuries ago or is it mostly a modern concern? How did people deal with pollution before industrialization? I have heard about smoke from coal in old cities and the problems it caused, but I do not know the full history. Has pollution always affected health and the environment or has it become worse only recently? I am curious about the timeline and what major events or developments made pollution a significant problem. Understanding this might help me see why solutions are urgent today. 
Pollution has been a problem for a long time, but it became much worse during the Industrial Revolution in the 18th and 19th centuries. Factories burning coal released large amounts of smoke and chemicals into the air, causing visible smog in cities like London. This period marked the beginning of widespread industrial pollution.
Before industrialization, pollution existed but was mostly local and smaller in scale. Fires for cooking, waste disposal, and small-scale metalworking released smoke and chemicals, but the overall impact on air quality and human health was limited compared to modern times.
I did not realize pollution was an issue even before modern factories. That is interesting!