They did not die “from pollution.” The cause of death would have been cardiovascular disease, cancer, pneumonia, hepatitis, AIDS, tuberculosis. Even poor working conditions are a huge contributor to an early death in developing nations, where the employees breath in toxic fumes or dusts. For what it’s worth, smoking is also popular in India.
I’m not saying polluted air is not a contributing factor, but crowded, impoverished, third world countries have a lot of issues that all contribute to diminished health.