One possible version:

With the air pollution becoming more and more serious, our living environment is getting worse and worse．People can hardly breathe any fresh air．They have to wear masks when they go out．To make things worse, millions of people die from illnesses related to air pollution every year．So I think that something must be done to change the situation before it is too late．For example, we can close down some factories that send out too much smoke．Besides，we can limit the number of cars running on the roads．Only in this way can we hope to have a clear sky and bright sunshine in the future．