White blood cells (WBC) are involved in immune responses of the body against any type of infection. These cells fight the infection by killing the pathogens, stimulating inflammatory responses and /or by the formation of antibodies to kill the antigens. Hence, when an infection occurs, the WBC count of blood increases. Since red blood cells are involved in oxygen and nutrient supply, they have no role in immune responses.
For the environmental risk, it is much better to prevent pollution than to deal with it after it has already been made. When you deal with the pollution, it is hard to say that you can eliminate completely. So, prevention is the first strategy.
