1. disease-causing agent non-infectious

2. an animal or insect that is known to transmit a specific disease pathogen

3. white blood cells that eliminate the chances of infection vector

4. non-communicable; cannot be spread through casual contact phagocytes

exposure to hazardous carcinogens and toxic substances can cause breathing problems, such as copd and various types of cancer. it also increases the risk of heart attacks and strokes and has serious (but no less unattractive) side effects, such as aging, yellow teeth, a terrible smell and damage to the vocal cords.