Essentially a cyanide derivative or some other cellular poison- It affects all fast growing cells. That includes all the hair follicles and epithelial lining of the intestinal tract (from mouth through stomach, small intestine and large intestine) and includes the lungs (same kind of cellular tissue). Chemotherapy is treated as a poison by the liver-the liver has the lungs and skin as backup organs of excretion (see Bernard Jensen).
Furthermore, chemotherapy interrupts the production of mucous-the slippery fluid in the lining of the lungs. There is more on this in the literature but I have to find it. About Radiation of the breasts: An oncologist explained that radiation of her breast, for breast cancer, would leave her skin burned and her lungs scarred.
Chemotherapy that can cause lung damage.
Interferon alpha, Carmustine, Lomustine, Bleomycin, Docetaxel. source
See our cancer page.