Chronic adverse affects may include carcinogenesis, teratogenesis, mutagenesis and reproductive toxicity. Carcinogenesis means the production of malignant tumors. Oncogenesis is a generic term meaning the production of tumors which may or may not be carcinogenic. The terms tumor, cancer, or neoplasm are all used to mean an uncontrolled progressive growth of cells. Carcinogenic or oncogenic substances are substances which can cause the production of tumors.
Examples are asbestos and cigarette smoke.
Teratogenesis Teratogenesis is the production of birth defects. A teratogen is anything that is capable of producing changes in the structure or function of the offspring when the embryo or fetus is exposed before birth. An example of a chemical teratogen is the drug thalidomide which caused birth defects in children when their mothers used it during their pregnancy. Measles virus infection during pregnancy also has teratogenic effects. Mutagenesis Mutagenesis is the production of changes in genetic structure.