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Types of Toxicants. Classification based on particular effects on health. Carcinogens. Chemicals or types of radiation Cause cancer - uncontrolled cell growth Greatest # of cancer cases is thought be related to carcinogens in cigarette smoke. Mutagens. Chemicals or types of radiation
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Types of Toxicants Classification based on particular effects on health
Carcinogens • Chemicals or types of radiation • Cause cancer - uncontrolled cell growth • Greatest # of cancer cases is thought be related to carcinogens in cigarette smoke
Mutagens • Chemicals or types of radiation • Cause mutations in DNA sequence • E.g. UV rays, x-rays, nitrous acids
Teratogens • Chemicals • Affect the development of human embryos in the womb • Cause birth defects • e.g. thalidomide – morning sickness pill in ‘50s cause severe birth defects.
Allergens • Over-activate the immune system, causing an immune response when it is not necessary. • e.g. asthma is thought to be a response to synthetic chemicals that are more prevalent in our environment.
Neurotoxins • Chemical • Attacks the nervous system - coordinates action and transports signals • e.g. heavy metals; lead, mercury (fish), cadmium, some pesticides, chemical weapons, etc.
Endocrine Disruptors • Chemicals that interfere with the endocrine system • Hormone system: messenger molecules that serve vital functions; • stimulate growth, development and sexual maturity, • regulate brain function, appetite, sex drive, other physiology and behavior