types of toxicants classification based on particular effects on health
TRANSCRIPT
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