Final Exam Flashcards
(100 cards)
toxicant
a toxic substance or poison that can be man-made or natural
toxicity
the degree of harm a chemical substance can inflict
toxins
toxic chemicals manufactured in the tissue of living organisms/naturally made in plants and animals
ex: snake venom
environmental toxicology
deals specifically with toxic substances that come from or are discharged in our environment
what are the four types of environmental hazards?
physical, chemical, biological, and cultural
physical hazards
arises from processes that occur naturally in our environment and pose risks to human life or health
ex: UV rays from the sun that cause skin cancer
chemical hazards
include many of the synthetic chemicals that humanity manufactures
ex: pharmaceuticals
biological hazards
result from ecological interactions among organisms
ex: mosquitoes causing diseases
cultural hazards
hazards that result from your place of residence, the circumstances of your socioeconomic status, you occupation, or your behavioral choices
ex: choosing to smoke cigarettes
what are hormones?
chemical messengers in the body that are produced in small quantities
how do hormones work?
receptors and hormones connect together which then tells the body to do a certain action
how can an endocrine disruptor disrupt the normal behavior of hormones?
endocrine disruptors mimic hormones when they connect to receptors and they then block and mimic those hormones
carcinogens
substances or types of radiation that cause cancer
mutagens
substances that cause genetic mutations in the DNA of organisms
- cause irreversible change in your DNA
teratogens
chemicals that cause harm to the unborn
- cause birth defects in the embryo
neurotoxins
chemical toxicants that assault the nervous system
ex: snake venoms, mercury, lead
allergens
over-activate the immune system, causing an immune response when one is not needed
endocrine disruptors
toxicants that interfere with the endocrine system
- affects and controls growth, development, sexual maturity, regulate brain function
examples of endocrine disruptors and their effects?
BPA- mimics estrogen and can interfere with basic bodily functions
Phthalates- cause males to become more feminine, females to become more manly, alters the development of genitals, and affects sperm count and quality
how do scientists understand the hazardous effects of toxicants?
- field observations
- natural tests
- manipulative experiments
LD 50
lethal dose- the amount of toxicant required to kill 50%of the subjects
ED 50
effective dose- the amount of toxicant required to effect 50% of the subjects
threshold dose
the smallest dose of radiation that will produce an effect
dose-response curve
it correlates the dose exposure with the changes in the human body/health that is then plotted on a graph