Lecture 18: Human health Flashcards
what are the leading environmental problems that humans face?
- air and water pollution are the main ones
Describe the kinds of heath threats to humans
- physical threats : risk of injury, frostbite, etc
- chemical threats: harm caused by substances due to their chemical makeup
- biological threats: threats posed by pathogens that cause disease
What are communicable and non-communicable diseases?
- communicable: can be transferred between people
- non-communicable :disease cannot be transferred between people
How do human actions and environmental factors contribute to the spread of infectious disease?
- infectious disease (including zoonotic) threaten many groups of people
- human modification of the environment can facilitate spread (warmer weather pests live longer, rat infestations, waste disposal, sanitation, , high population density and globalization)
What is public health?
- branch of science that deals with the health of human populations
What is an epidemiologist?
- researcher who studies patterns and trends of disease in human populations
- performs data analyses to identify specific health threats that may effect groups of people, and makes recommendations to mitigate those threats
What is environmental health?
branch of public health that focuses on how the natural world and human built environments impact the health of populations
- focuses on water, air, soil contamination
- also focus on human behaviour: hand washing, drinking water
What do public health programs do?
- educate, propose action plans, conduct risk analysis, provide health care
What are toxins? What are chemical hazards?
- substances that cause damage when the contact / enter the body
- chemical hazards are chemical that have toxic properties
What are the factors that determine toxicity?
- potency: how much is required to cause harm
- persistence: how resistant it is to desiccation / how long it takes to break down
- solubility: whether its fat or water soluble
What are acute and chronic effects?
- acute: immediate harm upon short term exposure
- chronic: harm after long term exposure to small amounts
How can toxicity be determined?
- both observational and experimental data is needed
- LD50: the amount required to kill 50% of test population
- dose response studies: evaluate the response to different levels of dosage
What is a safe dose?
- uncertainty in the determination of a safe dose, so often it is increased by a factor of 100, or 1000, to ensure we are on the safe side
What is NOAEL and LOAEL?
NOAEL: No Observed Adverse Effect Level
- the highest dosage that has no adverse effect
LOAEL: lowest observed adverse effect level
- the lowest dose that causes adverse effects
What is the difference between fat soluble and water soluble? Which is more harmful?
- fat soluble: more complex, can get through cell membrane and fatty tissue builds up long term in body
- leads to bioaccumulation and biomagnification
- water soluble: can be processed and excreted in the urine
What is environmental justice?
- the concept that access to a healthy, clean environment is a basic human right
where is cancer mortality shown to be the greatest?
- in black, impoverished, industrialized communities
What are some risk factors associated with higher cancer rates?
- economic status, genetics, UV exposure, smoking, obesity, drinking, air pollution
