Midterm 1 Flashcards
What is environmental toxicology?
- study of adverse effects of pollutants upon the structure and function of ecological systems
What is toxicology?
- the study of adverse effects of chemical/ physical agents on living organisms
What are DDT and DDE?
Persistent pesticide/metabolite
Who still uses DDT and why?
- India (for malaria control)
- China (exported till 2008)
- Sub-Saharan Africa (malaria and public health)
- Korea (agriculture and public health)
What are POPs?
-persistent organic pollutants
What is biomagnification?
-organisms higher in the food chain accumulate higher levels of chemicals/toxic ants than those lower down in the food chain
What are some commonalities of global problems?
- often involves one or several chemicals
- have major impacts on the environment
- lack of effective/precautionary management
- due to anthropogenic activities
What are some pollutants?
-pesticides, pharmaceuticals, detergents, household products, plastics, mining and metals, textile mills etc.
Why are risk assessments conducted?
-to establish ‘safe’ limits of exposure
Why do we normally look at individual level effect?
-difficult to assess what effects an entire population
What is a contaminant?
- a chemical that exists at levels above those that normally occur in any component of the environment
- may or may not cause environmental harm
What is a pollutant?
- a chemical that exist is at levels above those that normally occur in any component of the environment
- cause environmental harm (eg. Pesticide)
What is a toxicant?
- any chemical/agent that has an adverse effect in a living organism
- not made by plants or animals
What is a xenobiotic?
-any chemical foreign to a living organism
What is a toxin?
A xenobiotic of natural origins
What is ecotoxicology?
- specialized area within environmental toxicology and within ecology
- includes all organisms, except humans
What is environmental toxicology?
- study of the impacts of pollutants upon the structure and function of ecological systems
- includes all organisms
What info is required to determine organism effects of xenobiotics?
- Fate and transformation in organism
- Interaction of xenobiotic with site of action
- Impact on whole organism’s health
What is an Ecological Risk Assessment (ERA)?
Combination of analysis and inference of possible consequences of the exposure to a particular agent based on knowledge of the dose-effect relationship with that agent in a particular organism, system or (sub)population
What is an adverse effect?
Abnormal, harmful, unwanted effect that can be defined in terms of a specific biological response
What are some ecotoxicology effect analyses at a population level?
- species abundance (reduction if endangered, increases if invasive)
- reproductive success
- alterations in genetics
- likelihood of extinction
What are examples of ecotoxicology effect analyses at the community level?
- biodiversity changes
- reductions/increases in community structure
- species abundance/dominance
- predator/prey interactions
What is the definition of risk?
Likelihood that a hazardous material will cause harm to humans or the environment
What two factors increase/decrease risk?
- Hazard: harm that something will cause
2. Exposure: extent organism/environment is subjected to the hazard
What does the Ecological Risk Assessment (ERA) do?
Assesses the probability of a given adverse effect as a result of a human activity
What are the questions in a risk assessment?
- Which concentration do we find in the environment? In which ecosystems and in which parts of the ecosystem?
- Could these concentrations cause any harm?
- What is the relationship between dose/concentration and effect?
- When we characterize the relationship between probable concentration in the different parts of the environment and the corresponding effects, what is the risk for a harmful effect?
- Should we and could we reduce this risk?
What is bioavailability?
Proportion of the toxicant that enters the organism and is therefore able to have an effect