geog140 ch 4 study guide

why are public water supplies monitored for fecal coliform bacteria despite the fact that most strains of E. coli do not cause disease?

E. coli is the best indicator of sewage-contaminated water because it doesn't appear in the environment except from human and animal feces

the _____ and ____ were amended in response to the need to test chemicals for their potential to disrupt the endocrine system

Safe Drinking Water and Food Quality Protection Act

which of the following was the banning of hormone treated and GMO fed beef by the European Union based upon?

The Precautionary Principle

what is a pandemic?

a global disease

which of the following would be considered an infectious disease-causing agent?

a pathogen

which of the following is an LD50 used for?

determine the toxicity of a chemical

which of the following would be a symptom of acute toxicity?

dizziness

Pollutants that interfere with the normal functioning of hormones are called:

endocrine disrupters

acute toxicity is adverse effects that occur after a long period of low-level exposure to a toxicant.

false

risk assessment involves all of the following EXCEPT

financial costs of the predicted risk

the most common method of determining whether a chemical causes cancer is to expose groups of laboratory animals, such as rats, to various large doses and count how many animals develop cancer at the different levels. All of the following are problems with this approach in terms of understanding the health risks to humans EXCEPT:

for ethical reasons, rats in lab settings are given very small doses of suspected carcinogens relative to body size whereas humans are usually exposed to much higher amounts

How does bioaccumulation occur?

ingested toxins-that are slow to be metabolized and excreted- are instead stored in the body

What are most of the POPs listed in the Stockholm Convention "dirty dozen" used for?

insecticides

Risk:

is the probability of injury, disease, death, or environmental damage under a given set of circumstances

chemical A has a toxicity level of 1 and chemical B has a toxicity level of 2. If a mixture of the two chemicals has a toxicity level of 4, what can we say about the results of the mixture?

it was synergistic

A dose that is represented as LD50 is a dose that:

kills half of the population of test animals

which of the following diseases is transmitted by mosquitoes?

malaria

a chemical substance that is extremely stable and takes years to break down into a less toxic form would be considered to be:

persistent

acute toxicity:

produces an effect within a short period of a single exposure

DDT was sprayed in a Long Island salt marsh over a period of years for mosquito control. A portion of the food webs is as follows: algae-shrimp-American eel-ring billed gull in which organism would biological magnification be MOST evident?

ring billed gull

the process of figuring out what to do about an identified risk is called

risk management

which of the following statements about dose-response curves is FALSE?

studies of the dose-response curves of toxicants gives us assurance that for all chemicals there is a threshold level of the chemical so small amounts of chemical pollution pose no health risks

which of the following statements about children and chemical exposure is true?

the LD50 values are lower for children than adults

a dose-response curve shows:

the effect of different doses on a population of test organisms

why were POPs singled out for regulation by the international community?

they bioaccumulate in organisms and they are highly mobile toxic chemicals

What can be inferred from the graph below?

all of the above can be inferred from the graph

which of the following statements about risk, risk assessment, and risk management is CORRECT?

all of the above statements about risk, risk assessment, and risk management are correct

which of the following action(s) may unintentionally contribute to outbreaks and rapid spread of infectious disease?

all of these choices

which of the following characteristics caused DDT to have such a devastating impact of birds of prey like eagles?

all of these choices