APES Chapter 17 Test Review

Be able to calculate the 1/2 life of chemicals and how much will remain after a designated period of time.

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Draw and label all pertinent information on a dose-response curve?

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In developed countries what is the best way to reduce risk of disease?

By being healthier, such as, exercising and eating better.

What is a carcinogen and give an example?

A carcinogen is a chemical that causes cancer. Some examples are asbestos, radon, formaldehyde, and the chemcials found in tobacco.

What is a teratogen and give an example?

A chemical that interferes with the normal development of embroyos or fetuses. An example would be one of the most infamous teratogens known as the drug thalidomide, which was prescribed to preganant women during the late 1950s and early 1960s to combat morning sickness. Sadly, thousands of these mothers around the world gave birth to children with defects before the drug was taken off the market in 1961.

What is a retrospective study and when would it be used?

A retrospective study is a study that monitors people who have been exposed to an environmental hazard at some time in the past. These studies can be used to see if surviviors of an hazardous event have developed any additional health problems, such as in the accidental release of methyl isocynanate gas in Bhopal, India. In the studies scientists identify a group of people who have been exposed to the chemical and a second group of people who have not been exposed to the chemical. This study falls under epidomology and helps in understading the causes of illness and disease in human and wildlife populations.

What are the basic facts and characterisitics of HIV/AIDS?

AIDS is an infectious disease caused by HIV. HIV is a type of virus that causes AIDS. Aids are responsible for a weakened immune system. The HIV virus spreads through sexual spreads through sexual contact and blood transfusions, from mothers who pass it on to their fetuses, and among drug users who share unsanitized needles. The origin of this new disease was a mystery until 2006 when researchers found a genetically similar virus in wild chapanazees living in Cameroon. The reaserachers hypthized when butchering or eating the chimpanazees, the exposure the hunters faced made the virus able to infect a new hist, humans. New antiviral rugs are able to maintain low HIV populations inside th ehuman body and therby extend life. Due to the cost though, many in low-income areas cannot afford them.

What is an acute study and how is it different from a chronic study?

An acute study is an experiment that exposes organisms to an environmental hazard for a short duration. While a chronic study is an experiment that exposes organism to an environmental hazard for a long duration.

What is an allergen and give an example.

An allergen is a chemical that causes allergic reactions. Some examples are the chemicals naturally found in peanuts and milk and several drugs in penicillin and codeine.

What is the difference between an acute and chronic disease? Give an example of each.

Acute diseases rapidly impair the functioning of a person's body, For example, the Ebola hemorrhagic fever. Chronic diseases slowly impair the functioning of a person's body. Heart disease and most cancers, for example, are chronic diseases that develop over several decades.

What makes something an infectious agent and how can you lower the risk?

An infectious disease occurs when it passes from person to person. You can lower your risks by washing your hands and staying away from sick people.

What characterizes something as an emergent infectious disease?

An infectious disease that has not been previously described or has not been common for at least 20 years.

What are environmental hazards.

Anything in the environment that can potentially cause harm.

How can antibacterial soap be a problem?

As of 2014, there are more than 2000 antiseptic cleaners being sold including a large number of antibacterial soaps, these products typically kill a large proportion of harmful pathogens, but not all of them. As a result of our efforts to wipe out pathogens, we are inadverdently selecting for pathogens that possess a stronger resistance to our efforts.

How are biomagnification and bioaccumulation different?

Bioaccumulation is an increased concentration of a chemical within an organism over time. Biomagnification is the increase in chemical concentration in animal tissues as the chemical moves up the food chain.

Which virus most likely originated in fruit bats?

Ebola virus

Which virus most likely originated in monkeys?

Ebola virus

In developing countries what is the best way to reduce risk of disease?

Having better water sanitation and washing your hands.

What were the effects on agriculture due to Bovine Spongiform Encephalitis?

In 1996, scientists in Great Britiain anncounced that mad cow disease also known as Bovin Spongiform Encephalitis could be transmitted to humans who ate meat from infected cattle.

What are the facts and characterisitics of bird flu?

In 2006, reports emerged from Asia that a virus related to the swine flu, known as 5HN1 or bird flu had jumped from birds to people, primarily to people who were in close contact to birds. Infection are rarely deadly to wild birds but can frequently cause domesticated birds such as ducks, chickens, tuerkeys to become very sick and die. Human often contract a variety of flu viruses. Because humans have no evolutionary history with the H5N1 virus they have few defenses against it. Currently the H5N1 virus is not easily passed among people but if a future mutation makes transmission easier, scientists that H5N1 has the potential to kill 150 million people.

How are the leading causes of death in developed countries different from developing countries?

In developing countries, its based on sanitation , low nutrition and infections. While in developed countries its based on one's lifestyle, such as, tobacco use, inactivity, obesity and urban air pollution.

What are the basic facts and characteristics of malaria?

Is caused by an infection from any one of several species of protists in the genus Plasmodium and its another widespread disease that has killed millions of people over the centuries. The malaria parasite spends one stage of its life inside a mosquito and another stage of its life inside a human. Infections cause recurrent flulike symptoms. The hardest hit regions are the Middle East, sub-Saharan Africa, Asia and Central and South America. The traditional approach to combating malaria was widespread spaying of insecticides such as DDT to eradicate the mosquitoes. Eradication efforts have proven to be ineffective in many parts of the world. The widespread use of many insecticides can also create new problems.

What are the basic facts and characterisitics of tuberculosis?

Its a highly contagious disease caused by a bacterium that primarily infects the lungs. Tuberculosis is spread when a person coughs and expels the bacteria into the air. The bacteria can persist in the air for several hours and infect a person who inhales them. Symptoms of an infection include feeling weak, sweating at night, and coughing up blood. As is the case with many pathogens, a person can be infected but not develop tuberculosis disease. Indeed, it is estimated that one-third of the world's population is infected with tuberculosis. Taking antibiotics for a year can easily treat most tuberculosis infections. 95 percent of all tuberculosis deaths occur in low and middle income countries and is the leading cause of death by disease in the developing world. In these countries, the medicines are not as available or affordable and those who receive the medicine sometimes do not take the prescribed dose for the full duration of time. When a patient stops taking the antibiotics before the last bacteria have been killed, there are two consequences. First, the pathogen can quickly rebuild its population inside the person's body. Second, because the last few bacteria are generally the most drug-resistant, stopping the antibiotics before the bacteria are eradicated selects for drug-resistant strains. Such strains are harder to kill and therefore require newer antibiotics that can cost 100 times more than the traditional drugs.

What is the innocent until proven guilty principle and when is it used?

Its a principle based on the belief that a potential hazard should not be considered an actual hazard until the scientific data definitely demonstrates that it actually causes harm. This strategy allows benficial chemcials to be sold sooner.

What is REACH.

Its an acronym for registration, evaluation, authortization and restrictions of chemcials. It describes the 2007 agreement among the nations of the European Union about regulation of chemicals.

What is qualitiative environmental risk management and give an example?

Judgements based on our perceptions and not on acutal data. An example is when we choose to slow down on a wet highway or to buy a more expensive car because we feel it is safer.

How are LD 50 and ED 50 different?

LD50 is the lethal dose of a chemical that kills 50 percent of the individuals in a dose-response study. ED50 is the effective dose of a chemical that causes 50 percent of the individuals in a dose-response study to display a harmful, but nonlethal effect.

What disease is linked to prions?

Mad cow disease

Which bacterium causes plague?

Plague is caused by an infection from a bacterium called "Yersinia pestis" that is carried by fleas.

What class of chemicals do heavy metals fall into?

Neurotoxins

What do neurotoxins do?

Neurotoxins are chemicals that disrupt the nervous systems of animals.

What has allowed people who are HIV positive to live longer?

New antiviral drugs are able to maintain low HIV populations and extend life.

Where can endocrine disruptors be found in the environment?

One huge profile example of endocrine disruptors in our environment is the group of reproductive hormones that can be found in wastewater. Wastewater may contain hormones from a variety of sources including animal treating facilities, human birth control pills, pesticides that mimic animal hormones. In waterways exposed to hormones through wastewater, scientists are increasingly finding that male fish, reptiles, and amphibians are becoming feminized, males possess testes that have low sperm comunts and in some cases, testes that produce both eggs and sperms. Males normally convert the female hormone estrogen into the male chemical testosterone. Reproductive hormones in wastewater can interfere with the production of testosterone which causes males to have higher concentrations of estrogen and lower concentrations of testesoterone in their bodies.

What kind of judegments do most people make?

Qualitative judgements.

What is risk management?

Risk management is the third step of the risk-analysis process and it seeks to balance possible harm against other considerations. Risk management intergrates the scientific data, on risk assessment and the analysis of acceptable levels of risk with a number of additional factors including economic, social, ethical and political issues.

What are the basic facts and characterisitics of Ebola?

The Ebola hermorrhagic fever is an infectious disease with high death rates, caused by the ebola virus. It was 1st discovered in the Democratic Republic of the Congo near the Ebola river. Infections have been sporadic since its discovery and its of a particular concern because it kills a large percentage of those infected. Those infected begin to quickly experience fever, vomiting and sometimes internal and external bleeding. Death occurs within 2 weeks and currently only experimental drugs are available to fight the virus. The natural source of the Ebola virus has been difficult to determine because the virus also kills other primates at high rates, leaving no primate hosts for the virus, primates are not a likey long term hosts for the virus. In 2013 researchers discovered however that fruit bats carried the Ebola virus and were likely the reservoirs species that spread the virus to primates.

Which international agreement came up with the dirty dozen of chemcials?

The Stockholm Convention

What does the Toxic Substances Control Act say?

The Toxic Control Act of 1976 gives the EPA the authority to regulate many chemicals, but does not include food, comestics and pesticudes.

When looking at a dose response curve, how do you determine the threshold?

The dose at which an effect can be detected is called the threshold.

How are the precautionary principle and the innocent -until-proven-guility principle different?

The innocent until proven guilty principle is based on the belief that a potential hazard should not be considered a real hazard until the scientific data definitively demonstrates that it actually causes harm. In contrast, the precautionary principle is based on the belief that when a hazard is plausible but not yet certain, we should take actions to reduce or remove the hazard. The plausibility of the risk cannot be speculation it must have scientific basis.

What does chemical persistence refer to?

The persistence of a chemical refers to how long the chemical remains in the environment. Persistence depends on a number of factors including temperature, pH, whether the chemical is in water or soil and whether it can be degraded by sunlight or broken down microbes.

What is the route of exposure?

The way in which an individual might come into contact with an environmental hazard.

What are the basic facts and characterisitics of west nile virus?

The west nile virus lives in hundreds of species of birds and is transmitted among birds by mosquitos. Although the virus can be highly lethal to some species of birds, most birds survive the infection. During the latter half of the 20th century there were increasing reports that the virus could sometimes infect horses and human who had been bitten by mosquitos. In humans the virus causes an inflammation of the brain leading to illness and sometimes death.

Where do we find fat-soluble chemicals in the environment?

They can be found in higher concentrations bound to soils, including the benthic soils that underlie bodies of water. They can also become stored in the fatty tissues of animals.

Why all the worry about mosquitos?

They carry diseases and can spread them to people when they bite people.

How do scientists assess the risks of chemicals?

To assess the risk a chemical posess, we need to know the concentrations that cause harm. Scientists have three techniques to determine harmful concentrations: dose-response studies, prospective studies, and retrospective studies.

How do scientists use LD 50 to determine safety of chemicals for humans?

To compare the harmful effects of different chemicals scientists measure the LD50, which is an abbreviation for the lethal dose that kills 50 percent of the individuals in a dose-response study. The LD50 value helps assess the relative toxicity of a chemical to a particular species. For example, scientists can compare the LD50 value of a new chemical with the LD50 value of thousands of previously testes chemcials to determine whether the new chemical is more or less lethal to a given organism than other chemcials.

Which risk to human health causes the most deaths?

Various types of diseases/infectious diseases.

What historical pandemic is caused by a virus? A bacterium?

Virus- The Spanish flu. Bacterium- The black plague.

When do prions become dangerous?

When they occasionally mutate into deadly proteins that act as pathogens.

How do synergistic effects make chemcials in the environment even more toxic?

When two risks come together and causes more harm than expected based on the separate effects of each risk alone.