ENVR 600 final

List three advantages of a septic tank over a public sewer system.

1. Although public sewer systems can cover wide areas, septic tanks are useful for areas that public sewer systems don't reach 2. Septic tanks return the water to the ground (reusable for the household) 3. More cost effective than public sewer systems

10. List and explain three advantages that renewable energy sources have (currently) over fossil fuels

1. Better public health: the air and water pollution emitted by coal and natural gas plants is linked to breathing problems, neurological damage, heart attacks, and cancer. 2. Less toxic to the environment (i.e. less CO2 emissions, less radioactive wastes, etc.) 3. Inexhaustible energy supply that is more cost-effecient

8. Name and briefly describe three major renewable energy sources in the Westernized world

1. Biomass uses renewable organic materials (i.e. wood, charcoal, crops, manure, waste) to produce energy either by being burned directly or processed into biofuels such as ethanol and biodiesel (used for transportation, etc.). 2. Solar- energy derived from the sun's radiation which can be used passively (i.e. allowing sunlight to enter windows) or actively (i.e. via solar water heating, photovoltaics, etc.). 3. Hydropower- production of electrical power through the force of falling or flowing water.

4. Why might an over-supply of food be a greater and more likely health threat globally than a shortage of food ? Suggest two reasons

1. Crops will most likely be genetically modified to be produced in such a large quantity. We still do not know the health effects of GMOs to this day. 2. An over-supply of food might lead to over-consumption and health effects like obesity and diabetes will show up in this populations in future years

2. Name and briefly explain three ways that urbanization has impacted food production (consider both quantitative and qualitative impacts

1. Demand of food production increased- as the population increased, the demand for more food at one time has led to a need to increase production 2. Decreased food quality- Because of population increase, the rise of industrial agriculture (and subsidies for staple crops) came about and hence a decrease in the quality of cheaper, processed foods that are available to the public 3. New agricultural technology- The need of more food in a faster period of time has led to the creation of new agricultural production methods and machines

5. Name and briefly describe two actions that could be taken to use our current food supplies more efficiently

1. Finding alternative feed sources- As cereal products are increasingly used as feed for livestock, finding alternative feed sources provides a huge potential for increasing the availability of cereal for human consumption 2. Revamp the energy budget- In the U.S., about 10 percent of the energy budget goes to producing, distributing, processing, preparing and preserving the plant and animal matter we consume

6. Name and briefly describe the three major uses of energy in the Westernized world

1. Industrial- energy used to manufacture various products. 2. Transportation- personal and public transportation uses gasoline fuel, diesel fuel, etc. to power their automobiles, trains, planes, etc. 3. Electric power- electrical power companies use various types of fuels (fossil, nuclear, or renewable) to produce energy for residential and commercial energy use (i.e. for lighting, electronics, etc.)

3. Name and briefly describe two factors that limit our ability to produce more food

1. Limitations of natural resources- like not enough ammonia (natural fertilizer) in the dirt, or running out of "clean" water which is used for irrigation. 2. Using the same farmland over and over has led to soil degradation and over-irrigation and has decreased the quality of farmland soil, leading to less farmable land availability.

9. List and explain three advantages that fossil fuels have (currently) over renewable energy sources

1. More portable form of energy: a company easily stores and transports the energy until it needs to be used, allowing fuel to be processed at a separate location and transported to wherever you need power. 2. Relatively lower cost: fossil fuel extraction is relatively cheap in comparison to the initial high investment cost of obtaining renewable energy. 3. Produce large amounts of energy- fossil fuels are easily combustible, allowing most combustion engines to be powered with little amounts of fuel to produce large amount of energy

7. Name and briefly describe the three major currently-used energy sources in the Westernized world

1. Natural gas- gas mixture consisting primarily of methane (CH4 ) which produces energy for mostly heating, cooking, and electricity generation. 2. Petroleum- used for crude oil, heating oil, propane, diesel, gasoline, helping to provide transportation, heating, electricity generation, etc. 3. Solid fuels- such as coal, coke, wood, charcoal, and peat used for electricity generation and heating.

2. Name and briefly describe a vector-borne disease for which the mosquito is a vector.

A vector-borne disease for which the mosquito is a vector is West Nile Virus. West Nile Virus' disease agent is Flavivirus and targets humans, horses, and the like

Name and give one example of the class of genes that cause mutated cells to proliferate

Activated (or proto-) oncogenes, like ras

Name and briefly describe one currently acceptable alternative method of disposal for human wastes that does not involve flushing into a sewer or septic tank.

Composting toilet or chemical toilet where waste if decomposed on location and can be used as fertilizer

What are the major causes of habitat degradation ?

Deforestation, overgrazing, over-cultivation, improper irrigation, climate fluctuation, desertification, soil erosion, pollution

7. Name a country which possesses high water resources per capita yet consumes well below the average amount of water per capita ? What characteristic(s) of this country do you think explains this pattern ?

Equatorial Africa- low industrialization and electricity generation, but abundant rainfall and agriculture needs little irrigation

Name and briefly describe two factors that have increased food production over the last two centuries

GMOs, or genetically modified organisms- organisms whose DNA has been altered to increase crop resistance to diseases, improved nitrogen utilization, herbicide tolerance and resistance, hormone regulation, and increased crop yield. 2. Monoculture- agricultural practice of producing a single crop species over a wide area

What is cancer

It is a condition where there is excessive cell growth that results in a mass or a tumor divided into a multi-step process of initiation, promotion, and progression. It invades other parts of the body and spreads to other sites, and is often fatal. It can be caused by a number of things including heredity, carcinogens, viruses, and environmental factors.

Name and give one example of a chemical that is known to affect the nervous system.

Lead - Learning disabilities, lowered IQ, higher impulsivity

Name and briefly describe two major sources for chemical contamination of drinking water

Lead- Lead contamination is almost always caused after the water leaves the purification plant. The older the house and whether or not the house has lead plumbing are warning signs. Lead exposure through drinking water can be prevented by not drinking water that has been in contact with pipes for more than 6 hours and not cooking with hot tap water (because of solubility). b. Arsenic- Arsenic is naturally located in minerals in the earth's crust, and is able to dissolute into groundwater. Most notably, Bangladesh is suffering a "nationwide arsenic poisoning" because wells were drilled into aquifers, without checking the water quality, and naturally occurring arsenic was exceeding the WHO limitations.

Name and describe briefly one notorious example of wetlands loss

Louisiana after Hurricane Katrina

Name and briefly describe a cancer that is much more common in some parts of the world than in others. What is thought to cause that type of cancer ? Why are there such differences in occurrence

Lung cancer is much more common in developed, industrialized countries of the northern hemisphere. Pollution and toxicants (smoking cigarettes) are thought to cause this type of cancer and they are typically seen as part of the lifestyle more in these countries than those in the southern hemisphere.

In what regions of the world is the demographic transition essentially complete

North America and Western Europe

3. In the context of the Food Chain, what type of consumers are (most) humans

Omnivores, top predators and primary producers

7. What are the main sources of human exposure to lead

Primarily, human exposure from lead is due to industrial work or consumer goods, like the paint on children's toys. Lead in drinking water, the air, canned food, and beverages also contribute to human exposure.

What are the major stages of habitat change

Primary succession, secondary succession, and climax community

What are animals that eat dead animals or carrion called ? What is their place in the food chain ? What would be the consequences if they did not exist

Scavengers are animals that eat dead animals, or carrion. Scavengers play an important role in the ecosystem by consuming decaying biomass. They are in the third trophic level. If they did not exist, the carrion's nutrients would never be able to be recycled by the decomposers.

1. Which class of mutations affect only the individual in which they occur

Somatic cell mutations

2. What is the major force driving life on earth

Sun

1. Name a disease for which rodents are vectors

The black plague was spread by rat-fleas (the vector).

What is the major source of data for risk assessment ? Suggest one major problem arising from this

The major source of data for risk assessment is animal testing. This is a problem because toxins may affect us and not animals, which means that a toxin would go unnoticed when experimenting for risk assessment.

Name and give one example of the class of genes that stop mutated cells from proliferating

Tumor suppressor genes, like p53

2. Which two air pollutants contribute the most to visible air pollution?

a. Particulate matter and sulfur oxides contribute the most to visible air pollution, also known as smog (Nitrogen oxides)

Which class of mutations affect the descendants of the individual in which they occur ?

germline mutations

What are the major components of sewage, and what is their origin

Water. and Black water (water from toilets that contain urine & feces) and grey water (water from kitchen sinks and dishwashers, baths, laundry, etc

5. Is there a chemical rodenticide available for public use ? Could this chemical be toxic to humans ? If so, why is is still available for public use

Yes there is a general-use rodenticide available for public use, although studies show they might not be entirely safe to us (could be toxic). They are still available for public use because a few, like the ones commonly recommended for use by householders to rid rats, are extremely excellent at controlling and killing the pests. These act as anticoagulants, so we would have to consume them for multiple days to see any negative effects, like hemorrhaging.

4. Why is it sometimes difficult to determine whether a disease is foodborne or waterborne (give 2 possible reasons

1. Bacteria has the ability to grow in foods with water content (aka all foods). Even drying foods does not kill microbes, it only prevents their multiplication and when they become wet again bacterial growth will resume. 2. Food and water intermingle whether during harvest, packing, or in the kitchen and these microbes can be found in both food and water so differentiating between the two is almost nearly impossible.

Name and briefly explain three ways that urbanization has impacted food production

1. Destruction of farmland- the destruction of farmland greatly reduces the supply of food and this is especially dangerous when the population of cities is increasing exponentially 2. Soil erosion, salinization, desertification, and other soil degradations associated with urbanization reduce the quality of land resources and future agricultural productivity. 3. Urbanization may also cause the "impermanence syndrome" (a lack of confidence in the stability and long run profitability of farming), leading to a reduction in investment in new technology or machinery and overall a decline in food production.

Name and briefly explain three ways that urbanization has impacted /could impact environmental or public health

1. Destruction of habitat- Habitat loss leads to ecosystem changes, climate changes, and ultimately species extinctions. 2. Air, noise, light pollution- These pollutants affect both the environment's health and the public's health. Air pollution can lead to emphysema, lung cancer, heart disease, and many more diseases; noise and light pollution can disturb plants' and animals' overall lifestyle. 3. Heat islands- Heat islands can affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and water quality.

9. For a named non-renewable resource, briefly describe two major consequences of running out of that resource

1. If crude oil (fossil fuel) ran out, then we would have no naturally occurring fossil fuel in liquid form. 2. We also could not make liquid petroleum products like gasoline, diesel fuel, and heating oil.

6. List and briefly describe three major categories of non-renewable resources

1. Mineral resources- these are not currently being formed (from geological processes long ago), therefore are non-renewable 2. Fossil fuels like crude oil and natural gas- the rate of formation is slower than the rate of consumption/depletion 3. Nuclear energy- uranium ore is mined and converted, therefore it is nonrenewable

Name and briefly explain three ways in which mining can affect human health and/or the health of the environment

1. Mining wastes, often in waste ponds, that are toxic to human health and disruptive to the environment. 2. Uses and destroys land, leading to deforestation which affects the lives of plants, animals, and humans in that area. 3. Produces physical hazards, including explosions and mine collapses, which are dangerous to the miners in the mines and the workers around them

4. Name and briefly describe the three major sources of light pollution in the Westernized world

1. Misaligned light fixtures that causes sky glow (overhead clouds appearing orange, pink, or bright white in color). 2. Light trespass from skyscrapers- light that spills out from another property 3. Light clutter (or "glare") from urban cities- excessive groupings of lights, can cause glare and visual reduction

1. Name and briefly describe the three major sources of noise pollution

1. Occupational- Places of industry and construction are a source of constant noise pollution due to the noisy equipment and machines. In many industries, it is mandated that you must wear earplugs or noise-proof gadgets. 2. Transport- Transportation, such as commercial planes and trucks traveling, are constantly making a lot of noise, both over- and underground. 3. Entertainment- Concerts, places of worship, parties, etc. cause a plethora of noise pollution whether it is from music speakers, loud screaming/talking, or singing

7. Name and briefly explain three reasons why projected time-to depletion for non-renewable resources may be inaccurate

1. On a world scale, metal resources are largely inexhaustible (there are enough for the entire population for a long time). 2. The use of technology and rate of technological advancement is increasing, making non-renewable resources that weren't accessible before more accessible. 3. Conservation efforts of these non-renewable resources may slow the depletion of them down.

List three advantages of a public sewer system over a septic tank

1. Septic tanks are high maintenance: removal of sludge at bottom and scum at top so solids are not discharged into absorption field (public sewer systems are not as complicated) and are owners responsibilities 2. Septic tanks must be large enough for the household and their household's water usage; space consuming (public sewer systems requires less space) 3. Public sewer systems can cover a wider range of areas than one septic tank and can be used in densely populated areas

2. What is the major health/environmental consequence of noise pollution

1. Tinnitus- a noise or constant ringing in the ear that can be permanent, and a result of long-term exposure to loud sound. 2. Hearing Loss- Hearing loss occurs when there is damage to the inner ear or the auditory nerve. The WHO has directly correlated prolonged exposure to sounds exceeding 80 decibels to some health conditions, such as hearing loss.

6. List and briefly describe three major functions performed by State/County Environmental Health departments/divisions (or their equivalents)

1. Use the best scientific knowledge to set laws and public policy 2. Make sure these laws are being abided by and assure provision of services for an optimal, healthy life for all 3. Reduce health care costs through prevention with services such as disease screenings and vaccinations, and patient safety initiatives

1. What is the difference between a host and a reservoir ? Give an example of each and of a disease with which it is associated

A host is a living organism in which the pathogen spends part of its life-cycle and causes disease and a reservoir is a living organism or environmental medium in which the pathogen survives and reproduces without causing overt disease. An example of a host is a mosquito that transfers Malaria and an example of a reservoir are the rats that carried the plague

1. Name and briefly describe a major route for human exposure to environmental agents. Give an example of the type of agent for which that route would be important. What organ of the body would be principally involved

A major route for human exposure to environmental agents is the respiratory system. We inhale airborne substances, pathogens like the common cold, and they go to the heart through our blood and then are distributed to the rest of the body. This principally involves the lungs.

Name and very briefly describe chemicals that interfere with the body's endocrine system.

Endocrine disruptors (Bisphenol A, TCDD, PCBs, etc.) interfere with the body's endocrine system in a majority of ways, but mainly through binding to hormone receptors or the synthesis/elimination of steroids

6. Name a mineral fibre that is believed to be a human carcinogen. How are humans exposed to this substance

Asbestos is a mineral fiber believed to be a human carcinogen causing mesothelioma and many other diseases. It is primarily known for being an insulator in old public buildings that humans still work and do daily activities in to this day

5. Where are bacteria placed in the food chain ? Why do you classify them as such

Bacteria are placed into the decomposers category because they can break down just about any type of organic matter. They also recycle nutrients and the nutrient cycle depends on these organisms and are primary producers

9. Why is cadmium exposure currently of great concern

Cadmium is an extremely toxic metal and overexposures may occur even in situations where trace quantities of cadmium are found because of its low permissible exposure limit. Cadmium toxicity is increasing in incidence today primarily because of a zinc (which is protective against cadmium) deficiency in many commonly eaten foods. Food processing and eating of refined foods further reduces zinc intake

3. Name one class of insecticides that all have a similar mode of action. What is this mode of action

Carbamates such as Furadan and Sevin and organophosphates such as Lorsban and Counter, are both acetylcholine inhibitors

Briefly state one reason why documenting the relationship between an environmental exposure and neurotoxicity in humans can be difficult

Documenting the relationship between environmental exposure and neurotoxicity in humans can be difficult because since we are gathering data from live animals and humans, we must extrapolate the data from experimental dose levels to environmental exposure levels

What factors make a risk more acceptable? Less acceptable

Factors that make a risk more acceptable are when it occurs very rarely, is negligible in nature, and has a high predictability. Factors that make a risk less acceptable are a more frequent occurrence, tend to be catastrophic in nature, and have a low predictability.

3. Name and briefly describe two major food-borne diseases

Food poising from bacteria such as Staphylococcus aureus, Salmonella, and E. coli is a disease resulting from intake of food contaminated with microbial pathogens. Another food-borne disease can stem from living pathogens, such as Norovirus, which is the extremely common cause of stomach illnesses on cruise ships and confined areas

Suggest a reason why there are fewer health concerns associated with herbicide use than with insecticide use

Herbicides target plant-specific functions such as enzymes and growth hormones that are not found in/toxins to animals. Insecticides are known to target the nervous system of insects, and the nervous system is somewhat similar across animal species so this is more dangerous to humans

Is inorganic mercury more or less toxic to humans than organic mercury ? Why ?

Inorganic mercury is less toxic to humans than organic mercury, because organic mercury is water-soluble and can easily cross into the blood brain barrier. Inorganic mercury is less volatile and less lipophilic.

What are thought to be the major reasons why cancer in general has a long latency period

It is observed that the onset of cancer occurs many years after being exposed to the agent and this is why it is seen as having a long latency period. It can be explained by the fact that progression of cancer requires considerable time for a precancerous tumor to accumulate the additional, random mutations needed to cause the malignant growth

8. Name a country which possesses relatively low water resources per capita yet consumes well above the average amount of water per capita ? What characteristic(s) of this country do you think explains this pattern ?

Italy- warm/hot climate, intense agriculture needs irrigation, heavily industrialized,

5. What is a major health/environmental consequence of light pollution ?

Loss of length of day- disturbs the signaling and biological rhythms in plants and animals

What are the major consequences of habitat degradation

Loss of vegetation, loss of wetlands, and loss of biodiversity

How is the food chain related to the ecosystem

More than 1 chain, useful in conveying a general understanding of how energy, as well as biomass and nutrients, moves throughout an ecosystem

Name a microorganism that affects a function of the nervous system, and name the function that is affected

Mosquitoes carry West Nile Virus, and in its most serious form can cause a fatal inflammation of the brain (encephalitis).

Name and briefly describe one example of a naturally-occurring food contaminant that can adversely impact health. What measures can be taken to minimize this contaminant

One example of a naturally-occurring food contaminant that can adversely impact health is acrylamide, which can be found in certain foods that are heated to a temperature above 120 degrees Celsius, and have been found to cause neurological issues and multiples cancers in animal studies. There are currently guidelines the EPA and FDA have set into place for the levels of acrylamide in drinking water and substances that come into contact with food, but there are currently no guidelines governing the presence of acrylamide in food itself (an easy solution would be to ban the cooking of food over 120 degrees Celsius).

Name and briefly describe two major waterborne diseases

One waterborne disease is Cholera, which is common in underdeveloped countries where water filtration systems are not up to par and leads to extreme diarrhea, dehydration, and possible death. Another waterborne disease is Amebic Dysentery, which causes stomach problems and spread through fecal matter

Give an example of a type of chemical that affects a specific function of the nervous system, and name the function that is affected

Organophosphates (example: the pesticide Naled) affect neurotransmission and inhibit cholinesterase.

8. List and briefly describe the origin of and two major uses for the rare earth minerals

Origin: Mainly obtained from mining in countries like China. 1. National defense- Rare earth metals are key ingredients for making the very hard alloys used in armored vehicles and projectiles that shatter upon impact. 2. Technology- Rare earth metals are used for computer memory, DVDs, rechargeable batteries, cell phones, catalytic converters, magnets, fluorescent lighting and much more.

Name and briefly describe the major steps in wastewater treatment

Primary treatment - physical and mechanical removal of solids b. Secondary treatment - biological decomposition c. Tertiary treatment - disinfection (chlorination, UV)

4. What factors tend to make risks more acceptable to the general public

Risks are subject to perception bias. However, if something has a known risk but is not catastrophic, not fatal, controllable, and voluntary people are more willing to participate.

What is the importance of (i) variability and (ii) uncertainty on risk assessment, and how can these be mitigated

There is always some sort of variability and uncertainty amongst risk assessment of toxins. These factors can be mitigated by considering the cause/effects of each risk of isolation, approaching risks chemical by chemical, taking a combined risk assessment approach for multiple exposures, and accounting for multiple sources of exposure.

3. Name and describe one measure that can be used to control noise pollution

Technological approaches like acoustic tile for absorption, barrier walls on roadsides, and vibration damping and isolation

2. Which was the first widely-used synthetic insecticide ? What were some major problems identified with its use ? What is a current major controversy associated with this insecticide

The first widely-used synthetic organic insecticides was a chlorinated hydrocarbon called DDT, for its ability to reach a broad spectrum range of pests, its persistence, and its insolubility. Because of its insolubility, DDT accumulates in the fatty tissues of organisms and this causes indirect toxicity to those that the insecticide was not meant for. Recently, DDT has been banned from the US and many other countries and added to the list of Persistent Organic Polutants.

Name the principal components of the nervous system that could be vulnerable to toxicity

The principal components of the nervous system are the Central Nervous System (brain and spinal cord) and the Peripheral Nervous System (motor neurons and the automatic nervous system).

8. What are the major problems associated with human exposure to mercury

There are numerous ways humans can be exposed to elemental mercury (toxic), through inhalation, to inorganic mercury salts (corrosive), through ingestion, or to organic mercury (through either). Mercury accumulates in the brain and CNS, and is then converted to methyl mercury by bacteria, which binds to proteins that inhibit choline acetyltransferase. This ultimately decreases the production of acetylcholine and leads to debilitating diseases and death

5. What factors tend to make risks less acceptable to the general public ?

Things like handguns or GM foods, however, are known and dreaded. They are uncontrollable and have risks to future generations.

Give one reason why water is regarded as a limited resource.

Water is a finite resource. We take it for granted in our everyday lives, industry, and technology, but we cannot make more

6. Why would food adulteration be of concern now (as opposed to 100 years ago)

a. Adulteration has undoubtedly been used in the past, but now it is of bigger concern because large corporations are selling "foodstuffs" to faceless consumers. In other words, they simply want a profit

1. What are the three major (by weight) sources of solid waste in the USA

a. Agricultural waste b. Mining and primary metal smelting waste c. Industrial waste

Name and give an example of each of the major categories of environmental factors that are considered to be important in Environmental Health

a. Biological- microorganisms and pathogens, anything that is alive b. Chemical- chemicals from people and naturally the environment c. Physical- Safe water and clean air, safe houses d. Social- Greater support from family and friends is linked to better health

3. Describe briefly three advantages of landfilling over incineration for disposal of solid waste.

a. By incinerating waste, we eliminate the option to recycle and therefore they cannot be reused so the prices of materials are increasing. There are, however, dumps that can collect recyclables instead of landfills. b. Incinerators release thousands of toxic pollutants into the air while landfilling doesn't. c. Landfilling is not linked to climate change like incineration is. Incineration has been linked that the pollutants released are linked to the climate change and global warming (ozone layer degrading).

5. List the four criteria for classifying solid waste as hazardous waste (in the USA).

a. Catches fire easily b. Is reactive, unstable, explosive, releases toxic fumes c. Is corrosive d. Contains known carcinogens, mutagens, or teratogens

5. What are the major health effects listed by the affected individuals ?

a. Children born in the associated time frame were born with low birth weight, birth defects like neural tube defects, and childhood cancers. Adults were seen to develop kidney and liver cancers, lymphoma, myelomes, and ALS.

1. Name and briefly describe two major waterborne diseases - diseases that are transmitted through drinking contaminated water

a. Cholera- Scientifically known as Vibrio cholerae, Cholera is a waterborne bacterial disease that causes severe diarrhea and vomiting. b. Typhoid fever- Typhoid is waterborne and caused by the bacterial agent Salmonella typhi, and is characterized by headache, muscle pain, high fever, and constipation alternating with diarrhea.

2. State one reason why groundwater might be preferable to surface water as a source of drinking water.

a. Groundwater undergoes less fluctuation (such as evaporation and recharge), and is also cleaner because pathogens and agents soil filters and binds to them. Therefore, it needs less treatment and is cheaper

3. What measures were taken at Camp Lejeune to limit human exposure to these chemicals?

a. In 1980 when 11 chemicals including trichloroethylene, dichlororethylene and vinyl chloride were detected, no action was taken. By 1987, all wells containing drinking water were shut down and by 1989 USMC Base Camp Lejeune and ABC Cleaners placed on National Priorities List.

8. Name and briefly describe one example of a major problem associated with human exposure to food additives (past or present) ?

a. In 2006, Chinese cold medicines adulterated with the toxic sweetener diethylene glycol killed several hundreds of people, predominantly children in Panama. This led the FDA to issue an Industry Guidance Document intended to alert pharmaceutical manufacturers, pharmacy compounders, repackers, and suppliers to the potential public health hazard of glycerin contaminated with diethylene glycol

4. Is there a disadvantage to chlorination of drinking water ? If so, what is it ?

a. In the mid-1970s epidemiologists linked the presence of trihalomethanes, which include carcinogens like chloroform, to water treatments where chlorine is added. However, THMs are only present in minute amounts and pose a minimal health risk. The benefits of chlorine disinfection outweigh the risks by far.

4. Describe briefly three advantages of incineration over landfilling for disposal of solid waste.

a. Incineration doesn't take up space like landfilling does. b. Anaerobic decomposition of landfilled materials may result in the accumulation of dangerous amounts of methane, which can cause fires/explosions should they migrate to nearby structures or climate change. c. Landfills have the potential to pollute nearby surface streams or underlying aquifers with leachates.

4. Why might indoor air quality be of greater health concern than outdoor air quality

a. Indoor air can be polluted by the intrusion of outdoor air pollutants and indoor combustion such as smoking and heating (of wood, gas, kerosene, dung), biological contaminants, building materials, and household products. Indoor air is less circulated than outdoor air, so it may stay concentrated in one area for an extended amount of time, and we are generally indoors for longer than outdoors.

9. Name and briefly describe one example of a naturally-occurring food contaminant that does not impact health. What measures can be taken to minimize this contaminant

a. Insect filth, which includes insect fragments, is a naturally-occurring and non-harming food contaminant that can be found in processed food such as macaroni and cheese, peanut butter, and canned or frozen spinach. The FDA and EPA can work together to closely watch production, packaging, storage, handling (where contamination usually occurs) and make sure that it follows the "acceptable daily intake" level and maintain cleanliness of facility.

4. Name and very briefly describe three well-known developmental toxins/toxicants

a. Lead- High levels of this potent toxin were found in the blood of children mainly due to the paint on toys, but also contributed to lead in drinking water, the air, canned food, and beverages. b. Mercury- Dated back to ancient times, it is used mainly in industrial settings but a major factor of our Mercury consumption now comes from Mercury-tainted fish. Leads to mercury poisoning c. Asbestos- A collection of 6 fibrous materials found in public buildings that have caused in many deaths and diseases, such as Lung Cancer and Mesothelioma.

4. What are the major health effects associated in the older literature and in animal toxicity studies with exposure to these chemicals ?

a. Lifetime exposure to these chemicals has resulted in increased liver cancer in mice and increased kidney cancer and a change in brain chemistry. In some animal studies, exposure to these toxins during development caused decreases in body weight, increases in heart defects, changes to the developing nervous system, and effects on the immune system.

7. Name one of the major purposes of risk assessment

a. One of the major purposes of risk assessment is to produce a numerical probability of adverse effect so that officials can protect public health. This means that we will have quantitative data supporting the idea that something can produce opposite effects of what is intended and understand how to combat it

3. Which air pollutant is believed to be most responsible for human health effects

a. Particulate matter that is less than 2.5 mm in diameter is the most concerning when it comes to human health. It is directly related to cardiovascular disease, asthma, lung function and development, low birth weight, cancer and premature mortality from the Six Cities Study.

2. List three possible ways of disposing of solid waste

a. Sanitary landfilling b. Incineration c. Dumping at sea

3. Name the three major steps in drinking water treatment.

a. Sedimentation/Coagulation b. Filtration c. Disinfection

2. How did those chemicals get into the water

a. Solvents illegally dumped by the former ABC dry cleaners leaked into the water supply for the Camp Lejeune Marine base. Supply wells were also contaminated by leaking storage tanks.

1. List the six criteria air pollutants

a. Soot (Total Suspended Particulate Matter) b. Sulfur dioxide/sulfuric acid aerosol c. Nitrogen oxides d. Volatile Organic Compounds (Lead) e. CO, CO2 f. Ozone

List and briefly describe the five stages of the demographic transition, including the factors that initiate each stage

a. Stage 1- high birth rate, high death rate, stable population b. Stage 2- Death rate falls and population increases, improved health/hygiene/food c. Stage 3- Increased technology and education, birth rate falls d. Stage 4- Low birth-rate, low death-rate, stable population e. Stage 5- low death-rate, birth-rate lower than death-rate, population drops

7. Are food processors free to add any chemicals to their products ? What is to stop them from doing so

a. The Pure Food and Drugs Act in 1906, one of the first federal laws on food protection, which intended to protect consumers against adulteration, mislabeling of foods, and addition of harmful ingredients (chemicals) to their products. The FDA has also established "defect action levels," which describes the amount of contamination a legal product is allowed to have before the remove it from the shelves.

3. Name the critical periods for developmental toxicity. Why are these periods critical

a. The critical periods for development toxicity are the gestation, pernatal, infancy, and puberty periods and they are critical because exposure to a toxicant could be detrimental to the individual during this rapid extreme growth.

6. What are the four major steps in risk assessment ?

a. The four major steps in risk assessment are Hazard Identification, Exposure Assessment, Dose-Response Evaluation, and Risk Characterization

1. What were the four major chemicals of concern in the Camp Lejeune water ?

a. Trichloroethylene b. Perchloroethylene c. Benzene d. Vinyl chloride

5. Approximately how much of the water on Earth is natural freshwater

about 1%

5. Does the US EPA regulate indoor air? If so, why? If not, why not?

indoor air is not regulated by the US EPA because it would be close to impossible to regulate. Instead, you must take it upon yourself to mitigate the pollutants by removing possible pollutants (mold removal), ventilate the room properly, invest in an air cleaner, "green building" techniques, and/or control the source.

6. Name the two biggest uses of water worldwide.

industry (generation of electricity) and agriculture

3. Name and very briefly describe three instances of accidental human exposure to chemicals ?

• Oil spills during Hurricane Katrina: Hurricane Katrina was a catastrophe that destroyed most everything in its path. However, swimming through oil was probably one of the last things on people's minds; bigger problems included finding shelter, food, and water. • Fire at an Apex chemical plant in 2006- A leak at a hazardous-materials waste facility sent large plumes of gas into the air on Oct. 5, 2006, prompting the evacuation of about 17,000 Apex residents. • Fracking causes contaminated drinking water: In 2014, AP Reports posted 243 cases in which fracking caused contaminated drinking water in more than 22 countries.

2. Name and very briefly describe three instances of deliberate use of chemicals that can result in harm

• At home, as in when cleaning and disinfecting our houses. We might not realize it but there are hundreds of chemicals in our cleaning products that we use in our kitchens and bathrooms every day. • There are food additives in everything we eat. We often voluntarily put chemicals into our foods, such as sweeteners like aspartame. Most chemicals are used to keep the food fresh for a longer period of time. • Outdoors, the use of pesticides and herbicides in our gardens and farms. We may only think of the benefits that come from herbicides and pesticides (killing weeds and keeping bugs away), but these chemicals are also dangerous to as when we ingest them through our produce.