Directions: Please provide a response to each of the following questions using APA guidelines for formatting and citations.  Each response must be at least one paragraph in length consisting of three to five sentences.

 

 

 

1.      What are sources of indoor pollution in homes?

 

 

 

2.      What is carbon monoxide?  Name some sources of CO.

 

 

 

3.      What are some symptoms of carbon monoxide exposure?

 

 

 

4.      Describe the 1989 EPA rule regarding asbestos.

 

 

 

5.      Name some harmful effects of lead exposure.

 

 

 

6.      What is Radon?  How can a homeowner contribute to the remediation of radon levels in a home?

 

 

 

7.      What conditions do mold need to grow?

 

 

 

8.      Describe the kinds of infections that can be caused by species of mold.

 

 

 

9.      Name ways to improve indoor air quality.

 

 

 

10.    What is an advantage of using source control?

Overview

Indoor Pollutants, Moisture Management, and Whole-House Mechanical Ventilation

Part of a weatherization service provider’s job is to help a homeowner prevent unsafe conditions in the home.  This is done by having a thorough knowledge of the types of indoor air pollutants and conditions that lead to incorrect home moisture levels.  Proper home ventilation plays a significant role in managing this critical balance.

This module covers the details weatherization service providers need to know to ensure pollutant-free and moisture-appropriate safe homes.

Learning Objectives

Upon completion of this module, you should be able to:

5A

 

describe the relationship between ventilation and moisture management.

5B

 

apply sound design principles to ensure proper air flow throughout the home and explain the factors that contribute to its importance.

5C

 

recall the various types of home ventilations systems.

Module 8 Reading Assignment

Krigger, J., & Dorsi, C. (2012).  Residential Energy: Cost Savings and Comfort for Existing Buildings (6th ed.).  Helena: Saturn Resource Management, Inc.  Chapter 10.

Supplemental Reading Assignments (Required):

TSI (dd.) (2011, May).  Indoor Air Quality Handbook: A practical guide to indoor air quality investigations .  Available from TSI Incorporated, (pp 1–32).

U.S. Environmental Protection Agency (1991).  “Building air quality: A guide for building owners and facility managers.”  Indoor Air Quality.  Washington, D.C.: U.S. Government Printing Office, (pp. 1–228).

 

 

 

 

Lecture Notes

Indoor Environmental Quality

People do not often consider that they are breathing in biological contaminants when they inhale.  Biological contaminants include bacteria, molds, mildew, viruses, animal dander, cat saliva, dust mites, cockroaches, and pollen.

Over the last few years, scientific evidence has indicated that the air in homes and other buildings can be more polluted than outdoor air.  In fact, many building materials have been proven to contribute to indoor pollution.

Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes.  High temperature and humidity levels can also increase concentrations of some pollutants.  This poses risks to the health of people all across the nation.

Indoor pollutants are a legitimate concern for all weatherization service providers.  Assessing indoor environmental quality and taking steps to improve it, if necessary, are important aspects of the weatherization process.  If the weatherization service provider takes measures to seal the building envelope but does not test for the presence of indoor pollutants, the levels of indoor pollutants may increase.  This can be harmful to the health of the homeowner and any other building occupants.

There are many sources of indoor air pollution in homes:

• Asbestos

Building materials

Carbon monoxide

Central heating and cooling

Combustion sources such as oil, gas, kerosene, coal, wood, and tobacco products

Environmental tobacco smoke

Furnishings

Hobbies

Household cleaning chemicals

Humidification devices

Lead

Mold

Pesticides

Radon

Some pressed wood products

Urea formaldehyde

Wet or damp carpets

Common Indoor Pollutants

In most cases, special training is required to evaluate and remedy indoor environmental threats.  This does not mean that a weatherization service provider can continue his or her work without considering the possibility that indoor pollutants are present and advising the homeowner to hire a professional to evaluate the home.

The most common indoor pollutants are carbon monoxide, asbestos, radon, urea formaldehyde, and lead.

Carbon Monoxide

Carbon monoxide (CO) is an odorless, colorless, and toxic gas.  Sources of carbon monoxide include:

• unvented kerosene and gas space heaters.

leaking chimneys or furnaces.

back drafting from furnaces.

gas water heaters.

wood stoves and fireplaces.

gas stoves.

generators and other gasoline powered equipment.

automobile exhaust from attached garages.

tobacco smoke.

Harmful Effects

Because it is impossible to see, taste or smell the toxic fumes, CO can kill a building’s occupants before they are aware it is in the home.  Lower levels of exposure to CO cause mild effects that are often mistaken for the flu.  These symptoms include headaches, dizziness, disorientation, nausea, and fatigue.  The effects of CO exposure can vary greatly from person to person depending on age, overall health, and the concentration and length of exposure.

Remediation

Remediation is the act or process of eliminating environmental contamination on, in, or under property to restore property to an uncontaminated state.  A weatherization service provider can test for the presence of CO by using a monoxer or a comparable CO sensing device.  If there are levels of carbon monoxide inside the home, the weatherization service provider should educate the homeowner about ways to prevent exposure to it.  If any of the methods listed below have not been done recently, the weatherization service provider should encourage the homeowner to take action immediately.   Some ways to prevent and reduce exposure to CO include:

• keeping gas and all other combustion appliances properly maintained and adjusted.

considering the purchase of a vented space heater when replacing an unvented one.

using proper fuel in kerosene space heaters.

installing and using an exhaust fan vented to outdoors over gas stoves.

opening flues when fireplaces are in use.

choosing properly sized wood stoves that are certified to meet EPA emission standards.

making certain that doors on all wood stoves fit tightly.

having a trained professional inspect, clean, and tune up central heating systems annually.

repairing any leaks promptly.

not idling the car inside garage.

managing the use of vehicles near the home.

Additional ventilation can be used as a temporary measure when high levels of CO are expected for short periods of time.

Visit the Environmental Protection Agency’s (EPA) website for more information.

Asbestos

Asbestos consists of organic, fibrous silicate minerals that have properties that are useful in construction products, such as insulation, roofing shingles, and siding.  Asbestos is sometimes used in vinyl flooring, duct wrapping on heating and air conditioning systems, ceiling spray-on material, drywall, and drywall taping compounds.  Asbestos is not illegal but its use is restricted and has declined significantly in recent years.  Building materials for new construction are unlikely to contain asbestos.

Harmful Effects

When asbestos remains sealed in intact insulation bundles it is not harmful because the occupants will not come into contact with it.  When the asbestos is crushed into a fine powder it is dangerous.  If the fibers are released into the air, occupants can breathe them in and the fibers can become irretrievably lodged in the lungs.  This impairs breathing, causes scarring of the lungs (asbestosis), and can lead to lung cancer.  Asbestos also may cause mesothelioma, which is a tumor in the lining of the chest or abdomen.

EPA Ban

In July of 1989, the EPA issued a rule that is commonly known as the Asbestos Ban.  However, much of the original rule was remanded by the U.S. Fifth Circuit Court of Appeals in 1991.  Thus, the original 1989 EPA ban on the U.S. manufacture, importation, processing, or distribution in commerce of many asbestos-containing product categories was set aside and did not take effect.  Some asbestos-related products are still banned by the EPA.   Visit the  Environmental Protection Agency’s (EPA) website or more specific information on the ban of asbestos.

Remediation

No level of asbestos is considered safe.  A weatherization service provider should not try to verify that building materials contain asbestos because of the health hazard involved.  The provider should recommend that the homeowner call an expert who is certified by the appropriate state agencies to determine whether asbestos is present in a home.   Removal and thorough cleaning is expensive if done by a professional, but the homeowner and the weatherization service provider should not attempt it because of the inherent danger.

 

Asbestos should be remediated by professionals due to the danger.

Lead

The human body has very little tolerance for lead.  It is one of the few substances that are normally not found in humans.  Lead is a metallic chemical element that may be pervasive around the home.  Prior to 1978, many newly constructed houses and apartments were painted with lead-based paint.  Occupants of buildings that were constructed before 1978 may safely assume that there is lead-based paint somewhere in the building.

Lead can also be present in the soil outside the home as a result of flaking exterior paint and outside pollution in the air that makes contact with the soil.  Occupants entering the home can track contaminated dirt into the home.  Lead can also be brought into the home in imported food products, such as candy.  Imported toys, costume jewelry, and other items can contain unsafe amounts of lead that children can easily ingest with their natural hand-to-mouth movements.

Hobbies and workplaces can expose adults to lead, which can then be brought into the home.  Adults who have jobs in recycling, battery handling, painting, remodeling, some types of auto repair, ceramics, handling sinkers used in fishing, crafting, or handling stained glass can bring lead into the home on their hands, clothing, and shoes.

The two most common ways that people are exposed to lead toxicity are through drinking water and inhaled lead dust.  Lead is introduced into the drinking water when it is leached out of piping and into the air from surfaces painted with lead-based paints.

Harmful Effects

Lead is insidious and has devastating effects.  Lead poisoning can lead to serious health problems, including kidney disease, muscle and joint pain, high blood pressure, digestive problems, nerve disorders, and brain function issues.  Children can suffer brain damage, mental retardation, convulsions, reduced intelligence, or other serious disorders if they come into contact with lead.  Continued lead exposure can lead to premature death.

Remediation

The danger inherent in lead-based paint cannot be removed by painting over it.  Children may eat paint chips from the baseboards or window sills.  Scraping and sanding to remove the old paint can create a hazard that can harm the health of all occupants because people may breathe in the dust suspended in the air.

In order to eliminate the possibility of lead poisoning, hazardous items contaminated with lead must be permanently removed from the building and all areas where lead is encountered must be eliminated or dealt with cautiously.  As a precaution, the homeowner should keep the home as clean as possible and wash children’s hands as often as possible.

As with other chemicals and pollutants, the weatherization service provider should recommend that the owner contract a certified professional to do an assessment and any needed remediation.  This is the only way to be sure the remediation is thorough and that the occupants are safe.

 

When lead is present, a certified professional should assess and remediate the home.

Radon

Radon is a colorless, tasteless, odorless gas that is emitted from decaying uranium in the soil.  It is typically found in underground rocks, such as granite and shale.  Radon enters buildings from the ground through cracks in concrete slabs, openings in hollow-wall concrete blocks, floor drains, crawl spaces, and tiny pores in any material that it can get through.   Radon is most common in certain areas of the United States.  Visit the Environmental Protection Agency’s (EPA)  website to obtain its national radon map.

Harmful Effects

When radon is trapped in the house it becomes dangerous because it is a lung cancer-causing agent, although symptoms may not be noticed for several decades.

Remediation

Newer homes, which are built to tighter energy conservation standards than older homes, have little natural ventilation.  For this reason, a conscious ventilation plan should be employed to limit radon gas.  Ventilation is discussed further later in the module.   If the owner suspects that the building has radon, the building should be tested.  The average level of radioactivity in the United States is between .1 and .2 picocuries (2 pCi/L) for air outside and 1 and 2 picocuries inside the home.  The EPA recommends that levels above four picocuries (4 pCi/L) be reduced.

The weatherization service provider should notify the owner that once it has been verified that the building has radon, the best way to mitigate the presence of radon is to hire a certified professional to install a radon reduction system.

Urea Formaldehyde Foam Insulation

Urea formaldehyde foam insulation (UFFI) is a chemical compound that was widely used as a foam insulation material prior to its ban in 1982.  Although the ban was overturned, the use of UFFI greatly decreased.  The UFFI insulation was manufactured at the construction site using urea formaldehyde resin and foaming agents.  The mixture was pumped into the walls as foam that looked like shaving cream, where it would harden into a plastic.  During the process of curing, the resin would emit formaldehyde gas that would then enter the living space.

Harmful Effects

Sensitivity to formaldehyde varies from individual to individual.  Some symptoms of formaldehyde reaction are eye, nose, and throat irritation; coughing; headache; and nausea.

If these symptoms persist for more than a few days but disappear when the homeowner or other occupants leave the house, a laboratory test should be conducted to determine if formaldehyde is present.  While there is no specific threshold level that has been determined to cause illness, constant exposure should be avoided.  The risks associated with urea formaldehyde insulation decrease dramatically in the first year after installation.

Remediation

Two easy ways to lessen the levels of formaldehyde in a home are to ventilate the home so that large amounts of fresh air come inside and to remove products that give off formaldehyde from the home.

Visit the Environmental Protection Agency’s (EPA) website for more information about formaldehyde.

Moisture and Mold

A major problem resulting from deficient building envelopes is the intrusion of water into the interior environment.  Water can infiltrate a building’s exterior in any of its forms—gas, liquid, or solid.  Once the water has been absorbed into the building materials, it is called absorbed moisture.

If moisture accumulates inside a building, mold can develop.  Mold is composed of microscopic fungi that live in different environments.  Mold is becoming a more widespread and more widely-known problem in buildings today.  If mold is present in a building for a long period of time without being detected, it can destroy the structure.  In addition, it is important to know that the presence of mold affects the indoor air quality and can damage one or all of the occupants’ health.

Types of Mold

There are several types of mold that are commonly found in indoor and outdoor environments:

• Alternaria

Aspergillus

Chaetomium

Fusarium

Penicillium

Stachybotrys

Ulocladium

Poria

Mold only needs a little water to grow.  In addition, mold needs food to grow.  Lastly, molds require oxygen to complete their metabolism.

A weatherization service provider can check materials using a moisture meter to see if there is adequate moisture (more than 60 percent) for mold growth to occur.  A moisture meter is a device that is used to measure the percentage of water in a substance, such as wood, concrete, or grain.

Harmful Effects

Exposure to mold presents illness symptoms that are wide-ranging and often very non-specific.  The U.S. Environmental Protection Agency states the following about mold:

“Mold can threaten the health of a building’s occupants.  Inhalation exposure to mold indoors can cause health effects in some people.  Molds produce allergens (substances that can cause allergic reactions), irritants, and, in some cases, potentially toxic substances or chemicals (mycotoxins).  Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals.  Mold does not have to be alive to cause an allergic reaction.  Dead or alive, mold can cause allergic reactions in some people.” (2007)

There are about 100 species of mold that have been proven to cause infection in people.  There are three kinds of infection associated with mold exposure.

• Systemic

Opportunistic

Direct contact

Systemic infections are usually caused by inhalation of fungi spores.  A large majority of these infections are self-limiting and produce minimal or no symptoms.  However, immune-suppressed individuals may develop chronic localized infections or the disease may disseminate throughout the body, which generally proves fatal.

Opportunistic infections are generally limited to individuals with impaired immunological defenses in which infection is secondary to a primary disease or condition.

Direct contact fungi infect the hair, skin, and nails.  Infection usually occurs through direct contact with an infected individual or indirectly by sharing clothes, grooming utensils, towels, and so forth.

Allergens, Pathogens, and Toxins

Large amounts of mold, or colonies, can cause health problems in human beings and are divided into three groups.

• Allergenic

Pathogenic

Toxigenic

An allergen is a chemical or biological antigenic substance that is capable of causing allergic reactions in susceptible individuals.

Some fungi are able to cause disease under conditions that favor their growth, such as trauma, burns, chronic lung disease, or uncontrolled diabetes.  These are called pathogenic health problems.

If something is toxigenic it can produce toxins.  Some species of mold can produce toxins, but only at certain times and under certain conditions.  These toxins only affect certain individuals.

Allergens, Antigens, and Allergies

An allergen is a chemical or biological antigenic substance that is capable of causing allergic reactions in susceptible individuals.  An allergen is an antigen (most often eaten or inhaled) that is recognized by the immune system and causes a reaction.

An antigen is a substance that stimulates an immune response, especially the production of antibodies.

Allergies are an abnormal response of the immune system.  People who have allergies have an immune system that reacts to a usually harmless substance in the environment.

Mold Allergies

Depending on the climate, mold may or may not grow year-round.  In cold temperatures, mold lies dormant until spring and causes the most allergy problems during late summer.  However, in areas that are warm all year mold can cause allergic reactions during all four seasons.  Individuals who are sensitive to fungi may have allergic reactions.

Allergic reactions are caused by exposure to allergens, especially during infancy and early childhood.  Symptoms of an allergic reaction depend on the areas in the body that are the most sensitive.

Reactions to Inhaled Allergens

Asthma attacks

Coughing and wheezing

Hay fever and sneezing

Reactions to Ingested Allergens

Diarrhea

Hives/skin rash

Itchy throat

Nausea/vomiting/stomach cramps

Swollen mouth

Reactions to Touched Allergens

Itchy/blotchy skin

Skin rash/hives

In rare instances, sensitivity to an allergen is extreme and produces a reaction that is known as anaphylaxis or anaphylactic shock.  Anaphylaxis is a sudden, severe allergic reaction that results from exposure to an allergen and involves various systems in the body.  Symptoms of anaphylaxis include:

• difficulty breathing.

swelling of the face, throat, lips, and tongue.

tightness of the throat.

rapid drop in blood pressure.

dizziness.

lightheadedness.

hoarse voice.

unconsciousness.

hives.

Anaphylaxis can happen one second after being exposed to an allergen or symptoms can be delayed for up to 2 hours after exposure.  Avoiding the specific allergen is an important part of preventing anaphylaxis.  If anaphylactic shock is not treated immediately, it can result in the death of the individual.

If an individual who is living in a home that is being weatherized experiences any of the aforementioned allergy symptoms when in the home, the weatherization team should recommend that the individual seek a doctor’s advice.

Currently, there is no federal or state legislation regarding acceptable levels of mold exposure.  It is not likely that there will be mold exposure regulations because mold exposure affects each person differently.

Remediation

Mold is capable of polluting the air in and around homes.  Weatherization service providers should be familiar with the signs that there is mold growth in a home.

• Musty smell

Visible signs of water damage or standing water

History of water leakage from the roof, in the basement, or in any other area

History or evidence of sink or sewer overflow

Visible signs of mold

History of unexplained ailments such as headaches, difficulty breathing, skin irritation, allergic reactions, or aggravated asthma symptoms

If any of these indicators are present in a structure, the building owner should hire a professional to perform an investigation to determine the size and extent of the mold growth problem.

There is no practical way to completely eliminate mold and mold spores.  The only way to control indoor mold is to control moisture.  Moisture problems can be caused by structural or design problems or by human activity.

Mold grows on virtually any surface where moisture is present.  Therefore, it is important to find the source of the moisture to eliminate the mold.  A quick response to moisture intrusion can prevent or greatly reduce the threat of mold growth.  The key time frame to eliminate moisture before mold begins to grow and spread is between 24 and 48 hours.  Quickly eliminating the source of moisture intrusion is crucial to preventing the growth of mold.  If mold is found, it is best to remove the mold and then eliminate the source of moisture.

If the mold growth cannot be effectively cleaned and if materials are substantially damaged, they must be removed and replaced.  The size and type of the mold contamination will most likely dictate whether or not the cleanup can be done by the occupant or should be done by an outside professional.

Once remediation is complete, the owner should take steps to discourage further mold growth in the home, such as:

• Fixing leaks and plumbing failures.

Repairing any maintenance problems and/or construction defects.

Decreasing indoor humidity to between 30%-60%.

Preventing condensation on cold surfaces (windows, pipes, exterior walls, roof, or floors) by adding insulation.

Not installing carpeting in areas where there is moisture, such as laundry rooms and bathrooms.

Cleaning and drying any damp or wet building materials and furnishings within 24 to 48 hours in order to prevent mold growth.

Cleaning mold off of hard surfaces with water and detergent and then completely dried.

If mold is found on absorbent materials such as ceiling tiles, plasterboard, or wood, those materials must be replaced.

Some states require a professional to be a licensed mold inspector before taking any steps to inspect for and eliminate mold.  The weatherization service provider should be familiar with any such restrictions in his or her state or area.

Improving Indoor Air Quality

Improving the indoor air quality (IAQ) is important because if pollutants build up and remain in the indoor environment they can lead to health and comfort problems.  According to the EPA there are three basic strategies to improve IAQ.

• Source control

Improving ventilation

Air cleaners

Source Control

Source control is considered the most effective method to improve indoor air quality because it requires the elimination of the source of pollution or the reduction of emissions.  Some sources, like those that contain asbestos, can be sealed or enclosed.  Other sources, like gas stoves, can be adjusted to decrease the amount of emissions.  In many cases, source control is also a more cost-efficient approach to protecting indoor air quality than increasing ventilation because increasing ventilation can increase energy costs.

Improving Ventilation

Improving ventilation involves increasing the amount of outdoor air that comes into the home.  Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house.

Inadequate ventilation can increase indoor pollution levels by not bringing in enough air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home.  In the United States, ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers), has recommended minimum ventilation standards so that enough outdoor air is brought into the home to keep the level of indoor air contaminants to a specific minimum level.  This is often measured using the ventilation rate, which is the amount of total air changes that can be completed in a specific amount of time, such as one hour.  Visit the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) website for more information regarding minimum ventilation standards.

When the weather permits, opening windows and doors, operating window or attic fans, or running a window air conditioner with vent control can increase the outdoor ventilation rate.

 

Improving a home’s ventilation is a great way to reduce indoor pollutants.

Advanced designs that are used to build new homes are starting to feature mechanical systems that bring outdoor air into the home.  Some of these designs include energy efficient heat recovery ventilators, which are also known as air-to-air heat exchangers.   Improving ventilation is especially important when the occupant is involved in short-term activities that generate high levels of pollutants.  Such activities include:

• painting.

paint stripping.

heating with kerosene heaters.

cooking.

maintenance.

hobby activities such as welding, soldering, or sanding.

The weatherization service provider can recommended that the occupant do as many of these activities outdoors as possible.

Air Cleaners

An air cleaner is used to remove particles out of the air by filtering air as it passes through the device.  There are many types and sizes of air cleaners on the market, from inexpensive models to sophisticated and expensive whole-house systems.  Air cleaners are generally not designed to remove gaseous pollutants.

Some air cleaners are highly effective at particle removal while others, including most table-top models, are much less effective.  The effectiveness of the air cleaner depends on how much air it draws through the cleaning or filtering unit and how well it collects pollutants from the indoor air.  A very efficient collector with a low air-circulation rate will not be effective, nor will a cleaner with a high air-circulation rate but a less effective collector.

Another important factor in determining the effectiveness of an air cleaner is the strength of the pollutant source.  Table-top air cleaners, in particular, may not remove satisfactory amounts of pollutants from strong nearby sources.  People who are sensitive to particular sources may find that air cleaners are helpful only in conjunction with concerted efforts to remove the source.

Exhaust Fans

One more method that can be used to remove indoor pollutants is to use exhaust fans.  The primary purpose of an exhaust fan is to move moisture in vapor form to the outside of the building envelope.  Tighter, more energy efficient homes do not allow the humidity that is created indoors as a result of human activities to escape to the outside.

There are many moisture sources in any home, such as cooking, bathing, washing and drying clothes or dishes, plants, fish tanks, and perspiration and respiration from the occupants.

Most newer building codes specify a minimum of 100 cfm of air for a kitchen exhaust fan and 50 cfm of exhausted air for a bathroom fan.

Today’s residential codes specify that all exhaust fans must terminate outside the building and cannot exhaust to the attic, soffits, ridge vent, or crawlspace even though many fans still terminate in the attic.  Kitchen range hoods may be the exception because many of the newer kitchen fans are recirculating.  Recirculating kitchen hoods remove odors and moisture from the cooking area, but exhaust to the kitchen, which is still within the conditioned space.

A weatherization service provider can look for exhaust fans in the attic or determine the presence of vent registers on the roof to verify proper venting.

Visit the Environmental Protection Agency’s (EPA) website for more information on indoor air quality.

Required Videos:

Indoor air quality is a vital component of any type of weatherization program or procedure initiated on a project site.  Within the different modules of this course, we have looked at some of the concerns with indoor air quality related to HVAC systems and proper ventilation.  Indoor air quality became a major concern around the late 1970s after the Arab oil embargo, which caused many building and structural designers to change their philosophies on building designs.  Building designers started to make building more air tight in order to conserve on energy costs within the structure.  This proved to be a vital contributor to what is known as “sick building syndrome,” which occurs when buildings are not allowed to breathe properly and exchange enough indoor-to-outdoor air.  These YouTube video presentations will provide you with valuable information about the importance of monitoring indoor air quality problems that could affect the health and well-being of the structure’s occupants.  Providing proper air exchanges and ventilation can also remove harmful airborne contaminants.

Indoor pollution: How to protect yourself from indoor pollutants

How poor indoor air quality can affect you and your family

Learn about air duct cleaning & sick building syndrome – Indoor air and your health – Part 1

Indoor air quality problems in your home and air ducts? – Indoor air and your health – Part 2

What causes sick building syndrome?  Indoor air and your health – Part 3

What’s the best way to clean air ducts?  Indoor air and your health – Part 4

Required Presentations:

Indoor air quality

ASHRAE 62.2 for WAP

A Healthy Home Transformation

 

"Looking for a Similar Assignment? Get Expert Help at an Amazing Discount!"

This contains 100% correct material for UMUC Biology 103 LAB01. However, this is an Answer Key, which means, you should put it in your own words. Here is a sample for the questions answered:

 

 

Exercise 1: Data Interpretation  (2 pts each)

1. What patterns do you observe based on the information in Table 4?

No fish are present when the dissolved oxygen is zero. When there is more dissolved oxygen in the water, more fish are present. However, the number of fish tends to drop or level off when the dissolved oxygen is higher than 12 ppm.

 

2. Develop a hypothesis relating to the amount of dissolved oxygen measured in the water sample and the number of fish observed in the body of water.

Possible Hypotheses:

1.    The amount of dissolved oxygen affects the number of fish that can live in a body of water.

2.    As dissolved oxygen concentration increases, more fish can live in the body of water.

3.    There is an ideal dissolved oxygen concentration for fish to live in.

 

The rest of the questions are answered in full version:

 

1.    What would your experimental approach be to test this hypothesis?

 

 

2.    What would be the independent and dependent variables?

 

 

3.    What would be your control?

 

 

4.    What type of graph would be appropriate for this data set?  Why?

 

 

5.    Graph the data from Table 4: Water Quality vs. Fish Population (found at the beginning of this exercise).

 

 

6.    Interpret the data from the graph made in Question 7.

 

 

 

Exercise 2: Experimental Variables

Determine the variables tested in the each of the following experiments. If applicable, determine and identify any positive or negative controls.

 

Observations

1.    A study is being done to test the effects of habitat space on the size of fish populations. Different sized aquariums are set up with six goldfish in each one. Over a period of six months, the fish are fed the same type and amount of food. The aquariums are equally maintained and cleaned throughout the experiment. The temperature of the water is kept constant. At the end of the experiment the number of surviving fish is surveyed.

A.    Independent Variable:

 

 

B.    Dependent Variable:

 

 

C.   Controlled Variables/Constants:

 

 

D.   Experimental Controls/Control Groups:

 

 

2.    To determine if the type of agar affects bacterial growth, a scientist cultures E. coli on four different types of agar. Five petri dishes are set up to collect results:

§  One with nutrient agar and E. coli

§  One with mannitol-salt agar and E. coli

 

§  One with MacConkey agar and E. coli

§  One with LB agar and E. coli

§  One with nutrient agar but NO E. coli

 

All of the petri dishes received the same volume of agar, and were the same shape and size. During the experiment, the temperature at which the petri dishes were stored, and at the air quality remained the same. After one week the amount of bacterial growth was measured.

A.    Independent Variable:

 

 

B.    Dependent Variable:

 

C.   Controlled Variables/Constants:

 

 

D. Experimental Controls/Control Groups:

Exercise 3: Testable Observations

Determine which of the following observations are testable. For those that are testable:

Determine if the observation is qualitative or quantitative

Write a hypothesis and null hypothesis

What would be your experimental approach?

What are the dependent and independent variables?

What are your controls – both positive and negative?

How will you collect your data?

How will you present your data (charts, graphs, types)?

How will you analyze your data?

 

Observations

1.    A plant grows three inches faster per day when placed on a window sill than it does when placed on a on a coffee table in the middle of the living room.

 

 

2.    The teller at the bank with brown hair and brown eyes is taller than the other tellers.

 

 

 

3.    When Sally eats healthy foods and exercises regularly, her blood pressure is 10 points lower than when she does not exercise and eats fatty foods.

 

 

 

4.    The Italian restaurant across the street closes at 9 pm but the one two blocks away closes at 10 pm.

 

 

5.    For the past two days, the clouds have come out at 3 pm and it has started raining at 3:15 pm.

 

 

 

6.    George did not sleep at all the night following the start of daylight savings.

 

 

 

Exercise 4: Conversion

For each of the following, convert each value into the designated units.

 

 

1.    46,756,790 mg = _______ kg

 

 

2.    5.6 hours = ________ seconds

 

 

3.    13.5 cm = ________ inches

 

 

4.    47 °C = _______ °F

 

 

 

 

Exercise 5: Accuracy vs. Precision

For the following, determine whether the information is accurate, precise, both or neither.

 

1.    During gym class, four students decided to see if they could beat the norm of 45 sit-ups in a minute. The first student did 64 sit-ups, the second did 69, the third did 65, and the fourth did 67.

 

 

2.    The average score for the 5th grade math test is 89.5. The top 5th graders took the test and scored 89, 93, 91 and 87.

 

3.    Yesterday the temperature was 89 °F, tomorrow it’s supposed to be 88 °F and the next day it’s supposed to be 90 °F, even though the average for September is only 75 °F degrees!

 

4.    Four friends decided to go out and play horseshoes. They took a picture of their results shown to the right:

 

 

 

 

5.    A local grocery store was holding a contest to see who could most closely guess the number of pennies that they had inside a large jar. The first six people guessed the numbers 735, 209, 390, 300, 1005 and 689. The grocery clerk said the jar actually contains 568 pennies.

 

 

Exercise 6: Significant Digits and Scientific Notation

Part 1: Determine the number of significant digits in each number and write out the specific significant digits.

 

1.    405000

 

 

2.    0.0098

 

 

3.    39.999999

 

 

4.    13.00

 

 

5.    80,000,089

 

 

6.    55,430.00

 

 

7.    0.000033

 

 

8.    620.03080

 

Part 2: Write the numbers below in scientific notation, incorporating what you know about significant digits.

 

1.    70,000,000,000

 

 

2.    0.000000048

 

 

3.    67,890,000

 

 

4.    70,500

 

 

5.    450,900,800

 

 

6.    0.009045

 

 

7.    0.023

 

Exercise 1: Data Interpretation (2 pts each)

1. What patterns do you observe based on the information in Table 4?

No fish are present when the dissolved oxygen is zero. When there is more dissolved oxygen in the water, more fish are present. However, the number of fish tends to drop or level off when the dissolved oxygen is higher than 12 ppm.

 

2. Develop a hypothesis relating to the amount of dissolved oxygen measured in the water sample and the number of fish observed in the body of water.

Possible Hypotheses:

1. The amount of dissolved oxygen affects the number of fish that can live in a body of water.

2. As dissolved oxygen concentration increases, more fish can live in the body of water.

3. There is an ideal dissolved oxygen concentration for fish to live in.

 

3. What would your experimental approach be to test this hypothesis?

Possible Experimental Approach: Deposit an equal number of fish in several tanks. Maintain all other variables (temperature, light, food, etc.), but vary the dissolved oxygen concentration in each of the tanks. Observe the fish over time to determine how many fish can survive at different oxygen concentrations.

 

4. What are the independent and dependent variables?

Independent Variable: Dissolved oxygen concentration.

Dependent Variable: The number of fish.

 

5. What would be your control?

Possible Control: Aquarium with no fish. Measure the dissolved oxygen level in a fish tank at normal room conditions, and repeat this measurement every time you make an observation of the number of fish. [Use only one type of fish for your experiment, and control other variables such as light, food and temperature.]

 

6. What type of graph would be appropriate for this data set? Why?

A line graph is most appropriate because it can best display the relationship between the variables.

 

7. Graph the data from Table 4: Water Quality vs. Fish Population (found at the beginning of this exercise).

18

 

8. Interpret the data from the graph made in Question 7.

The number of fish in the body of water increases along with dissolved oxygen up to about 12 ppm. When the concentration is higher than 12 ppm, the relationship is less clear. There may be an ideal dissolved oxygen concentration that supports the greatest number of fish, but that conclusion would require further testing.

 

Experiment 2: Experimental Variables (2 pts each part, 8 total/question)

Determine the variables tested in the each of the following experiments. If applicable, determine and identify any positive or negative controls.

 

1. A study is being done to test the affects of habitat space on the size of fish populations. Different sized aquariums are set up with six goldfish in each one. Over a period of six months, the fish are fed the same type and amount of food. The aquariums are equally maintained and cleaned throughout the experiment. The temperature of the water is kept constant. At the end of the experiment the number of surviving fish are surveyed.

 

A. Independent Variable: Habitat Space (Different sized aquariums are tested)

B. Dependent Variable: Size of Fish Populations (The number of surviving fish are surveyed)

C. Controlled Variables/Constants: Type of food, amount of food, equal maintenance and cleaning, water temperature

D. Experimental Controls/Control Groups: There are no control groups in this experiment.

 

2. To determine if the type of agar affects bacterial growth, a scientist cultures E. coli on four different types of agar. Five petri dishes are set up to collect results:

One with nutrient agar and E. coli

One with mannitol-salt agar and E. coli

One with MacConkey agar and E. coli

One with LB agar and E. coli

One with nutrient agar but NO E. coli

 

All of the petri dishes received the same volume of agar, and were the same shape and size. During the experiment, the temperature at which the petri dishes were stored, and at the air quality remained the same. After one week the amount of bacterial growth was measured.

 

A. Independent Variable: Type of agar (nutrient agar, mannitol-salt agar, MacConkey agar, LB agar)

B. Dependent Variable: Bacterial growth (after one week the amount of bacterial growth was measured)

C. Controlled Variables/Constants: Volume of agar, size and shape of petri dishes, temperature, air quality

D. Experimental Controls/Control Groups: One petri dish with nutrient agar, but no E. coli is a negative control because no growth should be seen if no E. coli was added

 

Exercise 3: Testable Observations (2 pts each)

Determine which of the following observations could lead to a testable hypothesis. For those that are testable:

Write a hypothesis and null hypothesis

What would be your experimental approach?

What are the dependent and independent variables?

What is your control?

How will you collect your data?

How will you present your data (charts, graphs, types)?

How will you analyze your data?

 

1. A plant grows three inches faster per day when placed on a window sill than it does when placed on a coffee table in the middle of a living room.

Hypothesis: Plants in the window sill grow faster due to increased light.

Null hypothesis: Increased light does not make plants grow faster.

Approach: Place two plants in the window. Leave one in the window and take the second plant

and let it spend different amounts of time in the light (decreased light exposure).

Dependent variable: Height of the plant. Independent variable: Amount of time spent in the sunlight by each plant.

Control: A plant remaining out of direct sunlight (but not in total darkness), like on the table.

Data collection: Measure the height of each plant every day for a week and record the total growth after one week.

Data presentation: Use a bar graph to show the results. Each of the three plants will have its own bar representing the height it grew in one week

Analyze: Look for an increase in growth with increased time on window sill.

 

2. The teller at the bank with brown hair and brown eyes and is taller than the other tellers.

No testable hypothesis – This is an observation, but it is a statement with no testable component.

 

3. When Sally eats healthy foods, her blood pressure is 10 points lower than when she eats fatty foods.

Hypothesis: A healthy diet leads to lower blood pressure.

Null hypothesis: A healthy diet doesn’t lead to lower blood pressure.

Approach: Collect blood pressure data over time for groups eating healthy foods and a group eating fatty foods.

Independent variable: Healthy or Unhealthy Diet

Dependent variable: Blood pressure (would be affected by the change in diet).

Controls: All groups should be exposed to similar amounts of exercise and stress.

Data collection: Test the blood pressure of your study subjects at fixed intervals over time – alwaysat the same time of day, under similar diet conditions.

Presentation: Use a line graph for individual evaluation over time. Use a bar graph to show the average blood pressure for each of your study groups.

Analyze: Look at data gathered over time to see whether diet lowered blood pressure.

 

4. The Italian restaurant across the street closes at 9 pm but the one two blocks away closes at 10 pm.

No testable hypothesis – This is a statement with no testable relationship.

 

5. For the past two days the clouds have come out at 3 pm and it has started raining at 3:15 pm.

For this particular, specific observation, you could not create a controlled experiment, so you could have said it’s an observation only, and that would have been acceptable for the information given. If you did propose an experiment, since the the time appears to be the independent variable that the dependent variable (clouds) depends on, but that is not the case, you’d have to go further and propose what variables you’re going to look at–what atmospheric conditions (that aren’t observed in this case) are the variables related to the cloud formation? (So, you’d need additional observation before you could actually come up with a hypothesis. If you did make some assumptions about cloud formation and proposed a hypothesis, it might look something like this:

Hypothesis: As temperatures rise throughout the day, it increases the rate of evaporation, increasing the amount of moisture in the air. Temperatures and atmospheric water concentrations reach their maximum at mid-afternoon. Then, when temperatures begin to lower at about 3:00, clouds form and the evaporated moisture in the air condenses and it rains.

This experiment could be recreated in a microclimate, under lab conditions, or observed using daily weather station instruments to see if the pattern holds up.

 

Meteorologists can gather data about the atmospheric conditions to determine what variables are related to this and then develop experiments to see if their models work—looking for a correlation between those conditions and similar weather. Each observation would be a replication. Meteorologists gather a lot of data FIRST, then use it to make predictions–hypotheses–that they test by making more observations in the real world to compare with.

 

6. George did not sleep at all the night following the start of daylight savings.

Hypothesis: Daylight savings affected how much George was able to sleep.

Null hypothesis: Daylight savings did not affect how much George was able to sleep.

Approach: Study George’s sleeping habits before, during, and after daylight savings time.

Dependent variable: The number of hours George sleeps during daylight savings time.

Independent variable: The day/time.

Control: George’s average night’s sleep.

Data collection: Record George’s sleeping patterns for several weeks before, during, and after daylight savings time. Write down what time he goes to bed and how many hours he sleeps for each night.

Presentation: Use a line graph to plot the day/time on the x-axis and George’s hours of sleep on the y-axis.

Analyze: Use the data to show whether daylight savings time affected George’s sleep. Possible questions to answer with the data:

What did the graph look like leading up to the due date of George’s assignment? What happened around George’s paper’s due date? Did George’s sleeping patterns go back to normal after the assignment was due? If so, how long did it take?

 

Exercise 4: Unit Conversion

For each of the following, convert each value into the designated units.

1. 46,756,790 mg = 46.75679 kg

2. 5.6 hours = 20,160 seconds

3. 13.5 cm = 5.31 inches

4. 47 °C = 116 °F

 

Exercise 5: Accuracy vs. Precision

For the following, determine whether the information is accurate, precise, both or neither.

 

1. During gym class, four students decided to see if they could beat the norm of 45 sit-ups in a minute. The first student did 64 sit-ups, the second did 69, the third did 65, and the fourth did 67.

Precise because all the data is closely together, but not accurate since it is far from the norm of 45 sit ups.

 

2. The average score for the 5th grade math test is 89.5. The top 5th graders took the test and scored 89, 93, 91 and 87.

Both precise and accurate, because all the scores are closely gathered around the average score.

 

3. Yesterday the temperature was 89 °F, tomorrow it’s supposed to be 88 °F and the next day it’s supposed to be 90 °F, even though the average for September is only 75 °F degrees!

The data is precise, but not accurate.

 

4. Four friends decided to go out and play horseshoes. They took a picture of their results shown to the right:

Both accurate and precise.

 

 

 

 

5. A local grocery store was holding a contest to see who could most closely guess the number of pennies that they had inside a large jar. The first six people guessed the numbers 735, 209, 390, 300, 1005 and 689. The grocery clerk said the jar actually contains 568 pennies.

Neither precise or accurate.

 

 

Exercise 6: Significant Digits and Scientific Notation

Part 1: Determine the number of significant digits in each number and write out the specific significant digits.

 

1. 405000 = 3 significant digits – 4,0,5

 

 

2. 0.0098 = 2 significant digits – 9,8

 

 

3. 39.999999 = 8 significant digits – 3,9,9,9,9,9,9,9

 

 

4. 13.00 = 4 significant digits – 1,3,0,0

 

 

5. 80,000,089 = 8 significant digits – 8,0,0,0,0,0,8,9

 

 

6. 55,430.00 = 7 significant digits – 5,5,4,3,0,0,0

 

 

7. 0.000033 = 2 significant digits – 3,3

 

 

8. 620.03080 = 8 significant digits – 6,2,0,0,3,0,8,0

 

Part 2: Write the numbers below in scientific notation, incorporating what you know about significant digits.

 

1. 70,000,000,000 = 7 x 10^10

 

2. 0.000000048 = 4.8 x 10^-8

 

3. 67,890,000 = 678.9 x 10^5

 

4. 70,500 = 70.5 x 10^3

 

5. 450,900,800 = 450900.8 x 10^3

 

6. 0.009045 = 904.5 x 10^-5

 

7. 0.023 = 2.3 x 10^-2

 

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