Household Mercury

The following information illustrates how the average household contributes to the use and release of mercury to the environment. The idea is to provide a sense of how our daily activities, as well as devices and products in our homes, contribute to the overall picture of mercury release and use.

Charts are provided to show percentages of where mercury is most likely found in homes, "Presence/Use of Mercury in Households," and what contributes most to the release of mercury, "Annual Mercury Releases from Households." Mercury "releases" are defined very broadly and include air emissions, discharges to streams, lakes or sewers, and placement in landfills. The following types of uses or releases from households have been documented:

• coal combustion to produce electricity
  
• fluorescent lamps
  
• gasoline combustion in motor vehicles
  
• heating oil combustion
  
• appliance switches (chest freezers, washing machines)
• automotive switches
  
• thermostats
  
• dental fillings
  
• wastewater discharged to sewers
  
• button batteries
  
• gas-pilot ranges
  
• light switches
  
• thermometers
  

Adopted from "Mercury Source Sector Assessment for the Greater Milwaukee Area" by the Pollution Prevention Partnership and Milwaukee Metropolitan Sewage District, 1997

Activity 4 - Hunt for Mercury At Home

Purpose
Students will expand their school efforts by looking at where mercury occurs in their homes.

Objectives

• Involve students in a meaningful, real-life opportunity to do something about an environmental problem at home.
  
• Reduce or eliminate opportunities for students and their families to come in contact with mercury.
  
• Prevent the release of mercury into the environment from mercury or mercury-containing devices at home.
  
• Students will be able to analyze and then determine the level of threat of mercury in their home

Materials

• "Hunt for Mercury at Home," information for conducting a home mercury audit.
  
• Sample letter to the parents
  
• "Hunt for Mercury at Home - Inventory Results" form
  

Procedure

• If appropriate, get the permission of your principal and then inform your parent organization
  
• Introduce the topic of mercury to the class, using any or all of the materials included in the Focus on Mercury section of this package (pages 1-11). Consider doing one or more of the other mercury related activities first.
  
• Try to find out the local contacts for household hazardous waste collection and add these to the bottom of the third page of "Hunt for Mercury at Home." The sewage treatment plant or Dept. of Public Works are good places to find out if there is a household hazardous waste collection program in your area.
  
• Hand out copies of "Hunt for Mercury at Home" to students and allow them 3-7 days to complete the exercise.
  
• Have the students develop their own or use the sample letter provided to send home to each family
  
• Make sure that students understand that they need to discuss this activity with their families before they do it and that it works best if they get help from family members.
  
• Have students compare their results and discuss safe ways of addressing the mercury in their homes.
  

Sample Letter to Parent

Dear Parent,

One topic being covered at school is mercury. Mercury is an element that occurs naturally in the earth's surface. It can be found in many household products, and products at school. Mercury presents an environmental threat because it can accumulate in animals and people, and can be toxic. Its toxicity can endanger living organisms and can produce adverse health effects in people, such as headache, weakness, memory loss, and nervousness among others. Mercury poisoning is possible just by breathing mercury vapors, which are invisible.

There are many efforts across the nation to educate people about mercury, its risks, and how to dispose of it. Mercury can be found in common household items such as thermometers, thermostats, fluorescent lamps, and certain types of appliance switches. An important thing to know is that the primary concern about many of these mercury-containing products is when you dispose of them, and not by just having them in your home. Most are harmless unless broken or disposed of improperly. You do not need to throw out all the mercury-containing products that you find. Any device that contains mercury needs to be recycled properly and cannot be thrown in the trash. Try to find a household hazardous waste collection, or contact the sewage treatment plant or Dept. of Public Works. When it is time to replace a mercury-containing product, use a mercury-free alternative. There are safe, dependable, and easy to use alternatives for all mercury-containing devices used in your home.

At School, your child has studied mercury and its impacts on human health and the environment, and has been given an information packet entitled, "Hunt for Mercury at Home," along with an "Inventory Results" sheet. Please go through this with your child and fill out the "Inventory Results" sheet. Do not be alarmed if you come up with many objects in your home that contain mercury. The purpose of this is to make you aware of them, and what to do with them, and when it comes time to replace them, remember buying smart is a great way to prevent pollution.

Thank you

Hunt For Mercury At Home

Information and Checklist to Help You Inventory the Mercury in Your Home, Learn about Safe Disposal Options and Mercury-Free Products

This guide provides a list of what to look for, what to do about mercury-containing products if you find them and what mercury-free substitutes are available.

Before getting started, share information about mercury with your family and let them know why you are searching for it in your home. Family members may be able to help you identify products that contain mercury and help you decide what to do about them.

Remember, the primary concern about many of these mercury-containing products is when you dispose of them, and not necessarily contact with them in your home. You do not need to throw out all the mercury-containing products that you find.

A good example is thermostats. Many of you will find thermostats with mercury in your homes. These are designed to last a long time and are not a hazard to you and your family unless they break and spill the mercury. The best approach is to let your parents know that different types of thermostats are available and, if they replace the one they have now, they should install a mercury-free thermostat and properly recycle the old one.

This guide provides advice for what to do about each of the mercury-containing products that you may find in your home. Make sure to consider common sense, recycling, safety and pollution prevention before taking action. You can also use this guide to help you and your family buy products that do not contain mercury. If you are careful about not buying mercury-containing thermometers, toys, thermostats, etc., you won't have to worry about mercury in your home in the future. Buying smart is a great way to prevent pollution!

Hunt For Mercury At Home

Nearest Household Hazardous Waste Collection Facility:

Person to call to find out about Household Hazardous Waste Collection in your community:

Hunt For Mercury At Home

Mercury Thermometers

Some fever thermometers contain mercury and should not be thrown in the trash. A typical fever thermometer contains about 0.5 grams of mercury.

Many thermometers used to measure air and water temperature also contain mercury, and they are used by homeowners, businesses, institutions, and anglers. When these thermometers break outdoors, the mercury from them is difficult to capture.
Alcohol or digital thermometers are as accurate as mercury thermometers for most applications. Since they are mercury-free, no mercury will be released if they break or when they are thrown away. Digital thermometers last longer because they do not break. Consequently, they cost less in the long run.

Change to alcohol or digital thermometers whenever feasible. In the meantime, save old or broken mercury thermometers in a closed container. If a thermometer breaks, pick up all the mercury you can and add it to the container. Use two pieces of paper or two razor blades to scoop it up from a smooth surface. Use an eyedropper to pick up pieces of mercury from the floor or the ground. Mercury spill kits are available from safety equipment supply companies for larger mercury spills.

Homeowners can use local household hazardous waste collection programs* for broken thermometers.

Mercury-Containing Thermostats

Mercury-containing tilt switches have been used in thermostats for more than 40 years. They provide accurate and reliable temperature control, require little or no maintenance, and do not require a power source. However, each switch contains approximately 3 grams of mercury.

Mercury-free thermostats are available. Electronic thermostats for example, provide many of the same features as mercury thermostats and can be programmed to lower room temperatures at pre-set times. This results in fuel cost savings and environmental benefits from burning less fuel.

Contact your heating, ventilating, and air conditioning (HVAC) wholesaler. Thermostat manufacturers provide a special container for thermostats to each participating HVAC wholesaler. DO NOT REMOVE THE SWITCHES FROM YOUR THERMOSTATS. The wholesaler consolidates thermostats from heating contractors and mails them intact to the manufacture.

*These services may not be available in your area.

Hunt For Mercury At Home - Inventory Results

Mercury in Fluorescent Lights and the Environmental Impacts

The Use of Mercury in Efficient Electric Lamps - An Update
Due to the heightened concern about mercury build-up in the environment, there have been several recent legislative or regulatory actions targeted at all mercury-containing products. The general objective is to reduce or remove the mercury content of products.

Fluorescent Lamps
All efficient fluorescent lamps contain mercury. Fundamentally, these lamps are a discharge in mercury vapor. When excited, the mercury vapor discharge is an extremely efficient source of ultraviolet radiation; this is converted to visible light by the phosphor powder that coats the interior walls of the lamp.

HID Lamps
For the high-pressure sodium and metal halide lamps, mercury is used to initiate and maintain the discharge. Once started, the light output generated by the sodium, or by the metal halides, dominates the discharge.

Mercury-free developments
Mercury-free fluorescent discharges are available using Xenon. The efficiency is approximately 30% of a normal mercury-based fluorescent lamp, and therefore this technology is environmentally counterproductive for general lighting applications. Despite continuous research
by the private sector, government research labs, and academia, no viable replacement has been discovered for mercury in general purpose fluorescent lamps. The search continues. There are better prospects for mercury-free HID lamps, whereas metal halide lamps without mercury present a greater challenge. The high-pressure sulfur lamp is fundamentally mercury-free, but is unstable and requires forced cooling.

Disposal
The EPA mercury report to the U.S. Congress in 1997 identified combustion sources (coal-fired utilities, waste incineration and boilers) as the three major sources of manmade mercury emissions in the U.S. Together they represent 87% of the total. By contrast, lamp disposal represented <1% each for lamp breakage and lamp recycling. It is ironic that the use of efficient mercury containing lamps is the number one choice for reducing power demand and thereby influencing utility emissions. Lamp disposal by incineration with other municipal wastes is a relatively recent phenomenon in some states. This represents the riskiest form of disposal with <90% mercury emission into the atmosphere where no controls exist on the incinerator. Recycling of large quantities of lamps, where they are shipped intact to the recycling location, represents one of the lowest environmental emissions and the least legal liability arising from the U.S. Superfund (CERCLA) legislation.

* information taken from OSRAM SYLVANIA's website, the North American division of OSRAM GmbH

Activity 5 - Trade-offs

Purpose

One way to reduce mercury pollution from coal burning electrical plants is to use less electricity. Fluorescent light bulbs use much less energy than incandescent light bulbs, but most fluorescent bulbs contain tiny amounts of mercury. What makes sense ecologically?

Objective

• Evaluate the pros and cons of two alternative technologies.
  
• Learn how to organize data and determine the mathematical relationships needed to solve a problem.
  
• Coherently present the results of calculations to support a recommended choice or alternative.

Materials

• Handout entitled "Trade-Offs: Your Lights, Your Environment and your Checkbook"
  
• Trade-offs: Question sheet and Answer sheet
  

Procedure

• This activity can be done as homework, or as an individual or group assignment
  
• Make copies and distribute "Trade-Offs: Your Lights, Your Environment and Your Checkbook," and the "Questions" sheet to the students and ask them to prepare answers and justifications for all questions

	VS
Fluorescent bulbs		Incandescent bulb
(containing mercury)

Trade-offs

"Trade-Offs: Your Lights, Your Environment and Your Checkbook"
Incandescent vs. Compact Fluorescent Bulbs- Energy Use, Mercury Emissions and Cost

The largest source of mercury to the environment is coal-burning electric power plants. There is a very small amount of mercury in the coal that is burned to produce electricity. However, because vast amounts of coal are burned, the amount of mercury released up the smoke stacks is very significant.

One of the largest uses of the electricity produced by these power plants is for lighting homes, buildings and streets. Can the choice of light bulbs in our homes make a difference in terms of the amount of electricity used, the amount of mercury released and the amount that we pay for electricity? Let's figure it out.

Cost of electricity from the power plant-$0.07 per kilowatt-hour
Pounds of mercury released per kilowatt-hour of energy used = 3.69E-08 (= 0.0000000369)

Keep in Mind-

1 kilowatt =1,000 watts
A lumen is a measure of brightness
A kilowatt-hour is a measure of total energy used over a period of time
1 pound = 454 grams
It takes 10 Incandescent bulbs to last as long as 1 compact fluorescent bulb

Equations to Use:
1. Efficiency = light output / energy requirement

2. Amount of mercury released = hours of use x energy requirement x pounds of mercury released per kilowatt-hour of energy x 454 grams/pound of mercury / 1000 watts/kilowatt

3. Electricity cost = Hours of use x energy requirement x cost of electricity / 1000 watts/kilowatt

Trade-offs

Questions

1. Which type of light bulb - incandescent or compact fluorescent - is more efficient? Why?
2. After 10,000 hours of use, how much mercury (in grams) is released to the environment due to use of each of these two types of light bulbs?
3. After 10,000 hours of use, what are the total costs, including purchase price and electricity, for each type of light bulb?
4. Which type of bulb would you recommend? Why?

Optional

5. Make an educated guess as to how many light bulbs are in use in your community. Based on this estimate, design a study to determine the differences in cost and in mercury released if all those bulbs were either incandescent or compact fluorescent.

Trade-offs

Answers

Which type of light bulb - incandescent or compact fluorescent - is more efficient? Why?
Efficiency, in this case, is measured by light output per amount of energy used. For the compact fluorescent bulb, this is 925 lumens/15 watts = 61.67. For the incandescent bulb, this is 870 lumens/60 watts = 14.5. Thus, the fluorescent bulb is 4.25 times more efficient.

After 10,000 hours of use, how much mercury is released to the environment due to use of each of these two types of bulbs?
The amount of mercury released due to use of the compact fluorescent bulb is:
10,000 hours X 15 watts X .0000000369 pounds per kilowatt-hour X 454 grams per pound ¸ 1,000 watts per kilowatt = .0025 grams. The equation for the incandescent bulb is the same, except that 60 watts is substituted for 15 watts. Thus, the amount of mercury released is 4 times greater for the incandescent bulb, or .01 grams.

After 10,000 hours of use, what are the total costs, including purchase price and electricity, for each type of light bulb?

Thus, the incandescent bulb is 90% more expensive.

Which type of bulb would you recommend?
Consider efficiency (compact fluorescent is 4.25 times more efficient), amount of mercury released (4 times less for compact fluorescent) and total cost (90% less for compact fluorescent).

Study design to determine the differences in cost and in mercury released for the community if all those bulbs were either incandescent or compact fluorescent.

The study design should include identification of the following steps:

• estimates of the number of bulbs used in lighting homes, streets and businesses
  
• assumptions about the frequency of bulb replacement
  
• determination of the total amount of energy
  
• application of the mercury released per kilowatt factor to determine total mercury releases
  
• determination of purchase and electricity costs