Ms. Judith Dixon
Long Island Sound
The Long Island Sound is approximately 11,000 years old. Many centuries ago it was a river. Emerging into a valley then a lake. Today it’s a body of water. It is salt water and is considered to be an estuary. The bottom is muddy with beach ridges. The shoreline cliffs are dark and resemble ribbons. Clay exist form when it was a lake. In the sediments the shells of animals are buried deeply. They were alive during the days of being a valley.
Today Long Island sound houses more than 8 million people in its watershed. Twenty -- one million live within a 50-mile radius of Long Island Sound. The watershed is all the land from which the water drains into the sound. It extends into Canada, and covers an area of about 16,00 square miles. As an estuary fresh water from the draining rivers of Vermont, New Hampshire, Massachusetts, Connecticut, and New York mixes with the salt-water form the ocean.
Any pollutants that enter the water from as far as Canada and New Hampshire can harm the sound. It can cause problems for ate wildlife and people dependent upon the sound. The sound is a place where many plants and animals live, called a habitat.
It also has recreational and commercial uses for the people. The economy form the sound is more that 5 million dollars a year. The regional economy includes boating, fishing, swimming, and beach going.
Unfortunately, humans have been using the Long Island watershed as an disposal site since the beginning of the industrial era. Chemicals have been dumped into these rivers for centuries. In the last few years point sources of water pollution, which comes from factories and sewage treatmenat plants, has been reduced. The number one water pollution source now comes from cars that leak oil; fertilizers that runs off field, lawns and gardens; septic systems that aren’t in good working condition. When it rains these pollutants are washed into the storm water drainage system. The systems usually lead directly into the rivers, oceans, lakes, and ground water.
Mercury
Mercury can exist in many forms. Metallic mercury is a silver metal that is liquid at room temperature. Mercury salts and organic mercury compounds can be powders or liquid. In it liquid state, Mercury can be used in thermometers and some electrical switches. When Mercury evaporates it changes into an odorless, colorless vapor. Organic Mercury compound is derived from Methyl-mercury (MeHg). This type of Mercury is the greatest threat to the environment.
How can mercury affect our health?
High levels of Mercury especially in the form of Methyl-mercury can cause harm to an adults Kidneys and brain. Damage to the Nervous System can also occur. There may be a tingling sensation that affects the body extremities. Symptoms can also result from exposure to high levels of Mercury. They include irritability, shyness, and tremors, changes in vision or hearing, or memory problems. Some children can develop learning problems and poor growth development. Pregnant women should be especially cautious to Mercury exposure. Women who wish to become pregnant should avoid it as well.
Mercury can enter ponds, lakes and rivers through air pollution. The Mercury pollutes the water, which contaminates the fish supply. It is found more commonly in fresh water. Only a few types of fish are found in salt water that contains levels of Mercury. They can have high levels of PCB’s as well. Pregnant women should avoid eating the following types of fish: Shark, Swordfish, Bluefish, Striped Bass, Tuna and Catfish. The list below shows water bodies in CT. that have high levels of mercury, PCB’s and dioxins. Therefore, following fish species from these rivers should be avoided for human consumption.
(chart available in print form)
The EPA has put some safeguards in place for human health. Only two parts per million (ppm) for mercury is recommended in drinking water, nationwide. In the rivers, lakes and streams, there should be no more than 0.144 mercury ppm in water level for human health consumption. EPA’s Office of Water issued guidelines that make reference to methyl-mercury in the consumption of fish. The EPA has recently given a report that linked pollutants to the threat in our nation’s waters, which directly affect public health. It has been confirmed that the water has been contaminated from air pollution. The advisories have warned people to limit or avoid the consumption of fish.
The statewide advisory suggests one meal of fish per month. You should eat smaller fish, preferably pan fish, such as Yellow Perch, White Suckers and sunfish. When considering young children, limit the consumption of other seafood and also Tuna. They should only have one or two meals per week. The consumer should buy light tuna not white or chunk white. Light tuna has less Mercury than other types. Women who are pregnant are encouraged not to eat any Swordfish or Shark. The Mercury levels are too high.
Dioxins
Dioxins are known as persistent organic pollutants. They are very dangerous chemicals. Dioxins proper name is 2,3,7,8 tetrachlorodibenzo -- para -- dioxin (TCDD). Its name is also used to identify the family of structurally and chemically related polychlorinated dibenzofurans PCDDs and polychlorinated biphenyls PCB’s. There have been biphenyls PCB’s. There have been 419 types of dioxin related compounds identified. Only 30 are significantly toxic. TCDD is the most toxic compound.
When dioxins have entered the body or environment they stay there. The dioxins dissolve in fat cells along with their chemical stability. In the environment they can bio -- accumulate into the food chain. The higher one goes in the food chain the concentration of dioxins are evident.
Sources of dioxins are mostly by products of industrial processes. It can also be from Natural processes as well. They can come form volcanic eruptions and forest fires. These compounds are produce chlorine -- containing organic substances. They’re formed through a thermal process. These are also unwanted by products, through the manufacture process -- smelting, bleaching of paper pulp. Manufacturing herbicides and pesticides. Release of the compounds from solid waste incinerators is he worst culprit. The reasons it is so awful is that the combustion process s incomplete.
Dioxins are found in air, soil, water, sediment and food. Dioxins are found more frequently in dairy products, meat, fish, and shellfish. Higher levels are found in some soils, sediments and chemicals. Lower levels are found in the water and air. Throughout the world there are stores of waste industrials oils. The levels of dioxins are high. When waste is stored for along period of time the materials can be released. It then spread to the environment. Contamination can result affecting the human and animal food supply.
In Belgium high levels of dioxin were found in the eggs and poultry. It started with the feed that was given to the animals. TCDD has been linked to the herbicide Agent Orange which was used the Vietnam War.
In 1976 a chemical factory in Serveso, Italy had a serious chemical accident. A study discovered TCDD in the air. There were clouds of toxic chemicals in which dioxins were released. The contamination, covered 15 square kilometers, the population was 37,000.
In 1997 dioxin contamination was found in the southern part of the U.S.A. There were chickens, eggs and catfish that were contaminated with an ingredient bentonite, which is a dioxin. The ingredient was in manufacturing animal feed. When the incident was investigated it was speculated that perhaps the source of the dioxins were of a prehistoric origin.
Most contamination incidents have occurred in industrialized countries. The reason is that adequate monitoring; awareness of possible contamination in the food supply provides better regulatory controls and detection of any dangerous chemical substances.
The effects of dioxins on human health are both long and short term. Short-term exposure of humans to high levels of dioxins can result in adverse affects to the skin. Lesion can form, such as chloracne and also patchy darkening parts of the skin. The livers function can also be altered. Long-term exposure affect’s the immune system, developing nervous system, endocrine system and reproductive functions.
When animals were exposure frequently to dioxins the results found several types of cancer in the animals. The International Agency for Research on Cancer evaluated TCDD I 1997. Based on the data of human epidemiology dioxin was categorized as a known carcinogen. However TCDD does not affect genetic material. There is a level of exposure below which cancer risk would be negligible.
Fetuses are the most sensitive to dioxins exposure to dioxins because of their diet. Consumers of large amounts of fish in certain parts of the world are at a greater risk. Individuals who work in the paper and pulp industry, incineration plants, hazardous waste sites are also included. The risks to the dioxins are calculated case by case. Accurate information is given to assess the health impact on the sub groups or population. It can be used a basis for policy decisions to be made. A Tolerable Daily Intake (TDI) is an assessment that is used to assess long-term exposure to dioxins.
The TDI is then calculated based on how much the body has accumulated dioxins and over a long duration of time. It’s estimated that 90% of human exposure to dioxins is through the food. To ensure the safety of the food process good practices must be apparent. Processing from farm to the table must be carefully followed. Food contamination monitoring systems should be in place.
The consumer can reduce the risk of exposure by doing the following: trim fat from meat, consume low-fat diary products, a balanced diet with adequate amounts of fruits and vegetables, and cook foods which can eventually decrease the body’s exposure of dioxin compounds. The suggestions are limited. The government is ultimately responsible for monitoring the safety of the food supply.
To measure dioxins in the environment and food an analysis is conducted. Its availability is limited to a certain number of laboratories around the world. One --hundred laboratories are able to analyze dioxins in environmental samples such as, ashes, soil, or water and food. For analysis of dioxins in blood and breast milk there are approximately twenty laboratories. They are mostly located in industrialized countries. The cost varies from $1,200 of a single biological sample to $10,000 or more for a comprehensive waste and incinerator assessment in the U.S.A.
Dioxins are best destroyed through incineration. The process requires high temperatures that are over 850 0C. When destroying large amounts of contaminated material, higher temperatures of 100 0 C or more are required.
An agency called WHO has contributed to helping reduce dioxin intake. In 1988 held a consultation in Geneva to evaluate the TDI of dioxins to which humans are exposed without harm. The new epidemiological data showed the effects of dioxins at low levels of exposure. The data along with animal studies showed that the TDI was reduced from 10 picogrammes / kilogram body weight to a range of 1 to 4 picogrammes / kilogram body weight. Current levels of exposure in industrialized countries are 1 to 3 kilograms of body weight. This TDI is internationally recognized as a reference value to ensure that the levels of exposure are beyond the guidelines.
WHO has collaborated with the Food and Agriculture Organization. The Codex Alimentarius Commission is considering establishing guideline levels for dioxins in foods.
In 1976 WHO was responsible for the Global Environment Monitoring System’s Food Contamination Monitoring and Assessment Program. It’s known as GEMS / Food. The program provides information on levels and different trends of contaminates in food. The network has participating laboratories in over 70 countries.
(Dioxins, 1999)
Lesson Plan I
Geography
Objectives:
Students will be able to recognize and label the various rivers, lakes and ponds in Connecticut.
Procedure:
Students will be given a list of rivers, ponds, and lakes. This list will be used as a vocabulary list. The children will be divided into three groups. Each group will have maps of Connecticut.
Group A River
|
Group B Lakes
|
Group C Ponds
|
Activity:
The Connecticut Map (large) will be cut into pieces. The students will putthe map together as a puzzle.
Lesson Plan II
River Activity / Watershed Activity
Objectives:
-
The students will be able to name the parts of the river
-
They will also be able to explain the function of a watershed.
-
The students will be able to explain the process and functions of the Water Cycle.
Materials:
-
photocopies of the River System Diagram (interactive version of this river system can be found at www.nationalgeographic.com/geographyaction.)
-
blue enamel paint
-
miniature objects to simulate a model river system: e.g. Monopoly game houses or hotels, small plastics animals, trees, boats, cars
-
modeling clay
-
tempera paint
-
toothpicks and construction paper
-
sheet of plywood, or plastic or metal trays
-
water
Procedure:
Day One
With students, examine the river system diagram. Have students speculate where they are located in their watershed. Where is the nearest river? The nearest tributary? Remind students that the drawing is a generic representation of elements of rivers, and that every river system is unique. Does a local river resemble the river diagram?
Explain that rivers connect to land, and that people connect to rivers either directly or indirectly, via their watershed. Ask, How do people use rivers? (drinking water, other fresh --water needs, agriculture, industry, manufacturing, power, transportation, recreation) How does wildlife use rivers? (food, habitat) Write students’ answers on the board.
Now, divide students into three groups. Each group will build a model watershed from clay, either on a sheet of plywood, or on a plastic or metal tray. Have students label parts of the river: source, tributary, floodplain, meander, wetland, main river, mouth. Students should then paint “river” areas with blue enamel paint and paint the “land” with tempera paint. Have students place miniature objects on the model to stimulate a model river system, or make figures from construction paper and back them with toothpicks.
Day Two
Allow the model to dry overnight. The next day, have students pour a slow, steady stream of water from the top of the mountain. As students pour water, discuss flooding and drought.
End by reminding students that what people put into the water, and how people use the water available to them, is very likely to affect the quality of the water -- and the quality of life of its users -- both locally and in other areas of a watershed.
(lesson adapted from www.nationalgeographic.com/geographyaction)