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University of Toronto Scarborough
Environmental Science
E E S A10

Ahmed Sarwar 997471187 EESA10H3 Y "HUMAN HEALTH AND THE ENVIRONMENT" Assignment #1 TA: Aman Saini To be completed: By Monday, June 11 at 5 pm 1. Studies have found that some bottled water comes from municipal water supplies and that bottled water frequently contains contaminants. Considering also waste and energy associated with bottling, under what conditions does it make sense to drink bottled water or to avoid drinking it? (10 points) Support your statements with at least two scientific references. Bottled water is one of the few things that can be useful and wasteful. Under certain circumstances bottled water can be a blessing. It is helpful in disaster situations like earthquakes and tsunamis where clean water becomes scarce, bottled water can be shipped and transported safely and easily. Also in places such as Africa where the lakes and rivers are contaminated with harmful bacteria such as Salmonella and E.Coli, bottled water is one of the best sources for clean water. But when bottled water is used in large quantities by disaster victims, the empty plastic bottles become a pollution hazard. In recent years there have been developments in water purification that use nano fibre filters to purify water to the WHO safety level. These filters last thousands of liters and are easy to use, so bottled water usage can be reduced there too. The best advantage of bottled water is that it is convenient. It can be taken anywhere without the danger of contamination from harmful bacteria. But bottled water is a waste in developed urban cities where there is an abundance of clean filtered standardized water. As mentioned above, the empty plastic bottles are one of the major causes of pollution in the world today. Every year billions and billions of empty bottles are dumped into landfills, oceans and burned also causing air and water pollution. Bottled water stored over long periods of time becomes contaminated with chemicals from the plastics. Most plastic bottles are made of polyethylene terephthalate (PET). The concentration of chemicals such as antimony increases the longer the water sits in PET bottles. Antimony is a white metallic element that in small doses can cause nausea, dizziness and depression. In large doses, it can be fatal. Just after six months after sitting in plastic the antimony level doubles which is way below safety standard. Also some bottled water is distilled water which deprives the human body of many necessary chemicals such as sodium and fluorides. Bottled water also does not have the quality and standard checks that are required for household tap water. The FDA and EPA strictly ensure that the water reaching our houses is clean and up to drinking standards. Bottled water on the other hand does not have a fixed agency that regulates it. Each corporation has different regulation which give the water companies loopholes to slip past. Some bottled water brands are even below the WHO safety standards. Another reason to avoid bottled water is the cost. People in urban areas pay thousands of dollars each year to have clean drinking water that is available in their houses for free. Most people believe that the water that they have coming out of the tap is not safe which motivates them to buy bottled water. The Walkerton incident was one of the biggest blow to the safety of tap water. Most bottled water companies in their advertisements show how the water is obtained from springs and mountains, which makes people think that their water is the best, whereas its source is just municipal tap water. All in all, bottled water can be a blessing where it is most needed and a curse where it is just a luxury. Ahmed Sarwar 997471187 EESA10H3 Y 2. Assume that Canada and the U.S. are negotiating a treaty to govern their emissions of mercury to the environment. You are a science advisor to the Canadian team. Some members of the team want to press for “zero emissions” policy, believing that no emissions of mercury to the environment are acceptable. They ask for your advice on this issue. What kinds of information about that toxicity of mercury to humans do you need in order to give the team objective advice about the proposed zero emission policy? (Provide 5 different points). Also, is it physically possible to have zero emission? (10 points) Support your statements with at least two scientific peer-reviewed references (e.g. peer- reviewed journal articles). Mercury is one of the most poisonous elements that are fatal to human beings. It causes symptoms such as tachycardia, high blood pressure, kidney problems, neural symptoms to name a few. Many times these symptoms are misdiagnosed and are often not treated properly. Coal, manufacturing plants and other industrial processes such as steel and cement production and waste disposal are responsible for almost half of the mercury emissions in the air today. Once in the air mercury can circulate and accumulate for years. Inhalation of mercury can lead to pulmonary symptoms such as fever, difficulty in breathing and chills. It also settles in water which is then consumed by fish. Today, the consumption of fish is perhaps the most important source of mercury exposure. Mercury is present in sea water in very little amounts. Mercury in its elemental form is relatively harmless but when it is absorbed by algae which is then consumed by the fish, it overtime accumulates to large quantities in the fish knows as bioaccumulation which turns it into methylmercury. These fish when eaten by us especially young children and pregnant mothers are particularly harmful. The affects of mercury on human health depend on many factors; the dose, the chemical form, the age , the duration of exposure, the route of exposure and the persons health. Mercury has 3 forms elemental mercury, inorganic salts and organic compounds. Perhaps the most deadly form of mercury is methylmercury. Only 2-10% of the ingested mercury is absorbed from the gut, and ingested elemental mercury is not absorbed at all; however, 90% of any methylmercury ingested is absorbed into the bloodstream from the GI tract. More than 60,000 children are born each year with adverse neurodevelopment effects due to in utero exposure to methylmercury. It is not physically possible to reach ‘zero emissions’ for mercury as there are many natural surces like volcanoes that inject large amounts of mercury into the atmosphere. But the natural process has a knack of keeping things balanced, so as long as we don’t disturb it, the emissions of mercury is not a problem. 3. You have just been hired as the office manager for a high-tech start-up company that employs bright and motivated young people but is located in an old, dilapidated building. Despite their youth and vigor, the company’s employees seem perpetually sick with colds, headaches respiratory ailments, and other unexplained illnesses. Looking into the building’s history, you discovered that the water pipes and ventilation system are many decades old, and part of the building was remodeled just before your company moved in but there are no records of what was done in the remodel. Your company has all the latest furniture, computers, and other electronics. There is an indoor smoking lounge.You want to figure out what is making the employees sick, and you want to convince your boss to give you a budget to hire professionals to examine the building for hazards. Support your statements with at least two scientific references. Ahmed Sarwar 997471187 EESA10H3 Y A. What hazards might you expect? Describe at least 5 hazards (5 points) As the building is quite old the building material used might contain asbestos. Asbestos is a set of 6 natural silicates that have very useful properties. Asbestos is practically safe in its whole form but once its fibres break and become airborne it is deadly. When inhaled, it can form tumors in the body and affect the lungs. Prolonged inhalation can cause cancer, asbestosis and other serious illnesses. Asbestos was commonly used in building construction materials for insulation and as a fire retardant. The symptoms the workers were showing could be one of the illnesses caused by asbestos. Another dangerous chemical that might affect the health of the workers is formaldehyde. As the building was remodeled before they moved in, formaldehyde could have been present as it is commonly used in glue and adhesives in wood products, paints, coatings and insulation materials. Formaldehyde exposure
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