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University of Toronto Scarborough
Environmental Science
Jovan Stefanovic

EESA10 Notes LEC01 Introduction to environmental health threats Your environmental health threats: smog, air pollution Some things in the environment make people get sick some people get sick and other people dont why? Environment influences our health, but it is not the only factor other factors include genes The agents of the that affect environment are in crisis We change the environment through human activities: (we do these because we want to increase life satisfaction, but humans went beyond the boundaries beyond the sustainable environmental usage) o Geosphere: through mining area o Biosphere: by cutting and clearing forests o Industrialization o Overpopulation leads to overconsumption materialism and production of more goods which will lead to higher population The effect of these human activities on environment: o Wide species the health of these species decline we look at other organism that give us an indication that we are facing an environmental crisis example: frogs, the number of frogs declined significantly o these means that there could be potential threats to human health as well huge amount of diseases can be preventable if we do something about the environment two of the most hazardous environmental diseases (that kills many kids in countries like Africa and Asia) are diarrhea and respiratory infections these are very treatable in our environment but are deadly in other areas of the world difficult to assess its difficult to prove that air pollution or environment causes diseases controversy between scientists about whether some diseases are environmental diseases there is a big different between the occurrence of environmental diseases between people with different social class (rich and poor) and between different racial groups and difference between developed and developing countries chart of 1992 highest percentage of Hispanic people are affected by air pollution, African American most affected by sulfur dioxide pollution poverty (under social hazard) is the biggest risk to get sick / to get an environmental disease nd smoking is a social hazard it can be voluntary or involuntary (2 hand smoking) Video Everyday Carcinogens Sandra claims some cancers and other health problems are related to environmental conditions this claim remains very controversial, some scientists and regulators believe that her statements are not very strong and not very scientific another group (some scientist and environmental activists) believes she is very right there is no 1 study that constitute absolute truth to this issue but there are many smaller studies that link together to tell a story Evidence linking cancer to the environment o Cancer registries: measures incidence of cancer in our country incidence trends show that non-tobacco related cancer have been rising in all age groups (from infants to elderly) in both genders and they are apparent ever since the 1970s changes in hereditary cannot account for this, nor can better detection nor can changes in lifestyle (exercise and diet) childhood cancers have increased double since 1959 and jumped 10% in the last decade testicular cancer are also in rise among young men (tripped in incidence rate since WW2), bone marrow cancer, brain cancer, non-halogen cancer are also on the rise o Computer mapping: this takes the data from cancer registries and plot where the incidence occur on geographic areas not a random tragedy places that use the most pesticide have the highest rates of cancer this is a correlation a possible link between environment and cancer o Our own bodies: there are many chemical residues in our body these chemicals partition themselves in different parts of the body endocrine disruptors: mimic or interfere with our hormones (messengers for our genes) that get inside our cells to alter the expression of genes we cant just look at the chemicals that cause mutations timing of exposure (the dose makes the poison) we regulate according to this paradigm, but a new science tells us that there are windows of vulnerability that we each go through in which at different ages we are most sensitive to different amounts of chemicals that set us up for future risk of cancers (we enter and leave the windows of vulnerability) o Animal studies: there was a parallel epidemic in animals as it does in humans i.e. whales, fish, salamanders, etc with cancer also animals in more prestigious places do not have cancer while animals in other areas do Scientist proof making set the standards very high (95% chance) Occupational risk one group that has excess rates of non-hoegin are farmers, gold course supervisors, pesticide applicators all they have in common is that they are in contact with pesticide Dogs who use weed killers in backyard are more likely to have canine non-hogegins Contamination pyramid from plants to animals to humans dioxin in breast milk LEC02 Airborne hazards Smog and air pollution became a problems in the beginning of the industrial revolution Case 1 London smog 1952 o Lasted 2 weeks on December 1952 o The weather has some impact o London is known for its humid air, and during that 15 days, temperature was relatively low (1degree C) humididty was very high (80%), air was stagnant/still this cold weather and fog increased the demand for heating (by coal burning the major source of energy at that time) o Huge amount of ashe, particulate matter and sulfuric acid was released in a short period of time by burning coal in still air o In addition, industries have to burn coal o cars and busses need their headlights on o the smog was the cause of thousands of deaths in the 6 days (about 4000 people died as a result of air pollution) o the peak of number of death is on the same day of the peak of sulfur dioxide and smoke o the crisis was solved by themselves because of change in climate but this serves as a mark to warn other countries on the need to improve the quality of air o South Ontario has a lot of pollution, Hamilton, Kitchener, Waterloo all heavily affected by air pollution Case 2: Indonesian Fires 1997 o The case was slash and burn practices (very common in tropical countries) they simply burn the forest to clear up the area and use the land for agriculture and then after a couple of year, they just abandon the area and move and just burn another area these practices was very common o During the 1997 incident, in Indonesia, the rain was late (did not come on time), so people used this dry period to burn even more areas, and rain was not on time to solve put out the fire so it spread fast and vast o It solved itself when rainfall came o Huge amount of particulate matter (ashes) were leaked into the atmosphere o About 20million people asked for help due to respiratory problems related to this incident Indoor air pollution and outdoor air pollution both affect our health Outdoor air pollution o Air pollution can be divided into human sources and natural souces o Human sources can be further devided into two sources stationary (industries) and mobile (veicles) o All of these sources produce similar primary air pollutants when primary pollutants are released into the atmosphere, they will react with the normal chemicals in the atmosphere to yield secondary air pollutants Health effects of outdoor air pollution
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