HLTH101 Lecture Notes - Lecture 12: Environmental Health, Nitrogen Dioxide, Food Energy
19 Dec 2016
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WEEK 11: ENVIRONMENTAL HEALTH AND EMERGING ISSUES
Environmental health grew out of the efforts to control communicable diseases, for example,
providing clean water, having sanitary waste disposal, safe food, insect and rodent control, and
being able to respond to natural or human-made disasters. The focus on environmental health has
expanded and become more complex now. In terms of a definition, environmental health is the
collective interactions of humans with the environment and the short-term and long-term health
consequences of those interactions. We should have as our goal to pass on a world no worse
(preferentially better) than the one we enjoy today to the future generations. The world’s
population is increasing at a rate of about 83 million per year (160 people every minute!) and the
UN has projected the world population will reach 11 billion by 2100. The world’s age
distribution will also be quite different with more older people than children. Factors that
contribute to this population growth include high fertility rates, lack of family planning
resources, and lower death rates. In order to manage the population, we should improve the
conditions of peoples lives and remove the pressures for having a large family. We should
improve health, provide better education, increase literacy, increase employment opportunities
for women, and provide family planning resources. This rapid increase in population puts major
stresses on the environment as it makes it more difficult to provide basic components of public
health, like clean and disease-free water and food. It will also act as the driving force for
increased chemical pollution, global warming, thinning of the ozone layer, and other
environmental concerns. So how many people can the world hold exactly? This number is
limited by the amount of food, land, water, energy (non-renewable sources like natural gas and
fossil fuels!), and also by the minimum acceptable standard of living. If everyone consumed
energy like people in Canada and the US, the world would quickly be depleted of resources.
Let’s talk about our world’s natural ecosystems and biodiversity. What do those terms mean
exactly? Biodiversity refers to the variety of living things on the earth, including all the different
species of flora and fauna and the genetic diversity among individuals of the same species.
Ecosystem is the community of organisms (plants and animals) in an area and the nonliving
physical factors with which they interact. The community of organisms are linked together in a
food chain/web (showing the food energy transfer). Currently, there are many threats to
biodiversity, especially those done by humans. There is excessive consumerism in industrial
nations for example. The loss of species and populations or organisms is seen from the
overharvesting of elephants, whales, and certain fish, and the destruction of tropical rainforests.
16000 species of animals are in serious danger of extinction today! Air pollution is natural from
forest fires, pollen blooms, dust storms, and other natural pollutants, but humans also contribute
to this. Air pollution is linked to a wide range of health problems mostly from the very young
and older adults. It increases the risk of death in people with chronic ailments like diabetes or
heart failure. Sounds strange that it affects diabetes but it is true. We measure the air quality with
the Air Quality Health Index (AQHI) which indicates whether air pollution levels pose a health
concern. It measures nitrogen dioxide from motor vehicles and power plants, particulate matter
from the combustion of fossil fuels, industrial processes, and grinding operation, and ground-
level ozone levels from the emissions of cars or industrial plants chemically reacting in the
presence of sunlight. AQHI levels from 1-10+ and a level above 7 is a high health risk. Smog
today is a mixture of pollutants with ground-level ozone being the key ingredient. The
temperature of the earth’s atmosphere depends on the balance between the amount of energy the
planet absorbs from the sun and the amount of energy radiated back into space – the greenhouse
find more resources at oneclass.com
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Document Summary
Environmental health grew out of the efforts to control communicable diseases, for example, providing clean water, having sanitary waste disposal, safe food, insect and rodent control, and being able to respond to natural or human-made disasters. The focus on environmental health has expanded and become more complex now. In terms of a definition, environmental health is the collective interactions of humans with the environment and the short-term and long-term health consequences of those interactions. We should have as our goal to pass on a world no worse (preferentially better) than the one we enjoy today to the future generations. The world"s population is increasing at a rate of about 83 million per year (160 people every minute!) and the. Un has projected the world population will reach 11 billion by 2100. The world"s age distribution will also be quite different with more older people than children.
