ENVIRONMENTAL HEALTH DEFINED
The field of environmental health grew out of efforts to control communicable diseases. When certain insects and rodents were found to carry microorganisms that cause disease in humans, campaigns were undertaken to eradicate or control these animal vectors. It was also recognized that pathogens could be transmitted in sewage, drinking water, and food. These discoveries led to systematic garbage collection, sewage treatment, filtration and chlorination of drinking water, food inspection, and the establishment of public health enforcement agencies.
These efforts to control and prevent communicable diseases changed the health profile of the developed world. Americans rarely contract cholera, typhoid fever, plague, diphtheria, or other diseases that once killed large numbers of people, but these diseases have not been eradicated worldwide.
In the United States, a huge, complex public health system is constantly at work behind the scenes attending to the details of these critical health concerns. Every time the environment The natural and human-made surroundings in which we spend our lives. environmental health The collective interactions of humans with the environment and the short-term and longterm health consequences of those interactions.
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Answers (Test Your Knowledge)
1. b. The world’s current population is about 7.1 billion, and it is growing at a rate of about 75 million per year.
2. True. There are many types of naturally occurring air pollution, such as smoke from forest fires and dust from dust storms.
3. True. Compact fluorescent lightbulbs use 75% less energy and last up to 10 times longer than regular lightbulbs.
Natural disasters such as the 2013 floods in Uttarakhand, India can directly kill thousands of people while wiping out essential services, polluting water, and facilitating the spread of disease. system is disrupted, danger recurs. After any disaster that damages a community’s public health system whether a natural disaster such as a hurricane or a human-made disaster such as a terrorist attack prompt restoration of basic health s ervices becomes crucial to human survival. Every time we venture beyond the boundaries of our everyday world, whether traveling to a less-developed country or camping in a wilderness area, we are reminded of the importance of these basics: clean water, sanitary waste disposal, safe food, and insect and rodent control.
Over the past few decades, the focus of environmental health has expanded and become more complex, for several reasons. We now recognize that environmental pollutants contribute not only to infectious diseases but to many chronic diseases as well. In addition, technological advances have increased our ability to affect and damage the environment. Also, rapid population growth, which has resulted partly from past environmental improvements, means that far more people are consuming and competing for resources than ever before, magnifying the effect of humans on the environment.
Environmental health is therefore seen as encompassing all the interactions of humans with our environment and the health consequences of these interactions. Fundamental to this definition is a recognition that we hold the world in trust for future generations and for other forms of life. Our responsibility is to pass on a world no worse, and preferably
How often do you think about the environment’s impact on your personal health?
In what ways do your immediate surroundings (your home, neighborhood, school, workplace) affect your well-being? In what ways do you influence the health of your personal environment? better, than the one we live in today. Although many environmental problems are complex and seem beyond the control of the individual, there are ways that people can make a difference to the future of the planet.
POPULATION GROWTH AND CONTROL
Throughout most of history, humans have been a minor pressure on the planet. About 300 million people were alive in the year 1 CE; by the time Europeans were settling in the Americas 1600 years later, the world population had increased gradually to a little over half a billion. But then it began rising exponentially zooming to one billion by about 1800, more than doubling by 1930, and then doubling again in just 40 years (Figure 15.1).
The world’s population, currently about 7.1 billion, is increasing at a rate of about 75 million per year approximately 150 people every minute. The United Nations projects that world population will reach 9.3 billion by 2050.
The average number of children per woman fell from 5 in 1950 to half that (2.6) in 2010. This decline in fertility began in Western countries decades ago and is now also happening in poor countries. In Sub-Saharan Africa, Asia, and Latin America, women with more education have fewer children; these regions nevertheless contribute the most to population size. Changes are also projected for the world’s age distribution: For the first time in history, there are more older people than young children. By 2050 there will be 3.4 times the number of people age 60 and over than of children age 4 and under.
This rapid expansion of population, particularly in the past 50 years, is generally believed to be responsible for most of the stress humans put on the environment. A large and rapidly growing population makes it more difficult to provide the basic components of environmental health discussed earlier, including clean and disease-free food and water. It is also a driving force behind many of the relatively more recent environmental health concerns, including chemical pollution, global warming, and the thinning of the atmosphere’s ozone layer.