The role of environmental health in the health care system.
Determinants of Health
The four basic determinants of health are hereditary or biological factors, medical care, lifestyle, and environment.
Hereditary or Biological Factors
Major aspects of human biology are controlled by genetics. A person may be healthy in every other way but may have inherited conditions such as hemophilia, diabetes, Down's syndrome, various eye problems, lack of resistance to disease, or any number of other problems.
The medical care we receive during our lifetime can determine our health. For example, if a child develops streptococcal infection and does not get medical care, he or she might develop a rheumatic heart condition. Or, if a youngster breaks a limb and does not receive proper medical care, he or she might end up with a deformed arm or leg.
Ever-increasing technological advances have added productive years to thousands of lives. Technological devices include sophisticated equipment for kidney patients, artificial organs, monitoring instruments for the human fetus, and electrocardiograph devices worn by patients to detect an oncoming heart attack. These amazing instruments have captured the fancy of society and added to the cost of health care.
Lifestyle has a lot to do with one's health. Lack of sleep and rest reduces our resistance to infections and leads to bodily degeneration. A person who has an excellent body but eats poorly, does not exercise enough, smokes, and drinks heavily may develop health problems rather quickly. Many Americans indulge in high-fat, high-sugar, high-salt, low-fiber diets. Moving sidewalks, escalators, elevators, cars, buses, and other means of transportation may be leading people to an early demise. Like all muscles, the heart muscle will waste away if it is not used vigorously. Considering these factors, it is rather easy to understand why heart disease is the number one killer in the United States.
Overall, infectious diseases dominate the health problems of underdeveloped countries. Of all the health determinants, lifestyle may be the easiest to control. Even so, it will require much effort.
Considering the world's population as a whole, the environment affects people's health more strongly than any of the other determinants. The environment encompasses the water we drink, the food we eat, and the air we breathe. In the past, because of poor environmental management, many people died from environmentally related diseases such as typhoid fever. Some estimates, based on morbidity and mortality statistics, indicate that the impact of the environment on health status is as high as 80%.
People have acquired intelligence, knowledge, and expertise that have allowed them to make significant changes in the environment, thereby creating conditions that lessen the likelihood of disease. This is accomplished mainly by controlling the causative agents of disease while they are still in the environment, before they reach people, so the body does not have to produce defenses and therapeutic measures are not required.
Environmental health practice, as the name suggests, refers to the relationship between environment and health. Some important elements of environmental health practice--the first line of defense against disease--(with an example) include the following:
* water quality management--ensuring that potable water is available through treatment of water supplies;
* human waste disposal--disposing of human wastes in septic tank systems and sewage treatment plants;
* solid and hazardous waste management--treating and disposing of solid and hazardous wastes;
* rodent control--removing potential harborage and sources of food;
* insect control--utilizing natural, biological, and other methods to reduce insect populations;
* milk sanitation--ensuring that all milk for human consumption is produced under sanitary conditions and is pasteurized;
* food quality management--maintaining surveillance over food from the farm to the consumer so as to prevent contamination;
* occupational health practice--assuring a healthy and safe work environment;
* interstate and international travel sanitation--preventing the spread of communicable diseases between states and nations;
* air pollution control--reducing the emissions of pollutants into the atmosphere;
* water pollution control--reducing the effects of industrial and other waste on water supplies and recreational areas by the pretreatment of industrial and domestic waste;
* environmental safety and accident prevention--designing features into the environment such as pedestrian ramps that promote safety or compensate for people's inadequacies;
* noise control--abating high noise levels in industrial settings and in the community to avoid health degradation;
* housing hygiene--promoting housing conditions necessary for the physiological and psychological well-being of inhabitants;
* radiological health control--controlling radiation sources such as X-ray equipment, nuclear fission plants, and radioactive waste;
* recreational sanitation--monitoring the environment to prevent unsafe conditions at swimming pools and other recreational facilities;
* institutional environmental management--preventing the spread of nosocomial infections;
* land use management--zoning to direct land use to desirable purposes;
* product safety and consumer protection--ensuring that toys, appliances, and the like are safe for human use; and
* environmental planning--applying environmental design to minimize human stress and accidents.
Throughout history, reduction of disease and discomfort has been accomplished largely by altering the environment. Therapeutic programs are glamorous and tend to be successful in obtaining funding and publicity. Prevention programs--the preferable approach--many times are taken for granted and are not funded properly.
Human Defense Against Disease
Throughout recorded history, people have tried to reduce suffering and disease. The first attempts consisted of treating the symptoms of disease. Common practice to treat a fever was to put on more quilts and blankets (after the causative agent had entered the body) and raise the temperature until the fever "broke." (We now know that the microorganism causing the fever was killed by the high temperature.) In the next era, we administered a medicine such as penicillin to kill the organism after it had entered the body. The third era is characterized by immunization. Doctors give people an antigen to cause the body to produce antibodies against specific biological agents. This provides immunity so after that agent enters the body, the antibodies will kill it. In each of the cases mentioned above, except immunization, the treatment is administered after the causative agent had entered the body.
In the mid-19th century, Edwin Chadwick of England and Lemuel Shattuck of Boston, Massachusetts, wrote reports on the sanitary condition of the environment (Chadwick, 1842; Shattuck, 1850). They emphasized the environment's role in spreading germs and other causative agents of disease. In my text Environmental Health (Morgan, 2003), I acknowledge that through history we have become more knowledgeable about the causative agents of disease and the necessary ways to prevent the occurrence of adverse health effects. This book addresses aspects and mechanisms of immunity and practices to prevent the occurrence of disease. It identifies four lines of defense to prevent or control disease based upon concepts reported by Ng and Davis (1981).
First Line of Defense
The first line of defense addresses how environmental health practices can control man-made and naturally occurring environmental conditions and thus prevent disease. Examples of such controls include water quality management, proper human waste disposal, solid and hazardous waste management, rodent and insect control, food safety and sanitation, and others (see Morgan  for other examples).
Second Line of Defense
The second line of defense is the body's ability to adapt to prevent the disease agents from becoming established within it (Morgan, 2003). Mechanisms that deter disease-causing agents from entering the body include the skin, mucous membranes, cilia in the respiratory tract, secretions of various fluids (e.g., saliva, gastric juice, tears, and perspiration). The ears secrete wax that keeps out undesirable particles. Reflexes also play a role in protecting the body from disease. Nutrition and health condition are important defenses because they help the body resist disease. Examples of this line of defense include proper nutrition and good personal health practice (see Morgan  for other examples).
Third Line of Defense
The third line of defense involves cellular and humoral mechanisms (Morgan, 2003). Cellular mechanisms include the processes of phagocytosis and inflammation. When inflammation occurs, phagoctyes, a type of leukocyte or white blood cell, destroy pathogens involving the lymphatic system. When phagocytosis fails, immune mechanisms involving antibodies destroy pathogens. Antigens stimulate the production of antibodies in the body to destroy pathogens. Immunity can be active or passive (see Morgan  for further detail). There are many diseases for which one cannot be immune.
Fourth Line of Defense
Admittedly, when one is in pain, sick, or needs surgery, curative medicine professionals--doctors, dentists, and nurses--are the professionals one wants to see (Morgan, 2003).
Whenever possible, people would rather the pain or sickness be prevented. The role of environmental health, public health, and preventive medicine professionals is important in this respect. Thus, because of the high cost of curative medicine, there is a greater need for the fields of environmental health, public health, and preventive medicine than ever before. The public would rather pay for prevention than the fourth line of defense--curative medicine.
Chadwick, E. (1842). Report on the sanitary condition of the labouring population of Great Britain. London: W. Clowes and Sons. Morgan, M.T. (2003). Environmental health. Belmont, CA: Wadsworth/ Thompson Learning.
Ng, L., & Davis, D.L. (1981). Strategies for public health: Promoting health and preventing disease. New York: Van Nostrand Reinhold.
Shattuck, L. (1850). Report of the sanitary commission of the state of Massachusetts (report commissioned by the state legislature). Boston: Dutton and Wentworth.
MONROE T. MORGAN, DRPH
About the Author: Dr. Morgan is the founding professor and retired chair of the Department of Environmental Health at East Tennessee State University. He is also a past president of NEHA.
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|Title Annotation:||GUEST COMMENTARY|
|Author:||Morgan, Monroe T.|
|Publication:||Journal of Environmental Health|
|Date:||Jan 1, 2010|
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