Disease
Pathogens- Disease causing organisms, such as bacteria, viruses and parasites
Morbidity- illness
Mortality- death
* Illness Factors include diet and nutrition, infectious agents, toxic chemicals, physical factors and psychological stress.
* Antibodies are introduced to prevent disease, by introducing a foreign particle
* The Top Three Leading killers
1. Cardiovascular Disease
2. Cancers and Tumors
3. Acute Respiratory Disease
* Higher Death Rates occur in less fortunate counties where conditions are not ideal for human health and survival
* Pesticides- used to eliminate insect vectors. Problem: Insects tend to become very resistant to the pesticides being used to destroy them, therefore allowing the insect population to come back and infect others
- Currently, death rate is decreasing and life expectancy is increasing
**AIDS**- the largest cause of deaths in the world...killing 3 MILLION people in YEAR 2000!!!
* Over 36 million people are currently living with HIV.
* Largest occurrence in Africa
* Drug Addictions and Unprotected Sex are the two main causes, Heterosexuality
* Places such as Botswana, Zimbabwe and Zambia tend to have survival only of the very young and very old, as the middle ages of those living in these communities have died due to AIDS
**Other Diseases**
*Viruses*
- Ebola- 90% Mortality
- AIDS- 40 Million People now affected
*Bacteria*
- Tuberculosis- 256 cases resistant to drugs
- Anthrax-
- Botulism- most recognized in Botox injections (beauty purposes)
*Malaria*- One million die a year
- More people are being able to afford vaccines, as they are being made faster and cheaper
- U.S. spends $75 Million a year on infectious disease research
*DALY or The Disability-Adjusted Life Years measure the total burden of disease on productivity and quality of life.
*DALY measures are very high in poor countries such as Africa due to lack of sanitation, bad water and polluted drinking water
- Malnutrition creates many diseases
*Approximately 2 billion people suffer from worms, flukes, protozoa and other internal parasites...affects the immune system greatly!
* 30 new diseases have been introduced in the past two decades
*Emergent diseases are those never known before or that has been absent for at least 20 years
* Flu Epidemic of 1918 was LARGEST loss of life from an individual disease in a single year...(between 30 and 40 million)
*Most flu strains are transmitted by air, or by pigs, birds, monkeys and rodents
- As population grows, the faster a disease will spread
* Outbreaks can occur among livestock as well
* Strep is the most common form of hospital-acquired conditions
Toxicology (Toxic and Hazardous Materials)
- Hazardous = dangerous, including flammables, explosives, irritants, sensitizers, acids and caustics
- Toxins = poisons so they react with cellular components that kill cells
- Allergens = substances that activate the immune system, can act directly as antigens
* Antigens *- foreign white blood cells
****Four Main Categories of TOXINS****
1. Neurotoxins- kill neurons in the nervous system...example/ Mercury and Lead
2. Mutagens- cause mutations by altering DNA
3. Carcinogens- cause cancer
- The Delaney Clause to the US Food and Drug Act states that no known carcinogen causing "reasonable harm" may be added to food and drugs.
4. Teratogens- toxins that cause abnormal embryonic cell division and result in birth defects...example/ Alcohol and Thalidomide
* LD50- measures toxicity of a chemical, LD50 is the dose lethal to 50% of a test population; the lower the LD50, the more toxic the chemical
- The established dose curve will determine the dose below which none of the test subjects were harmed...creating the threshold level, or guide for setting human tolerance levels
- The Dose/Response Curves are not always symmetrical, making it difficult to compare toxicity of unlike chemicals
**Bioaccumulation of a toxin occurs when an organism absorbs and stores the toxin in its tissues
**Biomagnification, and the best-known example is with the insecticide DDT
- Effects of DDT were explained in Rachel Carson’s book "Silent Spring"
***Famous Cases***
- "Silent Spring" mentioned the persistence of pesticides in the environment, Bioaccumulation and biomagnification and effect on non-target species
- Love Canal- Mentions Social Justice, Persistence of toxic wastes and Superfund Site. Canal was dug beginning in 1892. When canal failed to be completed, it was used as an industrial dump for several toxic chemicals. The property was sold in order to build several homes and a community school. Many people became ill and when tests were conducted high toxic levels of chemicals were found and the company who originally sold the property was forced to pay for the removal of the waste found. Today, the people are allowed to move back to their old homes, the site is clean.
- Other cases include the Bhopal Crisis, Ebola and the Hot Zone, Agent Orange and the Vietnam Conflict and the Flu Vaccine
*Acute Toxicity occurs when a large dose inflicts immediate harm on an organism
*Chronic Toxicity occurs when a smaller dose is expressed over a long period of time, harder to detect because it may not be seen for years
*Chemical Synergism- when two toxins together have a greater effect than the SUM of the effects of the two toxins separately...example/ small amount of alcohol with small amount of barbiturates can have a severe effect on the central nervous system...or smoking and asbestos can expose a person to cancer ten times greater than if they were exposed to just one of the factors.
*Best way to destroy these chemicals and toxins-through neutralization or oxidation... Incineration, Air Stripping, Carbon Absorption or Flocculation
* Waste Disposal...Landfills and Dumps, Incineration or a huge problem creator, Selling the Waste to Poor Counties, by doing this the people of the country absorb these toxic wastes into their bodies, all so they get more money.
*HAZMAT Alternatives- You can replace your everyday cleaner with the right combination of harmless substances...things such as Lemon Juice, Vinegar, Water, Club Soda and so much more can replace more hazardous chemicals to make the result safer
*How to Help- Conserve, Recycle and Reduce!
