Environmental Science FINALS REVIEWER PDF

ENVIRONMENTAL SCIENCE WEEK 1: Epidemiological Environment Disease is caused by several factors that could be physical, biological or social. Humans can develop disease due to several factors like; age, nutritional condition, heredity, habits, vices etc. 1. Health — is a state of c...

ENVIRONMENTAL SCIENCE WEEK 1: Epidemiological Environment Disease is caused by several factors that could be physical, biological or social. Humans can develop disease due to several factors like; age, nutritional condition, heredity, habits, vices etc. 1. Health — is a state of complete physical, mental and social well-being, not merely the absence of disease. 2. Disease — is a deleterious change in the body's condition in response environmental factor that nutritional, chemical, to could biological an be or psychological. 4 Factors that cause morbidity (illness) and mortality (death) of a person 1. Diet and Nutrition — balance the food we eat with physical activity to maintain or improve weight. Eat less sugar & salt. Choose a diet low in fat & cholesterol. Eat plenty of grain products, vegetables & fruits. Eat less additives and processed food. 2. Stress — refers to physical, chemical or emotional factors that place a strain on an organism for which there is inadequate adaptation. 3. Infectious Organisms Infectious disease is 43% of all disease deaths annually Children: Diarrhea represents highest mortality Adults: Infections of respiratory tract represent highest mortality AIDS: 30 million people infected worldwide Diseases Caused by Infectious Organisms A. Respiratory Diseases (pneumonia, tuberculosis, influenza, whooping cough) cause more deaths worldwide. B. Gastrointestinal Infections (diarrhea, dysentery, cholera) caused by bacteria or protozoans. Caused by poor nutrition, poor sanitation, immune system. C. Pathogens - are bacteria that causes diseases. They can enter food supply (food borne illness) that cause nausea, vomiting, fever, diarrhea. Food Borne Illness (Gastrointestinal Infections) can be prevented by: Washing hands and utensils before cooking. Separate: Don't cross contaminate. Separate raw meat, poultry & seafood from other food in the grocery cart. Make sure that juices of raw meat inside the ref will not drip onto other foods. Use a separate chopping board for raw meat & cooked food or salads. ENVIRONMENTAL SCIENCE Thaw and cook food properly. Refrigerate foods such as hotdog, bacon & other cold culs. C. Malaria/Dengue/Filariasis or elephantiasis - transmitted by mosquitoes. d. Parasitic Nematodes (hookworm & Roundworms) poor sanitation. Guinea worms — can live for a year while growing up to 3ft. In length. e. Onchocerciasis (river blindness) transmitted by the bite of black flies. f. Trachoma — an eye disease caused by a bacterium, found where sanitation is Pool. g. HIV virus/AIDS — spread by contact with certain bodily fluids of a person with HIV, commonly during unprotected sex (without a condom or HIV medicine to prevent or treat HIV), or through sharing injection drug equipment. Emergent Disease — Disease never known before or one that has been absent for at least 20 years. Ex. Ebola. 4. Toxic Chemicals — Hazardous means dangerous, flammable, explosive, irritants, acids & caustic. Toxins are poisonous, and react with specific cellular components to kill cells. Examples of Toxic Chemicals Irritants - are corrosives (strong acids), caustics. Ex. Sulfuric acids, ammonia, nitric acid, sodium hydroxide, fumes of metals. Respiratory Fibrotic Agents - special class of irritants that damage the lungs, causing scar tissue formation that lowers respiratory capacity. Asphyxiants — pure nitrogen, methane, carbon dioxide, hydrogen sulfide, hydrogen cyanide. Neurotoxins — attack nerve examples are ether, chloroform, heavy metals. Mutagens — chemicals & radiation that damage or alter genetic material (DNA) in cells, can lead to birth defects.