Environmental Health How does pollution affect human health? How can we detect pollution & its impact on environmental health?
Ecology is the study of interaction between organisms & their environments. People depend on the Earth’s hydrosphere, atmosphere, lithosphere and biosphere for many needs. When these resources become polluted, they affect our health.
3 Basic Principles of Ecology 1. Everything is related to everything else. 2. Everything must go somewhere. • Nothing can really be thrown away.
3. Nature knows best. • Humans must live in harmony with the earth. • Resources removed from anywhere are not free & need to be returned at some point in time either by nature or human activity.
Categories of Pollutants • Nonpoint source pollutants (NPS) are carried far from their source. • Common NPS: fertilizers, pesticides, oil grease, pet wastes, livestock wastes
Point source pollutants (PS) are contaminates that are coming from an identifiable source. • Examples: factory pipes, slaughterhouses, domestic sewage & factory smokestacks
Water Pollution • Even though water may be clear it is not necessarily clean. In most countries, households use water that is treated to remove dangerous pollutants. Some pollutants still enter fresh bodies of water that are used by humans.
Water Pollutants 1. Common water pollutants are sediment & nutrients. These substances wash into the water from farmland, construction sites & other areas where the ground has been disturbed.
2. Other pollutants enter the water directly. • Effluent: waste water from factories & refineries that released pollutants directly into water supplies.
b. Sewage: is a type of effluent waste. Sewage contains human waste & other household wastewater. Most sewage is treated at a plant to remove the dirt, organic matter & other contaminants.
Eighty percent of US sewage is treated; another 10% passes through septic tanks before it is allowed to seep into the ground; another 10% is untreated & passes directly into the ground.
c. Sludge: is a sediment of sewage. Once it was untreated, however, today sludge is dried and maybe composted to be used as fertilizer for crops or forests.
Pollutants & Health 1. Lead can leak into the water from pipes & cause brain damage. 2. Hydrogen sulfide is a gas that comes from industrial waste & gives water a rotten egg smell.
4. Microbes (very tiny pathogens) that can cause disease. Common disease from microbes living in the water:
Cholera: intestinal infection caused by water contaminated with a bacteria. Cholera symptoms are watery diarrhea & vomiting….leads to dehydration. Cooking foods properly & peeling fruits can prevent cholera. Cholera is treated with antibiotics and rehydration fluids
Dysentery: is an illness caused by several types of bacteria. Symptoms include bloody diarrhea, abdominal cramps and fever.
Dysentery is spread by eating and drinking contaminated foods and water. Antibiotics are used to treat dysentery. Africa & Central America has experienced several epidemics in the past decades.
Malara: is a parasitic disease transmitted by mosquitoes that breed in still bodies of water. Parasite is transmitted to human when bitten.
Malaria symptoms typically include flulike symptoms: headache, fever, and vomiting. If left untreated, malaria can cause death. Most malaria cases occur in the tropical and subtropical regions.
Cryptosporidiosis: is a gastrointestinal disease caused by a protozoa that enters the human body in a cyst form. Cysts are ingested by drinking contaminated water or by eating contaminated food.
Symptoms include diarrhea, nausea, abdominal cramps, weight loss, and sometimes dehydration. Usually lasts 10-14 days.
Giardiasis: similar to cryptosporidiosis in symptoms and transmission. This is found in PA streams.
However, this illness differs because giardia cysts can be killed by chlorine. Medication can also be prescribed to kill the cysts as well.
From 1971-1985, PA reported more waterborne disease outbreaks than any other state. PA drinking water has improved since 1990’s because we have made improvements in the monitoring of the state’s water treatment plants.
Air Pollution • Air pollution is a serious problem in many parts of our world that is caused by both natural events & human activities.
Some causes of air pollution are forest fires, lightning, arson, dust storms, burning fossil fuels, industrial processes & driving vehicles.
Industrial processes & driving vehicles are the two main sources of air pollution. They release varies pollutants in the atmosphere.
Definitions Air pollutant– is any substance which changes the physical or chemical properties of clean air and causes measurable affects on humans, animals, vegetation or materials.
Air pollution is a very complex subject. It can be caused by natural events like fires, lightning and volcanoes as well as mankind.
Anthropogenic (related to mankind) activities like industries and cars also help to pollute.
Types of Air Pollution • Ozone (O3) is a form of oxygen that protects the Earth’s from solar radiation. Ozone that is very close to the surface can cause illness including eye irritation, coughing, shortness of breath, nausea, wheezing & headaches.
Types of Air Pollution • Ozone has been associated with asthma & respiratory disease.
Carbon monoxide (CO) is a colorless and odorless gas that forms from the burning of fossil fuels. Very small amounts of this gas in the bloodstream can produce toxic chemical reactions that results in serious illness.
Symptoms of low-level carbon monoxide exposure include headaches, fatigue and flu-like symptoms.
Sulfur dioxide (SO2) is a pollute that is a result of burning coal. This gas combines with moisture in the air to form sulfuric acid which damages plants and harms organisms.
Health problems associated with SO2 include difficulty breathing, respiratory illness, decreased lung functions & aggravation of existing heart disease.
Nitrogen dioxide (NO2) is present in smog and forms when fuels are burned. Smog causes eye irritation, stuffy nose, coughing, sore throat, lung inflammation & various human respiratory illnesses.
Particulate Matter are solid particles in the air. Particulate matter comes from soil and construction dust carried by wind as well as bits of rubber, asbestos from brake lining and vehicle exhaust.
Particulate matter causes irritation and illnesses of the human respiratory system and some kinds of cancer.
Air quality & Health Issues • Clean Air Act – 1963, 1970, revised in 1990 • Covers the entire country but the state and local governments are responsible for implementing the law.
Air quality & Health Issues • EPA also formed in 1970. (December 2, 1970) • http://www.epa.gov/40th/timeline.html
Act was made stronger because a cloud of industrial pollution hovered over Donora, PA for 5 days. Twenty people were killed and 6,000 out of the town’s 14, 000 were sick.
Allergies & asthma are the respiratory disease most triggered by air pollutants.
Air Quality index looks at five major pollutants. • Ground level Ozone* • Particulate Pollution* • Carbon monoxide • Sulfur dioxide • Nitrogen dioxide *Greatest health threat
Soil Pollution Many soil pollutes are a result of human activities. Soil pollutions can be caused by farming, landfills, industrial processes, mining and radioactive wastes.