Severe Weather Thunderstorms Lighting occurs when current flows between the regions in the clouds w/ opposite electrical charges Thunder results from the rapid heating of air around a flash of lighting (air expands rapidly forming sound waves)

Severe Weather 2. Tornadoes Warm air is forced upward causing very low pressure on the Earth’s surface Winds from different directions approach the center, collides and rotates violently A funnel cloud appears at the base and picks up dirt and debris from the surface

Severe Weather 3. Hurricane Storm w/ wind speed of at least 120 km/hr Formed by trade wind collisions on surfaces of warm seas A low pressure area develops Warm moist air is forced up and cools leading for moisture to condense

Pollution The introduction of substances, biological organisms, or energy into air, water or soil, resulting on a change of its quality, which is likely to affect its normal use or endanger public health and the living environment

Pollution Can be caused by natural processes such as volcanic eruption

Effects of Pollution: Harm organisms thriving in contaminated areas Reduces the use of contaminated resources Increase the risk of health hazards to man

Sources of Land Pollution Accidental chemical spills Improper disposal of chemicals and industrial wastes Agriculture Mining and quarrying Sewage sludge Household solid wastes Other physical degradation of land

Sources of Water Pollution Chemicals (acids, heavy metals, pesticides) Radioactive materials from nuclear plants Dissolved organic matter Pathogens (E. coli, coliforms from human excreta) Nutrients (nitrogen, phosphorus w/c leads to algal blooms)

Sources of Air Pollution Natural phenomena (volcanic eruptions) Chemicals CO2 from coal mining, fossil fuel burning Benzene from gasoline Asbestos Sulfates and nitrates from factories and emissions Smog (Smoke + fog)

The Water Cycle

The Carbon Cycle

It should be noted that air pollutants may also contaminate the soil and water (acid rain)

Soil pollutants may also contaminate water (solid waste transported by runoffs).

Eutrophication can lead to: Algal bloom Increase water turbidity Depeltion of dissolved oxygen Heavy detritus deposits at the bottom

Toxins can become concentrated in successive trophic levels of food webs Humans produce many toxic chemicals that are dumped into ecosystems. These substances are ingested and metabolized by the organisms in the ecosystems and can accumulate in the fatty tissues of animals. These toxins become more concentrated in successive trophic levels of a food web, a process called biological magnification.

The pesticide DDT (dichlorodiphenyltrichloroethane), before it was banned, showed this affect.

AGENT MAN DISEASE ENVIRONMENT