Notes

Environmental Science Reviewer Quarter 3

Pollutants in the Environment

Pollution is defined as an undesirable change in the physical, chemical, or biological characteristics of air, water, and land that may be harmful to human life and other animals, living conditions, industrial processes, and cultural assets. Pollution can be natural or manmade. The agents that pollute are called pollutants.

Pollutants are by-products of man’s action. These are chemicals that have ended up in the environment because of human activities and are hazardous to health.

1. Non-degradable Pollutants
These are the pollutants which are degraded at a plodding pace by the natural biological processes. These are inorganic compounds such as salts (chlorides), metallic oxides, waste-producing materials, and materials like aluminum cans, mercuric salts, and even DDT (Dichloro-diphenyl- trichloroethane). These may continue to accumulate in the environment.

2. Biodegradable Pollutants
These include domestic sewage that quickly decomposes under natural processes and can be
rapidly decomposed by natural/ artificial methods. These cause serious problems when accumulated in large amounts as the pace of deposition exceeds the decomposition of disposal.

Pollutants can also be classified based on the form in which they persist after their release into the environment:

1. Primary Pollutants - these include those substances which are emitted directly from some identifiable sources.

2. Secondary Pollutants – are produced by a combination of primary emitted pollutants in the atmosphere.

3. Smog - The fog deposited with smoke and chemical fumes forms a dark and thick covering, the smog. Smog is widespread in almost all the industrial areas as the smog is trapped for many days by the stagnant air. The smog is harmful both for animals and plants.

Types of Pollution
A. Air pollution is the presence of materials in the air in such concentrated concentrations to man and his environment. Several ingredients find their way in the air, and these are mostly gases, which rapidly spread over vast areas. Various air pollution sources are fossil fuels, industries, agricultural activities, wars, and natural causes of arid emissions from vehicles.

B. Water pollution happens when undesirable substances are added to water sources that alter the basic chemistry of water. Sources of water pollution come from household waste like food waste, synthetic detergents, and water- based paints. It may also come from industrial wastes, fertilizers, pesticides, or mineral oils.

C. Soil pollution is an occurrence in which soil is undergoing degradation because of contamination. Any substance that reduces soil productivity is called a soil pollutant. Several materials adversely affect the soil’s physical, chemical, and biological properties and thus reduce its productivity.

D. Noise can be defined as an unwanted/unpleasant sound. So, noise pollution is unwanted sound dumped into the atmosphere without care for its unfavorable effects. All the boons of industrialization and civilization such as motors, horns, heavy and light machinery, work and movement, blaring radios, supersonic airplanes have become disturbing and irritating.

E. Radiation Pollution – or Radioactive Pollution is the accumulation of natural radiation levels caused by human activities. The radiations contains high energy levels which cause electrons from atoms to be removed. Radioactive pollution is caused by mining, handling and storing radioactive waste materials, and the use of radioactive reactions to produce energy, such as
nuclear power plants.


Causes and Effects of Natural Disasters to Humans and Environment

Natural disasters are catastrophic events with atmospheric, geological, and hydrological origins. UNISDR (United Nations International Strategy for Disaster Reduction) defines it as “a natural process or phenomenon that may cause loss of life, injury or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage”.

-Floods
Floods are defined as a relatively high flow of water discharged from the river and stream network, which sets the riverbank margins to overflow and lead to the submerging of low land areas surrounding the riverbed.

-Earthquakes
An earthquake happens when two blocks of the earth suddenly slip past one another (source: usgs.gov). The surface where they slip is called the fault or fault plane. The location below the earth’s surface where the earthquake starts is called the hypocenter. The location directly above it, on the surface of the earth, is called the epicenter.

Cause of Earthquakes:
Earthquakes are caused mainly by the imbalance in any part of the crust of the earth. Other causes of earthquakes occur due to volcanic eruptions, faulting and folding, gaseous expansion, and contraction inside the earth.





-Typhoons

Tropical cyclone is a rapidly rotating warm air and water created from a low- pressure area. It always forms over oceans where sea surface temperature is greater than 26 degrees Celsius. The term ‘Typhoon’ is used when a tropical cyclone is developed in the northwest Pacific basin.

Impact of Climate Change on the Environment

Weather is described as the immediate condition in a specific place. For example, if you see that it is raining outside right now, that is a way to describe today’s weather. Rain, snow, wind, hurricanes, tornadoes — these are all-weather events.

On the other hand, the climate is more than just one or two rainy days. It describes the weather conditions that are expected in a region at a particular time of year. It is also the usual weather of a place. The climate can vary in every season. A place might be mostly warm and dry in the summer, while it may be cool and wet in the winter. Different places can have different climates.

Climate change, broadly interpreted, is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or weather distribution around the average conditions (such as more or fewer extreme weather events). Climate change is caused by
factors that include oceanic processes (such as oceanic circulation), biotic processes
(e.g., plants), variations in solar radiation received by Earth, plate tectonics and volcanic eruptions, and human-induced alterations of the natural world. The latter effect is currently causing global warming, and “climate change” is often used to describe human-specific impacts.

Climate change is a change in the usual weather found in a place. It could
be a change in how much rain a place usually gets in a year, or it could be a change
in a place’s usual temperature for a month or season.
Climate change is also a change in Earth’s climate. It could be a change in
Earth’s normal temperature, or it could be a change in where rain and snow usually
fall on Earth. (National Aeronautics and Space Administration, 2014)

Causes of climate change
Humans are increasingly influencing the climate and the Earth’s temperature by burning fossil fuels, cutting down rainforests, and farming livestock. It adds enormous amounts of greenhouse gases to those naturally occurring in the atmosphere, increasing the greenhouse effect and global warming. Greenhouse gases


Some gases in the Earth’s atmosphere act a bit like the glass in a greenhouse, trapping the sun’s heat and stopping it from leaking back into space. Many of these gases occur naturally. However, human activity is increasing the concentrations of some of them in the atmosphere, in particular:

Global warming refers only to the Earth’s rising surface temperature,
while climate change includes warming and the “side effects” of warming—like
melting glaciers, heavier rainstorms, or more frequent drought. Said another way,
global warming is one symptom of the much larger problem of human-caused climate
change.