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Common Molecules:
Environmental Molecules
spray of pesticides smoke




The Earth is our home we must take care of it. However, the environment is affected and often polluted by human activities. The increase in population highly raises the contamination problem the world faces today. In agriculture, the use of chemicals such as pesticides and fertilizers is often more harmful to the environment than beneficial for the crop protection and harvest. The use of coal and petroleum in factories and automobiles send billions of tons of pollutants to the air each year. Intensive agriculture as well as byproducts and waste from the manufacture of consumer products contaminate soil and water. Used and abandoned articles enter the waste streams and pollute as well.

Pollutants are responsible for smog, contaminated water, ozone_layer depletion, and global_warming, to name just a few problems. For instance, global warming is predicted to cause rising ocean levels, lower plant productivity, and more frequent and dangerous weather patterns as result of the accumulated greenhouse_gases that are trapped in the atmosphere. Depletion of the ozone layer in the stratosphere by industrial pollutants such as chlorofluorocarbons (CFCs) allows the sun's harmful UV-light to reach the surface of the earth. This has resulted in higher incidents of skin cancer and eye cataracts in people and is harmful to other animals and plants as well. Climate changes will also result in a water_crisis as pointed out in the UN report, "Water for the people, water for life." Water is essential for life and only about 2.5 % of the water on our planet is freshwater. This precious resource is more and more contaminated by agricultural runoff or industrial pollution. Daily some 2 million tons of industrial, human, and agricultural wastes are disposed within receiving waters. The proportion of people who are unable to reach, or to afford, safe drinking water is increasing rapidly. Pollutants may undergo global_distillation and thus reach remote, pristine parts of the world or they may biomagnify and endanger health and well being of all species, especially those on top of the food chain.

The ozone layer depletion, global warming, the freshwater scarcity and other global ecological imbalances are interrelated and put human kind in situation of a global environmental crisis.

In a UN report published in 2002, more than 1000 scientists warn that 70% of the natural world will be destroyed over the next half century due to over-population, deforestation, pollution, global warming, spread of non-native species, and other human impacts, causing the mass extinction of species and the collapse of human society in many countries.

All of us, no matter where one lives, are suffering the consequences of our own actions and decisions. Scientists are constantly striving to decrease pollution by improving industrial processes. However, there are many things you can do right at home or in your day-to-day life to help protect and preserve the environment like recycling, conserving nature, reducing energy consumption and use of consumer goods, and teaching others to do the same and move towards a sustainable_way_of_life. In this section you learn about compounds affecting the environment like chemicals used in agriculture (pesticides, herbicides, fertilizers etc.) as well as industrial pollutants and byproducts.

Fog that has become mixed and polluted with smoke.
A layer of the atmosphere between 10 and 40 km above the earth’s surface, called the stratosphere, where ozone molecules absorb dangerous ultraviolet radiation from the sun.
An increase in the average temperature of the earth's atmosphere, especially a sustained increase sufficient to cause climatic change.
Gases such as carbon dioxide, methane, water vapor, nitrous oxide, ozone and halocarbons in the atmosphere that trap heat from the sun and warm the earth.
Gradual destruction and provoked pollution of water resources in many world regions that decreases the access to clean water for the human population.
Volatile or semi-volatile substances (DDT, lindane, etc.) volatilize in temperate and tropical regions and are then deposited in colder areas like remote arctic regions. This continuous transfer of contaminants in the global atmosphere towards the poles resembles a giant distillation process. As a result these contaminants are present at alarmingly high concentrations in cold ecosystems where they have never been used. The highest concentration of pesticides in human breast milk is found in the Inuit people living in the artic regions.
The progressive build up of pollutants in organisms by successive trophic levels, such that the concentration ratio in the tissue of a predator organism is higher compared to that in its prey.
Living in a sustainable manner means that we are "meeting the needs of the present without compromising the ability of future generations to meet their own needs." The peace Nobel prize 2004 was given to Dr Wangari Maathai, a Keynian biologist and environmentalist who founded the "Green Belt Movement," and is an important visionary for sustainability in the local and the global community.
Element and IonsMaterials and TechnologyBiological MoleculesMinerals and GemsEnvironmental Molecules
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