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Environmental factor

Apart from the true monogenicgenetic disorders, environmental factors may determine the development of disease in those genetically predisposed to a particular condition. Stress, physical and mentalabuse, diet, exposure to toxins, pathogens, radiation and chemicals found in almost all personal care products and household cleaners are common environmental factors that determine a large segment of non-hereditary disease. Environmental factors such as the weather affect business interests. If a disease process is concluded to be the result of a combination of genetic and environmental factor influences, its etiological origin can be referred to as having a multifactorial pattern.

An example of an environmental trigger would be a component of a human's drinking water which holds the possibility of activating (triggering) a change in a person's body. These changes are mainly negative ones. Using this example, what is in the drinking water may affect one person entirely different than another -- someone may be affected greatly, whereas someone may not be at all.

Many cancers (osteosarcoma, etc), along with a plethora of other diseases, are thought to be a result of environmental triggers.

Nitrates may be an environmental trigger for Alzheimer's, diabetes, and Parkinson's disease.

Environmental triggers for asthma and autism have been studied too.


Biology is a natural science concerned with the study of life and living organism s, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines. Among the most important topics are

Hypoxia (environmental)

Hypoxia, or oxygen depletion, is a phenomenon that occurs in aquatic environments as dissolved oxygen (DO; molecular oxygen dissolved in the water) becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system. Dissolved oxygen is typically expressed as a percentage of the oxygen that would dissolve in the water at the prevailing temperature and salinity (both of which affect the solubility of oxygen in water; see oxygen saturation and underwater). An aquatic system lacking dissolved oxygen (0% saturation) is termed anaerobic, reducing, or anoxic; a system with low concentration—in the range between 1 and 30% saturation—is called hypoxic or dysoxic. Most fish cannot live below 30% saturation. A "healthy" aquatic environment should seldom experience less than 80%. The exaerobic zone is found at the boundary of anoxic and hypoxic zones.

Where hypoxia occurs

Hypoxia can occur throughout the water column and also at high altitudes as well as near sediments on the bottom. It usually extends throughout 20-50% of the water column, but depending on the water depth and location of pycnoclines (rapid changes in water density with depth) it can occur in 10-80% of the water column. For example, in a 10-meter water column, it can reach up to 2 meters below the surface. In a 20-meter water column, it can extend up to 6 meters below the surface.

Causes of hypoxia

Oxygen depletion can result from a number of natural factors, but is most often a concern as a consequence of pollution and eutrophication in which plant nutrients enter a river, lake, or ocean, and phytoplankton blooms are encouraged. While phytoplankton, through photosynthesis, will raise DO saturation during daylight hours, the dense population of a bloom reduces DO saturation during the night by respiration. When phytoplankton cells die, they sink towards the bottom and are decomposed by bacteria, a process that further reduces DO in the water column. If oxygen depletion progresses to hypoxia, fish kills can occur and invertebrates like worms and clams on the bottom may be killed as well.

Hypoxia may also occur in the absence of pollutants. In estuaries, for example, because freshwater flowing from a river into the sea is less dense than salt water, stratification in the water column can result. Vertical mixing between the water bodies is therefore reduced, restricting the supply of oxygen from the surface waters to the more saline bottom waters. The oxygen concentration in the bottom layer may then become low enough for hypoxia to occur. Areas particularly prone to this include shallow waters of semi-enclosed water bodies such as the Waddenzee or the Gulf of Mexico, where land run-off is substantial. In these areas a so-called "dead zone" can be created. The World Resources Institute has identified 375 hypoxic coastal zones around the world, concentrated in coastal areas in Western Europe, the Eastern and Southern coasts of the US, and East Asia, particularly in Japan.

Hypoxia may also be the explanation for periodic phenomena such as the Mobile Bay jubilee, where aquatic life suddenly rushes to the shallows, perhaps trying to escape oxygen-depleted water. Recent widespread shellfish kills near the coasts of Oregon and Washington are also blamed on cyclic dead zone ecology.


To combat hypoxia, it is essential to reduce the amount of land-derived nutrients reaching rivers in runoff. Defensively this can be done by improving sewage treatment and by reducing the amount of fertilizers leaching into the rivers. Offensively this can be done by restoring natural environments along a river; marshes are particularly effective in reducing the amount of phosphorus and nitrogen (nutrients) in water.

Technological solutions are also possible, such as that used in the redeveloped Salford Docks area of the Manchester Ship Canal in England, where years of runoff from sewers and roads had accumulated in the slow running waters. In 2001 a compressed air injection system was introduced, which raised the oxygen levels in the water by up to 300%. The resulting improvement in water quality led to an increase in the number of invertebrate species, such as freshwater shrimp, to more than 30. Spawning and growth rates of fish species such as roach and perch also increased to such an extent that they are now amongst the highest in England.

In a very short time the oxygen saturation can drop to zero when offshore blowing winds drive surface water out and anoxic depthwater rises up. At the same time a decline in temperature and a rise in salinity is observed (from the longterm ecological observatory in the seas at Kiel Fjord, Germany). New approaches of long-term monitoring of oxygen regime in the ocean observe online the behavior of fish and zooplankton, which changes drastically under reduced oxygen saturations (ecoSCOPE) and already at very low levels of water pollution.

Bog chemistry

In certain northern European sphagnum acidic bogs, a condition of hypoxia arises that prevents tissue decay by impeding micro-organisms in th

From Yahoo Answers

Question:I need to write a research paper based on an environmental chemistry issue. We have already discussed the ozone hole quite extensively so I cannot do that. Remember, it has to be based mostly on CHEMISTRY - meaning, I can use equations! Stuff like acid rain and its effect on aquatic life is leaning more into biology and I cannot use that.

Answers:You could do acid rain, and how it erodes buildings / metal. You could do CO2, how it lowers the pH of the ocean, and how that erodes / bleaches coral. You could do ozone, and how kudzu makes the things that make it (NOx and VOCs), so that it can take over areas it "fumigates".

Question:Hello, I need to write a paper involving a topic of environmental science. I don't want my paper to be boring, or highly-covered already(like the greehouse effect) Will you please throw a few suggestions my way so I can come up with something good? It's a wide subject....it just has to pertain to earth and/or it's environment. Thanks for answering!

Answers:Here's one, The effect of nuclear waste on the environment. Thanks, Drew

Question:The project should be in about 30- 40 pages in projects there should be colour images and project should unique where to search it ????

Answers:don't worry about projects the world has developed so much that there is nothing to fear just find on google or wikipedia....and get ur solution..here i have some information.. Environmental chemistry Environmental chemistry is the scientific study of the chemical and biochemical phenomena that occur in natural places. It should not be confused with green chemistry, which seeks to reduce potential pollution at its source. It can be defined as the study of the sources, reactions, transport, effects, and fates of chemical species in the air, soil, and water environments; and the effect of human activity on these. Environmental chemistry is an interdisciplinary science that includes atmospheric, aquatic and soil chemistry, as well as heavily relying on analytical chemistry and being related to environmental and other areas of science. Environmental chemistry involves first understanding how the uncontaminated environment works, which chemicals in what concentrations are present naturally, and with what effects. Without this it would be impossible to accurately study the effects humans have on the environment through the release of chemicals. Environmental chemists draw on a range of concepts from chemistry and various environmental sciences to assist in their study of what is happening to a chemical species in the environment. Important general concepts from chemistry include understanding chemical reactions and equations, solutions, units, sampling, and analytical techniques.

Question:I need to fulfill my science requirement but science has been my strong point in school. I've already failed biology twice so my counselor suggested I take a less challenging science course. Below are the class descriptions. If anyone has taken these classes please help. Earth Science 1 This course provides a broad-based, integrated introduction to the geosciences. The course content includes a survey of topics from geology, geography, oceanography, meteorology, and astronomy. This course is designed to fulfill a natural science requirement. Environmental Science 1 The Human Environment: This introductory course discusses the effects of humans on their physical environment. Particular emphasis is placed upon modifications of physical processes due to industrialization and urbanization. Energy and pollution are stressed. Topics include energy sources and the environment, air pollution, climatic change, solid waste and water pollution, as well as topics of current interest.

Answers:i took both classes; to me, if you are more of a visual person, take earth science. it deals with a lot of topographic maps and the same things i learned in Geography. if you like to voice opinion and learn about surroundings ''why things are the way in this world'' and what we can do to help it; go ahead with enviormental science. they are both challenging classes and are really meant for juniors-seniors. but, if you enjoy the class more and are intrested, it won't seem like so much work :D good luck. and have a great school year