Microbiological pollution:
- Bacilli (typhoid)
- Virus (viral hepatitis) from sewage discharged into rivers and the sea
- Contamination of swimmers and shellfish beds.

Human pollution:
Spill:
- Liquid whose temperature is higher than the environment (plant, power station …) whose effects alter the habitat (algae, disappearance of certain species of fish, the appearance of others …)
- Off silt-laden water (central hydroliques in the draining, mining aggregate)

Industrial Pollution:
- Organic solvents
- Oils
- Hydrocarbons
- Heavy metals
- Thermal discharges warm water from nuclear power stations in rivers (killing animals)

Agriculture:
- Fertilizers
- Insecticides
- Pesticides
- Intensive livestock contamination is through runoff and seepage into groundwater.

Accidental pollution:
- Oil spills
- Road accident
- Human error
- Disbursement untimely

Pollutants may act at different levels on the human body:

* At the skin – this is the case particularly irritating fumes and phenomena of allergies.
* The mucosa,
* The pulmonary alveoli. Pollutants dissolve and pass into the blood or in liquid superficial.
* Through the bodies – some toxic conveyed by the blood can accumulate in organs.

Pollutants can have effects in various scales:

* Immediate effects, such as those observed in historical accidents,
* Effets in the short term,
* Long-term effects, observed after chronic exposure to concentrations that can be very low.
The limits of concentration in ambient air of certain pollutants (SO2, dust, NO 2, Pb, O 3) imposed by European directives take account of these effects. The World Health Organization (WHO) makes the rules should be followed for various pollutants.

Particles: the more particles are fine they penetrate more deeply into the respiratory system and their residence time is important. They have a dual action related to the particles themselves and they carry pollutants (metals, hydrocarbons, sulfur dioxide, etc.They irritate the human respiratory system and may contribute to the onset of acute respiratory diseases.

Effects on Materials

The materials are mainly affected by the pollution that causes acid degradation of buildings, monuments and building facades. Air pollution threatens our cultural heritage and leads to expensive restoration of the facade or facade restoration of monuments.

Effects on forest ecosystems

The trees live for and die of natural causes varied even that age. The sudden decline observed since 1980 seems to mostly fall causes quite unusual. The officials believe that air pollution is one of the many elements involved in forest dieback. In France, the program DEFORPA (forest decline attributed to air pollution ) as well as research laboratories, have shown that the causes of forest decline are very complex, such as poor soils, drought abnormal presence of pollutants in the atmosphere mainly acid pollution and ozone.

Effects on freshwater ecosystems

The acidification of lakes and rivers often causes irreversible destruction of aquatic life.The decrease in pH causes the dissolution of metals contained naturally in the soil as toxic aluminum in the dissolved state in almost all living organisms.

In the world during the twentieth century, tobacco has killed 100 million people and this number may rise to 1 billion for the XXI century if behaviors do not evolve (OFDT, 2005). Tobacco is currently responsible for the deaths of 10 adults (about 5 million deaths a year). If smoking continues on its current course, it will cause some 10 million deaths annually by 2020 according to WHO. In Europe, nearly 500 000 people die prematurely each year from diseases related to smoking, according to statements by David Byrne Commissioner for Health and Consumer Protection. In France, around 66 000 people die each year from tobacco (over 10% of deaths) of which 27 000 per lung cancer (85% were caused by smoking) by the National League against Cancer. For a smoker in four, the average loss of life expectancy is twenty years and results in death before 65 years, according to a study by the Regional Health Observatory of France. France has about 15 million smokers are young people between 20 and 25 who smoke the most (48% of the age by OFDT).

Compared to a non-smoker, the risk of cancer of a smoker is multiplied by:

* 10 for lung and pharynx.
* 7 for the pharynx.
* 4 for the mouth and esophagus.
* 2 pour la vessie.
* 2 for the bladder.

The incidence of lung cancer is proportional to the number of cigarettes smoked per day. Indeed if one smokes 5 x 365 days for 15 to 20 years, this represents tens of thousands of cigarettes.

The phenomena of acid pollution on a large scale have been highlighted by the acidification of lake waters Scandinavians and Canadians. The pH of water became acid causing significant changes in the fish fauna. Some rain has a pH between 3 and 4, while pure water has a pH of 5.6. Acid deposition have effects on materials, forest ecosystems and freshwater ecosystems.

Eutrophication:-
Eutrophication is a disturbance of the biological equilibrium of soil and water due to excess nitrogen including atmospheric (NOx and NH3) over the absorption capacity of ecosystems.

Photochemical pollution
Photochemical pollution (pollution or photochemical) is a complex set of phenomena that lead to the formation of ozone and other oxidizing compounds (hydrogen peroxide, aldehydes, peroxy acetyl nitrate or PAN) from primary pollutants ( called precursors) of nitrogen oxides and volatile organic compounds (VOCs) and energy provided by the Ultra Violet radiation (UV) solar. These phenomena occur in the layers of air near the ground and in the free troposphere. Ozone in the stratosphere (19-30 km altitude), the opposite is called “good ozone” because it protects us from solar UV radiation.

Surprisingly, concentrations of ozone measured away from sources of precursors (eg agglomeration) are higher than those measured near the sources. Indeed, on a city for example, emissions of NO (relating to trafficking in particular) are high. Ozone is destroyed by NO. If the cloud of pollutants formed in the city moves to the countryside, or NOx emissions are reduced, ozone concentrations increase because more ozone is consumed. Photochemical pollution is a phenomenon characteristic of the summer anticyclonic situations.

Ozone’s effects on human health, ecosystems, forestry and agriculture, over this phenomenon of photochemical air pollution is closely linked to acid rain.

Gases which are involve in Global Warming:-

The gases involved in the greenhouse effect are mainly water vapor, carbon dioxide, methane, nitrous oxide and ozone. Greenhouse gas emissions include industrial CFCs or HFCs, perfluorocarbons or PFCs and sulfur hexafluoride, or SF6, these gases are also responsible for the attack of the ozone layer.

These are the 6 gases covered by the Kyoto Protocol. Each gas has a power of global warming (or GWP) compared to carbon dioxide and a stay in the atmosphere.

Length of stay and power global warming greenhouse gas emissions:-

The main greenhouse gases are naturally occurring and scarce. But because of human activity, the atmospheric concentration of some of them increased significantly, mainly ozone (O3), carbon dioxide (CO2) and methane (CH4). Since 1750, the rate of CO 2 in the atmosphere has increased by 30%, that of CH4 to 145%. But the combined effects of all greenhouse gas emissions equivalent to an increase of 50% CO 2 from the same period.

Today and after many hesitations, there is consensus on the impact of human activity on climate change. The Intergovernmental Panel on Climate Change (IPCC) issued a new report in 2001 which estimated that “evidence more recent and conclusive can be said that most of the warming observed over the last fifty years is due to human activities “.