The accelerated techno scientific development in recent decades has generated as a consequence the disposure of many chemical compounds in the environment. Thousands of new formulas are created daily to be applied in medicines, herbicides, pesticides, foods, clothes and new products, without taking in consideration the impacts generated in the atmosphere, the degradation in new composed or consequences of no degradation, with the accumulation in the ecosystems.
Environmental impacts arc any alterations of the physical, chemistries, biological, cultural and socioeconomic properties of the environment, occurring directly or indirectly from the man activities that might affect the health, safety and/or the quality of the natural resources. Men are responsible for most of the poisonous compositions that seek the increase of the agricultural production, disappearance of classic diseases with the application of new drugs are also victim of the situation with the emergence of new diseases, more aggressive and difficult to treat.
The way of contamination range might be air, radiation, food and countless xenobiotic. Several cause-effect relations can be observed between illnesses and atmospheres or habits potentially poisonous, the best-known is the habit of smoking that causes several diseases, among them the cancer and lung emphysema.
It is slashing the need to understand the dose and concentration, the first depending on the individual's body mass and the second to the amount of substance in this particular vehicle (water, solvent, food and so on).
Considering that many compounds do not suffer degradation in the environment or when they suffer degradation a compound generate an even more toxic compound as the original, it is clear the situation of the accumulation of these in the ecosystem as for instance DDT and PCBs, both chlorinated aromatic compounds. The DDT was intensively used after the Second World War in agriculture and public health, providing exceptional performance that helped save millions of lives. However this is non-biodegradable compost that builds up in the fat of living organisms and through the chains food arrives to humans. The same thing happens when the subject are the PCBs, widely used recently as fluid for electrical capacitors, plasticizers in paints and typographical additive in marine varnish.
The emission of poisonous compositions increased significantly the aggressive capacity to the atmosphere, turning the pathologies much more linked with physiochemical and environmental factors than microbiological, so that the environment is the most significant agent for the states of indisposition of populations.
It is estimated that more than 10% of all diseases are linked to environmental factors. In the case of water, one can say that it is responsible for 1.7 million deaths every year, equivalent to the fall of ten jumbo jets every day, of which 90% of the passengers are children. The projection for 2050 is that the planet will have a total population of 8.9 billion people worldwide and about four billion of these may have to live in countries with chronic shortages of water (not just of quantity but mainly quality).