Diseases affecting the respiratory tract are a major cause of mortality worldwide. The increase of these diseases is due to many reasons, but mainly to factors such as:
- Air Pollution: The emission of pollutants into the atmosphere is one of the main reasons for the emergence or aggravation of respiratory diseases.
Smoke emitted by industries without being properly filtered, exhaust gases from vehicles, burning of industrial waste such as plastics, rubber and so on are responsible for many illnesses such as bronchitis or asthma, not to mention more serious diseases such as lung cancer.
- Tobacco: Smoking is the first cause of respiratory illnesses. From lung cancer to chronic pulmonary obstructions are caused by the components of this plant. Among them not only the alkaloid nicotine must be mentioned . Nicotine is fatal in concentrated doses, but there are also others components, such as tar or ammonia, with very poisonous properties. Smoking does not only affects active smokers, but nonsmokers who share with them indoors tobacco smoke.
- The emergence of new respiratory diseases (SARS - Severe Acute Respiratory Syndrome - commonly known as atypical pneumonia) The resurgence of infectious diseases that were thought to be eradicated is another cause that has increased respiratory diseases.
Tuberculosis has resurfaced with virulence and appears to be resistant to antibiotics. It causes 3 million deaths annually and over a third of the world population is carrying it. Similarly, the main cause of pneumonia - Sptreptococcus pneumoniae - is becoming increasingly resistant to penicillin.
The root causes which explain the increase of these diseases can be very varied: global population increase and consequent overcrowding that makes contagion more possible; general poverty implying low hygienical measures; overuse of antibiotics that makes the virus more resistant, stress which weakens the defensive system, and so on.
- Change of weather conditions : global warming has led to the spread of diseases in areas where they did not previously produce. Similarly, warmer climates enhace the possibilities of expansion of respiratory diseases vectors (mosquitoes, flies, rodents, etc) .. For example, Hantavirus pulmonary syndrome, which killed half of those infected in 1993 in the USA, is transmitted by contact with the feces of mice, the population of which increased greatly during that year.
- Immune system diseases increase : The appearance or increase of diseases such as AIDS - Acquired Immunodeficiency Syndrome, (HPS) - Hantavirus pulmonary syndrome- or cancer has been taking place in patients with weaker immune systems, which allows the expansion of infectious diseases.
There are many diseases that can affect the respiratory system. The main ones are: