3.Enviromental Factors Affecting Lungs. Environmental Factors affecting lungs: 1,2,3,4.

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1 Environmental Factors affecting lungs: 1,2,3,4. Enviromental pollution is the major cause of health related problems now a days. Prolonged exposure to enviromental pollution causes one-fourth of all the diseases. Improper management of waste, fumes from industries, traffic, household waste contributes to enviromental pollution.the waste from these sources may be toxic, infectious or radioactive and cause cardiovascular, cerebral and diseases. Environmental factors affect lungs more than other organs in the body as the lungs come in direct contact with these agents. Intake of toxicants in any form leads to upper problems like pharyngitis, laryngitis, and rhinitis and lower tract problems like, chronic bronchitis and asthama.there are two types of environmental pollutants indoor and outdoor agents. 2.Outdoor Air Pollution 1

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3 Types of Outdoor air pollutants: 1) Nitrogen dioxide (NO 2 ), 2) Ozone (O 3 ), 3) Sulphur dioxide (SO 2 ), 4) Particulate matter (PM), 5) Aeroallergens, such as fungal spores and allergenic pollen. 2.Indoor Air Pollution 3

4 Types of Indoor pollutants: 1) Tobacco smoke, 2) Nitrogen dioxide, 3) Formaldehyde (HCHO) and 4) Other volatile organic compounds (VOCs), 5) Particulate matter, 6) Sulphur dioxide (SO2), 7) Ozone (O3) 8) Allergens derived from a diverse range of plants, animals and insects Ozone (O 3 ) is the most important factor contributing for summer smog, ozone is formed by photochemical reaction between ultraviolet rays, nitrogen dioxide and hydrocarbons. O 3 levels depend of NO 2 levels in the atmosphere as photolysis of nitrogen dioxide is the key initiater of photochemical formation of ozone. On exposure to ozone there is decrement in lung function, and exacerbation of pre-existing lung diseases like bronchitis, emphysema. Ozone exposure also increases the symptoms of asthma by increasing airway inflammation. Ozone affects the mucociliary system of the lungs and targets the defence system of lungs which increases the suspectibility of growth of bacterias and other infections. It stimulates the production of interleukin factors and granulocyte macrophage colony stimulating factor (GM- CSF) and fibronectin in Broncho alveolar lavage fluid (BALF) thus increasing the incidence of asthma. Nitrogen Dioxide (NO 2 ) is less potent and reactive than ozone but it is a major contributor in the formation of ozone. Nitrogen dioxide is a major indoor pollutant. It is formed in the homes which use kerosene or industries that using fossil fuels as a fuel or from natural sources such as bacterial and 4

5 volcanic actions. Exposure of lungs to higher concentration of NO 2 causes lung edema, increase in antioxidant metabolism and an increase in enzymes associated with cell injury. The epithelial cells and ciliary cells are most sensitive to nitrogen dixide. Nitrogen dioxide also causes inflammation of the airways by recruiting T lymphocytes and macrophages. Long term exposure leads to thickening of the alveolar capillary membrane, loss of ciliated epithelium, and increases in lung collagen. Exposure to NO 2 leads to lower tract infections. data/assets/pdf_file/0017/123083/aqg2nded_7_1nitrogendioxide.pdf Particulate matter (PM) are the major component of environmental pollutants. PM consist of extremely small particles and liquid droplets containing acids, organic chemicals, metals, and soil or dust particles. The particulate matter causes inflammation by influx of leukocytes into the airspaces. Long term exposure of particulate matter leads to remodelling of the lung anatomy and physiology. Inhalation of particulate matter leads to exacerbation of allergies, asthma and chronic obstructive pulmonary diseases by causing bronchoconstriction, inflammation and dysfunction of alveolar macrophage phagocytosis, together with histamine release from mast cells in healthy individuals. Sulphur dioxide (SO 2 ) is an outdoor pollutant. It is produced by combustion of fuel, from vehicles and from industries. SO 2 has been shown to produce reactive oxygen species in the lungs, but high concentrations are needed to cause important effects on the antioxidant mechanism. Asthmatics may be more susceptible n normal subjects to SO2 bronchoconstriction. 5

6 Tobacco smoke is complex mixture of 7000 chemicals out of which 69 are cancer causing chemicals. Tobacco smoking adversely affects almost all the organs of the body, lungs being the first target of assault suffer the most. 90% of the lung cancers are caused by cigarette smoking. Passive smoking or secondhand smoking or environmental tobacco smoke (ETS) is a known carcinogen and is equally dangerous. The passive smokers can inhale the same carcinogens by the side stream smoke. Smoking can cause cancer almost anywhere in the body. Smoking causes cancer of the mouth, nose, throat (larynx), esophagus, bladder, kidney, pancreas, cervix, stomach, blood, and bone marrow (acute myeloid leukemia). The data suggest that each year in the United States alone, tobacco smoke is responsible for 49,400 deaths in 'passive smokers'. Effect on lung defenses and association with lung disease Summary Table: Type Origin Effect on lung Lung defenses 1.Lung function reduction. Antioxidant system. Ozone Photochemical reaction 2.Bronchial hyper responsiveness 3.Increased symptoms Permeability of epithelial cells, Inflammatory cytokines, Mucociliary clearance. 6

7 4.Increased hospitalization 5.Decrease exercise tolerance 1.Lung function reduction. 2.Bronchial hyper responsiveness 2. Nitrogen Dioxide 1.Gas combustion 2.Vehicle traffic 3.Increased symptoms. 4.Increased hospitalization 1.Antioxidant system 2.Inflammatory cytokines 5. Decrease exercise tolerance 1.Increased symptoms. 1.Antioxidant system Particulate matter 1.Vehicle traffic 2.Industrial activity 2.Reduced exercise tolerance 3.Lung function reduction 2.Inflammatory cytokines 3.Mucociliary clearance 4.Increased symptoms 4.Antioxidant system 7

8 5.Increased mortality from cardio disease 1.Bronchoconstrition 1.Inflammatory cytokines Diesel Exhasut. 2.Antioxidant system 2.Airway inflammation 3.Bronchial hyper responsiveness 3.Macrophage phagocytosis 1.Lung function reduction Sulphur dioxide 1.Fuel combustion from 2. Industry. 2. Increased symptoms Antioxidant system 3. Vehicle traffic 3.Increased mortality from disease 8

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