Earth’s atmosphere.Earth’s atmosphere. Air pollution. Air pollution.

Earth’s atmosphereEarth’s atmosphere is a layer of gases surrounding the planet

Earth and retained by the Earth's gravity. It contains roughly 78%nitrogen, 21%oxygen, 0.97%argon, 0.04%carbon dioxide, and trace amounts

of other gases, in addition to water vapor.

AAn an air pollutir pollutantant can be a can be a

chemicalchemical physical (particulate matter or dust)physical (particulate matter or dust) biologicalbiological

agent that modifies the natural agent that modifies the natural characteristics of the atmosphere. characteristics of the atmosphere. Worldwide air pollution is responsible Worldwide air pollution is responsible for large numbers of deaths and for large numbers of deaths and cases of respiratory diseases.cases of respiratory diseases.

Health problems resulting Health problems resulting from air pollutionfrom air pollution

aggravated asthmaaggravated asthma bronchitisbronchitis emphysemaemphysema lung and heart diseaseslung and heart diseases respiratory allergiesrespiratory allergies

Air quality standardsAir quality standards In the United States there was issued In the United States there was issued

the Clean Air Act that has already the Clean Air Act that has already reduced concentrations of some reduced concentrations of some pollutants.pollutants.

The Clean Air Act sets numerical limits The Clean Air Act sets numerical limits on the concentrations of basic group of on the concentrations of basic group of air pollutants and provides reporting air pollutants and provides reporting and enforcement mechanismsand enforcement mechanisms..

The European Union follows the The European Union follows the initiative.initiative.

Antropogenic (manmade) Antropogenic (manmade) sources of air pollutionsources of air pollution

Marine vessels Burning fossil fuels Burning wood, fireplaces, stoves,

furnaces and incinerators Combustion-fired power plants Controlled burn practices in

agriculture and forestry Motor vehicles

Other antropogenic Other antropogenic sourcessources

Chemicals, dust and crop waste burning in farming.

Fumes from paint, varnish, aerosol sprays and other solvents.

Waste deposition in landfills, which generate mathane.

Military uses, as nuclear weapons, toxic gases, and rocketry.

Oil refining, power plant operation and industry.

Natural sourcesNatural sources Methane, emitted by the digestion of food

by animals, for example cattle. Pine trees, which emit volatile organic

compounds (VOCs). Radon gas from radioactive decay within the

Earth's crust. Smoke and carbon monoxide from

wildfires . Volcanic activity, which produce sulfur,

chlorine , and ash particulates. Dust from natural sources.

Indoor air pollution, or Indoor air pollution, or Indoor air quality (IAQ)Indoor air quality (IAQ)

RadonRadon is a gas of carcinogenic is a gas of carcinogenic properties trapped inside houses.properties trapped inside houses.

FormaldehydeFormaldehyde is emitted by building is emitted by building materials.materials.

Volatile Organic Compounds Volatile Organic Compounds (VOCs)(VOCs) are given off by paints and are given off by paints and solvents.solvents.

LeadLead paint can degenerate into lead paint can degenerate into lead containing dust and be inhaled.containing dust and be inhaled.

Indoor air pollutionIndoor air pollution Air fresheners, incense and other Air fresheners, incense and other

scented items.scented items. Smoke from wood fires in stoves and Smoke from wood fires in stoves and

fireplaces.fireplaces. Arsenic and manganese in shower Arsenic and manganese in shower

water (damaging to inhale). water (damaging to inhale). Arsenic can be trapped in shower Arsenic can be trapped in shower

nozzle filter.nozzle filter. Pesticides.Pesticides.

Indoor air pollutionIndoor air pollution

Carbon monoxide from incomplete Carbon monoxide from incomplete combustion.combustion.

Hydrogen sulfide, deadly sewer gas Hydrogen sulfide, deadly sewer gas (to stop it special traps are built (to stop it special traps are built into all domestic plumbing).into all domestic plumbing).

Tetrachloroethylene from dry Tetrachloroethylene from dry cleaned clothes.cleaned clothes.

Asbestos from building materials.Asbestos from building materials.

SmogSmog is a type of air pollution; the word "smog" was coined in the is a type of air pollution; the word "smog" was coined in the

early 20th century as a portmanteauearly 20th century as a portmanteau of the words of the words smoke smoke and fog and fog to refer to smoky fog.to refer to smoky fog. The word was then The word was then intended to refer to what was sometimes known as intended to refer to what was sometimes known as pea pea soup fogsoup fog, a familiar and serious problem in , a familiar and serious problem in LondonLondon from from the 19th century to the mid 20th century. This kind of the 19th century to the mid 20th century. This kind of smog smog is caused by the burning of large amounts of is caused by the burning of large amounts of coal within a city; this smog contains soot coal within a city; this smog contains soot particulates from smoke, sulfur dioxide particulates from smoke, sulfur dioxide and other and other components. components.

Modern smog, as found for example in Modern smog, as found for example in Los AngelesLos Angeles, is a , is a type of air pollution derived type of air pollution derived from vehiculafrom vehicularr emission emission from internal combustion engines and industrial from internal combustion engines and industrial fumes fumes that react in the atmosphere with sunlight to form that react in the atmosphere with sunlight to form secondary pollutants secondary pollutants that also combine with the primary that also combine with the primary emissions to form emissions to form photochemical smogphotochemical smog..

Health effects of ground -Health effects of ground -level ozone and level ozone and

photochemical smogphotochemical smog Inflammation of breathing Inflammation of breathing

passages, decreasing the lung’s passages, decreasing the lung’s working capacity, shortness of working capacity, shortness of breath, pain, wheezing, and breath, pain, wheezing, and coughing.coughing.

Eye and nose drying and irritationEye and nose drying and irritation.. It increases susceptibility to It increases susceptibility to

infectious diseases.infectious diseases.

Carbon monoxideCarbon monoxide (CO) (CO) is a colourless, odourless and is a colourless, odourless and

tasteless gastasteless gas.. is the product of incomplete is the product of incomplete

combustioncombustion burns in air with a blue flameburns in air with a blue flame.. is toxic as when inhaled, it takes the is toxic as when inhaled, it takes the

place of oxygen in haemoglobin. It place of oxygen in haemoglobin. It binds haemoglobin 200-400times binds haemoglobin 200-400times more strongly than oxygen producing more strongly than oxygen producing carboxyhaemoglobin.carboxyhaemoglobin.

From 1999 through 2004 there were 439 unintentional, non-fire related carbon monoxide poisoning deaths annually in the U.S.

In 2007, there were 2,302 hospitalizations for confirmed cases of unintentional, non-fire related carbon monoxide poisoning in the U.S.

In 2009 there were 552 persons with unintentional, non-fire related carbon monoxide poisoning who received hyperbaric oxygen treatment in the U.S.

Acute poisoning with COAcute poisoning with CO The main manifestations of poisoning develop in the The main manifestations of poisoning develop in the

organ systems most dependent on oxygen use, organ systems most dependent on oxygen use, the central nervous system and the heartthe central nervous system and the heart. The initial . The initial symptoms of acute carbon monoxide poisoning symptoms of acute carbon monoxide poisoning include include headache, nausea, malaise, headache, nausea, malaise, and fatigueand fatigue. These symptoms are often mistaken for a . These symptoms are often mistaken for a virus such as influenza or other illnesses such as food virus such as influenza or other illnesses such as food poisoning or gastroenteritis. Headache is the most poisoning or gastroenteritis. Headache is the most common symptom of acute carbon monoxide poisoning; common symptom of acute carbon monoxide poisoning; it is often described as dull, frontal, and continuous. it is often described as dull, frontal, and continuous. Increasing exposure produces cardiac abnormalities Increasing exposure produces cardiac abnormalities including including fast heart rate, low blood pressure, fast heart rate, low blood pressure,

and cardiac and cardiac arrhythmia.arrhythmia.

Acute poisoning with COAcute poisoning with CO Central nervous system symptoms Central nervous system symptoms

include include delirium, hallucinations, dizziness, unsteady delirium, hallucinations, dizziness, unsteady gait, confusion, seizures, central nervous system gait, confusion, seizures, central nervous system depression,unconsciousness, respiratory arrest, depression,unconsciousness, respiratory arrest, and deathand death. Less common symptoms of acute carbon . Less common symptoms of acute carbon monoxide poisoning include myocardial ischemia, atrial monoxide poisoning include myocardial ischemia, atrial fibrillation, pneumonia, pulmonary edema, high blood fibrillation, pneumonia, pulmonary edema, high blood sugar, lactic acidosis, muscle necrosis, acute kidney sugar, lactic acidosis, muscle necrosis, acute kidney failure, skin lesions, and visual and auditory problems.failure, skin lesions, and visual and auditory problems.

One classic sign of carbon monoxide poisoning is more One classic sign of carbon monoxide poisoning is more often seen in the dead rather than the living - people have often seen in the dead rather than the living - people have been described as looking been described as looking pink-cheekedpink-cheeked and healthy. and healthy.

Concentration Symptoms

35 ppm (0.0035%)Headache and dizziness within six to eight hours of constant exposure

100 ppm (0.01%)Slight headache in two to three hours

200 ppm (0.02%)Slight headache within two to three hours; loss of judgment

400 ppm (0.04%)Frontal headache within one to two hours

800 ppm (0.08%)

Dizziness, nausea, and convulsions within 45 min; insensible within 2 hours

1,600 ppm (0.16%)

Headache, tachycardia, dizziness, and nausea within 20 min; death in less than 2 hours

3,200 ppm (0.32%)

Headache, dizziness and nausea in five to ten minutes. Death within 30 minutes.

6,400 ppm (0.64%)

Headache and dizziness in one to two minutes. Convulsions, respiratory arrest, and death in less than 20 minutes.

12,800 ppm (1.28%)Unconsciousness after 2–3 breaths. Death in less than three minutes.

Chronic exposure to CO Chronic exposure to CO Chronic exposure to relatively low levels of carbon monoxide Chronic exposure to relatively low levels of carbon monoxide

may cause persistent headaches, lightheadedness, may cause persistent headaches, lightheadedness, depression, confusion, memory loss, nausea and vomiting. It depression, confusion, memory loss, nausea and vomiting. It is unknown whether low-level chronic exposure may cause is unknown whether low-level chronic exposure may cause permanent neurological damage. Typically, upon removal permanent neurological damage. Typically, upon removal from exposure to carbon monoxide, symptoms usually from exposure to carbon monoxide, symptoms usually resolve themselvesresolve themselves.. Chronic exposure may worsen Chronic exposure may worsen cardiovascular symptoms in some people. Chronic carbon cardiovascular symptoms in some people. Chronic carbon monoxide exposure might increase the risk of developing monoxide exposure might increase the risk of developing atherosclerosis. Long-term exposures to carbon monoxide atherosclerosis. Long-term exposures to carbon monoxide present the greatest risk to persons with coronary heart present the greatest risk to persons with coronary heart disease and in females who are pregnantdisease and in females who are pregnant

First aid in CO poisoningFirst aid in CO poisoning

Remove the victim from the Remove the victim from the exposure.exposure.

AApply CPR if needed.pply CPR if needed. PProvide 1rovide 10000% oxygen for % oxygen for

breathing.breathing. Hyperbaric oxygenHyperbaric oxygen increases increases

carboxyhaemoglobin dissociation.carboxyhaemoglobin dissociation.

Carbon dioxide (COCarbon dioxide (CO22)) exists in Earth's atmosphere as a trace exists in Earth's atmosphere as a trace

gas at a concentration of 0.039gas at a concentration of 0.039%% by volume by volume Carbon dioxide is colorless. At low Carbon dioxide is colorless. At low

concentrations, the gas is odorless. At higher concentrations, the gas is odorless. At higher concentrations it has a sharp, acidic odor.concentrations it has a sharp, acidic odor.

At standard temperature and pressure, the At standard temperature and pressure, the density of carbon dioxide is around density of carbon dioxide is around 1.98 kg/m1.98 kg/m33, about 1.5 times that of air, about 1.5 times that of air..

Is a greenhouse gas.Is a greenhouse gas. In solid state it is called dry ice.In solid state it is called dry ice.

plants absorb carbon dioxide, light, plants absorb carbon dioxide, light, and water to produce carbohydrate and water to produce carbohydrate --energy for themselves and oxygen as energy for themselves and oxygen as a waste product.a waste product.

In medicine up to 5% of COIn medicine up to 5% of CO2 2 is added is added to pure oxygen for to pure oxygen for stimaulation of stimaulation of breathingbreathing after apnea and to after apnea and to stabilize the Ostabilize the O22/CO/CO22 balance in blood. balance in blood.

COCO2 2 toxicitytoxicity

COCO22 is an asphyxiant gas and not  is an asphyxiant gas and not classified as toxic or harmfulclassified as toxic or harmful..

Concentrations of 7% to 10% may Concentrations of 7% to 10% may cause suffocation, manifesting as cause suffocation, manifesting as dizziness, headache, visual and dizziness, headache, visual and hearing dysfunction, and hearing dysfunction, and unconsciousness within a few unconsciousness within a few minutes to an hour.minutes to an hour.

Acute carbon dioxide physiological effect Acute carbon dioxide physiological effect is hypercapnia or asphyxiation sometimes known is hypercapnia or asphyxiation sometimes known by the names given to it by miners: blackdamp. by the names given to it by miners: blackdamp. Blackdamp is primarily nitrogen and carbon Blackdamp is primarily nitrogen and carbon dioxide and kills via suffocation (having displaced dioxide and kills via suffocation (having displaced oxygen). Miners would try to alert themselves to oxygen). Miners would try to alert themselves to dangerous levels of blackdamp and other gasses dangerous levels of blackdamp and other gasses in a mine shaft by bringing a caged in a mine shaft by bringing a caged canarycanary with  with them as they worked. The canary is more them as they worked. The canary is more sensitive to environmental gasses than humans sensitive to environmental gasses than humans and as it became unconscious would stop singing and as it became unconscious would stop singing and fall off its perchand fall off its perch..

Sulfur (sulphur) dioxide Sulfur (sulphur) dioxide (SO(SO22))

Sulfur dioxideSulfur dioxide is the chemical compound with the is the chemical compound with the formula SOformula SO22. It is a toxic gas with a pungent, irritating . It is a toxic gas with a pungent, irritating smell, that is released bysmell, that is released by volcanoes and in various volcanoes and in various industrial processes. Since coalindustrial processes. Since coal and petroleum often and petroleum often contain sulfur compounds, their combustion generates contain sulfur compounds, their combustion generates sulfur dioxide unless the sulfur compounds are sulfur dioxide unless the sulfur compounds are removed before burning the fuel. Further oxidation of removed before burning the fuel. Further oxidation of SOSO22, usually in the presence of a catalyst such as NO, usually in the presence of a catalyst such as NO22, , forms Hforms H22SOSO44, and thus acid rain.Sulfur dioxide , and thus acid rain.Sulfur dioxide emissions are also a precursor to particulates in the emissions are also a precursor to particulates in the atmosphere. Both of these impacts are cause for atmosphere. Both of these impacts are cause for concern over the environmental impact of these fuels.concern over the environmental impact of these fuels.

Inhaling sulfur dioxide is associated with increased Inhaling sulfur dioxide is associated with increased respiratory symptoms and disease, difficulty in respiratory symptoms and disease, difficulty in breathing, and premature deathbreathing, and premature death.. In 2008,  In 2008, the American Conference of Governmental Industrial the American Conference of Governmental Industrial HygienistsHygienists reduced the short-term exposure reduced the short-term exposure limit from 5 ppm to 0.25 ppm. limit from 5 ppm to 0.25 ppm.

EExposure to sulfur dioxide is associated with preterm xposure to sulfur dioxide is associated with preterm birth.birth.

In the United States, the Center for Science in the In the United States, the Center for Science in the Public Interest lists the two food preservatives, sulfur Public Interest lists the two food preservatives, sulfur dioxide and sodium bisulfite, as being safe for human dioxide and sodium bisulfite, as being safe for human consumption except for certain individuals who may consumption except for certain individuals who may be sensitive to it, especially in large amountsbe sensitive to it, especially in large amounts

Acid rainAcid rain oor r acid precipitationacid precipitation occurs when S occurs when SOO22

and Nand NOOxx are emitted into atmosphere, are emitted into atmosphere, undergo chemical transformations and undergo chemical transformations and are absorbred by water droplets in are absorbred by water droplets in clouds. Acid rain has clouds. Acid rain has pH less than 5.6pH less than 5.6..

Acid rain Acid rain accelerates weathering in accelerates weathering in carbonate rocks and accelerates carbonate rocks and accelerates building weatheringbuilding weathering. It also contributes . It also contributes to to acidificaton of rivers, streamsacidificaton of rivers, streams and and damage to conifer forestsdamage to conifer forests..

Oxides of nitrogen (NOOxides of nitrogen (NOxx))

Nitric oxide (NO)Nitric oxide (NO) Nitrogen dioxide (NONitrogen dioxide (NO22))

Dinitrogen monoxide (NDinitrogen monoxide (N22O)O)

Dinitrogen trioxide (NDinitrogen trioxide (N22OO33))

Dinitrigen tetraoxide(NDinitrigen tetraoxide(N22OO44))

Dinitrogen pentaoxide (NDinitrogen pentaoxide (N22OO55))

Nitrogen oxides Nitrogen oxides are a mixture of gases that are composed

of nitrogen and oxygen. Two of the most toxicologically significant nitrogen oxides are nitric oxide and nitrogen dioxide; both are nonflammable and colorless to brown at room temperature. Nitric oxide is a sharp sweet-smelling gas at room temperature, whereas nitrogen dioxide has a strong, harsh odor and is a liquid at room temperature, becoming a reddish-brown gas above 70°F. Nitrogen oxides are released to the air from the exhaust of motor vehicles, the burning of coal, oil, or natural gas, and during processes such as arc welding, electroplating, engraving, and dynamite blasting. They are also produced commercially by reacting nitric acid with metals or cellulose. Nitrogen oxides are used in the production of nitric acid, lacquers, dyes, and other chemicals. Nitrogen oxides are also used in rocket fuels, nitration of organic chemicals, and the manufacture of explosives.

Oxides of nitrogen (NOOxides of nitrogen (NOxx)) aare produced during combustionre produced during combustion. . The most The most

important source of NOimportant source of NO22 is internal combustion is internal combustion enginesengines..

aggravate asthmatic conditionsaggravate asthmatic conditions.. react with the oxygen in the air to produce react with the oxygen in the air to produce

ozoneozone.. can form can form nitric acidnitric acid; when dissolved in ; when dissolved in

atmospheric moisture the result can be atmospheric moisture the result can be acid acid rainrain damaging trees and forest ecosysytems. damaging trees and forest ecosysytems.

NONO2 2 is toxic by inhalation, causes lung edema.is toxic by inhalation, causes lung edema.

OzoneOzone (O (O33))

Is a triatomic molecule, consisting Is a triatomic molecule, consisting of three oxof three oxyygen atomsgen atoms..

The highest levels of oThe highest levels of ozzone in the one in the atmosphere are in the stratosphere atmosphere are in the stratosphere ((oozzon laon layyer er is between is between 1010 to to 50km 50km above the surfaceabove the surface)). There it filters . There it filters out the short wavelengths out the short wavelengths ((leslesss than 320than 320nm)nm) of ultraviolet light. of ultraviolet light.

Ozone (OOzone (O33)) Low level ozoneLow level ozone or or tropospheric ozonetropospheric ozone is is

regarded as a regarded as a pollutantpollutant b byy the WHO. It is the WHO. It is formed bformed byy the reaction of sunlight an air the reaction of sunlight an air containing hcontaining hyydrocarbons and nitrogen oxides drocarbons and nitrogen oxides that to form ozone.that to form ozone.

Ozone present in the upper troposphere acts Ozone present in the upper troposphere acts as a as a greenhouse gasgreenhouse gas absorbing some of the absorbing some of the infrared energy emitted by earth. infrared energy emitted by earth. Ozone Ozone depletiondepletion occurs due to occurs due to chlorofluorocarbons (CFCs or freonschlorofluorocarbons (CFCs or freons)) and and bromofluorocarbons (halons)bromofluorocarbons (halons)..

AAt the eartht the earth’’s surface ozone can s surface ozone can harm lungharm lung function and function and irritate respiratorirritate respiratoryy s syystemstem..

Ozone (OOzone (O33)) Ozone is produced by laser printers Ozone is produced by laser printers

photocopiers and arc welders. photocopiers and arc welders. Ozone is used forOzone is used for bleaching substances bleaching substances

and for killing bacteria, for water and for killing bacteria, for water and and food food disinfectiodisinfection,n, to deodori to deodorizze air and e air and objectsobjects, , for plactics processing, cleaning for plactics processing, cleaning and bleaching of fabricsand bleaching of fabrics..

IIn medicinen medicine to decontaminate to decontaminate operating roomsoperating rooms..

ParticulatesParticulates Or particulate matter (PM) are tinOr particulate matter (PM) are tinyy

particles of solid (a smoke) or liquid (an particles of solid (a smoke) or liquid (an aerosol) suspended in gas. Theaerosol) suspended in gas. Theyy range range in siin sizze from 10 nanometers to more e from 10 nanometers to more than 100 micrometers in diameter.than 100 micrometers in diameter.

Some PSome PMM originate from volcanoes, originate from volcanoes, dust storms and forest fires.dust storms and forest fires.

Human activities, especiallHuman activities, especiallyy f foossil fuels ssil fuels burning also produce PM. burning also produce PM.

PneumoconiosesPneumoconioses

Are lung diseases caused bAre lung diseases caused byy inhalaton of dust. Theinhalaton of dust. Theyy can be can be fibrogenicfibrogenic ((caused bcaused byy silica dust silica dust oror asbestosasbestos)) or or non fibrogenicnon fibrogenic..

Effects of asbestos

Significant exposure to any type of asbestos will increase the risk of lung cancer, mesothelioma and nonmalignant lung and pleural disorders, including asbestosis, pleural plaques, pleural thickening, and pleural effusions.

When asbestos fibers are inhaled, most fibers are expelled, but some can become lodged in the lungs and remain there throughout life. Fibers can accumulate and cause scarring and inflammation. Enough scarring and inflammation can affect breathing, leading to disease.

Inhaling longer, more durable asbestos fibers (such as tremolite and other amphiboles) contributes to the severity of asbestos-related disorders.

Exposure to asbestos can increase the likelihood of lung cancer, mesothelioma, and non-malignant lung conditions such as asbestosis (restricted use of the lungs due to retained asbestos fibers) and changes in the pleura (lining of the chest cavity, outside the lung).

Changes in pleura such as thickening, plaques, calcification, and fluid around the lungs (pleural effusion) may be early signs of asbestos exposure. These changes can affect breathing more than previously thought. Pleural effusion can be an early warning sign for mesothelioma (cancer of the lining of the lungs).

Most cases of asbestosis or lung cancer in workers occurred 15 years or more after the person was first exposed to asbestos.

Most cases of mesothelioma are diagnosed 30 years or more after the first exposure to asbestos.

AsbestosisAsbestosis Results from heavResults from heavyy exposure to asbestos exposure to asbestos SySymptoms: shomptoms: shorrtness of breath, cough, tness of breath, cough,

respiratorrespiratoryy failure. There is also an failure. There is also an increased risk for increased risk for lung cancerlung cancer and and mesotheliomamesothelioma..

Pathogenesis: asbestos fibres cause Pathogenesis: asbestos fibres cause intersitial fibrosis in lower lobesintersitial fibrosis in lower lobes..

TThere is no curative treatment.here is no curative treatment. OxOxyygen gen theraptherapyy relieves shortness of breath. relieves shortness of breath.

Asbestosis is a serious, progressive, long-term disease of the lungs. Asbestosis is not a cancer. Inhaling asbestos fibers that irritate and inflame lung tissues, causing the lung tissues to scar, causes asbestosis. The scarring makes it hard to breathe and difficult for oxygen and carbon dioxide pass through the lungs. Asbestosis generally progresses slowly. The latency period for the onset of asbestosis is typically 10-20 years after the initial exposure. The disease can vary from asymptomatic (no symptoms) to disabling and potentially fatal.

Signs and Symptoms of asbestosis can include:

Shortness of breath is the primary symptom

A persistent and productive cough (a cough that expels mucus)

Chest tightness Chest pain Loss of appetite A dry, crackling sound in the lungs while

inhaling.

Mesothelioma

Mesothelioma is a rare cancer, which may affect the lining of the chest cavity, outside the lung (pleura) or the abdominal contents (peritoneum). Most mesotheliomas are caused by exposure to asbestos.

Lung Cancer

Lung cancer is a malignant tumor that invades and obstructs the lung's air passages. Cigarette smoking greatly increases the likelihood of a person developing lung cancer as the result of asbestos exposure. The most common symptoms of lung cancer are cough, wheezing, unexplained weight loss, coughing up blood, and labored breathing. Other symptoms of lung cancer include shortness of breath, persistent chest pain, hoarseness, and anemia. People who develop these symptoms do not necessarily have lung cancer, but they should consult a physician for advice.

AsbestosisAsbestosis Heavy Heavy asbestos asbestos

fibres cause fibres cause intersitial intersitial fibrosis in lower fibrosis in lower lobeslobes..

SilicosisSilicosis Silica dust causesSilica dust causes nodular lesionsnodular lesions (nodular (nodular

fibrosis) fibrosis) in upper lobesin upper lobes.. SySymptoms:mptoms: tach tachyypnea, shortness of breath, pnea, shortness of breath,

cough, fatigue, changes in breathing pattern cough, fatigue, changes in breathing pattern ((rapid breathing or shallow breathingrapid breathing or shallow breathing)), loss of , loss of appetiteappetite, , chest pain, fever, cchest pain, fever, cyyanosis, cor anosis, cor pulmonalepulmonale,, respirator respiratoryy insufficienc insufficiencyy, patients , patients are particularlare particularlyy susceptible to tuberculosis susceptible to tuberculosis (silicotuberculosis).(silicotuberculosis).

Silicosis is an Silicosis is an irreversible conditionirreversible condition. There . There is no cure.is no cure.

SilicosisSilicosis Silica dust causesSilica dust causes

nodular lesionsnodular lesions (nodular fibrosis) (nodular fibrosis) in upper lobesin upper lobes..

Black lung diseaseBlack lung disease Black lung Black lung

disease is a disease is a pneumoconiosis pneumoconiosis caused by caused by inhalation of inhalation of carbon dust and carbon dust and silica dust by silica dust by workers in coal workers in coal miners.miners.

AAirborne diseasesirborne diseases   refers to any diseases which are caused by refers to any diseases which are caused by

pathogens and transmitted through the air. pathogens and transmitted through the air. These viruses and bacteria can be spread These viruses and bacteria can be spread through coughing, sneezing, laughing or through coughing, sneezing, laughing or through close personal contact. These through close personal contact. These pathogens ride on either dust particles or pathogens ride on either dust particles or small respiratory droplets and can stay small respiratory droplets and can stay suspended in air and or are capable of suspended in air and or are capable of traveling distances on air currents.traveling distances on air currents.

AAirborne diseasesirborne diseases Tuberculosis Tuberculosis Anthrax (inhalationalAnthrax (inhalational

), ),  Chickenpox, Chickenpox,  Influenza, Influenza,  Measles, Measles,  SmallpoxSmallpox  . .

Airborne diseases are most commonly seen in Airborne diseases are most commonly seen in unsanitary household conditions and overcrowded unsanitary household conditions and overcrowded areas. Also, these diseases thrive in areas of areas. Also, these diseases thrive in areas of poverty and poor hygienic conditions. Tuberculosis poverty and poor hygienic conditions. Tuberculosis happens to be one of the most leading causes of happens to be one of the most leading causes of death in adults from infectious diseases. Around death in adults from infectious diseases. Around 9595%% of people suffering from this disease are from of people suffering from this disease are from developing areas in the world. Measles and developing areas in the world. Measles and diphtheria are two diseases found in poverty diphtheria are two diseases found in poverty conditions, but over the years these diseases have conditions, but over the years these diseases have been eliminated due to vaccines in developed been eliminated due to vaccines in developed countries.countries.