AIR and AIR POLLUTION Learning Objectives Review: Identify the layers of the atmosphere. • Greek: atmos (vapor/steam), sphaira (ball/ globe) • Modern Latin: atmosphaera • Gaseous envelope surrounding the Earth 3 § The total mass of the atmosphere is about 5.3 x 1018 kg § Water is excluded from this table because its concentration in air can vary drastically from location to location. Troposphere Stratosphere Mesosphere Thermosphere (Ionosphere) Exosphere § Closest to Earth’s surface (7-18 km above the equator) § Most active region – where all the dramatic events of weather (rain, lightning, hurricanes) occur § Contains almost 80% of the total mass of air and practically all the atmosphere’s water vapor (forms clouds and rain) § Thinnest layer of the atmosphere (10 km) § Temperature decreases with increasing altitude § Consists of nitrogen, oxygen and ozone. § 19-50 km above the equator § Air temperature increases with altitude due to the exothermic reactions triggered by UV radiation from the sun. § One of the products of this reaction sequence is ozone (O3), which serves to prevent harmful UV rays from reaching Earth’s surface. § 30-50 km above the equator § The concentration of ozone and other gases is low § The temperature decreases again with increasing altitude § 50-400 km above the equator § Temperature increases with altitude – as the result of the bombardment of molecular O2 and N2 and atomic species by energetic particles, such as electrons and protons, from the sun. § In reverse, these processes liberate the equivalent amount of energy, mostly heat. § Ionized particles are responsible for the reflection of radio waves back toward Earth. § ~400 km above the equator § The outermost layer of our atmosphere § This layer separates the rest of the atmosphere from outer space – 10,000 km thick § There is a lot of empty space in between of very spread out hydrogen and helium gases. § There is no air to breathe and it is very cold. § § Spectacular celestial light shows as a result of ejection of myriad electrons and protons in space during solar flares or violent eruptions on the surface of the sun. § Aurora borealis – Northern Hemisphere; § Aurora australis – Southern Hemisphere These electrons and protons collide with the molecules and atoms in Earth’s upper atmosphere, causing them to ionized and electronically excited. e- + O O* + e- p+ + N2 N2+* + p+ + e- Solar Radiation § The excited molecules and ions return to the ground state with the emission of light. § An excited oxygen atom emits photons at wavelengths of 558 nm (green) and between 630 and 636 nm (red). § The blue and violet colors often observed in auroras result from the transition in the ionized nitrogen molecule. The wavelengths for this transition fall between 391 and 470 nm. • The atmosphere performs several ecosystem services: • Protects Earth from most radiation from the sun and space • X-rays, Cosmic rays and Ultraviolet (UV) • Without this atmospheric radiation shield, life as we know it would cease to exist § Ozone (O3) in the stratosphere prevents UV radiation emitted by the Sun from reaching the Earth’s surface. § photodissociation of molecular oxygen : 𝑂! § UV <240 nm 𝑂+𝑂 reactive O atom combines with molecular oxygen (O2) to form ozone (O3) 𝑂 + 𝑂! + 𝑀 → 𝑂" + 𝑀 § Formed ozone absorbs UV light 𝑂" UV 𝑂 + 𝑂! where: M = inert substance (N2) • The atmosphere performs several ecosystem services: – Naturally occurring greenhouse gases absorb some reradiated heat • Keeps surface temperature within habitable range for life to exist § The trapping of heat near Earth’s surface by gases in the atmosphere, particularly CO2. – Atmosphere is modified and partially maintained by living organisms • Photosynthesis contributes O2 , cellular respiration CO2 Learning Objectives Identify the types, sources, and effects of chemicals that pollute the air. WHAT IS AIR POLLUTION? The presence of various chemicals in the atmosphere in concentrations high enough to harm organisms, ecosystems, or human-made materials, or to alter climate • Primary Air Pollutant Øchemicals or substances emitted directly into the air from a source (natural processes and human activities) at concentrations high enough to cause harm • Secondary Air Pollutant ØHarmful substance formed in the atmosphere when a primary air pollutant reacts with substances normally found in the atmosphere or with other air pollutants Natural Sources: • wind-blown dust • Pollutants from wildfires and volcanic eruptions • Volatile organic chemicals released by some plants Ø Spread out over the globe Ø Removed by chemical cycles, precipitation, and gravity Ø Some chemicals emitted by volcanic eruptions or forest fires can temporarily reach harmful levels Human (Anthropogenic) Sources: • combustion of fossil fuels • industrial by-products Types of Human Sources: • Mobile sources - such as cars, buses, planes, trucks, and trains • Stationary sources - such as power plants, oil refineries, industrial facilities, and factories OUTDOOR POLLUTION This refers to exposures that occurs outside of the built environment. Ozone (O3) § Has a sharp odor that you may have detected around electric motors or welding equipment § Can be found both in troposphere and stratosphere § At troposphere, it is as major part of smog § At stratosphere, it is a protective layer against UV radiation (ozone layer) § Formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) combine chemically with oxygen in sunlight Carbon Monoxide (CO) § “the silent killer” – no color, taste, nor smell § CO is released when engines burn fossil fuels – automobile exhaust, charcoal fires, propane pumping stoves § When inhaled, CO passes into the bloodstream and interferes with the ability of the hemoglobin to carry oxygen • Carbon dioxide (CO2) – Colorless, odorless, tasteless gas – Greenhouse gas – Major sources: 93% of CO2 in the atmosphere is the result of the natural carbon cycle; human activities – burning of fossil fuels, clearing of CO2– absorbing forests and grasslands Nitrogen Oxides (NOx) § Refer to a binary compound of nitrogen and oxygen, or a mixture of such compounds § NO: nitric oxide § NO2: nitrogen dioxide § N2O: nitrous oxide § N4O: nitrosylazide § Formed when N in the fuel is burned or when N in the air reacts with O at very high temperature – vehicle engines and coal-fired power plants Nitrogen Monoxide (NO) § Common name: nitric oxide § A colorless gas Nitrogen Dioxide (NO2) § NO2 is a reddish-brown gas that comes from the burning of fossil fuels § Has a strong smell at high levels § Primary visible component of urban smog § Can also react in the atmosphere to form ozone, acid rain or particles § Can combine with the moist tissue in lungs to produce an acid Dinitrogen Monoxide (N2O) § Common name: nitrous oxide § Greenhouse gas emitted from fertilizers and animal wastes, and is produced by the burning of fossil fuels § It is the largest cause of ozone layer depletion. Sulfur Oxides (SOx) • Refer to a binary compound of sulfur and oxygen, or a mixture of such compounds § SO: sulfur monoxide § SO2: sulfur dioxide § SO3: sulfur trioxide § S2O: disulfur monoxide § S2O2: disulfur dioxide § Lower sulfur oxides (S7O2, S6O2) § Higher sulfur oxides (SO3, SO4, etc.) Sulfur Dioxide (SO2) § SO2 is a corrosive gas that cannot be seen or smelled at low levels but can have a “rotten egg” smell at high levels § Mostly comes from burning of coal or petroleum in power plants; also comes from factories that make chemicals, paper or fuel § Like NO2, it reacts in the atmosphere to form acid rain § SO2 exposure can affect people with asthma or emphysema by making it more difficult to breathe § Also irritates eyes, noses and throats § Can harm trees and crops, as well as damage buildings Sulfur Trioxide (SO3) § a secondary air pollutant that forms when SO2 reacts with oxygen in the air § reacts with water to form sulfuric acid Particulate Matter (PM) § Solid or liquid matter that is suspended in the air § To remain in the air, particles must be less than 0.1 mm wide and can be as small as 0.00005 mm § Divided into 2 types: coarse particles and fine particles § Coarse particles: road dust, sea spray, construction § Fine particles: burning of fuels in power plants and automobiles § Can enter the lungs - asthma attacks, respiratory problems, premature death § Reduces visibility and corrodes metals Particulate Matter (PM): PM2.5 and PM10 § PM10 § particles with an average diameter of 10 μm (1.0 x 104 nm), length on the order of 4 x 10-4 (0.0004) inches or one-fifth of the width of a human air. § PM2.5 § is a subset of PM10 and includes particles with an average diameter 2.5 um (2.5 x 103 um) or less. https://blissair.com/what-is-pm-2-5.htm Particulate Matter (PM) https://www.ucair.org/pollutants/pm2-5/ Sources: 62% natural sources – dust, wild fires, sea salt; 38% human sources – coal-burning power and industrial plants, motor vehicles, road constructions http://www.bestratedairpurifier.in/pm2-5-pm10-effects-human-health/ Lead § Blue-gray metal that is very toxic and found in a number of forms and locations § From cars in areas where leaded gasoline is used; from power plants and other industrial sources § Lead paint (peeling paint), lead in old pipes (drinking water) § High amounts can be dangerous for small children that may cause lower IQ and kidney problems § In adults, increased chances of heart attack and/or stroke Toxic Air Pollutants (TAPs) or Hazardous air pollutants (HAPs) § Each toxic air pollutant comes from a slightly different source, but many are created in chemical plants or are emitted when fossil fuels are burned § Chlorine, formaldehyde, arsenic, asbestos, benzene and dioxin § Asbestos and formaldehyde can be found in building materials and can lead to indoor air problems § TAP can also enter food and water supplies § Some TAP can cause cancer § Some TAP can cause birth defects (teratogenic); § teratogen – mutagen which causes birth defects § Some TAP can cause skin & eye irritation and breathing problems Toxic Air Pollutants (TAP) - Asbestos § According to the World Health Organization (WHO), asbestos can cause mesothelioma (rare cancer of the lung), as well as lung, laryngeal and ovarian cancer. § The material can also cause asbestosis, or fibrosis of the lungs – a scarring or thickening of the lung lining, both of which cause shortness of breath. § Asbestos was used for wall insulation, mixed with plastic, sealed into floors and built into cars. § It is resistant to heat and corrosion. https://www.livescience.com/63280-epa-asbestos.html Toxic Air Pollutants (TAP) - Dioxins § Group of chemically-related compounds that are persistent organic pollutants (POPs). § Found throughout the world in the environment and they accumulate in the food chain, mainly in the fatty tissues of animals. § More than 90% of human exposure is through food, mainly meat and dairy products, fish and shellfish. § Dioxins are highly toxic and can cause reproductive and developmental problems, damage the immune system, interfere with hormones and may cause cancer. § Burning of municipal and/or hospital waste, backyard burning and automobile emissions contribute to the release of low levels of dioxins into the environment. http://www.who.int/news-room/fact-sheets/detail/dioxins-and-their-effects-on-human-health Stratospheric Ozone Depleters § Chemicals that can destroy ozone in the atmosphere § Include chlorofluorocarbons (CFCs e.g. CFCl3, CF2Cl2, C2F3Cl3 and C2F3Cl3), hydrochlorofluorocarbons (HCFCs), halons and other compounds containing Cl or Br § CFCs are used in air conditioners & refrigerators as coolants, aerosol cans and fire extinguishers § Other ozone depleters are used as solvents in industry Volatile Organic Compounds (VOCs) § Diverse group of organic compounds emitted as gases from certain solids or liquids § Concentration of many VOCs are consistently higher indoors (>10x) than outdoors § Variety of health effects, depending on the individual chemical § Many are respiratory tract irritants and carcinogenic § Most contribute to photochemical smog https://www.epa.gov/ Volatile Organic Compounds (VOCs) Sources • Paints, paint strippers and other solvents • Wood preservatives • Aerosol sprays • Cleansers and disinfectants • Moth repellents and air fresheners • Stored fuel and automotive products • Hobby supplies • • • • Dry-cleaned clothing Pesticide Building materials and furnishings Office equipment, such as copiers and printers, correction fluid and carbonless copy paper • Graphics and craft materials including glues and adhesives, permanent markers and photographic solutions 39 Volatile Organic Compounds (VOCs) Health Effects § Eye, nose and throat irritation § Headaches, loss of coordination and nausea § Damage to kidney, liver and central nervous system (CNS) § Some organics may can cause cancer in animals, some are suspected or known to cause cancer in humans https://www.haywardscore.com/ Pollens § Pollen from trees, weeds and grass can cause allergies and hay fever § Pollen pollution is expected to increase with global warming as growing seasons lengthen https://greenliving.lovetoknow.com/Types_of_Air_Pollution Molds § Mold is a problem affecting indoor air quality § Some molds produce toxins that bring on allergies and asthma § Molds occur in damp buildings or those with high humidity § Air pollution in an urban area is referred to as smog or industrial smog. § Industrial smog is generally worse during the winter months. § Smog is composed of sulfur oxides and particulate matter § Industrial smog significant problem in developing countries due to the lack of pollution-control laws that developed countries have in place. How pollutants are formed from burning of coal and oil. The result is industrial smog. Industrial smog in China © 2017 John Wiley & Sons, Inc. All rights reserved. § A brownish-orange haze formed by chemical reactions involving sunlight, nitrogen oxide and hydrocarbons is referred to as photochemical smog. § Photochemical smog was first noted in Los Angeles in the 1940s - Worse in the summer months § Ozone is a principal component of photochemical smog § Results in eye irritation, aggravates respiratory illness, and harms plant tissue § Sources include car exhaust, dry cleaners, and bakeries Photochemical reaction – any chemical reaction activated by light Typical Variations with Time in Concentration of Air Pollutants on a Smoggy Day. Primary pollutants: NO, CO and unburned hydrocarbons Secondary pollutants: NO2 and O3 N2 (g) + O2 (g) 2NO (g) + O2 (g) NO2 (g) + hn O (g) + O2 (g) + M 2NO (g) 2NO2 (g) NO (g) + O (g) O3 (g) + M lachrymator – tear producer and causes breathing difficulties Formation and composition of photochemical smog © 2017 John Wiley & Sons, Inc. All rights reserved. § A catalytic converter is a unit that fits into the front part of exhaust system of a vehicle, close to the engine, to reduce the emission of gaseous pollutants, such as carbon monoxide (CO), nitrogen oxides (NOx) and hydrocarbons (HCs). https://www.cars.com/auto-repair/glossary/catalyticconverter/ § Sulfur dioxide and nitric oxide emissions react with water vapor in the atmosphere to form acids that return to the surface as either dry or wet deposition. § Wet deposition - includes sulfuric acid and nitric acid in precipitation § Dry deposition – dry particles of sulfuric acid and Acid rain – usually has a pH between nitric acid that settle out of the air 4.2 and 4.4 § Acid rain can corrode limestone and marble (CaCO3) CaCO3 (s) + H2SO4 (aq) CaSO4 (s) + H2O (l) + CO2 (g) § SO2 directly react with CaCO3 2CaCO3 (s) + 2SO2 (g) + O2 (g) 2CaSO4 (s) + CO2 (g) • Harmful effects: • Damages statues and buildings • Contributes to human respiratory diseases • Leach toxic metals (such as lead and mercury) from soils and rocks into lakes used as sources of drinking water • Harms aquatic ecosystems • Affects forests in two ways: • Leaching essential plant nutrients such as calcium and magnesium from soils • Releasing ions of aluminum , lead, cadmium, and mercury, which are toxic to the trees Acid Fume Scrubber liming – a process of adding quicklime (CaO) to lakes and soils to reduce their acidity Ozone Depletion (in purple) Over the South Pole § Stratospheric Ozone Thinning is the accelerated destruction of ozone in the stratosphere by humanproduced chlorine and bromine containing chemicals. ozone hole – a region of exceptionally depleted ozone in the stratosphere over the Antarctic https://ozonewatch.gsfc.nasa.gov/ O3 destruction CFCl3 UV CF2Cl2 UV CFCl2 + Cl CF2Cl + Cl Cl + O3 ClO + O2 ClO + O Cl + O2 O3 + O 2O2 Cl catalyzes the reaction ClO is an intermediate CHLOROFLUOROCARBONS (CFCs): § CFC-12 (CF2Cl2) – used as coolant and refrigerant § CFC-11 (CFCl3) – used to blow holes in soft plastics § CFC-13 (CF2Cl - CFCl2) – cleaning circuit boards • Harmful effects: • Exposure to any amount of UV radiation increases the risk of skin cancer and genetic mutations. • Linked to ocular cataracts and weakened immunity • Damage ecosystems, crops, materials and finishes Ozone Damage to Grape Leaves Montreal Protocol § A global agreement to protect the stratospheric ozone layer by phasing out the production and consumption of ozone-depleting substances (ODS). It was finalized in 1987 in Montreal, Canada. § The protocol sets limits on the production of chlorofluorocarbons (CFCs), halons and related substances that release chlorine or bromine to the ozone layer of the atmosphere. https://www.ibtimes.co.uk/world-without-montreal-protocolozone-hole-would-have-grown-by-40-by-2013-1503015 53 • Injures organisms • Reduces visibility • Corrodes materials • Metals, plastics, rubber, fabrics • Harms the respiratory tract, and can worsen existing medical conditions • Reduces crop productivity • Involved in acid deposition, global warming, and stratospheric ozone depletion © 2017 John Wiley & Sons, Inc. All rights reserved. EFFECTS OF AIR POLLUTANTS HEALTH EFFECTS: § Irritates eyes and respiratory tract § Produces chest discomfort § Aggravates respiratory conditions such as asthma and chronic bronchitis § Can lead to sore throat, cough, breathing difficulty OZONE (O3) ENVIRONMENTAL EFFECTS: § Reduces air visibility § Stresses plants and reduces their vigor § Chronic ozone exposure lowers crop yields § Forest decline § Greenhouse gas associated with global climate change EFFECTS OF AIR POLLUTANTS HEALTH EFFECTS: § Reduces the amount of oxygen reaching the body’s organs and tissues. § Acute exposure: dizziness, headache, decreased physical performance, vomiting, nausea and death § Chronic exposure: stress on cardiovascular system, fatigue at low levels, CARBON MONOXIDE heart attack (CO) § Mental impairment due to high exposure levels (CO poisoning) ENVIRONMENTAL EFFECTS: § Contributes to climate change and global warming (greenhouse gas) § Damage to plants and crops exposed CARBON DIOXIDE (CO2) ENVIRONMENTAL EFFECTS: § Causes climate change and global warming (greenhouse gas) EFFECTS OF AIR POLLUTANTS HEALTH EFFECTS: § Acute exposure: lung irritation § Chronic exposure: bronchitis § Can cause cough, shortness of breath, respiratory infections, and aggravate asthma § Cause chronic lung disease (High exposure) § Affect the senses (e.g. ability to smell an odor) NITROGEN OXIDES(NOx) ENVIRONMENTAL EFFECTS: § Damage to vegetation (including leaf damage, decreasing growth) § Involved in the production of photochemical smog (NO and NO2) § Reacts with surfaces § Can fade and discolor fabrics and furnishings § Harms historical buildings and structures made of limestone and marble (involved in acid deposition) § Contributes to acid rain which can corrode metals § Associated with global warming and ozone depletion in the stratosphere § Reduces visibility (N2O) EFFECTS OF AIR POLLUTANTS HEALTH EFFECTS: § Difficulty in breathing § Acute exposure: inflammation of respiratory tract, aggravation of asthma § Chronic exposure: emphysema, bronchitis SULFUR OXIDES (SOx) ENVIRONMENTAL EFFECTS: § Main contributor to acid rain § Secondary main contributor to particulate matter § Harms historical buildings, structures, statues and monuments made of limestone or marble § Corrode metals § Damage paints, paper, leather § Damage to plants and crops (e.g. leaf damage), soils and aquatic life in lakes § Decreasing growth to plants EFFECTS OF AIR POLLUTANTS PARTICULAR MATTER (PM) HEALTH EFFECTS: § Heart disease, irregular heartbeat, reduced lung function, tightness of the chest § Premature death in people with heart or lung diseases § Asthma § Increased respiratory symptoms (irritation, coughing or breathing difficulty) § Severe respiratory diseases § Chronic exposure: bronchitis ENVIRONMENTAL EFFECTS: § Poor visibility § Making lakes and rivers acidic § Damage to agricultural crops § Imbalance of nutrients in coastal waters and river banks § Contributes to acid rain EFFECTS OF AIR POLLUTANTS HEALTH EFFECTS: § Damages the nervous system § IQ loss; change in behavior; impacts on learning and memory § Risk in high blood pressure, heart disease and kidney disease § Reduced fertility LEAD (Pb) ENVIRONMENTAL EFFECTS: § Body functions of phytoplankton can be disturbed § Imbalance in nutrients of soil § Damages to internal organs of animals resulting to break of food chain • Respiratory system protection from air pollutants: – Hair in nose filter out large particles – Sneezing and coughing expel contaminated air – Cilia - hundreds of thousands of tiny mucuscoated, hair-like structures, line your upper respiratory tract, continually move back and forth and transport mucus and the pollutants they trap to your throat where they are swallowed or expelled • Effect of prolonged exposure to air pollutants and tobacco smoke: – Overload or break down of our natural defenses – Lung cancer, asthma attack, heart attack, and stroke – Chronic bronchitis and emphysema, which leads to acute shortness of breath Emphysema - a lung condition wherein the air sacs, or alveoli, become damaged which can result to breathlessness and wheezy breathing. • Natural factors that help reduce outdoor air pollution – Settling of particles due to gravity – Rain and snow – Salty sea spray from the oceans – Winds – Chemical reactions § Urban buildings – slow wind speed and reduce dilution of pollutants § Hills and mountains – reduce flow of air in valleys, thus allowing pollutant levels to build up § High temperatures – promote chemical reactions leading to formation of photochemical smog § Emissions of VOCs from certain trees and plants – formation of photochemical smog § Grasshopper effect § Temperature inversions Grasshopper Effect or Global Distillation § occurs when air pollutants are transported at high altitudes by evaporation and winds from tropical and temperate areas through the atmosphere to the earth’s polar areas; § air toxics involved are polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) § happens mostly during winter; § explains why pilots have reported seeing dense layers of reddish-brown haze over the Arctic; § also explains why polar bears, sharks, and other native people in remote arctic areas have high levels of various toxic pollutants in their bodies Global distillation – the process whereby volatile chemicals evaporate from land as far away as the tropics and are carried by air currents to higher latitudes, where they condense and fall to the ground Temperature Inversion § Normally, warm air and most of the pollutants it contains rise to mix with the cooler air above and are dispersed. § Under certain atmospheric conditions, however, a layer of warm air can temporarily lie atop a layer of cooler air nearer the ground, creating a temperature inversion. § Traps air pollutants on ground level and allows their concentrations to increase. Temperature inversion – a deviation from the normal temperature distribution in the atmosphere, resulting in a layer of cold air temporarily trapped near the ground by a warmer upper air. • Urban heat islands – Heat from sunlight heated streets, rooftops, and parking lots, radiates into the atmosphere at night – Heat from human activities is highly concentrated in urban areas – These pockets of heat in urban areas surrounded by cooler rural and suburban areas, are called heat islands – Can affect local air currents and weather conditions – Cause higher concentrations of particulate matter called dust domes This figure shows how temperatures might vary on a summer afternoon. The city stands out as a heat island against the surrounding rural areas © 2017 John Wiley & Sons, Inc. All rights reserved. • Urban heat islands encourage the formation of a dome of heated air that surrounds an urban area – This contributes to the buildup of air pollutants, especially particulate matter • If wind speeds increase, the polluted air spreads over rural areas • Cities in valleys are highly susceptible to buildup of pollutants on low wind days • Increased number of thunderstorms in summer associated with urban heat islands A dust dome of pollutants forms over a city when the air is somewhat calm and stable. When wind speeds increase, the pollutants move downwind from the city. © 2017 John Wiley & Sons, Inc. All rights reserved. • At least 2.4 million premature deaths per year world-wide – Mostly in Asia – About 2/3 of these deaths result from breathing indoor air pollutants • This refers to the air quality within and around buildings and structures. • Four most dangerous indoor air pollutants: – Tobacco smoke – Formaldehyde – Radioactive radon-222 gas – Very small (ultrafine) particles • Indoor air pollution can lead to serious health problems – People in rural areas and developing countries use solid fuels (wood, coal, peat, and dung) to cook indoors, with poor or no ventilation – WHO estimates 1.6 million die annually from indoor cooking smoke • Women and children are harmed the most by indoor cooking • In developed countries, the most common indoor air contaminants are radon, cigarette smoke, CO, NO2, formaldehyde, pesticides, cleaning agents, ozone, and asbestos • Viruses, bacteria, fungi, dust mites, pollen, and other organisms, are frequently found in ventilation ducts • Health effects: – Respiratory aggravators – Potential carcinogen – Sick building syndrome © 2017 John Wiley & Sons, Inc. All rights reserved. • Sick building syndrome (SBS) – is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. – Eye irritation, nausea, headaches, respiratory infections, depression, and fatigue caused by indoor air pollution • The Labor Department estimates that more than 20 million employees are exposed to health risks from indoor air pollution Homes may contain higher levels of air pollutants than outside air, even near polluted industrial sites. © 2017 John Wiley & Sons, Inc. All rights reserved. • Some alarming facts released by EPA – Levels of 11 common pollutants generally are 2 to 5 times higher inside homes and buildings than they are outdoors, and as much as 100 times higher in some cases – Pollution levels inside cars in traffic-clogged urban areas can be up to 18 times higher than outside levels – Health risks from exposure to such chemicals are magnified because most people in developed urban areas spend 7098% of their time indoors or inside vehicles • At greatest risk: – Smokers – Children younger than 5 years old – Elderly – Sick people – Pregnant women – People with respiratory or heart problems – Factory workers • Radon (Rn) is a naturally occurring, colorless, tasteless, odorless, radioactive gas the comes out of the ground all around and below us. • Rn comes from the natural (radioactive) breakdown of uranium in soil, rock and water and gets into the air. • Radon is ubiquitous. It can get into any type of building, homes, offices, schools, and result in high indoor radon levels. • The US-EPA has determined that high levels of Radon causes lung cancer more often than secondhand tobacco smoke. How radon infiltrates a house – Cracks in basement walls or floors, openings around pipes, and pores in concrete blocks provide some of the entries for radon. How to protect against Radon exposure: 1. Install Rn reduction systems during house remodeling or when building an addition to the house. 2. Employ Rn-resistant construction techniques. 3. Use home Rn detectors. 4. Increase ventilation. Home Radon Detectors © 2017 John Wiley & Sons, Inc. All rights reserved. Learning Objectives • Enumerate the solutions to reduce threats of air pollution on human health and ecosystems • Technology exists to control all of the forms of air pollution discussed here – Smokestacks with precipitators, fabric filters, and scrubbers, remove particulate matter from air – Careful land-excavation activities reduce the creation of particulate matter – More fuel efficient automobiles produce fewer polluting emissions – Sulfur removal from fuel, or using low or no sulfur energy sources, decreases sulfur pollutants – Measures taken to increase fuel efficiency and conservation reduce pollution – Reduction of combustion temperatures reduces formation of nitrogen oxides – Modification of furnaces and engines and use of catalytic converters can reduce CO and hydrocarbon emissions – Careful handling of petroleum products reduces their evaporation and spills © 2017 John Wiley & Sons, Inc. All rights reserved. Uncontrolled emissions. Industrial stacks without emission control devices can release substantial amounts of particulate matter and other pollutants. Electrostatic precipitator. In an electrostatic precipitator, the electrode imparts a negative charge to particulates in the dirty gas. These particles are attracted to the positively charged precipitator wall and then fall off into the collector. Stacks with emission controls. Effective emission control devices can reduce particulate matter and other pollutants. © 2017 John Wiley & Sons, Inc. All rights reserved. • Philippine Clean Air Act of 1999 • Provides the policy framework for the country’s air quality management program • It seeks to uphold the right of every Filipino to breathe clean air by addressing air pollution from mobile and stationary sources • Emission trading or cap-and-trade program • Enables most polluting coal-burning power plants to buy and sell SO! pollution rights • Proponents: Cheaper and more efficient than government regulation of air pollution control • Critics: allows utilities with older, dirtier power plants to buy their way out of their environmental responsibilities and continue polluting • Makes cheating possible because it is based largely on selfreporting of emissions • Ultimate success depends on two things: how low the initial cap is set and how often it is lowered in order to promote continuing innovation in air pollution prevention and control Ways to Reduce Outdoor Air Pollution Ways to Reduce Outdoor Air Pollution Methods for reducing emissions from motor vehicles: Ways to Reduce Indoor Air Pollution: Individuals Matter: What Can You Do? Pollution Prevention Ways to prevent outdoor and indoor air pollution over the next 30-40 years Analyzing Air Pollutants: Air Quality Index (AQI) An index determined by calculating the degree of pollution in the city or at the monitoring point and includes five main pollutants: • Particulate matter • Ground level ozone (O3) • Sulfur dioxide (SO2) • Carbon monoxide (CO) • Nitrogen dioxide (NO2) AQI unit: (ug/m3) https://forum.airnowtech.org/t/aqi-calculations-overview-ozone-pm2-5-and-pm10/168 85 Thank you Have a great day ahead.
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