Unit 4 Air pollution. What is air pollution 9/16/2013. ES 541 Contemporary Environmental Issues. Atmosphere as a Resource.

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1 ES 541 Contemporary Environmental Issues Unit 4 Air pollution Atmospheric Composition Nitrogen 78.08% Oxygen 20.95% Argon 0.93% Carbon dioxide 0.04% Atmosphere as a Resource Ecosystem services Blocks UV radiation Moderates the climate Redistributes water in the hydrologic cycle Air? Not Ordinary Air! It is Life-Air from the Skies! Life-Air Without Food (but Water ) human can live for 3 Days. Without Water (and no Food ) human can live for 1 Day. Without Air (even with Food and Water ) human can live for 1 Minute. Ques: Guess, what is Death? Ans: No Air for 1 Minute is called as Death. Air is so important. Pollution is a serious issue. Air is Expensive than Blood Air is what we Breathe every Second, even during Sleep! Air is sucked into lungs every few seconds and the alveolar system of the lungs helps the oxygenation of blood in every drop. Heart pumps Blood and Blood carries O 2 (by Hemoglobin) to every part/cell of the body to sustain Life inside. More O 2 into the body is called More Life. Similarly Better O 2 into the body is called Better Life. But then Polluted O 2 into the body is called Polluted Life. What is air pollution THE RESULT OF EMISSION INTO THE AIR OF HAZARDOUS SUBSTANCES AT A RATE THAT EXCEEDS THE CAPACITY OF NATURAL PROCESSES IN THE ATMOSPHERE TO CONVERT, DEPOSIT, OR DILUTE THEM Factors that affect air pollution Emissions (traffic, industrial, domestic) Geography (terrain) Weather conditions (rain, winds, humidity) Season Time of day Population density Indoor vs outdoor 1

2 Types of air pollution Types and Sources of Air Pollution Aerosols Particulates solid phase Dust Ash Fumes Solid and liquid Smoke (from combustion) Coastal aerosols Liquid Aggregate gases (sulfate, nitrate) Gases COx SOx NOx PAH Two categories Primary Air Pollutant Harmful substance that is emitted directly into the atmosphere Secondary Air Pollutant Harmful substance formed in the atmosphere when a primary air pollutant reacts with substances normally found in the atmosphere or with other air pollutants Six primary or criteria air pollutants Carbon monoxide (CO) Ozone (O 3 ) Nitrogen dioxide (NO 2 ) Sulfur oxides (SO x ) PM 2.5 and PM 10 Lead (Pb) Major Air Pollutants Air Pollution Around the World Air quality is deteriorating rapidly in developing countries Shenyang, China Residents only see sunlight a few weeks each year Developing countries have older cars Still use leaded gasoline 5 worst cities in world Beijing, China; Mexico City, Mexico; Shanghai, China; Tehran, Iran; and Calcutta, India 2

3 Long Range Transport of Air Pollutants Long-range transport of air pollutants (LRTAP) refers to the atmospheric transport of air pollutants within a moving air mass for a distance greater than 100 kilometres. Types of air pollution Individual pollutants Reducing pollution (SO 2 ) Acid rain (fog) Corrosive, eroding Photochemical pollution Aldehydes, electrophilic HCs Oxidative, carcinogenic? Mixtures and complex patterns Combustion pollutants Sources of combustion VOCs NOx N-organics Halo-organics Metals CO Tobacco Power plants Incinerators Automobiles Industry Diesel pollutants Outdoor air pollution Particulate matter C + PAHs + N-aromatics Gases NOx, CO, SOx VOCs formaldehyde, acrolein, aldehydes Delhi Beijing Respiratory inflammation Cytotoxicity to airway cells 3

4 Outdoor air pollution Air Pollution - Side Effects Mexico City Santiago Side Effects of Air Pollution are many! A few are mentioned below: Acid Rain - and therefore Water Pollution. Global Warming 1 - due to Air Pollution. Ozone Layer Depletion - due to Air Pollution. Global Warming 2 - due to Ozone Layer Depletion. Increase of Smog, Haze, Particulate, Dust, Toxic Brue. Global Dimming - due to Air Pollution. Ecological Issues - too much Rain or no Rain - destruction of Farmers plans - Farmer suicides in some Countries - Ethiopian famine, etc. Environmental Disorder - disturbs natural Human Life. Present Need of the Hour Other Pollutions/Corruptions 1. Arise 2. Awake 3. Attend 4. Act Water Pollution.ppt Food Pollution.ppt Sound Pollution.ppt Society Pollution.ppt Politics Pollution.ppt Reservations Pollution.ppt Government Pollution.ppt Law & Order Pollution.ppt Strikes/Riots Pollution.ppt Relationships Pollution.ppt Cultures Pollution.ppt Religions Pollution.ppt Mind Pollution.ppt Quality of Thought Pollution.ppt Security Pollution.ppt Health Pollution.ppt Indoor pollutants What is sick building syndrome? Non-specific symptoms Household vs work space Sick building syndrome (20% exposed) Cigarette smoke, combustion products Organic offgasing (glue, fabrics, furnishings) Biological agents (infections, allergens) Additional factors (stress, fatigue, diet, alcohol) The feeling of illness among majority of occupants of a conditioned space is called Sick Building Syndrome. A variety of illness symptoms reported by occupants in sick buildings are Headache, fatigue, irritation in eyes, nose and throat, shortness of breathe etc. Causes :Inadequate ventilation, insufficient supply of outside air; poor mixing; fluctuations in temperature & humidity; 4

5 Indoor air quality Indoor air pollution: Poor countries Indoor air quality (IAQ) is a term referring to the air quality within and around buildings and structures. IAQ can be affected by microbial contaminants (mold, bacteria), gases (including carbon monoxide, radon, volatile organic compounds), and particulates. 5

6 Control of Indoor Air Pollution Main indoor air Main pollutant indoor pollutants and their and sources,continue their Pollutant Sources Basic approaches to control indoor air pollution include source control, source isolation, increased ventilation, dehumidification, and the use of filters. Possible sources of contamination are eliminated in a sourcecontrol strategy. Examples include banning smoking in public buildings. Source-isolation strategy is used in situations where a source cannot be completely eliminated. For instance, copy machine areas, food service stations, and bathrooms are often separately vented outside buildings to avoid the recirculation of return air. Environmental tobacco smoke Carbon monoxide Lead Asbestos Cigarette and water pipe smoking Unburned kerosene, gas water heaters, gas stoves, automobile exhaust, tobacco smoke Lead based paints, contaminated soil, dust and drinking water Deteriorating, damaged, or disturbed insulation, fireproofing, acoustical materials, and floor tiles Main indoor air pollutant and their sources NO2 Kerosene heaters, un-vented gas stoves and heaters. Environmental tobacco smoke Formaldehyde Volatile organic compounds Respirable particles Furniture made with pressed wood products, ureaformaldehyde foam insulation, environmental tobacco smoke, glues Paint, paint stripper, solvent aerosol sprays Kerosene heaters, wood stoves, fireplaces, environmental tobacco smoke Biological pollutants Dust mite, Pet dander, droppings and body parts of cockroaches rodents and other pests Radon Building materials and well water 6

7 Particulate matter pollution Properties - varied Mixture of solid phase and absorbed materials (organic, inorganic and biological) Carbonaceous core 40-60%, C 7% Sources Combustion - oil and coal Industry Automobiles Tobacco smoke Biomass burning Metal smelters NAAQS: PM 10 : 150ug/m 3, 24h 50ug/m 3, annual PM ug/m 3, annual 65ug/m 3, 24h Physical size Large Small ~10um Fine ~2.5um Particulates - features Aerodynamic diameter (size equivalent of density=1) Large - local irritation (>100um) Inhalable (<100um) Thoracic fraction (<20um) respirable Coarse PM 10 (<10um) Fine PM 2.5 (<2.5um) Ultrafine (<0.1um) Chemical reactivity Shape (fibers) and Water content Urban Particulates Health effects of particulate pollutants In the <2.5um range Large water content, trace metals, acid gases, organic chemicals, biological Rather uniform distribution Include diesel Eye irritation Respiratory tract infection Exacerbation of asthma Bronchial irritation Heart disease - starting at 10ug/m 3 Possibly cancer (controversial) (diesel, TiO 2, talc, carbon black, toner black) Elevated hospital admissions, mortality Causation(s) not fully understood Gas pollutants - O 3 Good O 3 - stratosphere Bad O 3 - troposphere Properties NAAQS: 0.12ppm, 1h 0.08ppm, 8h Short lived, highly reactive, water soluble Scrubbed in nasopharynx Reaches terminal bronchioles and alveoli Sources Photochemical reactions Health effects Degenerative lung disease Loss of lung function Photochemical pollution NO2 uv NO + O O2 + O O3 O3 + NO O2 + NO2 Twist: In absence of HC- the reaction reaches equilibrium Car emitted HC- (PAH) react with O.. 7

8 Hydrocarbons shift photochemical reaction HC- + O. Oxidized free radicals NO NO2 + Aldehydes Balance of photochemical reaction shifts toward O 3 build-up!! O 3 Photochemical pollution NO 2 O 2 Hydrocarbons O3 uv O 3 The O 3 molecule is highly reactive. O 2 O. H 2 O 2 (HO. ) Ultimate toxicant: No enzyme can detoxify it Only protection: prevention of its formation particulates (especially lead) nitrous oxides potassium Carbon monoxide Other toxic chemicals What s in smog Acid rain contains high levels of sulfuric or nitric acids contaminate drinking water and vegetation damage aquatic life erode buildings Alters the chemical equilibrium of some soils Acid Deposition Sulfur dioxide and nitrogen dioxide emissions react with water vapor in the atmosphere and form acids that return to the surface as either dry or wet deposition ph scale 8

9 How Acid Deposition Develops Volatile Organic Pollutants (VOCs) Sources: Petroleum emissions, fuel combustion, incineration, biomass burning Account for ~14% of all air pollution Important factor of indoor air pollution Types Aliphatic Alcohols (ethylene glycol, MTBE) Aldehydes (formaldehyde) Aromatic (benzene, toluene, xylene) Halogenated (TCE, PERC, Methylene Chloride) Polycyclic (PAHs) Other (Carbon disulfide) VOCs Health Effects Controlling Air Pollution Alkanes (solvents, varnishes, lacquers) Irritants, lung and skin CNS depressants, neuron degeneration, paralysis Pulmonary edema React with OH radical in photochemical pollution Alkenes (gasoline and aviation fuel) more reactive than alkanes - chains, oxides, halogenated HC CNS effects - cramps, tremor GI tract - nausea, vomiting Smokestacks with electrostatic precipitator (right) Without Electrostatic precipitator With Electrostatic precipitator Controlling Air Pollution Smokestacks with scrubbers (right) Particulate material can also be controlled by proper excavating techniques Controlling Air Pollution Phase I Vapor Recovery System for gasoline 9

10 Catalytic Converters and Particle Traps Catalytic converters can be fitted to cars to reduce NOx emissions. CO + HC + NOx H 2 O + N 2 + CO 2 Platinum Honeycomb Multi-pollutant/multi-effect analysis for identifying cost-effective policy scenarios RAINS computer model Particle traps can be used to reduce PM10 and NOx, but the effectiveness is severely reduced if the fuel the vehicle burns has a high sulphur content. PM SO 2 NH 3 NO x VOC The major target in the battle for cleaner cities is diesel. Health Eutrophication Acidification Ozone CAFE policy targets for 2020 NAAQ Standards for six criteria pollutants Pollutant Primary Stds. Averaging Times Secondary Stds. Carbon Monoxide 9 ppm (10 mg/m3) 35 ppm (40 mg/m3) Lead 1.5 µg/m3 Quarterly Average Same as Primary Nitrogen Dioxide Particulate Matter (PM10) Particulate Matter (PM2.5) ppm (100 µg/m3) Revoked(2) Annual(2) (Arith. Mean) 150 µg/m3 24-hour(3) 15.0 µg/m3 Annual(4) (Arith. Mean) 35 µg/m3 24-hour(5) Ozone 0.08 ppm 8-hour(6) Same as Primary Sulfur Oxides *Applies only in limited areas 8-hour(1) 1-hour(1) Annual (Arithmetic Mean) None None Same as Primary Same as Primary 0.12 ppm * 1-hour(7) Same as Primary 0.03 ppm Annual (Arith. Mean) ppm 24-hour(1) hour(1) 0.5 ppm (1300 µg/m3) US Regulation history Air pollution control Act 1963 Federal - Clean Air Act (1967 am) 1965 Federal - Motor vehicle Air pollution control Act 1970 The Clean Air Act: national level (EPA) O 3, SO 2, NO 2, CO, PM, Pb, total hydrocarbons (dropped) 1970 Lead is banned as fuel additive 1990 CCA amendment: 118 chemicals, some carcinogenic Maximum achievable control technology Additional risk assessment if health effects beyond the MACT level Emission standards for motor vehicles (CO solution - MTBE new problem) 1997 New standard for PM 2.5 The Clean Air Act Authorizes EPA to set limits on amount of specific air pollutants permitted Focuses on 6 pollutants: lead, particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides, and ozone Act has led to decreases! Other Ways to Improve Air Quality Reduce sulfur content in gasoline from its current average of 330 ppm to 30 ppm Sulfur clogs catalytic converters Require federal emission standards for all passenger vehicles Including SUVs, trucks and minivans Require emission testing for all vehicles Including diesel 10