chapter 6 - air pollution 1

CHAPTER 6A

Air Pollution: Origin, Fate and Effects of Pollutants

Air Pollution

Learning Objectives:

At the end of this topic the students should be able to;

• recognize the importance of monitoring and control of air pollution

• implement the various rules and regulations • implement the various rules and regulations stipulated in the EQA 127 pertaining to the monitoring and control of air pollution

• apply the air pollution standards to monitor and control air pollution

• understand the impact of emission on the environment and human health

Air Pollution

• Indoor

• Regional

• Global• Global

• Stratospheric

– Sources

– Effects

– Treatment

Air Pollution and Public Opinion• Problems in many European urban areas

in late 1800s and early 1900 due to coal use

• 1000’s of deaths attributed to air pollution episodes in London episodes in London

– large number of pollution sources

– restricted air volume

– failure to recognize problem

– water droplets of certain size

• Photochemical smog: CO+NOx+HC+light

Air Pollution Standards

• Criteria pollutants

–Primary standards designed to protect human health with an “adequate margin of safety.”of safety.”

–Secondary standards are intended to prevent environmental and property damage.

A primary pollutant is an air pollutant emitted directly from a source.

A secondary pollutant is not directly emitted as such, but forms when other pollutants (primary pollutants) react in the atmosphere.

Examples of a secondary pollutant include ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight; NO2, which is formed as NO combines with oxygen in the air; and acid rain, which is formed when sulfur dioxide or nitrogen oxides react with water.

Air Pollution Standards

LAW/REGULATIONS AND

STANDARDS SETTING

The Environmental Quality Act 1974 sets standards for emission sourcessets standards for emission sources

• The EQA controls pollution through :

– Licensing

– Regulations, order, guidelines

ENVIRONMENTAL QUALITY ACT 1974

(AMMENDMENT 2001)

Control of Industrial Emissions

• Environmental Quality (Clean Air) Regulations 1978

• Environmental Quality (Compounding of Offences) Rules 1978;

Control of Motor Vehicle Emissions

• Motor Vehicles (Control of Smoke & Gas • Motor Vehicles (Control of Smoke & Gas Emission) Rules 1977

• Environmental Quality (Control of Lead Concentration in Motor Gasoline) Regulations 1985

• Environmental Quality (Control of Emission From Diesel Engines) Regulation 1996

• Environmental Quality (Control of Emission From Petrol Engines) Regulation 1996

Malaysian Air Pollution Index (API)

• The ambient air quality measurement in Malaysia is described in terms of Air Pollutant Index (API). The API is developed in easily understood ranges of values as a means of reporting the quality of air instead of using the reporting the quality of air instead of using the actual concentration of air pollutants. This index also reflects its effect on human health ranging from good to hazardous and also can be categorized according to the action criteria as stipulated in the National Haze Action Plan

Malaysia : API• The air pollutant index scale and terms used in describing the air quality levels are

as follows :

LAWS APPLICABLE TOOPEN BURNING

Section 29A EQA (Amendment 1998)Section 29AA EQA (Amendment 2001)• Environmental Quality (Prescribed

Activities)(Open Burning) Order, 20002000

• Environmental Quality (Delegation of Powers)(Investigation of Open Burning) Order, 2000

• Environmental Quality (Compounding of Offences)(Open Burning) Rules, 2000

ENVIRONMENTAL QUALITY ACT1974 (AMMENDMENT 2006)

EQA SECTION 29A

No person shall allow or cause open burning on any premises

• Maximum fine RM 500,000• Maximum fine RM 500,000

• Maximum jail term 5 years

• Or Both

Malaysia : Ambient Air Quality Standard

• Six criteria pollutants, namely Carbon Monoxide , Nitrogen Dioxide, Ozone, Sulphur Dioxide and Particulate Matter (PM10) were monitored continuously at 52 locations while lead concentrations was measured once in every six days at two locations.

• The ambient air quality standard in Malaysia addressed in terms of major pollutants including ground level ozone,

• The ambient air quality standard in Malaysia addressed in terms of major pollutants including ground level ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, total suspended particulate (TSP), particulate matter below 10 microns (PM10), and lead. The averaging time, which varies from 1 to 24 hours for the different air pollutants in the MAAQS, represents the period of time over which measurements is monitored and reported for the assessment of human health impacts of specific air pollutants.

Malaysian Ambient Air Quality Guideline

Malaysia Unhealthy Days

Malaysia Air Quality Status

Malaysia Air Quality Status

Malaysia Air Quality Status

Control of “Criteria” Air Pollutants

• A geographic area that meets or does better than the primary standard is called an attainment area; areas that don't meet the primary standard are called nonattainment areas.are called nonattainment areas.

• Although EPA has been regulating criteria air pollutants since the 1970 CAA was passed, many urban areas are classified as nonattainment for at least one criteria air pollutant. It has been estimated that about 90 million Americans live in nonattainment areas.

Air Pollutants & Sources

Carbon Monoxide

produced by the incomplete

burning of carbon-

containing fuels, such as

petrol, coal and wood.

Ozone

produced by the reaction of

oxygen gas with free atoms of

oxygen which are formed from

the reactions between nitrogen

oxides and hydrocarbons in

sunlight.

produced by petrol- or

diesel-burning engines and

coal/oil furnaces.

Nitrogen oxides

Major Air

Pollutants

Text in hereproduced by burning of

fossil fuels (e.g. fuel oil and

coil). A large proportion is

produced by power stations

and metal smelters which

burn sulphur-containing

coal, and also by the

manufacturing industries

which burn fuel oil.

petrol, coal and wood.

Particulates

produced by refuse

incineration, factories, diesel

vehicles, construction sites,

and coal/charcoal burners.

Particulates are solid or

liquid particles which are so

small that they remain

suspended in the air for a

long period of time.

sunlight.

Hydrocarbons

Sulphur dioxide

formed from the

evaporation of materials

such as petrol, diesel and

solvents when exposed to

air.

Carbon Monoxide

• Most abundant air pollutant

• Produced by incomplete combustion

– insufficient O2– insufficient O2

– low temperature

– short residence time

– poor mixing

• Major source (~ 77%) is motor vehicle exhaust

Carbon Monoxide

• Colorless and odorless

• When inhaled, binds to hemoglobin in blood to form carboxyhemoglobin, reducing the oxygen carrying capacityreducing the oxygen carrying capacity

• brain function reduced, heart rate increased at lower levels

• asphyxiation occurs at higher levels

Carbon Monoxide

Carbon Monoxide• Typical Levels

– busy roadways: 5 – 50 ppm

– congested highways: up to 100 ppm

– bars: up to 30 ppm

• Vehicle emission rates:• Vehicle emission rates:

Model year Hydrocarbons

(grams/km)

Carbon

monoxide

(grams/km)

Precontrol (before 1968) 6.59 52.2

1996-2003 0.155 2.11

2004-2006 0.0777 1.06

Malaysia : CO

Carbon Monoxide: Trends in Levels

• Air quality still an issue:

– Increasing vehicle population

– Increasing travel per vehicle

• 1980: average 9,500 miles/year• 1980: average 9,500 miles/year

• 1995: average 11,800 miles/yr

• Vehicle miles of travel: Increase of 3.1%/ yr

– Departures from Federal standards

– Greater use of light trucks (including SUVs)

Oxides of Nitrogen (NOx)

• Primarily NO and NO2

• NO3, N2O, N2O3, N2O4, N2O5 are also known to occur

• Thermal NOx created by oxidation of atmospheric N2 when T > 1000 K

• Fuel NOx from oxidation of N in fuel

Oxides of Nitrogen (NOx)

• NO has few health effects, but is oxidized to NO2

• NO2 irritates lungs and promotes respiratory infectionsrespiratory infections

• NO2 reacts with hydrocarbons in presence of sunlight to produce smog

• NO2 reacts with hydroxyl radicals to produce nitric acid – acid precipitation

Malaysia : NO2

Hydrocarbons

Harmful Effects of Hydrocarbons

Hydrocarbons in air by themselves alone cause no harmful effects. However, they undergo chemical reactions in the undergo chemical reactions in the presence of sunlight and nitrogen oxides. They form photochemical oxidants leading to photochemical smog. This causes irritation in the eyes and lungs leading to respiratory diseases.

Photochemical Smog

hydrocarbons + NOx + sunlight →

photochemical smog (oxidants)

• primary oxidants produced:

– ozone (O3)

– formaldehyde

– peroxyacetyl nitrate (PAN)

Photochemical Smog

Photochemical Smog

Ozone: Health Effects

• Increased incidents of respiratory distress.

• Repeated exposures to ozone:

– Increased susceptibility to respiratory infection

– Lung inflammation

– Aggravation of pre-existing respiratory diseases such as asthma.

– Decreases in lung function and increased respiratory symptoms such as chest pain and cough.

Ozone: Environmental Effects

• Ozone also affects vegetation and ecosystems

– reductions in agricultural and commercial forest yields ($0.5 billion/yr in US alone)($0.5 billion/yr in US alone)

– reduced growth and survivability of tree seedlings

– increased plant susceptibility to disease, pests, and other environmental stresses (e.g., harsh weather).

http://www.ncl.ac.uk/airweb/ozone/greece.jpg

Malaysia : Ozone

Sulfur Oxides (SOx)

• SO2, SO3, SO42

formed during combustion of fuel containing sulfur

• H2S released is converted to SOconverted to SO2

• 10 Tg/yr natural sources

• 75 Tg/yr anthropogenic sources

http://www.epa.gov/oar/aqtrnd97/brochure/so2.html

Sulfur Dioxide: Health Effects

• High concentrations of SO2 can result in temporary breathing impairment.

• Longer-term exposures to high concentrations of SO2, in conjunction with high levels of PM, include respiratory illness, alterations in the include respiratory illness, alterations in the lungs' defenses, and aggravation of existing cardiovascular disease

• Short-term exposures of asthmatic individuals to elevated SO2 levels may result in reduced lung function.

Manmade SO2 Emissions

US SO2 emissions pie.

50% of electricity produced in US comes from coal.

Sfuel + O2 SO2

Sulfur Dioxide: Environmental Effects

• Acid Rain� Decreased Visibility

Acid Rain

Impacts of Acid Rain

• Acid rain causes acidification of lakes and streams and contributes to the damage of trees at high elevations and many sensitive forest soils.

• In addition, acid rain accelerates the decay of building materials and paints, including irreplaceable building materials and paints, including irreplaceable buildings, statues, and sculptures that are part of our nation's cultural heritage.

• Prior to falling to the earth, sulfur dioxide (SO2) and nitrogen oxide (NOx) gases and their particulate matter derivatives—sulfates and nitrates—contribute to visibility degradation and harm public health.

Malaysia : SO2

Particulate Matter

• Solid or liquid particles with sizes from 0.005 – 100 µm

• General term is aerosols

• Dust originates from grinding or crushing

• Fumes are solid particles formed when • Fumes are solid particles formed when vapors condense

• Smoke describes particles released in combustion processes

• Smog used to describe air pollution particles

Health Impacts of Particulate Matter

Health Efffects of Particluate Matter

• Impact depends on particle size, shape and composition

• Large particles trapped in nose

• Particles >10 µm removed in • Particles >10 µm removed in tracheobronchial system

• Particles <0.5 µm reach lungs but are exhaled with air

• Particles 2 – 4 µm most effectively deposited in lungs

Particulate Matter

• PM-2.5 (1997)

< 2.5 µm diameter • PM-10 (1987)

< 10 µm diameter

Original standards did not account for size –larger particles that were not problematic dominated

Similar sources, but tend to be more toxicologically active particles

EPA estimates new standard will save 15,000 lives/yr

< 10 µm diameter

fuel combustion (45%)

industrial processing (33%)

Transportation (22%)

Particulate Matter: Revised Standards

• Two new PM-2.5 standards

– 15 micrograms per cubic meter (µg/m3) and 65 µg/m3, respectively, for the annual and 24-65 µg/m , respectively, for the annual and 24-hour standards. In addition, the form of the 24-hour standard for PM-10 was changed.

– Beginning in 2002, EPA will designate areas as nonattainment that do not meet the new PM-2.5 standards.

Malaysia : PM10

Malaysia : PM10

Particulate Matter: Health Effects

• Inhalable PM includes both fine and coarse particles.

• Coarse particles – aggravation of respiratory conditions, such as

asthma. asthma.

• Fine particles – increased hospital admissions and emergency

room visits for heart and lung disease– increased respiratory symptoms and disease– decreased lung function– premature death

Particulate Matter: Environmental Effects

• Decreased visibility

– the visual range can be reduced 70% from natural conditions natural conditions (natural visibility can be up to of 150 km)

• Damage to paints and building materials

http://www.epa.gov/oar/vis/bryce.html

Lead

• Sources:

– gasoline (historical)

– metals processing

• Highest air Pb • Highest air Pb concentrations

– in the vicinity of nonferrous and ferrous smelters, and battery manufacturers.

Lead: Health Effects

• Accumulates in the blood, bones, and soft tissues.

• Adversely affects the kidneys, liver, nervous system, and other organs.

• Excessive exposure to Pb may cause neurological impairments, such as seizures, mental retardation, and behavioral disorders.

• May be a factor in high blood pressure and subsequent heart disease.

Effects of Air Pollution

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