Ambient Air Pollution

Carbon monoxide

Colorless, odorless, poisonous gas produced by the combustion of of carbon or organic fuels, is part of cigarette smoke, 50% comes from vehicles, Concentrations are decreasing in the U.S because newer cars have higher fuel efficiency, Short-lived in the environment, oxidizes to CO2, Highly poisonous to most animals,When inhaled, it reduces the ability of hemoglobin to attach oxygen.EPA standards limits human exposure to 9nL L-1 per 24-hr.

Hydrocarbons are composed

Composed of hydrogen and carbon, Methane is the most abundant in the atmosphere, and an active greenhouse gas. Produced naturally from the decomposition of organic matter and certain type of plants (i.e. pine trees, creosote bush), r

indoor air pollution

Compounds that affect breathing that occur indoors. Examples: wood stove smoke, furnace emissions, formaldehyde, radon, household chemicals & Tobacco smoke.

Air pollution

Concentration of trace substances such as carbon monoxide, sulfur oxide, hydrocarbons, and solid particulates, at a greater level than occurs in average air.

A major source of particulate matter

(62%) comes from roads and transportation. Some particulates, especially those containing sulfur compounds, are emitted by volcanoes26% from agriculture, forestry, and fires.

sulfur oxides

(SOx) Primary source is coal burning. Primary and secondary effects include acid deposition, respiratory irritation, plant damage. Reduction methods include: scrubbers, burn low sulfur fuel.

atmospheric deposition

Contaminants carried by air currents and precipitated into watersheds or directly onto surface waters, The wet or dry deposition on land of a wide variety of pollutants, including mercury, nitrates, organochlorines, and others.

sulfur dioxide

Created naturally by volcanoes. 90% from the burning of fossil fuels (coal), also oil refineries & oil smelters Creates respiratory problems in humans and acid rain in the environment. colorless gas but pungent odor.

radon

2nd leading cause of indoor air pollution., A colorless, odorless, radioactive gas. can cause lung cancer.

Health effects of smog include

Ground-level ozone, sulfur dioxide, carbon monoxide and nitrogen dioxide can cause respiratory illnesses in children and the elderly, includes asthma, bronchitis, emphysema, heart issues

photochemical smog (brown)

A brownish haze (caused by lots of NO2)that is a mixture of ozone and other chemicals, formed when pollutants react with each other in the presence of sunlight, requires sunlight, can produce over 100 different chemicals including tropospheric ozone, hot windless days in urban areas contribute

Lead

A highly toxic metal that can damage the nervous system, blood, and kidneys, and can cause harm to the development of a children's intellectual abilities. Main source was gasoline.

dry acid particle deposition

Acid precipitation in the form of gases and particles, usually occurring two to three days after emission into the atmosphere

Secondary pollutants

Air pollutants produced through reactions between primary pollutants and normal atmospheric compounds. ie: tropospheric ozone, sulfuric acid, photochemical smog, acid rain

mobile sources

All forms of transportation that burns fossil fuels. This make up for 56% of pollutants emitted to the atmosphere in the U.S.

Pollution dispersal is controlled by:

Atmospheric motion, which is affected by wind. Wind determines the horizontal movement of pollution in the atmosphere. Stability, influences both air turbulence and the depth at which mixing of polluted air takes place. Vertical variation of temperature within the boundary layer.

The impact of hydrocarbons

Carcinogenic,Influences climate variability (Methane) Enhancement of greenhouse gases. Relatively reactive HC contribute to the creation of ozone in photochemical smog.

Other primary pollutants include

Chlorofluorocarbons (CFCs) - harmful to the ozone layer, Odors- waste material such as sewage, garbage and industrial processes, Radioactive pollutants- nuclear weapons, war explosives, radon gas

acid rain mitigation

Coal washing - removal of sand, clays, sulfur and trace elements, Reduction of particulates from industry emission,Electrostatic precipitators, Fabric filters, Wet scrubbers-captures particulates and SO2, Hot gas filtration systems

volcanic eruptions

Volcanic eruption can release dust, ash, sulfur dioxide, carbon dioxide and hydrogen fluoride in the atmosphere, Effects:Sulfur dioxide: acid rain, Hydrogen fluoride: skin irritation, conjunctivitis, bone degeneration.

Acid deposition

acid-forming pollutants from the atmosphere onto the Earth's surface, Acid Deposition originates from the emission of sulfur dioxide and nitrogen oxides from fossil fuels, industries or electrical appliances

nitrogen oxides

Nitrogen oxides are formed primarily by nitrogen (N2) and oxygen (O2) from combustion of fuels under high temperature, Natural sources of nitrogen oxides include metabolic processes from soil bacteria, NOx may be produced from thunderstorms by electrical discharge

Particulate matter

Particles have no general chemical composition and may, in fact, be very complex. Particulate matter can include: solid particles or liquid droplets (aerosols), soot, smoke, dust, asbestos fibers, pesticides and metals ( such as Hg, Fe, Cu and Pb).

Particulate matter 2.5

Particulate matter that is 2.5μm or less

anthropogenic sources of air pollution

Power plants (manufacturing facilities), Motor vehicles (carbon monoxide), Chemical, dust, controlled burns, Fumes (aerosol sprays), Landfills (methane),Military (nuclear weapons, germs warfare, toxic gases and rocketry)

Clean Air Act 1970

Required EPA to develop and enforce regulations to protect the public from airborne contaminants; forced states to follow and make sure the laws for followed in relation to the EPA. States allowed to decide officials for enforcement.

Effects of Particulate Matter

Some Particulate Matter can reach the stratosphere, where they may significantly alter the radiation and thermal budgets of the atmosphere and thus produce cooer temperatures at the earth surface.Tropospheric particulates can exacerbate human respiratory illnesses (PM10 and PM2.5). Particulates can reduce visibility in large cities ( i.e. Los Angeles)

natural sources of air pollution

Subtropical deserts (Dust), Animals (Methane emission), Radon gas, (radioactive material), Smoke (wildfires),Volcanic activity

Volatile organic compounds (VOCs)

The fumes given off by organic chemicals such as paints, aerosol sprays, cleaner, disinfectants, new carpets, and glues. include the nonmethane hydrocarbons (NMHCs) such as benzene and derivatives such as formaldehyde.

chlorofluorocarbons (CFCs)

These reduce concentration of ozone in the stratosphere and created the ozone hole, they are responsible for more UVB radiation in the surface of earth

US Clean air act of 1955

This act designated funds towards air pollution research

US Clean Air Act of 1960

This act pertained specifically to air pollution control

Pollutant concentrations depend on

Total mass of pollution emitted into the atmosphere. Atmospheric conditions, which affects fate and transport

outdoor air pollution

ambient air pollution, ubiquitous especially in developing countries and urban areas, Outdoor pollution can be natural and man-made

Particulate matter particles of 10μm or less are known

as PM10 Construction practices are believed to be a major source of PM10 .

US Clean Air Act of 1967

authorized the expansion of air pollutant emission inventories , ambient monitoring techniques and control techniques

three technologies that decrease air pollutants

baghouse filters, electrostatic precipitators and scrubbers

Effects of SO2

can cause respiratory problems at relatively high concentration, source of acid rain,harmful to plant tissues at sufficiently high concentrations, can cause cooling of temperature in certain regions

Smog can be mitigated by

catalytic converters, Emissions test must be performed on older cars, Removal of lead from gasoline, Regulate driving days based on license plate number (Greece)

Uptake of pollutants through leaf stomata or deposition of pollutants on leaf surface can

cause harm to vegetation.

Effects of NOx

causes a reddish-brown haze in urban air spaces that contributes to heart and lung problems and may be carcinogenic,Contributes to acid rain.

Green house gases, due to the role they play in warming up the earth, may

change rainfall patterns which could markedly alter the distribution of life on earth.

Particulate matter can be

characterized by size. which can influence residence time in atmosphere. Particles with diameters less than 10μm or larger generally settles out of the atmosphere in less than a day, Particles with diameters of 1μm or less remains suspended in the atmosphere for weeks.

acid precipitation

deposition of acidic or acid-forming pollutants from the atmosphere onto the Earth's surface, originates from the emission of sulfur dioxide and nitrogen oxides from fossil fuels, industries or electrical appliances. includes Fog, Gases, Deposition of dry particles, Precipitation (acid rain, snow, sleet etc.)

scrubbers

devices containing alkaline substances that precipitate out much of the sulfur dioxide from industrial plants.

Forest fires

emit carbon monoxide, sulfur dioxide, nitrogen oxide, ozone and particulate matter

Teenagers chronically exposed to polluted air are

five times likely to develop asthma than individuals in clean air.

Hydrocarbons are released into the atmosphere by

fossil fuel combustion, Evaporation from gasoline when fueling cars and other motor vehicles, Heavily urbanized areas may have a higher concentration of HCs in the atmosphere

ozone

gas that absorbs ultraviolet solar radiation, found in the stratosphere, a zone between 15 and 50 kilometers (9 to 30 miles) above Earth's surface, depends on the relative concentrations of nitrogen oxides, hydrocarbons and other pollutants, slow and builds up in polluted air masses, development requires prolonged sunny days and low wind speed

Lead Pb

highly toxic substance, can produce chronic impairment in blood,Affects neurological development in infants, Lead based paints continue to be a source of concern in situations where children are exposed to paints that have peeled from building surfaces,Lead based paint was banned in the U.S. in 1978.

Sufficiently high levels of sulfur dioxide or ozone may cause

leaf lesion in susceptible plant.

Dust storms

meteorological phenomenon that is common in arid and semi arid areas, Strong winds or gust fronts blows loose sand and dirt from a dry surface, Sahara and drylands around Arabian peninsula are main source of terrestrial sources of dust

industrial smog consists of

mostly of sulfur dioxide, suspended droplets of sulfuric acid (formed from some of the sulfur dioxide) and a variety of suspended solid particles and droplets. thermal or temperature inversion created during the day can trap air pollutants near the surface of the Earth

stationary sources

non-moving sources of pollution, such as factories, Electrical,Power Plants, Ore smelters, Farms, 15% of pollutants emitted in the U.S.

wet acid deposition

occurs in the form of rain and snow

Primary (6) criteria pollutants

pollutants that are put directly into the air by human or natural activity i.e: soot, carbon monoxide, hydrocarbons, particulate matter, lead, SO2, nitrogen oxide

Impacts of acid rain deposition

produce adverse impact on natural ecosystems such as forests, freshwater and soils, causes death to insects and aquatic organisms, destruction of building and human health impacts.

Chronic exposure of plant to relatively low levels of pollutants can

reduce their resistance to disease and insect predators.

Impacts of ozone

slow and builds up in polluted air masses, Very small amounts of ozone in the air can impact human health, Impacts cardiovascular and respiratory systems, Vegetation such as crops, forests, flowers etc are damaged by ground-level ozone

Research shows that breathing polluted air

slows lung development in children as much as having a parent who smokes tobacco.

industrial smog (gray)

smog resulting from emissions from industry and other sources of gases produced by the burning of fossil fuels. formed when smoke and sulfur emissions from coal burning combines with fog. Creates a yellowish-brown colored haze close to ground level

Clean Air Act 1990

strengthened regulations for auto emissions, toxins, acid deposition, ozone depletion, while introducing market incentives, emissions trading

toxic air pollutants

substances known to cause cancer, reproductive defects, or neurological, developmental, immune system, or respiratory problems.

Breathing polluted air can

thicken human artery walls, which is an important risk factor for heart failure and stroke.

Smog

type of air pollution that can be formed through the mixing of different types of pollutants. (Secondary Pollutant) typically formed over urban area, can be categorized as industrial or photochemical smog,

chlorofluorocarbons CFCs

widely regarded as harmful bc they are chemically unreactive to normal conditions. but over Antarctica they condense into tiny ice crystals that break down and produce chlorine which attacks and destroys the ozone