ATMOSPHERIC AEROSOL AND HEALTH EFFECTS ON HUMANS

PRESENTATION AT

DEPARTMENT OF CHEMISTRY KNUST

BY

KWABENA BOADU OFFEI-KORANTENG

(MPHIL POLYMER SCIENCE AND TECHNOLOGY 1)1

OUTLINE

Introduction

Definition

Sources

Composition

Classification

Health effects2

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Why do we care?Atmospheric aerosols affect global temperaturesHealth pollution weather

INTRODUCTIONThe positive links existing between airborne particulate matter concentrations and a wide range of adverse health effects have been of growing concern in recent years. Both long and short–term exposures influence population health issues and hence the need for more concerted effort to improve on air quality (WHO, 2000).The air we breath always contain aerosols and sufficient concentration are toxic to our body.4

WHO, 2000. Air Quality Guidelines for Europe. WHO Regional Publications, European Series, No. 91.

AEROSOLS

Aerosols are Suspensions of liquid or solid

particles in air/ atmosphere. Diameter range 1nm

to 100μm

1. Liquids – mist, fog

2. Solids – smoke, fumes, fly ash, dust

3. Smog = Smoke + fog5

SOURCES OF AEROSOL

Primary aerosol: emitted directly and are often

entrained into the air/atmosphere by the wind. e.g.

desert dust or sea-salt, Volcanic dust, particles

Secondary aerosol: aerosols formed in the atmosphere

by chemical reaction or condensation of gases. e.g.

NH4NO3 or (NH4)2SO4

Either type may be

Natural source or

Anthropogenic source

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TYPICAL ATMOSPHERIC AEROSOLS

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Soil erosion

Pollen,gaseous

precursors

NATURAL SOURCE

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Mineral dust

Sea spray aerosol

Biogenic emission, eg. Pollen, fern

spores, fungal spores

Volcanic eruptions

ANTHROPOGENIC SOURCE

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exhaustTraffic

non- exhaust eg. Road – tyre interaction

Industrial activities like

welding, crushing, grinding

Wildfire

Domestic biomass burning

Food cooking

Garbage burning

Tobacco

Fireworks

Construction and

demolition

welding

NATURAL AND ANTHROPOGENIC PROCESSES PRODUCING GASES AND PARTICLES IN THE ATMOSPHERE

10Pollution Fire Vegetation Sea salt Mineral dust

Soot andcarbonaceousspecies Biogenic and

organic volatilespecies

Secondary aerosols

Long-range transport, aerosol mixing, aging, chemistry

OH + NO2 + SO2 + HOOH + HNO3 + NH3...

AEROSOLS CHEMICAL COMPOSITION

Fine Particles vs. Coarse Particles

Fine Particles: acidic and made up of sulfates,

ammonium compounds, hydrocarbons, elemental carbon

(soot), toxic metals, and water in the atmosphere

Coarse Particles: basic and contain most of the

crustal materials and their oxides, such as

silicon, iron, calcium, and aluminum, as well as

large sea salt particles and vegetation debris11

WHERE ARE THESE AEROSOLS FOUND?

12http://frobinett.edublogs.org/files/2011/02/layers-of-the-atmosphere- 29q693x.jpg

AEROSOL CLASSIFICATIONThe most important aerosol Classifications are:

size and shape: nm to 100μm , Many irregular shapes , sphericalparticle size: fine mode (d < 1μm) and coarse mode (d > 2.5μm); fine mode is divided on the nuclei mode (about 0.001μm - 0.1μm) and accumulation mode (d 0.1μm - 2.5μm).

Concentration: the total number of particles per unit volume

Lifetime: the time aerosols reside in the atmosphere before being removed

by precipitation or conversion in something else.

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FINE PM2.5COMPOSITION IN ASHAIMAN.ACCRA, GHANA

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industrial emissions

fresh sea salt

diesel emissions

biomass burning

two stroke engines

aged sea salt

gasoline emissions

soil dust

11.40%

15.50%

18.40%

9.50%

5.10%6.20%

15.80%

17.70%

Ofosu G.F et al (2012). Atmospheric Pollution Research 3 (2012) 301-310

FINE PM2.5COMPOSITION IN BEIJIN

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unknown trace crustal ammonium sulphate nitrate chloride EC organic

23%

4%

12%

5%

9%

5%

1%

5%

36%

DATA FOR BEIJIN IN 2000

Air quality guidelines for Europe, 2nd ed. Copenhagen, World Health Organization Regional Office for Europe, 2000 (WHO Regional Publications, European Series, No. 91).

REMOVAL OF AEROSOLS FROM THE ATMOSPHERE

Wet depositionMostly, rainfall will remove aerosols from the atmosphere.

For example, when an eruption happens but it is reach only into the lower atmosphere (troposphere), rainfall usually will remove the pollution within days.

Dry deposition

When aerosol particles are removed from the atmosphere by falling directly to the ground, this process is called as dry deposition.

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HEALTH EFFECTS

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> 5μm

<< 0.1μm

0.2-1.5μm

From ENV 6130 Course on Aerosol Mechanics by Prof. Chang-Yu Wu, University of Florida, Department of Environmental Engineering Sciences

HEALTH EFFECTSIrritation of the airways in the extra thoracic region, resulting in symptoms such as runny nose and sneeze

Irritation and inflammation of the conducting airways in the tracheobroncial region, resulting in symptoms of cough and shortness of breath (asthma-like symptoms), and possibly long-term effects such as bronchitis or lung cancer

Damage to the alveolar cells, resulting in scarring, remodeling, and decreased lung capacity, which may lead eventually to clinically-significant fibrosis or emphysema

Penetration through the epithelial lining to the circulatory system and thence to other organs, such as the heart

Kreyling et al., Journal of Nanoparticle Research, 2006

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HEALTH EFFECTSWHO, 2006

Aggravated asthma

chronic obstructive pulmonary disease (COPD)

Chronic bronchitis

worsening of cardiovascular diseases like heart attacks

and stroke

Increase in respiratory symptoms

Pneumonia

Lung cancer

Decreased lung function

Premature death

Brunekreef B., Holgate S. T. (2002) Air pollution and health. Lancet 360(9341):1233-1242.

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