Jacobson M.Z. Atmospheric Pollution

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Concentrations

The U.S. National Ambient Air Quality Standard for lead is 1.5 g m

3

, averaged

over a calendar quarter. Ambient concentrations of lead between 1988 and 1997

decreased from about 0.17 to 0.06 g m

3

, or by 67 percent (U.S. EPA, 1998). The

highest concentrations of lead are now found near lead-ore smelters and battery manu-

facturing plants.

Health Effects

Health effects of lead were known by the early Romans. Marcus Vitruvius Pollio, a

Roman engineer, stated in the ﬁrst-century

B.C.,

We can take example by the workers in lead who have complexions affected

by pallor. For when, in casting, the lead receives the current of air, the fumes

from it occupy the members of the body, and burning them thereon, rob the

limbs of the virtues of the blood. Therefore it seems that water should not

be brought in lead pipes if we desire to have it wholesome. (Kovarik, 1998)

Lead accumulates in bones, soft tissue, and blood. It can affect the kidneys, liver,

and nervous system. Severe effects of lead poisoning include mental retardation,

behavior disorders, and neurologic impairment. A disease associated with lead

accumulation is plumbism. Symptoms at various stages include abdominal pains,

a black line near the base of the gums, paralysis, loss of nerve function, dizzi-

ness, blindness, deafness, coma, and death. Low doses of lead have been linked to

nervous system damage in fetuses and young children, resulting in learning deficits

78 ATMOSPHERIC POLLUTION: HISTORY, SCIENCE, AND REGULATION

Table 3.16. Selected Toxic Compounds, Their Major Sources, and Their Major Effects

Benzene Gasoline combustion, solvents, Respiratory irritation, dizziness, headache,

tobacco smoke nausea, chromosome aberrations,

leukemia, produces ozone

Styrene Plastic and resin production, Eye and throat irritation, carcinogenic,

clothing, building materials produces ozone

Toluene Gasoline combustion, biomass Skin and eye irritation, fatigue, nausea,

burning, petroleum reﬁning, confusion, fetal toxicity, anemia, liver

detergent production, painting, damage, dysfunction of central nervous

building materials system, coma, death, produces ozone

Xylene Gasoline combustion, lacquers, Eye, nose, and throat irritation, liver and

glues nerve damage, produces ozone

1,3-Butadiene Manufacture of synthetic rubber, Irritation of eyes, nose, throat, central nervous

combustion of fossil fuels, system damage, cancer, produces ozone

tobacco smoke

Acetone Nail polish and paint remover, Nose and throat irritation, dizziness,

cleaning solvent produces ozone

Methyethylketone Solvent in paints, adhesives, and Headaches, vision reduction, memory loss

cosmetics

Methylene chloride Solvent, paint stripper, degreaser Skin irritation, heart and nervous system

disorders, carcinogenic

Vinyl chloride Polyvinylchloride (PVC) plastics, Liver, brain and lung cancer, mutagenic

building materials

Compound Source Effect

Sources: U.S. EPA (1998), Rushton and Cameron (1999), Turco (1997).

and low IQs. Lead may also contribute to high blood pressure and heart disease

(U.S. EPA, 1998).

3.6.10. Hazardous Organic Compounds

The 1990 Clean Air Act Amendments (CAAA90) required that the U.S. EPA develop

emission standards for each of 189 hazardous air pollutants that were thought to pose a

risk of cancer or birth defects or environmental or ecological damage. About 8.1 mil-

lion tons of toxic compounds are released into the air in the United States each year.

Of the toxic emissions, about 18 percent originate from area sources (e.g., buildings,

industrial complexes), 61 percent from stationary point sources (e.g.,

smoke stacks),

and 21 percent from mobile sources (U.S. EPA, 1998). Whereas most toxics do not

affect concentrations of ozone, the main component of photochemical smog, the U.S.

EPA has identiﬁed several that do. Table 3.16 identiﬁes selected hazardous organics,

their sources, and their effects on health and ozone levels.

3.7. SUMMARY

In this chapter, the structure and composition of the present-day atmosphere were dis-

cussed. Pressure, density, and temperature are interrelated by the equation of state.

Pressure and density decrease exponentially with increasing altitude throughout the

atmosphere. Temperature decreases with increasing altitude in the troposphere and

mesosphere but increases with increasing altitude in the stratosphere and thermos-

phere. Temperatures depend on energy transfer processes, including conduction,

convection, advection, and radiation. The troposphere is divided into the boundary

layer and free troposphere. The daytime boundary layer is often characterized by a sur-

face layer, a convective mixed layer, and an elevated inversion layer. The nighttime

boundary layer is often characterized by a surface layer, a nocturnal boundary layer, a

residual layer, and an elevated inversion layer. Pollutants emitted from the surface are

often conﬁned to the boundary layer. Total air pressure consists of the partial pressures

of all gases in the air, which consist of ﬁxed gases – namely molecular nitrogen,

molecular oxygen, and argon – and variable gases, including water vapor, carbon diox-

ide, methane, ozone, and nitric oxide. Some variable gases have adverse health effects;

others affect radiation transfer through the air. Most variable gases are chemically

reactive.

3.8. PROBLEMS

3.1 How tall must a column of liquid water, with a density of 1,000 kg m

3

, be to

balance an atmospheric pressure of 1,000 mb?

3.2. What do the balloon of Charles and an air parcel experiencing free convection

have in common?

3.3. Calculate the conductive heat ﬂux through 1 cm of clay soil if the temperature

at the top of the soil is 283 K and that at the bottom is 284 K. How does this

ﬂux compare with the ﬂuxes from Example 3.3?

STRUCTURE AND COMPOSITION OF THE PRESENT-DAY ATMOSPHERE 79

3.4. If T  295 K at 1 mm above the ground and the conductive heat ﬂux is H



250 W m

2

, estimate the air temperature at the ground.

3.5. If oxygen, nitrogen, and ozone did not absorb UV radiation, what would you

expect the temperature proﬁle in the atmosphere to look like between the sur-

face and top of the thermosphere?

3.6. If temperatures in the middle of the sun are 15 million kelvin and those on

Earth are near 300 K, what is the relative ratio of the thermal speed of a hydro-

gen atom in the middle of the sun to that on the Earth? (Assume the mass of

one hydrogen atom is 1.66  10

27

kg molecule

1

.) What are the actual speeds

in both cases? How long would a hydrogen atom take to travel from the center

of the sun to the Earth if it could escape the sun and if no energy losses

occurred during its journey?

3.7. Do convection, conduction, or advection occur in the moon’s atmosphere?

Why or why not?

3.8. In the absence of an elevated inversion layer in Fig. 3.4a, do you expect pollu-

tant concentrations to build up or decrease? Why?

3.9. Why does the lower part of the daytime convective mixed layer lose its buoy-

ancy at night? How does the loss of buoyancy in this region affect

concentrations of pollutants emitted at night?

3.10. Why are the coldest temperatures in the lowest 50 km on Earth generally at the

tropical tropopause?

3.11. Why does the tropopause height decrease with increasing latitude?

3.12. According to the equation of state, if temperature increases with increasing

height and pressure decreases with increasing height in the stratosphere, how

must density change with increasing height?

3.13. If N

 1.5  10

molecules cm

3

for ozone gas, T  285 K, and p



980 mb, ﬁnd the volume mixing ratio and partial pressure of ozone.

3.14. If carbon dioxide were not removed from the oceans by shell production and

sedimentation, what would happen to its atmospheric mixing ratios?

3.15. When the carbon dioxide mixing ratio in the atmosphere increases, what hap-

pens to the concentration of dissolved carbon dioxide in the ocean?

3.16. Show and explain a possible chemical weathering process between carbon

dioxide and magnesite [MgCO

(s)].

3.17. Explain why the volume mixing ratio of oxygen is constant but its number con-

centration decreases exponentially with altitude in the bottom 100 km of the

atmosphere.

80 ATMOSPHERIC POLLUTION: HISTORY, SCIENCE, AND REGULATION

URBAN AIR POLLUTION

rban air pollution problems have existed for centuries and result from the

burning of wood, vegetation, coal, natural gas, oil, gasoline, kerosene, diesel,

waste, and chemicals. Two general types of urban-scale pollution were identi-

ﬁed in the twentieth century: London-type smog and photochemical smog. The former

results from the burning of coal and other raw materials in the presence of a fog or

strong inversion, and the latter results from the emission of hydrocarbons and oxides

of nitrogen in the presence of sunlight. In most places, urban pollution consists of a

combination of the two. In this chapter, gas-phase urban air pollution is discussed in

terms of its early history, early regulation, and chemistry.

4.1. HISTORY AND EARLY REGULATION OF URBAN AIR POLLUTION

Before the twentieth century, air pollution was not treated as a science but as a regula-

tory or legal problem. Because regulations were often weak or not enforced and health

problems associated with air pollution were not well understood,

pollution problems

were rarely mitigated. In this section, a brief history of air pollution and its regulation

until the 1940s is discussed.

4.1.1. Before 1200

In ancient Greece, town leaders were responsible for keeping sources of odors outside

of town. In ancient Rome, air pollution resulted in civil lawsuits. The Roman poet

Horace noted thousands of wood-burning ﬁres (Hughes, 1994) and the blackening of

buildings (Brimblecombe, 1999). Air pollution events caused by emissions under

strong inversions in Rome were called heavy heavens (Hughes, 1994).

Another ancient source of pollution was copper smelting. The smelting of copper

to produce coins near the Mediterranean Sea during Roman times and in China during

the Song dynasty (960–1279) caused airborne copper concentrations to increase, as

detected by Greenland ice-core measurements (Hong et al., 1996).

4.1.2. 1200–1700

In London in the Middle Ages, a major source of pollution was the heating of lime-

stone [which contains CaCO

(s), calcium carbonate] in kilns, using oak brushwood as

an energy source, to produce quicklime [CaO(s), calcium oxide]. Quicklime was then

mixed with water to produce a cement, slaked lime [Ca(OH)

(s), calcium hydroxide], a

building material. This process released organic gases, nitric oxide, carbon dioxide,

and organic particulate matter into the air.

Sea coal was introduced into London as early as 1228 and gradually replaced the

use of wood as a source of energy in lime kilns (and forges). Wood shortages may

have led to a surge in the use of sea coal by the mid-1200s. The burning of sea coal

resulted in the release of sulfur dioxide, carbon dioxide, nitric oxide, soot, and particu-

late organic matter. Coal merchants in London lived in Sea Coal Lane, and they would

sell their coal to limeburners on nearby Limeburner’s Lane (Brimblecombe, 1987).

The quantity of coal burned per forge may have been only one-thousandth of that

burned per lime kiln.

The pollution in London due to the burning of sea coal became so severe that,

starting in 1285, a commission was set up to remedy the situation. The commission

met for several years, and by 1306, King Edward I banned the use of coal in lime

kilns. The punishment was “grievous ransom,” which may have meant ﬁnes and fur-

nace conﬁscation (Brimblecombe, 1987). By 1329, the ban had either been lifted or

lost its effect.

Between the thirteenth and eighteenth centuries, the use of sea coal and charcoal

increased in England. Coal was used not only in lime kilns and forges, but also in glass

furnaces, brick furnaces, breweries, and home heating. One of the early writers on air

pollution was John Evelyn (1620–1706), who wrote Fumifugium, or The

Inconveniencie of the Aer and the Smoake of London Dissipated in 1661. He explained

how smoke in London was responsible for the fouling of churches, palaces, clothes,

furnishings, paintings, rain, dew, water, and plants. He blamed “Brewers, Diers,

Limeburners, Salt and Sope-boylers” for the problems.

4.1.3. 1700–1840 – The Steam Engine

Air quality in Great Britain (the union of England, Scotland, and Wales) worsened in

the eighteenth century due to the invention of the steam engine, a machine that burned

coal to produce mechanical energy. The idea for the steam engine originated with the

French-born English physicist Denis Papin (1647–1712), who invented the pressure

cooker (1679) while working with Robert Boyle. In this device, water was boiled

under a closed lid. The addition of steam (water vapor at high temperature) to the air in

the cooker increased the total air pressure exerted on the cooker’s lid. Papin noticed

that the high pressure pushed the lid up. The phenomenon gave him the idea that steam

could be used to push up a piston in a cylinder, and the movement of the cylinder

could be used to do work. Although he designed such a cylinder-and-piston steam

engine, Papin never built one.

Capitalizing on the idea of Papin, Thomas Savery (1650–1715), an English

engineer, patented the first practical steam engine in 1698. The engine replaced

horses as a source of energy for pumping water out

of coal mines. Its main limitation was that it did

not work well under high pressure. Following

Savery, Thomas Newcomen (1663–1729), an

English engineer, developed a modified steam

engine in 1712 that overcame some of the prob-

lems in Savery’s engine. Because Savery had a

patent on the steam engine, Newcomen was forced

to enter into partnership with Savery to market the

Newcomen engine. Newcomen’s engine was used

to pump water out of mines and power water-

wheels. Steam engines in the early eighteenth

century were inefficient, capturing only 1 percent

of their maximum possible energy (McNeill,

2000). Because coal mines were not located in

cities, early steam engines did not contribute great-

ly to urban pollution.

In 1763, Scottish engineer and inventor James

Watt (1736–1819; Fig. 4.1) was given a Newcomen

steam engine to repair. While fixing the engine, he realized that its efficiency could

be improved. After years of work on the idea, he developed an engine that contained

URBAN AIR POLLUTION 83

Figure 4.1. James Watt (1736–1819).

a separate chamber for condensing steam. In 1769, he received a patent for the

revised steam engine. Watt made further modifications until 1800, including an

engine in which the steam was supplied to both sides of the piston and an engine in

which motions were circular instead of up and down. Watt’s engines were used not

only to pump water out of mines, but also to provide energy for paper mills, iron

mills, flour mills, cotton mills, steel mills, distilleries, canals, waterworks, and loco-

motives. For many of these uses, steam engines were located in urban areas,

increasing air pollution. Pollution became particularly severe because, although Watt

had improved the steam engine, it still captured only 5 percent of the energy it used

by 1800 (McNeill, 2000). Because the steam engine was a large, centralized source

of energy, it was responsible for the shift from the artisan shop to the factory system

of industrial production during the Industrial Revolution of 1750–1880 (Rosenberg

and Birdzell, 1986).

In the nineteenth century, the steam engine was used not only in Great Britain, but

also in many other countries, providing a new source of energy and pollution in those

countries. The steam engine played a large part in a hundred-fold global increase in

coal combustion between 1800 and 1900. Industries centered around coal comb

ustion

arose in the United States, Belgium, Germany, Russia, Japan, India, South Africa, and

Australia, among other nations.

Pollution problems in Great Britain worsened not only because of steam-engine

emissions, but also because of coal combustion in furnaces and boilers and chemical

combustion in factories. Between 1800 and 1900, air pollution may have killed people

in Great Britain at a rate four to seven times the rate it killed people worldwide (Clapp,

1994).

4.1.4. Regulation in the United Kingdom, 1840–1930

The severity of pollution in the United Kingdom (the 1803 union of Great Britain and

Northern Ireland) was sufﬁcient that, in 1843, a committee was set up in London to

obtain information about pollution from furnaces and heated steam boilers. Bills were

brought before Parliament in 1843 and 1845 to limit emissions, but they were defeat-

ed. A third bill was withdrawn in 1846. In 1845, the Railway Clauses Consolidated

Act, which required railway engines to consume their own smoke, was enacted. In

1846, a public health bill passed with a clause discussing the reduction of smoke emis-

sions from furnaces and boilers. The clause, was removed following pressure by

industry. Additional bills failed in 1849 and 1850.

In 1851, an emission clause passed in a sewer bill for the city of London, and this

clause was enforced through citations. In 1853, a Smoke Nuisance Abatement

(Metropolis) Act also passed through Parliament. This law was enforced only after

several years of delay. In 1863, Parliament passed the Alkali Act, which reduced emis-

sions of hydrochloric acid gas formed during soap production. Air pollution legislation

also appeared in the Sanitary Acts of 1858 and 1866, the Public Health Acts of 1875

and 1891, and the Smoke Abatement Act of 1926.

4.1.5. Early Regulation in the United States, 1869–1940

Most pollution in the United States in the nineteenth century resulted from the burning

of coal for manufacturing, home heating, and transportation. Early pollution control

84 ATMOSPHERIC POLLUTION: HISTORY, SCIENCE, AND REGULATION

was not carried out by state or national agencies, but delegated to municipalities. The

ﬁrst clean air law in the United States may have been an 1869 ordinance by the city of

Pittsburgh outlawing the burning of soft coal in locomotives within the city limits.

This law, was not enforced. In 1881, Cincinnati passed a law requiring smoke reduc-

tions and the appointment of a smoke inspector. Again, the ordinance was not

enforced, although the three primary causes of death in Cincinnati in 1886 were lung-

related: tuberculosis, pneumonia, and bronchitis (Stradling, 1999). In 1881, a

smoke-reduction law passed in Chicago. Although this law had the support of the judi-

ciary, it had little effect.

St. Louis may have been the ﬁrst city to pass effective legislation. In 1893, the city

council passed a law forbidding the emission of “dense black or thick gray smoke” and

a second law creating a commission to appoint an inspector and examine smoke-

related issues. The ordinance, was overturned by the Missouri State Supreme Court in

1897. The Court stated that the ordinance e

xceeded the “power of the city under its

charter” and was “wholly unreasonable” (Stradling, 1999). Nevertheless, by 1920, air

pollution ordinances existed in 175 municipalities; by 1940, this number increased to

200 (Heinsohn and Kabel, 1999).

In 1910, Massachusetts became the ﬁrst state to regulate air pollution by enacting

smoke-control laws for the city of Boston.

The ﬁrst federal involvement in air pollu-

tion was probably the creation of an Ofﬁce of Air Pollution by the Department of

Interior’s Bureau of Mines in the early 1900s. The purpose of this ofﬁce was to control

emission of coal smoke. The ofﬁce was relatively inactive and was eliminated shortly

thereafter.

Although early regulations in the United Kingdom and the United States did not

reduce pollution, they led to pollution-control technologies, such as technologies for

recycling chlorine from soda-ash factory emissions and the electrostatic precipita-

tor, used for reducing particle emissions from stacks. Inventions unrelated to air

pollution relocated some pollution problems. The advent of the electric motor in the

twentieth century, for example, centralized sources of combustion at electric utilities,

reducing air pollution at individual factories that had relied on energy from the steam

engine.

4.1.6. London-type Smog

In 1905, the term smog was introduced by Harold Antoine Des Voeux, a member

of the Coal Smoke Abatement Society in London, to describe the combina-

tion of smoke and fog that was visible in several cities throughout Great Britain. The

term spread after Des Voeux presented a report at the Manchester Conference of

the Smoke Abatement League of Great Britain in 1911 describing smog events in the

autumn of 1909 in Glasgow and Edinburgh, Scotland, that killed more than 1,000

people.

The smoke in smog at the time was due to emissions from the burning of coal and

other raw materials. Coal was combusted to generate energy, and raw materials were

burned to produce chemicals, particularly soda ash [Na

(s)], used in consumable

products, such as soap, detergents, cleansers, paper, glass, and dyes. To produce soda

ash, many materials, including charcoal, elemental sulfur, potassium nitrate, sodium

chloride, and calcium carbonate were burned, emitting soot, sulfuric acid, nitric acid,

hydrochloric acid, calcium sulﬁde, and hydrogen sulﬁde, among other compounds.

URBAN AIR POLLUTION 85

Emissions from soda-ash factories were added to the landscape of the United Kingdom

and France starting in the early 1800s.

Today, pollution resulting from coal-and chemical-combustion smoke in the pres-

ence of fog or a low-lying temperature inversion is referred to as London-type smog.

Some of the chemistry associated with London-type smog is described in Chapter 10.

Several deadly London-type smog events have occurred in the nineteenth and twenti-

eth centuries. These episodes provided motivation for modern-day air pollution

regulation. The episodes are discussed brieﬂy next.

4.1.6.1. London, United Kingdom

Several London-type smog events were recorded in London in the nineteenth and

twentieth centuries. These include events in December 1873 (270–700 deaths more

than the average rate), January 1880 (700–1,100 excess deaths), December 1892

(1,000 excess deaths), No

vember 1948 (300 excess deaths),

December 1952 (4,000

excess deaths), January 1956 (480 excess deaths), December 1957 (300–800 excess

deaths), and December 1962 (340–700 excess deaths) (Brimblecombe, 1987). The

worst of these episodes was in December 1952, when 4,000 excess deaths occurred.

Excess deaths occurred in every age group, but the number was greater for people

older than 45. People with a history of heart or respiratory problems made up 80 per-

cent of those who died. During the episodes, temperature inversions coupled with fog

and heavy emissions of pollutants, particularly from combustion of coal and other raw

materials, were blamed for the disasters. During the 1952 episode, peak concentrations

of SO

(g) and particulate smoke were estimated to be 1.4 ppmv and 4,460 g m

3

respectively. (This compares with 24-hour federal standards in the United States today

of 0.14 ppmv for SO

(g) and 150 g m

3

for particulate matter less than 10 m in

diameter.) The particle and fog cover was so heavy during that event that the streets of

London were dark at noontime, and it was necessary for buses to be guided by lantern

light.

4.1.6.2. Meuse Valley, Belgium

In December 1930, a 5-day fog event in the presence of a strong temperature inver-

sion and heavy emissions of sulfur dioxide (SO

) from coal burning resulted in the

death of 63 people and the illness of 6,000 others, mostly during the last two days of

the pollution episode. The majority of those who died were elderly and previously had

heart or lung disease. Symptoms of the victims included chest pain, cough, shortness

of breath, and eye irritation.

4.1.6.3. Donora, Pennsylvania, United States

Pittsburgh, Pennsylvania, is located near large coal deposits and major river arter-

ies. In 1758, coal was ﬁrst burned in Pittsburgh to produce energy for iron and glass

manufacturing. By 1865, half of all glass and 40 percent of all iron in the United

States were produced in Allegheny County, where Pittsburgh is located (McNeill,

2000). In the late 1800s, the county emerged as a major industrial consumer of coal,

particularly for steel. In 1875, Andrew Carnegie opened the Edgar Thomson Works at

Braddock, Pennsylvania, introducing a source of high-volume steel to Allegheny

County. Steel manufacturing spread to many other cities in the region, including

Reading, Pennsylvania; Youngstown, Ohio; and Gary, Indiana. These cities burned

coal not only for steel manufacturing, but also for iron manufacturing and railway

86 ATMOSPHERIC POLLUTION: HISTORY, SCIENCE, AND REGULATION

transportation. Figure 4.2 shows that the burning of coal in Reading, Youngstown, and

Gary darkened the skies of these cities.

Uncontrolled burning of coal in Allegheny County continued through 1941, when

the ﬁrst strong smoke abatement laws were passed in Pittsburgh. However, the 1941

laws were suspended until the end of World War II, and even then resulted in only

minor improvements due to a lack of enforcement.

Donora, Pennsylvania, is a town south of Pittsburgh along the Monongahela

River. Between October 26 and 31, 1948, heavy emission of soot and sulfur diox-

ide from steel mills and of metal fumes from the Donora Zinc Works a zinc

smelter, under a strong temperature inversion resulted in the death of 20 people

and the respiratory illness of 7,000 out of the town’s 14,000 residents. Of the 20

people who died,14 had a known heart or lung problem. Young and old people

became ill. Most of the illnesses arose by the third day. Symptoms included cough,

sore throat, chest constriction, shortness of breath, eye irritation, nausea, and vom-

iting. The smog event darkened the city during peak daylight hours, as shown in

Fig. 4.3.

4.1.7. Photochemical Smog

Although short, deadly air pollution episodes have attracted public attention, persist-

ent pollution problems in sunny regions have also gained notoriety in the twentieth

URBAN AIR POLLUTION 87

(a)

(b)

(c)

Figure 4.2. Panoramic views of (a) Reading, Pennsylvania, c. 1909; (b) Youngstown, Ohio, c. 1910; and (c)

Indiana Steel Co.’s big mills, Gary Indiana, c. 1912. Photos (a) and (b) by O. Conneaut, (c) by Crose Photo

Company, all available from the Library of Congress Prints and Photographs Division, Washington, DC.