Urban Air Pollution - Air Pollution and Global Warming: History, Science, and Solutions - page 73

Chapter 4

Urban Air Pollution

Anthropogenic air pollution has affected the environ-
ment since the development of the first human com-
munities. Today, pollution arises due to the burning
of wood, vegetation, coal, natural gas, oil, gasoline,
kerosene, diesel, liquid biofuels, waste, and chemicals.
Two general types of urban-scale pollution were iden-
tified in the twentieth century: London-type smog and
photochemical smog. The former results from the burn-
ing of coal and other raw materials in the presence of
afogor strong temperature inversion, and the latter
results from the emission of hydrocarbons and oxides
of nitrogen in the presence of sunlight. In most places,
urban air pollution consists of a combination of the two.
In this chapter, urban outdoor gas-phase air pollution is
discussed in terms of its history, early regulation, and
chemistry.

both to metal production and wood burning. From
500 BC to 300 AD, lead concentrations in Greenland
ice cores were four times their natural values. These
concentrations were due to the transport of pollution
from Greek and Roman lead and silver mining and
smelting operations (Hong et al., 1994). Lead emis-
sions in ancient Greece occurred predominantly from
smelting during the production of silver coins. Each
gram of silver resulted in 300 g of lead by-product.

Lead emissions rose further during the Roman Empire
because the Romans used lead in cookware, pipes,
face powders, rouges, and paints. Cumulative lead
pollution from smelting reaching Greenland between
500 BC and 300 AD was about 15 percent of that
from leaded gasoline worldwide between 1930 and
1990.
Whereas the Romans mined up to 80,000 to 100,000
tonnes/yr of lead, they also mined 15,000 tonnes/yr of
copper, 10,000 tonnes/yr of zinc, and 2 tonnes/yr of
mercury (Nriagu, 1996). Ores containing these metals
were smelted in open fires, producing pollution that was
transported locally and long distances. For example,
as evidenced by Greenland ice core data, the smelting
of copper to produce coins during the Roman Empire
and in China during the Song Dynasty (960-1279)
increased atmospheric copper concentrations (Hong
et al., 1996).
However, pollution in Rome was due to both metal
smelting and wood burning. 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

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4.1. History and Early Regulation
of Outdoor Urban Air Pollution
Before the twentieth century, air pollution was treated
as a regulatory or legal problem rather than a scientific
problem. Because regulations were often weak or not
enforced and health effects of 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: Metal Smelting
and Wood Burning
Available data suggest that air pollution in ancient
Greece and the Roman Empire was likely severe due