International Regulation of Urban Smog Since the 1940s - Air Pollution and Global Warming: History, Science, and Solutions - page 203

Figure 8.14. Sugarcane field burn, April 12, 2009. C Sean van Tonder/Dreamstime.com.

large-scale subsidence inversion. As such, winds are
often light and rainfall is scarce, exacerbating pollution
problems.
Pollution regulations in Santiago were first enacted
in 1987. That year, a law was passed allowing only cars
with specified last digits on their license plates to oper-
ate within the city limits on a given workday. Starting
in 1989, inspections of carbon monoxide, particulate
matter, and hydrocarbon emissions from vehicles were
mandated.
In 1992, the Chilean government outlined a long-
term plan to combat air pollution. The two main con-
trol strategies were emission regulations and economic
incentives. This plan culminated in the Basic Environ-
mental Law , passed in 1994, which set up a frame-
work for environmental management. Just before that,
in 1993, a law was passed requiring catalytic converters
in all new passenger vehicles. The same year, emis-
sions from stationary industrial sources were regulated
and open-burning wood stoves were banned unless they
contained control devices to reduce particle emissions.
In 1995, a measure requiring stationary sources to shut
down when particle concentrations rose above a critical
level was passed. In 1997, laws controlling emissions
from nonindustrial stationary sources and residential
heating boilers were passed. Another method of reduc-
ing pollution in Santiago was to eliminate old buses.
Between 1980 and 1990, the number of buses in the
city increased from 9,500 to 13,000, but by 1997, the

number had decreased back down to 9,000 (Jorquera
et al., 2000).
Chile's first emission standards for light-duty passen-
ger vehicles and trucks were passed in 1992. Medium-
duty vehicle standards were set in 1995. Heavy-duty
vehicle standards were first set in 1994. More strin-
gent standards were set for the Santiago metropolitan
region than for the rest of the country. All standards
were updated in 2005 and 2006. Dual emission stan-
dards exist in Chile: new engines can meet either U.S.
or EU standards.
Pollution abatement in Santiago has been modestly
effective. Ozone levels decreased between 1989 and
1995, but they did not change from 1995 to 1998.
Between 1989 and 1998, particulate matter levels
decreased by 1.5 to 7 percent per year. Monthly aver-
age PM 2.5 levels still ranged from 100 to 150 gm − 3

(Jorquera et al., 2000), and black carbon and organic
matter levels in Santiago were still more than seven
times those in Los Angeles (Didyk et al., 2000) How-
ever, since 2000, particulate matter pollution has dou-
bled (Morales, 2010).

8.2.16. South Africa
Ninety percent of South Africa's electricity is obtained
from coal. Coal is also burned in boilers and stoves in
factories and hospitals. Millions of people in townships
and villages without electricity burn coal and wood