Geoscience Reference
In-Depth Information
expenses. These shocks represent either a reduction in effective resource supply to
the regional economy, directly reducing regional GDP, or in the case of medical
expenses, a diversion of regional income to cover otherwise avoidable costs. The
behavioral effect relates to economic adjustments stemming from fear and risk
perception on the part of firms, households and government. Behavioral effects
generate regional economic loss additional to the resource loss effects. Employees
may require compensating higher wages to work, businesses may require compen-
sating higher returns to invest, and consumers may switch their preferences away
from goods produced in the affected region. Such responses will increase produc-
tion costs in the affected region, while simultaneously reducing demand for the
region's output.
Scientists, public officials and laypeople have long recognized society's vulner-
ability to large-scale disasters. This has been especially evident with respect to
disasters involving potentially toxic substances such as radiological and chemical
materials. Hazards that are poorly understood and that are potentially catastrophic
carry for the public a high risk signal value (Slovic
1987
). In fact, such hazards tend
to inspire fear and heightened perceived risk well beyond what risk experts would
expect based on their assessed likelihood of occurrence. Public reaction to radio-
logical risks has been well documented since the accident at Three Mile Island, but
these same concerns extend to chemical hazards as well. Kraus et al
.
(
1992
) studied
public judgments of chemical risks and found that laypeople: (1) largely view
chemicals negatively and see little benefit to them; (2) believe harmful exposure
to potentially toxic chemicals is all or nothing rather than dose specific and (3) feel
any contact with toxic chemicals is contaminating. These findings are important for
understanding the consequences of a chlorine attack. Chlorine is a highly toxic
chemical capable of killing large numbers of people. It also dissipates quickly if
released in an outdoor area; hence, hours later it poses little risk. However, as noted
above, toxic chemicals are thought by the public to contaminate objects and areas
they touch and so people may be reluctant to resume normal activities in an area
impacted by such an attack regardless of what officials and experts believe. This
contrast between expert and public assessment poses a challenge for local
authorities wishing to communicate about public safety following such events.
Public reaction to different hazards also poses a challenge to risk managers who
need to gauge the economic impact of a potential mishap.
16.2 Attack Description
16.2.1 Attack Scenario and Direct Loss Estimation
Our scenario is based on a combination of DHS' National Planning Scenario
8, “Chemical Attack—Chlorine Tank Explosion” (HSC
2004
) and the chlorine
tank truck attack scenarios of Barrett and Adams (
2011
). In our scenario, the
attacker drives a tank truck of pressurized chlorine into the financial district of
downtown LA (zip code 90071). Detonation of the tank releases tons of chlorine,
