PU 430PU 430Unit 6

Chapters 4 and 9

Chemical Disasters

Chapter Four

Background: Recent Chemical Background: Recent Chemical Warfare Agents Terrorist Warfare Agents Terrorist EventsEvents

1993 World Trade Center Bombing

1995 Aum Shinrikyo sect released Sarin vapor into Tokyo Subway

Basic Facts about Chemical Health Threats

Chemical toxicity

Response

Dose

Dose–response relationship

Chemical agentsChemical agents

Range from warfare agents to toxic chemicals commonly used in industry.

Criteria for determining priority chemical agents include◦chemical agents already known to be used as

weaponry◦availability of chemical agents to potential terrorists◦chemical agents likely to cause major morbidity or

mortality◦potential of agents for causing public panic and

social disruption◦agents that require special action for public health

preparedness

Source CDC

Routes of Entry

Inhalation

Skin/mucous membrane absorption

Ingestion

Injection

Chemical Exposure Factors

The route & rate of an exposure determines the dose received. The results can include:◦Acute poisoning - a rapid absorption resulting

in an especially fast & severe response◦Chronic poisonings - result from prolonged

exposures over a longer period of time ranging from days to years

There are a variety of factors that determine poisoning outcomes

Exposure Factors

DoseTime of exposureRoute of ExposurePhysical characteristics of chemical

substancePrevious or simultaneous exposures to

other chemical substancesEnvironmental conditionsPhysiological characteristics of the

exposed

CWA CharacteristicsCWA Characteristics

Volatility◦Tendency to evaporate from liquid to gas form◦Greater volatility= shorter persistence

Vapor Density◦Weight of the vapor or mist relative to air◦All CWA’s (except HCN) heavier than air

Persistence◦Most evaporate > 24 hours◦Present increased risk for skin exposure to

victims and risk to responders

How do we prepare public health How do we prepare public health agencies for chemical attacksagencies for chemical attacks

Globally Harmonized System (GHS) of Human Health Classes

Includes 10 classes of chemical threats to human Health

Is being implemented in the U.S. but requires a tremendous effort

Although the implementation of this system is necessary, it will come with a substantial learning curve for nations that have firmly established practices

Communicating Hazards: NFPA Fire Diamond

NFPA “Fire Diamond”

Nomenclatures: Chemical CategorizationThere continues to be fundamental differences in the

nomenclature of various hazards

CDC lists them by category: http://www.bt.cdc.gov/agent/agentlistchem-category.asp

Chemical Accidents versus Terrorism

Chemical Terrorism The most likely chemical terrorism scenarios are also the

most likely industrial accident scenarios

Chemical Accidents Chemical accidents are preventable & with the knowledge,

tools, & regulations that exist in the U.S., these incidents should be exceptionally rare

Prevention

Community Prevention Activities EPCRA (“List of Lists”) - This document lists the chemicals required to be

reported by industry to local & state officials LEPCs - Carry out preparedness activities at the community level SERC – Maintained by each state to appoint members & establish

jurisdictional areas for each LEPC

Reducing Building Vulnerability High-risk facilities need to complete a comprehensive vulnerability

assessment of their AHU & ensure a detailed risk reduction plan is developed & implemented.

Home Prevention Activities In the home, many household products are accumulated that individually

or combined can pose a risk to residents

Immediate Actions

Individual Response

Healthcare Response

Public Health Response

General Treatment GuidelinesGeneral Treatment Guidelines

Nerve Agents◦ Atropine, pralidoxime chloride (2-PAMCl), or diazepam

Incapacitating Agents◦ Remove to fresh air, decon w/water, 6% bicarbonate solution

Pulmonary Agents◦ Supplemental oxygen, restrict physical activity, medical attention

Vessicants/Blister Agents◦ Remove to fresh air, remove clothing, decontaminate skin,

supplemental oxygen, hospitalization, extensive irrigation of eyes

Blood Agents◦ Amyl nitrate, sodium nitrate, sodiumthiosulfate

Prehospital Care and Prehospital Care and DecontaminationDecontaminationFirst responders: Respirators, goggles,

protective clothingSelf-contained breathing apparatus

(SCBA) is recommended in response to any nerve agent vapor or liquid.

Butyl rubber gloves (most agents are lipophilic)

20% of healthcare workers in Tokyo had mild symptoms after taking care of patients. These symptoms included nausea, eye pain, and headache.

Prehospital Care and Prehospital Care and Decontamination (continued)Decontamination (continued)

Inhalation exposure

Dermal

Ingestion

Psychological ImpactPsychological Impact

Psychological impact ◦Examples

Post traumatic stress disorder

Fear and depression

Sleep disturbances

Recovery Actions

Once a chemical emergency is over, residents of the affected area should:◦Not reenter the area until local authorities

announce that it is safe to return◦Thoroughly ventilate the structure by

opening all windows & turning the air handling systems on

◦Avoid any potentially contaminated food or water

◦Watch for household hazardous materials◦Never smoke or initiate any open flames

Nuclear & Radiological Disasters

Chapter Nine

Basic Facts about Nuclear & Radiological Threats

A Nuclear Event Distinguished by a nuclear detonation or

fission

A Radiological Event Does not involve a fission reaction or

nuclear explosion

Possible ScenariosPossible Scenarios

Nuclear power plant incidentHidden source“Dirty bomb” Improvised nuclear deviceNuclear weapon

Exposure vs. ContaminationExposure vs. Contamination

Exposure: irradiation of the body absorbed dose (Gray, red)

Contamination: radioactive material on patient (external) or within patient (internal)

Nuclear & Radiological Health Threats

Acute Radiation Syndrome (ARS) It includes four stages:

◦ Prodromal stage - can begin within minutes or days of the exposure & last up to several days & includes gastrointestinal symptoms such as nausea, vomiting, & diarrhea

◦ Latent stage - the patient will feel fine for a period of time ranging from hours to weeks

◦ Manifest stage - includes one or more of three classic syndromes◦ Final stage - either recovery or death

Cutaneous radiation injury (CRI) There is usually a delay between the exposure & the onset of

symptoms & the progression is in stages There is a prodromal, latent, & manifest illness stage,

sometimes followed by a third wave before recovery

Injuries Associated with Injuries Associated with Radiological Incidents Radiological Incidents

Acute Radiation Syndrome (ARS)Localized radiation injuries/ cutaneous

radiation syndromeInternal or external contaminationCombined radiation injuries with - Trauma - Burns Fetal effects

Skin EffectsSkin EffectsSkin EffectsSkin Effects

NUREG / CR-4214, p II-68NUREG / CR-4214, p II-68

EpilationEpilation ErythemaErythema PigmentationPigmentation Dry desquamationDry desquamation Moist desquamation Moist desquamation

that healsthat heals

EpilationEpilation ErythemaErythema PigmentationPigmentation Dry desquamationDry desquamation Moist desquamation Moist desquamation

that healsthat heals

Patient DecontaminationPatient Decontamination• Remove and bag the patient’s

clothing and personal belongings (this typically removes 80 - 90% of contamination)

• Handle foreign objects with care until proven non-radioactive with survey meter

• Survey patient and collect samples- Survey face, hands and feet- Survey rest of body

Nuclear & Radiological Accidents versus Terrorism

There are five distinct differences:◦ Most radiological emergency planning is focused on

accidents that are much smaller events & would not include the same hazards

◦ Due to the alarm systems in place, most accident scenarios will have several hours of warning before a release begins

◦ Most nuclear reactors are located in rural areas where fewer people & less infrastructure will be affected by an accident

◦ The management of an emergency at a nuclear facility is likely to be much better coordinated

◦ The type of radiological material involved in a nuclear facility accident is likely to be different from what would be seen with the IND or RDD attack

Prevention

Nuclear Non-Proliferation Treaty (NPT) ◦Expresses support for nonproliferation of nuclear weapons programs, disarmament, & peaceful use of nuclear technologies for energy & other peaceful applications

◦Has been signed by 189 nations over the past 30 years

Immediate Actions

With radiological events, the principles are well understood &

there are fewer unknowns:◦ The detection instrumentation is ubiquitous, dependable, & quick to use◦ The ability to predict those at risk & offer recommendations is much

more straightforward than other threats There are four broad scenarios that should be considered during

planning so the proper actions are incorporated into preparedness activities:◦ A transportation accident involving radiological materials◦ An accident at a nuclear facility ◦ The RDD or dirty bomb with the explosion of a package or a vehicle

carrying radioactive materials ◦ A small IND that could appear like the September 11, 2001 attacks on

the U.S. with a block or several blocks of buildings as “Ground Zero”

Public Health & Protective Actions

The primary roles of public health agencies in the aftermath of a nuclear or radiological incident

Protective Action Guides (PAGs) include recommendations for the general public & separate recommendations for first responders

There are recommended initial actions for the general public for the time prior to the availability of radiological measurements & associated protective action guidance.

Psychological CasualtiesPsychological Casualties

Terrorist acts perceived as very threatening

Large numbers of concerned with no apparent injuries

Mental health professionals should be included

For more information on radiation exposure and pregnancy

www.bt.cdc.gov/radiation/prenatalphysician.asp

Dealing With Staff StressDealing With Staff Stress

Preplanning

Establish information center

Train staff on radiation basics

Post Event

Debrief immediately after event

Offer Counseling

Medical Response

According to the Centers for Disease Control & Prevention, there are six areas that need to be considered by healthcare organizations as they prepare for nuclear & radiological incidents: ◦Notification & communication◦Triage◦Patient management◦Healthcare worker protection◦Surveillance◦Community planning

Unique Pharmaceutical Issues

The Strategic National Stockpile (SNS) has a variety of critical radiological pharmaceutical resources available to support a radiological incident response

Recovery

The only way to minimize the chronic social impact is to manage it well

from the moment it occurs, including the registration & close monitoring

of those truly at risk