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Koenig_and_Schultz_s_Disaster_Medicine_Ch_14.pdf

Decontamination

Howard W. Levitin and Christopher A. Kahn

DEFINITION OF DECONTAMINATION

Decontamination is the reduction or removal of contaminating material by a dilutional, chemical, and/or mechanical process. It should be performed whenever there is likelihood of contami- nation or risk of secondary exposure.

In general, decontamination is accomplished by removing the victim’s clothing followed by copiously rinsing the patient with tepid water.1 Gently scrubbing the skin with soap and a soft brush removes any remaining fat-soluble chemicals and solid materials. Eliminating contaminants from a victim’s skin and clothing is important for two reasons. It reduces the risk for further absorption or inhalation and the subsequent toxicity caused by the offending agent. In addition, decontamination helps to prevent others from becoming secondarily exposed or contaminated.2

The degree of decontamination performed depends on the situation. In general, removing and bagging the victim’s cloth- ing eliminates 60%–90% of the contaminants (depending on the extent of clothing worn at the time of exposure) and mini- mizes the risk of spreading the toxic agent to others.3,4 This initial step in the decontamination process should always be performed regardless of the agent or setting. Depending on the availability of resources, the victim’s symptomatology, and the availabil- ity of resources, additional decontamination measures may be necessary.2

In this chapter, discussion will be limited to the decontami- nation of humans after exposure to a hazardous substance. Issues related to regulatory standards, personal protective equipment (PPE), and training are addressed elsewhere.

OVER V IEW

Hazardous materials, in various forms, quantities, and configu- rations, are ubiquitous. They are incorporated into communities in the form of manufacturing, commercial and retail establish- ments, medical facilities, and laboratories, as well as in vari- ous configurations in the home. Hazardous materials also move through communities in the transportation process, by truck, rail, ship and pipeline. For example, in the United States, over

800,000 shipments of these materials occur daily – more than 90% of which occur via highways.5 Europeans spend approxi- mately 40 billion Euros per year managing the logistics of ship- ping nearly 2 billion tons of chemicals across their continent (i.e., 8% of the total volume of freight shipped).6 Modern soci- eties must use hazardous materials to produce goods and ser- vices vital for healthy living and a robust economy. An often overlooked byproduct of this economic growth is the creation of hazardous waste. In Canada alone more than 3 million tons of it is generated yearly.7

The potential for an environmental release of a hazardous material, regardless of etiology, is significant. In the U.S. there are approximately 850,000 facilities that manufacture, store, or use hazardous or extremely hazardous substances. Many of these sites are located in urban areas with populations at risk exceed- ing 1 million.2 In 2004 more than 7,700 acute releases of haz- ardous materials were reported to the U.S. Agency for Toxic Substances and Disease Registry in 15 states. During this report- ing period, 620 events (8.0% of all reported events) resulted in a total of 1,838 victims, 41 of whom (2.4%) died. The most fre- quently reported injuries were respiratory irritation, headaches, and dizziness/central nervous system symptoms. Health officials ordered evacuations during 499 (6.4%) events.8

Individuals may become contaminated through direct con- tact with chemicals in their various physical states (vapor, gas, mist, liquid, or solid) or from others who are already contam- inated. In most cases of airborne releases, simply evacuating persons from the source and removing their outer clothing when possible is sufficient to prevent further exposure or injury.9–11

Clothing can act like an occlusive dressing; failure to remove it quickly after chemical exposure may prevent the evapora- tion of volatile skin contaminants.9 In chemical mass casualty incidents, procedures geared toward detaining ambulatory vic- tims near the scene to direct them through a mass shower- ing system (e.g., tents or trailers) needlessly delays evacuation and treatment. This commonly practiced approach may inad- vertently increase the potential for harm to the victims as well as to the first responders and the first receivers caring for these individuals.9,12

Those contaminated with liquids or solids require copious skin lavage and wound irrigation with water within minutes of

195 Koenig and Schultz's Disaster Medicine : Comprehensive Principles and Practices, edited by Kristi L. Koenig, and Carl H. Schultz, Cambridge University Press, 2009. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/apus/detail.action?docID=564432. Created from apus on 2018-03-08 08:54:12.

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196 ■ HOWA R D W. LEV I T I N A N D CH R I S TO P H E R A. KA H N

skin contact to minimize the degree of injury. Rinsing the patient with a high-volume, low-pressure water source dilutes, neutral- izes, and helps rid the skin of reactive surface contaminants. In the case of corrosive agents, decreasing the duration of skin con- tact helps restore tissue to its normal pH, thereby minimizing the incidence of full-thickness burns.9,13–17 Using soap to help emul- sify fat-soluble agents and a soft brush to remove mechanically any remaining solid materials is also beneficial.

The intensity of chemical injury is based on a number of factors, including concentration and reactivity of the agent, pH, duration of skin contact, and the integrity of the skin.9,16,18–20

When the duration of skin contact is prolonged, the potential for tissue damage, agent absorption, and systemic toxicity is increased. Pesticides, hydrogen fluoride, and phenolic substances rapidly penetrate the skin and enter the general circulation (e.g., malathion penetrates the skin almost immediately upon con- tact).20 Corrosives and solvents damage the outer skin layers within minutes, yet beneficial effects have been seen even when irrigation was delayed up to 1 hour.9,14 It appears that treat- ment within an hour of injury is critical in reducing the severity of burns.9,13,14 Decontamination beyond this “golden hour” is most beneficial in reducing the risk of secondary contamina- tion of emergency personnel and may offer some psychological benefit to exposed patients.

Water reacts exothermically when combined with metallic substances such as sodium, potassium, lithium, cesium, and rubidium, and its use is contraindicated when these rare agents are present or suspected. Other agents such as white phosphorus, sulfur, strontium, titanium, uranium, zinc, and zirconium will ignite on contact with air. If any of these materials are present they will react with the ambient air and the moisture on the victim’s skin until the proper method of decontamination is per- formed. After these exposures, despite the potential for reactivity, quickly removing the victims’ clothing and flushing them with large volumes of water should minimize the injury.21

Decontamination for radiological agents is the same as used for chemicals. Stable patients should have their clothing removed and double bagged, followed with a soap and water showering. Unstable victims, or those with life-threatening injuries, should have gross decontamination (i.e., clothing removal) performed quickly so life-saving interventions can be initiated immedi- ately. The presence of radioactive materials is of minimal risk to providers and should not delay these activities. Specialized detectors can confirm and measure the presence of radiation as well as serve as a guide to the effectiveness of the decontamination process.

The proper decontamination procedure for biological agents has not been established. Historically, these agents were classi- fied as nonvolatile and exhibited no absorption capability in the presence of intact skin. They were also thought to pose minimal risk of re-aerosolizing, a belief that changed after the intentional release of anthrax through the U.S. Postal Service in 2001. In general, a biological agent exposure does not require decontam- ination, although it is worthwhile to instruct patients to remove and wash their clothing and take a shower at home. If dermal or mucous membrane contamination is suspected, the area should be thoroughly irrigated with water.

The science of decontamination is in its infancy. Much of the current knowledge surrounding decontamination and the management of the contaminated patient is based primarily on anecdotal evidence, personal experience, and common sense. The U.S. military and fire services have contributed consider-

ably to the procedural approach to the contaminated patient; however, research designed to advance knowledge on the proper care of the contaminated patient does not lend itself to placebo- controlled, double-blind studies. As a result, the advantages of using water in the decontamination process are derived indirectly from studies of burns. This research demonstrated the benefits of hydrotherapy on cutaneous skin pH and clinical outcomes when experimental skin models were contaminated with harsh chemicals.13–16 The urgency of decontamination after exposure is derived from measuring chemical absorption rates in animal skin models.16,17,19 Finally, the essential role of clothing removal in the decontamination process is based on studies using clothed manikins where evaporation rates and exposure levels of volatile agents are easily measured.22 Despite these advances, a number of questions remain.

HOW CLEAN IS CLEAN?

The effectiveness and completeness of decontamination is dif- ficult to measure objectively. The goals of decontamination are to terminate a substance’s harmful effects on the patient (elimi- nate continued absorption), reduce the risk of secondary expo- sure/contamination to other people and to eliminate the need for an advanced level of PPE (beyond standard precautions) for caregivers working in the treatment area. Yet it is difficult to determine when decontamination efforts are sufficient to achieve these goals and can therefore be stopped. This concept has been expressed by the phrase “how clean is clean?” In most instances, a thorough washing with soap and water accomplishes this objec- tive; however, some insoluble chemicals are resistant to soap and water decontamination and other primary decontamina- tion agents must be identified. For example, tars and heavy oils require the use of petroleum-based solvents (e.g., petroleum jelly, mineral spirits, or vegetable oil) to degrade the agents, followed quickly by standard soap and water decontamination.

Clinical determination of the effectiveness of soap and water decontamination is unreliable because symptoms may persist despite adequate decontamination. Likewise, victims cannot be continuously decontaminated until symptoms resolve. The longer they remain in the system, the more wastewater is gen- erated and the more resources are consumed. Furthermore, responders cannot wear advanced levels of PPE indefinitely because it impacts body temperature, hydration status, and stress levels, and may lead to injuries such as falls. An unnecessary pro- longation of the decontamination process may divert personnel resources from other critical services.

Studies have indicated that 5–6 minutes of thorough decon- tamination is adequate to dilute and remove most contaminants. Some chemicals, such as ammonia and chlorine, are highly water soluble and will virtually disappear within the first few minutes of decontamination. Human senses, however, may still detect the presence of various agents even though the actual skin concen- tration is well below a harmful threshold as confirmed by studies of swab samples from specific areas of the victim’s body pre- and postdecontamination.23

The process of decontamination also influences its effective- ness. Washing in a head-to-toe manner reduces the likelihood of drawing contaminants from the lower extremities back into vital areas such as the face, eyes, and airway. Also, irrigating open wounds first and covering them with water occlusive dress- ings reduces the amount of contaminated wash flowing into the

Koenig and Schultz's Disaster Medicine : Comprehensive Principles and Practices, edited by Kristi L. Koenig, and Carl H. Schultz, Cambridge University Press, 2009. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/apus/detail.action?docID=564432. Created from apus on 2018-03-08 08:54:12.

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DE C O N TA M I NAT I O N ■ 197

wound. Similarly, a thorough washing of the victim’s hair and other body recesses reduces the retention of contaminants.

All devices applied to the patient at the initial site of exposure (e.g., cervical collars, splinting devices, backboard, and intra- venous lines) should be considered contaminated and ought to be either replaced or cleaned during the decontamination pro- cess. It is clearly disadvantageous to focus efforts solely on decon- taminating the patient’s skin while contaminants may remain on these devices.

Decontamination effectiveness is directly correlated with the patient’s ability to self-decontaminate, evidence-based, standard- ized protocols and procedures, and the identification of the contaminants and their properties. Individuals who are able to walk into a shower and clean themselves receive a more thorough decontamination than nonambulatory individuals. Although detectors are available for chemical and biological agent identification, they play a very limited role in determining the effectiveness of decontamination. Radiological detectors, on the other hand, are more prevalent and have a defined role in decontamination.

Other agents such as bleach and specialized soaps have very little impact on the overall effectiveness of decontamination. Soap and water has clearly been shown to be the most effective and readily available decontamination solution. Nonabrasive liq- uid soap should be used and should not contain perfumes, lano- lin, or other additives.

In addition to soap, water temperature dramatically impacts the effectiveness of decontamination. Cold water reduces victim compliance and may make some agents more viscous and diffi- cult to remove. Showering in cold water may also trap volatile contaminants in constricted skin pores, increasing the likelihood that release of these agents from the skin will continue (i.e., off- gassing) once the victim is removed to a warmer environment such as the emergency department. In addition, cold water may lead to hypothermia in victims, particular in cooler climates. On the other hand, victims suffering from skin lesions or burns may not tolerate hot water. Water at an elevated temperature may also cause pores to open thereby increasing the skin’s surface area and absorption rate of the agent. Tepid water is the ideal temperature for optimum results.

WHEN SHOULD EARLY TREATMENT/ STABILIZATION SUPERSEDE COMPREHENSIVE DECONTAMINATION?

Aggressive patient treatment must be balanced with caregiver protection. Intuitively, the sicker the patient the greater perceived need for emergent intervention. If, however, the victim’s critical injuries or state of distress is a direct result of chemical exposure, the responders must don appropriate PPE prior to providing care or they may become victims themselves. This key principle is counterintuitive to the normal desire to provide immediate aid to the victim.

Responders should provide emergent patient care simulta- neously with decontamination; however, the advanced level of protection required in most decontamination scenarios dramat- ically affects the caregiver’s ability to render care. In most cir- cumstances, basic life support skills such as maintaining a patent airway, stabilizing a fracture, and controlling significant bleeding can be accomplished concurrently with providing decontami- nation. Advanced life support techniques, however, must often

be delayed until immediately after decontamination when care- givers can wear a reduced level of protective attire (e.g., standard precautions) that allows them greater mobility, dexterity, sight, and hearing.

In some circumstances, previously exposed staff, such as emergency medical services personnel who transported the patient, may be called on to provide additional stabilization before patient decontamination to increase the chance that the patient will survive through the decontamination process.

WHO PERFORMS DECONTAMINATION?

With a proper system in place, the vast majority of contaminated victims are ambulatory and can be guided to remove their own clothing, package and manage their personal valuables, and thor- oughly wash themselves. Creating an environment where decon- tamination can be self-administered is essential. Some individ- uals are debilitated to the point at which responders must assist or intervene in the decontamination process.

Although some patients require total assistance, others may have only minimal injuries or existing conditions that inhibit their ability to ambulate through the decontamination process. Placing these individuals on backboards and accompanying them through decontamination is labor intensive, potentially dan- gerous to the caregivers and victims, and may be a less effec- tive means of fully removing the contaminants compared with aggressive self-decontamination.

Patients who can walk with assistance and sit unattended can be categorized as semiambulatory. These individuals may be placed in chairs inside the decontamination unit and in most cir- cumstances can thoroughly wash all accessible areas themselves with minimal intervention or assistance. Decontamination team members in appropriate PPE should wash those areas of the body that are not readily accessible to the patients themselves. Once complete, victims can then be assisted out of the decontami- nation area to an awaiting wheelchair or other mobility device. This simple procedure reduces the physical demands placed on responders and may be inherently safer for the patient.

WHO SHOULD BE DECONTAMINATED?

Anyone suspected of being acutely exposed to or contaminated by a potentially toxic material whether it is chemical, biological, or radiological should be provided adequate decontamination. Decontamination procedures vary depending on the type and degree of exposure. For example, those individuals exposed to vapors require only clothing removal, whereas persons contami- nated from direct contact with hazards require clothing removal followed by aggressive washing with soap and water.

WHAT INFORMATION RESOURCES ARE MOST USEFUL IN AN EMERGENCY DECONTAMINATION OPERATION?

Planners should identify decontamination resources prior to an event. These may include chemical databases (e.g., Internet based), information from government authorities, and phone numbers for Poison Control Centers. Responders should partic- ipate in pre-event exercises that include how to access key infor- mation so that the process becomes second nature when an event

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198 ■ HOWA R D W. LEV I T I N A N D CH R I S TO P H E R A. KA H N

occurs. Although external resources may offer vast amounts of information, the decontamination process should not be delayed while awaiting this intelligence. In the case of a hazardous mate- rial exposure from a transportation incident, vehicle placards are useful to help determine the type of substance involved. In addi- tion, the patient may be a good source of information regarding the nature of the exposure, its related toxicity, and the number of other victims.

IN A CHEMICAL MASS CASUALTY INCIDENT, IS CLOTHING REMOVAL SUFFICIENT?

Historically, mass exposure to chemicals has been due to agents in the form of a vapor or gas. In the majority of circum- stances (>80%) the survivors are ambulatory and have had min- imal to no symptoms once they have evacuated the immediate release area.24 Once patients are removed from the vapor source, the chemical agent remains on the clothing, but its effects on the skin, eyes, and lungs typically dissipate quickly.9,10 Cloth- ing removal essentially completes the decontamination process. Although some may consider soap and water showering to be ideal after a chemical exposure, when large numbers of casu- alties are involved, the time and resources needed to initiate and complete the process successfully must be weighed against the marginal benefit that results. Resources that are diverted to shower minimally impacted, ambulatory victims may not be available for the rescue and care of the nonambulatory survivors whom the release affects most severely.9

STATE OF THE AR T

Although several advances in the field of decontamination have been reported in trade papers and by manufacturers, very few peer-reviewed scientific publications are available regarding the state of the art. Notable works include publications on disas- ter planning for medical facilities and the need to use the best available evidence for disaster planning. However, peer-reviewed articles specifically focusing on decontamination methods and evidence are rare.25–27 Due to the paucity of scientifically rigor- ous publications in the field, a synthesis of review papers and expert consensus serves as the best available scientific evidence.

The ideal approach to decontamination consists of several key steps

■ Rapid recognition that a contaminant is present ■ Identification of the contaminant (or its basic properties if

identification is not immediately possible) ■ Prevention of further contamination ■ Stabilization of victims’ immediate medical conditions ■ Removal of contaminant from victims ■ If appropriate, preservation of evidence ■ Removal of contaminant from the environment ■ Disposal of contaminant

RECOGNITION OF A CONTAMINATION EVENT

Recognizing that contaminated victims are present is the first critical step for a successful decontamination program. Several clues may help first responders determine that victims of an event are contaminated. These include identifying of a constella-

tion of signs and symptoms that suggest a specific poisoning class (i.e., toxidrome), observation of suspicious materials, previous warnings of a contamination event, or labels identifying contam- inating agents as present in the response area. Upon recognition of a contamination event, first responders must activate a coordi- nated response, which rapidly removes victims from the contam- inated area and contaminant from the victims. These steps must occur while providing for stabilizing medical care and protecting responders and public safety. It is also incumbent on responders to recognize that victims may present with symptoms without a known exposure; even if it is determined that a particular victim is definitely not exposed to the contaminant, symptoms con- sistent with psychogenic illness may be present and necessitate treatment.28 In the initial aftermath of an exposure, it may be difficult to determine whether patients have actually been con- taminated or are merely concerned about contamination and exhibiting symptoms. Resources must be available for patients who have not been truly exposed as well as for those who have.

IDENTIFICATION OF CONTAMINANT

Although general decontamination measures can proceed with- out contaminant identification, determination of the specific material can focus decontamination methods and make the pro- cess more efficient. In some cases, it can also increase safety for victims and responders. For example, certain metals are explo- sive when mixed with water; as water is the most common choice of decontamination agent, failure to identify these metals as the contaminant could prove dangerous.

The most reliable method of identifying a contaminant is to have advance knowledge of which contaminants are present in the environment where the exposure occurred. This is feasible in the context of laboratory or research settings, as well as incidents involving properly labeled shipments of hazardous materials or those occurring at regulated industrial sites. In the setting of a criminal act or a release at an unregulated site, it is much less likely that responders will have advance knowledge of the contaminant.

Detectors for various chemical and biological agents exist, but suffer from imperfect reliability. Recognition of a specific toxidrome is potentially the most reliable method for rapidly identifying the class to which a particular chemical contaminant belongs. Biological contaminants, by virtue of causing disease, may be more recognizable by the presentation of victims; how- ever, their usually delayed presentation may make overall recog- nition of a biological release event more difficult. Radiological contaminants can be easily identified by the use of radiological detectors such as Geiger counters.

If witnesses to the contamination event are able to identify the phase of a chemical contaminant (i.e., solid, liquid, or vapor/gas), the decontamination process can be further streamlined. Patients exposed to solid/powder and liquid contaminants will benefit from soap and water decontamination, whereas vapor/gas con- taminant exposure, in general, requires only clothing removal to mitigate further injury to the victims or threat to responders.9

PREVENTION OF FUR THER CONTAMINATION

A basic tenet of emergency response is ensuring scene safety; fail- ure to ensure the safety of responders and other nearby persons

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DE C O N TA M I NAT I O N ■ 199

risks the creation of more victims. Contaminated persons and items should be kept separate from non-contaminated persons and items. PPE should be used at all times (discussed further in Chapter 13). Guidelines from several countries state that when faced with an unknown contaminant, the highest available level of PPE should be used.29–32 Identification of the contaminant will likely allow the use of a lower level of PPE. There is no cur- rent consensus on which PPE level should be used when medi- cal procedures are urgently indicated on contaminated patients; studies have been performed indicating that higher-level protec- tion may significantly impair the ability of medical personnel to perform life-saving procedures such as airway stabilization or obtaining intravenous access for medication administration. The creation of a hospital-specific category of PPE to help maximize procedural ability and minimize risks to hospital staff has been suggested.1

STABILIZATION OF ACUTE MEDICAL CONDITIONS

An ongoing debate exists as to the level of medical treatment that responders should provide prior to and during decontamination. In general, life-saving care such as airway management should be provided, if possible, even if decontamination has not been completed. It is critical, however, to maintain responder and civil- ian safety while performing these interventions. If a treatment cannot be provided without contaminating and therefore endan- gering responders and other persons, that treatment should be withheld until safety can be reasonably assured. Treatment that can safely be deferred should be delayed until the patient has been decontaminated. Ideally, decontamination should occur at (or close to) the incident scene(s), with transport of victims occurring after decontamination; this approach minimizes the spread of contaminant. This ideal must be balanced with the need to remove victims promptly from a contaminating source to minimize further contamination.9 In addition, victims may self-present to healthcare treatment sites distant from the site of exposure without first undergoing decontamination. Hence, first-receivers must be prepared to decontaminate victims.

In addition to people, transportation vehicles and medical equipment applied to or used on victims may become contam- inated (unless the contaminant is a vapor or gas). Accordingly, replacement equipment (e.g., cervical collars, backboards, and splints) should be available for exchange at the conclusion of the decontamination process.

REMOVAL OF CONTAMINANT FROM VICTIMS

Several resources exist to describe both general decontamination approaches as well as individual decontamination methods for specific agents.33–37 A discussion of the complete details for every agent is beyond the scope of this chapter; the focus will be on general decontamination principles.

Koenig coined the term “strip and shower” to describe the most common decontamination method, the use of soap and water after removal of all clothing and other items from a contam- inated victim.1 Although considered largely effective, and relying on inexpensive materials, several logistical concerns are raised when employing this method. Patient throughput (the number of patients that can be decontaminated per hour) may be limited

by the availability of private areas with access to running water. In cold weather, stripping and being washed may cause icing injury to responders and equipment and could result in hypothermia if decontamination is prolonged, particularly if warm water is unavailable. Having water available may require the use of high- pressure systems (such as fire apparatus), which could injure people, or, if at a fixed facility, the acquisition of equipment requiring maintenance and capital investment. Privacy is also an issue. Despite these concerns, this technique remains the most common decontamination method in use today.

Dry powder decontamination is an alternative method used in Israel and many other countries to absorb liquid substances. After removal of clothing, a dry powder such as Fuller’s Earth (a highly absorbent, claylike earthy material) is applied to the victim. The adsorbent nature of the powder helps remove con- taminant from the victim. This method is more cumbersome to apply and requires the availability of the powder. It is an attractive option when the contaminant is a thickened agent, when access to water is limited, or when the agent is known to be reactive with water.

Foam is a more recent innovation for decontamination. Sev- eral foam agents are being investigated at the time of this writing. Advantages include less production of waste products, a potential for enhanced skin coverage, and activity against a broad range of agents. Disadvantages include expense and the need to store large quantities of decontamination agent.

Whatever decontamination method is used, orifices, mucous membranes, and injured areas require special attention. In gen- eral, these areas should be decontaminated first to most rapidly minimize the continued absorption and effects of the contami- nant. Water-based methods are the most rapid and appropriate means of decontaminating these areas.

PRESER VATION OF EV IDENCE

Many contamination incidents will result in investigation by either occupational health and safety agencies or by law enforce- ment. In either case, contaminated items may be crucial pieces of evidence to assist in investigations. Although preservation of evidence is clearly a lower priority than the preservation of life and health, whenever possible, evidence should be maintained by identifying, isolating, and maintaining the chain of custody for evidentiary items. Because evidence preservation is resource intensive and may not be necessary for a given event, determi- nation that evidence collection is desirable should be made early in conjunction with the appropriate agencies. Procedures may include the removal of personal items from contaminated vic- tims and sealing them in a nonreactive container (a plastic bag will often suffice). Containers should be labeled and maintained in a secure area, or if possible, with the patient. Coordination with the investigating agency/agencies during the early stages of the incident will help determine the need for and extent of evidence preservation.

REMOVAL OF CONTAMINANT FROM ENV IRONMENT

After adequately addressing decontamination and the medical needs of victims, responsible officials should begin a more thor- ough assessment of the incident scene and surrounding environs.

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200 ■ HOWA R D W. LEV I T I N A N D CH R I S TO P H E R A. KA H N

Although environmental cleaning will almost certainly be con- ducted by different response crews at a later time, first respon- ders can mitigate later work by their initial actions. For example, directing the flow of water such that entry into watersheds and storm drains is minimized is beneficial in limiting contamination of the environment. As with evidence collection, environmental concerns are a lower priority than the preservation of life and safety.

DISPOSAL OF CONTAMINANT

To assist with environmental protection, medical and health workers should dispose of contaminant and contaminated items in a fashion consistent with safe practices. In the U.S., special- ized contractors and governmental agencies are generally better equipped and more familiar with regulatory issues regarding dis- posal of hazardous waste than individuals or small agencies and facilities. Any waste disposal should be performed with careful attention to regulatory guidance. One particular issue regarding disposal of contaminant is management of wastewater produced during water decontamination. In general, it is preferred that water be contained for later treatment or disposal; however, the U.S. Environmental Protection Agency has issued guidance that in emergency situations with no other alternatives, discharge of wastewater into sewers is acceptable to preserve life. Specif- ically, avoidance of contaminated runoff “should not impede necessary and appropriate actions to protect human life and health.”38

SPECIAL CONSIDERATIONS

Decontamination in the Healthcare Facility Setting

Although many community decontamination plans describe methods for providing decontamination at the exposure site, after a mass casualty contamination event, many victims will spontaneously present at medical facilities distant from the loca- tion of exposure for treatment.25,39–42 Treatment of contami- nated victims has resulted in injuries to facility medical staff.41–45

It is imperative that medical facilities have a decontamination program, both for the case in which they receive contaminated victims from a distant location and also for situations in which they are the site of exposure.46

Decontamination in the hospital or other healthcare facility setting follows the same principles delineated earlier. A crucial step is to minimize the risk to other patients and to facility staff by minimizing exposure. Decontamination should occur in a designated area with staged equipment to allow for mitigation of the contaminant without the need to move the patient through other areas of the hospital. The designated decontamination area should have restricted access.

Special Populations

Children, elderly, and disabled victims will likely present addi- tional challenges to the decontamination team. Children will have additional difficulty following instructions and may not be developmentally able to participate in self-decontamination measures. The elderly and disabled may also be unable to self- decontaminate due to decreased mobility. Although the basic tenets of medical stabilization and contaminant removal do not

change, additional personnel (appropriately protected) may be required to assist these populations. With appropriate safety measures, involvement of the victims’ families or caregivers may help alleviate victim anxiety and enhance efficiency of the decon- tamination process.

Recommendations for Further Research There is still much that needs to be learned about patient

decontamination. Scientific studies are lacking and most current guidelines are based predominantly on personal experience and dogma. Questions for future research include the following:

■ How does one measure the adequacy of decontamination? ■ Should this determination be based on victim symptomatol-

ogy, duration of showering time, measurements made from new promising technology, or other parameters?

■ Is traditional soap and water showering appropriate decon- tamination for victims of a chemical mass casualty incident?

■ How frequently should healthcare facility staff be trained so that they will maintain their knowledge, skills, and abilities related to the use of PPE, patient decontamination, and other related competencies?

■ Is annual training sufficient (as dictated by U.S. federal standards) or does knowledge quickly wane after the initial instruction period?

■ Who should be trained? ■ In the hospital setting, who predominantly performs decon-

tamination (what level of staff: medical or nonmedical per- sonnel)?

■ Does age or sex make a difference? Does currently available PPE and decontamination equipment adequately address the needs of both sexes, various age groups, and the unique demands of the hospital?

■ What medical interventions (e.g., airway management, intra- venous catheter placement, and insertion of chest tubes) can staff wearing PPE be expected to perform?

Conclusion

A decontamination program must be multidisciplinary and inte- grated; it requires planning, retraining, and teamwork to be effective. The fact that an exposure has occurred must be recog- nized early. First responders, first receivers, and facilities must be adequately protected and decontamination must be performed quickly, safely, and efficiently. The involvement of multiple cate- gories of personnel (e.g., medical staff, administrators, trainers, security personnel, and regulatory officials) demands a unified approach including collaborative and detailed pre-event plan- ning. An incident command system, such as that promulgated by the U.S. National Incident Management System, is an excel- lent framework within which the structure of a decontamination response can be formed. Ongoing training will help ensure that response team members are familiar with their roles and are capable of achieving the goal of rapid contaminant removal and victim stabilization while protecting themselves and the public from injury.

REFERENCES

1. Koenig KL. Strip and shower: the duck and cover for the 21st century. Ann Emerg Med. 2003;42(3):391–394.

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