This month we decided to re-issue a selection from our Pulse Point March-April 1999 issue, which looked at the Nuclear, Biological, and Chemical (NBC) terrorist threat from the health and safety perspective. Industrial hygienists and other EH&S professionals have the right kind of background, training and expertise to develop effective strategies for protecting first responders and emergency medical services personnel as they perform their critical functions in such an event. This article and others on our web site explore several areas where EH&S professionals can help in preparedness planning and will guide you to other online resources to learn more about this important issue.
The ABCs of the NBC (Nuclear, Biological & Chemical) Threat
While the majority of terrorist incidents worldwide result from the use of explosive devices, the NBC threat is a sad fact of life today. NBC weapons can be relatively inexpensive, easy to make, difficult to detect, and can disseminate through the air making them ideal for use in large, crowded or enclosed spaces. Let’s take a look at the basics of NBC weapons.
The U.S. has strict controls over sources of ionizing radiation. However, releases can result from accidental or intentional incidents. Radioactive materials can emit alpha, beta and gamma radiation, as well as neutrons. Exposure can be internal (i.e., from breathing or ingesting alpha particles), or external, (from exposure to beta particles, gamma rays and X-rays). There are detection instruments that measure the amount of radiation in the air or emanating from an object. The ways to protect ourselves from radiation exposure are time, distance and shielding. While the probability of such releases is low, emergency medical facilities need to prepare their staff to treat victims of such an incident in a safe and protective manner.
Biological agents are the most toxic per unit of weight compared to chemical agents. They are easily accessible and can be mass-produced. Their small size, ranging from 1 to 5 microns, makes them an inhalation hazard. They are of three general types: bacteria (i.e. plague, anthrax, and tularemia), virus (smallpox, Ebola, Viral Equine Encephalitis), and toxins (botulism, ricin, and Staphylococcus Enterotoxin B). Their effects can range from incapacitating to lethal and may take from hours to days depending on the organism’s incubation period or the toxin’s mode of action in the body. Their limitations are mostly related to their delivery and dispersal mechanisms.
The most widely used are the chemical warfare agents. These are generally liquids dispersed as vapors or aerosols, although some are gases. They range from very volatile to very persistent agents, which can be more difficult to remove and may cause secondary damage after the initial release. Much faster acting than biological agents, they can cause cellular damage from seconds to hours after exposure. Injuries from chemical agents range from irritation or incapacitation to death. The routes of exposure are through inhalation and dermal contact. The categories are: nerve agents (Sarin, Tabun, Soman, VX), pulmonary intoxicants (chlorine, phosgene), vesicants or blistering agents (mustard, Lewisite), riot control agents (mace, pepper spray), incapacitating agents (BZ), and miscellaneous chemicals, such as ammonia.
NBC incident Decontamination
Decontamination after an NBC incident applies not only to the victims, but also to first responders and medical staff, as well as EMT vehicles and Emergency Department (ED) facilities and equipment. At a minimum, decontamination involves removing the patient’s clothes, shoes and jewelry. Remember that these items are evidence and need to be properly bagged, labeled and secured. It is best to train and assign one person to oversee this task, in coordination with law enforcement. In cases of biological agents, this step may be all that is needed as the patient will only come in after the incubation period and will probably not be contaminated. Otherwise, washing with soap and water should be sufficient.
For chemical agents, decontamination performed early on can significantly reduce exposure and subsequent degree of illness or injury. This is more important for liquid chemicals than vapors, which will evaporate more quickly and have fewer residual effects. In all cases, the patient should be washed with soap and water as soon as possible. Incidents involving nerve agents (Sarin, VX), sulfur mustard and Lewisite also require a 1:10 chlorine bleach-water solution after washing to neutralize the chemical’s action. This should be followed by a fresh water rinse to avoid the bleach’s irritant effects. Exposure to ammonia, chlorine, mace, tear gas and pepper spray should also include thorough eye irrigation with water or saline for 15-20 minutes.
In addition to patient decontamination, it’s important to maintain containment to prevent the spread of radioactive, chemical or biological agents. The decon area should be located outside of the ED. Water runoff from decon showers should not be allowed to flow to ground or storm sewers, to prevent further contamination or environmental damage. Decon water may be needed as evidence or to provide samples for identifying the agent. The decon system must have provisions for privacy, protection from exposure to inclement weather, and for keeping a clear separation between “dirty” and “clean” areas.
Health and Safety professionals at medical facilities need to cooperate with local responders, HazMat teams and other area health care facilities to find creative ways for mass decontamination and conduct practice drills. Some options to consider include designating shower areas in the hospital with controlled ingress and egress, renting portable decon trailers used in hazardous waste cleanups, setting up portable showers and collection pools, or even using fire hoses or fire truck deck guns to spray large groups of people. Health care personnel involved with patient decon and treatment will need access to disposable supplies and equipment and personal protection gear to ensure their safety, and will need to undergo decon when entering the ED’s “clean” areas.
If you are interested in learning more about and ways to prepare for an NBC threat, here is a short list of web sites that can provide you with additional information. Most are linked to many more additional sites:
Chemical and Biological Defense Information and Analysis Center’s page on Domestic Preparedness: http://www.cbiac.apgea.army.mil/
US EPA Chemical Emergency Preparedness and Prevention Office home page:
US Army Medical Research Institute of Chemical Defense (USARMICD) information for military, government and private health care professionals, first responders and other interested people. http://chemdef.apgea.army.mil/
From the Pulse Point Archives:
Preparing for a Terrorist Incident: A Practical Approach for Hospital ERs
The START (Simple Triage and Rapid Treatment) System
If you have questions about how this article or
other health, safety or environmental issues, please contact us at (619)
297-1469 or send us an email at email@example.com.
Alliance Consulting International
Partners in Environmental and Occupational Health and Safety
3361 28th St.
San Diego, California 92104
For articles in previous issues of Pulse Point visit our web site's
"archive" section at: www.pulse-point.com/
To unsubscribe, just reply to this message and write "Unsubscribe" in the Subject bar.
All material Copyright © 2001 Pulse Point.
Pulse Point is written for the benefit of our readers with the sole intent to provide general information. The articles are not intended as specific opinions or as a substitute for professional advice in individual cases.