While environmental remediation and containment are essential to controlling the spread of contamination, emergency management protocols for controlling chemical spread should also include plans for decontaminating survivors and their pets prior to their transport and/or entry into medical facilities, and decontaminating first responders, their vehicles, and their equipment. The implementation of such protocols will significantly reduce the risk of contamination spread and re-contamination of areas that have been decontaminated.
Although not all individuals exposed during a chemical incident (survivors) may be contaminated, and not all individuals that experience health consequences as a result of a chemical incident may be contaminated, in general, decontamination has the potential to reduce health consequences for incident survivors by reducing their exposure time. In a sense, decontamination of survivors is a type of treatment. Moreover, decontamination of survivors (and medical equipment) before their transport to a care facility avoids downstream contamination of responders and healthcare personnel. For this reason, a major goal of the initial response to a chemical incident that involves human or animal exposures is the decontamination of contaminated individuals.37,57 Sources of primary and secondary contamination for survivors and responders are discussed in the box below.
Primary and Secondary Contamination58
Primary contamination is the contamination of persons or equipment as a result of direct contact with the initial chemical release source.
Secondary contamination refers to the contamination of healthcare or other responding personnel or equipment as a result of contact with a person (survivor/patient) or equipment that is covered with adherent solids or liquids that have been removed from the release source. Secondary exposures may arise from either:
Direct contact hazards: Contact exposures occur via the touching of surfaces (clothing, floors, walls, seats, turnstiles, handrails, etc.) on which the substance is present. The substance may be present on a surface due to a direct spill, its deposition onto the surface from a release that created airborne liquid droplets, or contact with other contaminated surfaces. Contact exposures followed by human movement can lead to contaminant spread; contact exposures can also lead to responder exposure/ contamination while treating patients prior to their decontamination. Certain substances (especially low volatility chemicals such as the nerve agent VX) may remain on surfaces for a long time, even after an initial decontamination, and thus represent long-term exposure risks.
Airborne hazards: Chemicals can evaporate from the skin and clothing of exposed individuals that came into contact with liquids. Again, this can lead to responder exposure/contamination while treating patients prior to their decontamination. Greater hazards exist in smaller and/or poorly ventilated spaces. To reduce evaporation hazards, contaminated clothing should be removed as quickly as possible and placed in sealed containers for disposal.
Footnotes
37. U.S. Environmental Protection Agency. (2016). National Response System.
57. Nelson, L.S., Lewin, N.A., Howland, M., Hoffman, R.S., Goldfrank, L.R., & Flomenbaum, N.E. (2011). Goldfrank’s Toxicologic Emergencies. (9th ed.). The McGraw-Hill Companies, Inc. Print.
58. National Institute for Occupational Safety and Health. (1985). Occupational Safety and Health Guidance Manual for Hazardous Waste Site Activities. Occupational Safety and Health Administration, U.S. Coast Guard, U.S. Environmental Protection Agency.