Biological hazards
- Biological hazards include disease-causing organisms; poisonous plants and animals; and biological agents used in bioterrorism.
Wastes from hospitals and research facilities may contain disease-causing organisms that could infect site personnel. Like chemical hazards, infectious agents may be dispersed in the environment via water and wind. Other biological hazards that may be present at a hazardous waste site include poisonous plants, insects, animals, and indigenous pathogens.
Protective clothing and respiratory equipment can help reduce the chances of exposure. Anyone who has been exposed should thoroughly wash any exposed body parts and equipment to help protect against infection.
Biological hazards can also stem from terrorist acts. Terrorism is the use of force or violence against persons or property for purposes of intimidation, coercion, or ransom. Bioterrorism is the use of biological agents to inflict casualties.
Biological agents are organisms, bacteria, viruses, or toxins that have illness-producing effects on people, livestock, and crops. Biological agents include:
| Agent | Dissemination | Transmission (person to person) | Incubation | Lethality |
|---|---|---|---|---|
| Anthrax | Spores in aerosol | No (except cutaneous) | 1–5 days | High |
| Cholera | Ingestion and aerosol | Rare | 12 hours to 6 days | Low with treatment |
| Plague | Aerosol | High | 1–3 days | High if untreated |
| Tularemia | Aerosol | No | 1–10 days | Moderate if untreated |
| Q Fever | Ingestion and aerosol | Rare | 14–16 days | Very low |
| Smallpox | Aerosol | High | 10–12 days | Low |
| VEE | Aerosol and infected vectors | Low | 1–6 days | Low |
| Ebola | Contact and aerosol | Moderate | 4–16 days | Moderate to high |
| Botulinum Toxin | Ingestion and aerosol | No | Hours to days | High |
| T-2 Mycotoxins | Ingestion and aerosol | No | 2–4 hours | Moderate |
| Ricin | Ingestion and aeroso | No | Hours to days | High |
| Staphylococcal Enterotoxin B | Ingestion and aerosol | No | Hours | Less than 1 percent |
Biological agents can be dispersed as aerosols or airborne particles. Some devices used for intentional biological terrorism may have the capacity to disseminate large quantities of biological materials in aerosols.
Terrorists may also use biological agents to contaminate food or water. Because biological agents cannot necessarily be detected and may take time to grow and cause harm, it is very difficult to determine that a biological attack has occurred until people begin showing the signs and symptoms.
Biological agents are infectious through one or more of the following mechanisms of exposure, depending upon the type of agent:
- Inhalation, with infection through respiratory mucosa or lung tissues;
- Ingestion;
- Contact with the mucous membranes of the eyes or nasal tissues; or
- Penetration of the skin through open cuts (even very small cuts and abrasions of which employees might be unaware).
Existing recommendations for protecting workers from biological hazards require the use of half-mask or full facepiece air-purifying respirators with particulate filter efficiencies ranging from N95 (for hazards such as pulmonary tuberculosis) to P100 (for hazards such as hantavirus) as a minimum level of protection.
Emergency first responders typically use self-contained breathing apparatus (SCBA) respirators with a full facepiece operated in the most protective, positive pressure (pressure demand) mode during emergency responses.