COHN Toxicology and Biohazards Questions and Answers — Questions and Answers
Question 1: An employee in a battery manufacturing plant presents with peripheral neuropathy, abdominal pain, and irritability. The occupational health nurse suspects chronic exposure to a heavy metal. Which of the following is the MOST likely causative agent?
- Cadmium
- Lead (Correct answer)
- Mercury
- Arsenic
Correct answer: Lead
Chronic lead exposure classically presents with a combination of neurological symptoms (peripheral neuropathy, irritability), gastrointestinal issues (abdominal pain or 'lead colic'), and hematological effects like anemia. While other metals can cause some of these symptoms, the specific constellation is most characteristic of lead poisoning, a known hazard in battery manufacturing.
Question 2: When reviewing a Safety Data Sheet (SDS) for a new chemical being introduced in the workplace, the occupational health nurse notes it has a very low LD50 value. How should the nurse interpret this information?
- The chemical has low acute toxicity.
- A large amount of the substance is required to cause a lethal effect.
- A small amount of the substance is required to cause a lethal effect. (Correct answer)
- The chemical is highly flammable but not very toxic.
Correct answer: A small amount of the substance is required to cause a lethal effect.
LD50 (Lethal Dose, 50%) is the amount of a substance that, when administered in a single dose, is expected to cause the death of 50% of a defined animal population. A low LD50 value indicates high acute toxicity, meaning that only a small amount of the substance is needed to be lethal.
Question 3: A laboratory worker accidentally splashes a chemical onto their forearm. Which route of entry is the primary concern for the occupational health nurse in this scenario?
- Inhalation
- Ingestion
- Injection
- Absorption (Correct answer)
Correct answer: Absorption
Absorption occurs when a chemical passes through the skin and enters the bloodstream. A chemical splash directly onto the skin makes absorption the primary and most immediate route of entry. Inhalation would be a concern for airborne vapors, ingestion for swallowing, and injection for a puncture wound.
Question 4: Which of the following is a key component that MUST be included in an OSHA-required Bloodborne Pathogens Exposure Control Plan?
- A list of all employees' personal health conditions.
- The brand names of all personal protective equipment (PPE) to be used.
- The procedure for evaluating the circumstances surrounding an exposure incident. (Correct answer)
- A requirement for all employees to receive the influenza vaccine annually.
Correct answer: The procedure for evaluating the circumstances surrounding an exposure incident.
OSHA's Bloodborne Pathogens Standard (29 CFR 1910.1030) mandates that an Exposure Control Plan include procedures for post-exposure evaluation and follow-up. This involves documenting the routes of exposure and the circumstances under which the incident occurred to help prevent future incidents.
Question 5: An industrial painter who works with solvents complains of dizziness, headache, and confusion by the end of their shift. The occupational health nurse recognizes these as potential symptoms of acute toxicity primarily affecting which body system?
- Renal system
- Central nervous system (Correct answer)
- Gastrointestinal system
- Integumentary system
Correct answer: Central nervous system
Organic solvents are known to be central nervous system (CNS) depressants. Acute, high-level exposure via inhalation can cause symptoms such as dizziness, headache, confusion, and lack of coordination. While solvents can affect other organ systems with chronic exposure, these immediate symptoms are characteristic of CNS effects.
Question 6: In toxicology, the term LC50 refers to which of the following?
- The lowest concentration of a chemical that causes a chronic effect.
- The legal concentration limit for a chemical in the workplace.
- The lethal dose of a chemical when ingested by 50% of a test population.
- The lethal concentration of an airborne substance that kills 50% of a test population. (Correct answer)
Correct answer: The lethal concentration of an airborne substance that kills 50% of a test population.
LC50 stands for Lethal Concentration, 50%. It is a standard measure of the toxicity of an airborne substance (like a gas, vapor, or dust) and represents the concentration that is lethal to half of the tested animal population during a specific exposure period.
COHN Toxicology and Biohazards Questions and Answers
An employee in a battery manufacturing plant presents with peripheral neuropathy, abdominal pain, and irritability.
The occupational health nurse suspects chronic exposure to a heavy metal.
Which of the following is the MOST likely causative agent?