COHN Toxicology and Biohazards 2 — Questions and Answers
Question 1: A worker is exposed to an organophosphate pesticide. Which set of symptoms is MOST characteristic of this exposure?
- Dry mouth, dilated pupils, tachycardia
- Excessive salivation, miosis, bradycardia (Correct answer)
- Cherry-red skin, headache, confusion
- Metallic taste, hair loss, peripheral neuropathy
Correct answer: Excessive salivation, miosis, bradycardia
Organophosphates inhibit acetylcholinesterase, causing cholinergic toxidrome with SLUDGE symptoms (salivation, lacrimation, urination, defecation, GI distress, emesis), miosis, and bradycardia.
Question 2: Under OSHA's Bloodborne Pathogen Standard, which of the following is classified as Other Potentially Infectious Material (OPIM)?
- Sweat and tears
- Urine and feces (without visible blood)
- Cerebrospinal fluid and semen (Correct answer)
- Nasal secretions and saliva (not during dental procedures)
Correct answer: Cerebrospinal fluid and semen
OSHA's Bloodborne Pathogen Standard classifies cerebrospinal fluid, semen, vaginal secretions, and several other body fluids as OPIM regardless of visible blood content.
Question 3: The biological exposure index (BEI) for a chemical is BEST described as:
- The air concentration at which no adverse effects occur in any worker
- A reference value for assessing biological monitoring results in exposed workers (Correct answer)
- The maximum permissible skin absorption rate per work shift
- The IDLH concentration divided by a safety factor of 100
Correct answer: A reference value for assessing biological monitoring results in exposed workers
BEIs are reference values established by ACGIH for evaluating biological monitoring results, representing levels of determinants observed in healthy workers exposed at the TLV.
Question 4: A chemical with a Threshold Limit Value-Ceiling (TLV-C) must NEVER be exceeded:
- During any 15-minute period in the work shift
- At any time during the work shift (Correct answer)
- For more than 30 cumulative minutes per shift
- On more than 2 occasions per 8-hour shift
Correct answer: At any time during the work shift
TLV-C is a ceiling concentration that should not be exceeded at any time, unlike TLV-TWA or TLV-STEL which allow time averaging.
Question 5: A laser cutter operator reports eye irritation and blurred vision. Which type of radiation hazard is MOST relevant to this worker?
- Ionizing radiation from X-ray scatter
- Non-ionizing radiation from coherent light (Correct answer)
- Infrared radiation from heat generation only
- Ultraviolet radiation from fluorescent safety lighting
Correct answer: Non-ionizing radiation from coherent light
Lasers emit coherent non-ionizing radiation that can cause severe retinal burns and corneal damage; proper laser safety eyewear rated for the specific wavelength is required.
Question 6: Which federal agency sets Permissible Exposure Limits (PELs) for chemical hazards in the workplace?
- NIOSH
- EPA
- OSHA (Correct answer)
- ACGIH
Correct answer: OSHA
OSHA establishes legally enforceable PELs under 29 CFR 1910.1000, while NIOSH issues recommended exposure limits (RELs) and ACGIH publishes non-mandatory TLVs.
Question 7: A worker with chronic low-level mercury vapor exposure is MOST likely to present with which early symptom?
- Blue-black gum line and loose teeth
- Fine tremor of the hands and irritability (Correct answer)
- Mees' lines on fingernails and hyperkeratosis
- Peripheral cyanosis and Raynaud's phenomenon
Correct answer: Fine tremor of the hands and irritability
Early chronic mercury vapor toxicity classically presents with erethism (irritability, shyness, memory loss) and fine intentional tremor before more severe neurological signs appear.
COHN Toxicology and Biohazards 2
A worker is exposed to an organophosphate pesticide.
Which set of symptoms is MOST characteristic of this exposure?