Question 4 of 7: Biological Hazards

Question 4: Biological Hazards (20 marks: 7/7/6)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

(i) Agents and Sources

• Agents: bacteria, viruses, fungi, parasites and their toxins; blood/bodily fluids.
• Sources: infected people/animals; contaminated water, air, food, surfaces; sewage/waste; lab cultures; agricultural/organic dusts; healthcare (needles, specimens); HVAC (mould, legionella).

(ii) Broad Examples

• Bloodborne pathogens (hepatitis B/C, HIV); airborne infections (TB, influenza, legionella); zoonoses (rabies, anthrax); moulds/organic dusts (asthma, "farmer's lung"); sewage-related infections; pathogenic lab cultures.

(iii) Classification (Risk / Biosafety Levels)

• Group 1 — unlikely to cause disease (minimal risk).
• Group 2 — can cause disease; treatment/prevention available, limited spread.
• Group 3 — serious disease, may spread; treatment usually available.
• Group 4 — serious, readily transmitted, no reliable treatment.
• Each risk group dictates progressively stricter containment. In Canada the levels are CL1–CL4 under the Canadian Biosafety Standard (Public Health Agency of Canada / CFIA, made under the Human Pathogens and Toxins Act); the equivalent international/US designation is BSL-1 to BSL-4.