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; sewage-related infections; pathogenic lab cultures.

(iii) Classification (Risk / Biosafety Levels)

• Group 1 — minimal risk. Group 2 — moderate; treatment/prevention available, limited spread. Group 3 — serious, may spread; treatment usually available. Group 4 — serious, readily transmitted, no reliable treatment. Each dictates stricter containment (BSL-1 to BSL-4).