1. Identify and comment on the major components in the relationships between environmental issues and human activities. (50 marks)

2. Heavy metals are a ubiquitous pollutant, and they can easily enter our food chain easily.

a. The table below shows the concentrations of heavy metals detected in fish. Using the information provided below.
i. Calculate Hazard Index (HI) of each heavy metals. (8 marks)
ii. Do the levels of heavy metals pose non-cancer risks to consumers? (2 marks)

Average: 64 kg
Amount if fish consumed daily: 180 g
Concentrations of metals and RfDo
Concentrations RfDo
Arsenic 0.47 mg/kg 3 x 10-4
Chromium 0.25 mg/kg 3 x 10-3
Cadmium 1.37 mg/kg 1 x 10-3
Mercury 0.22 mg/kg 3 x 10-4

b. E-waste dismantling accounts for a significant part of soil contamination in China. Write an 800-word essay to discuss what measures can be adopted to reduce the levels of metal contaminations. (40 marks)