Waec Model Questions Vol1 2019 Geography Question 31
Practice objective / multiple choice question 31 from the 2019 Waec Model Questions Vol1 Geography examination.
A chemical spill releases a pollutant into a river that initially has a concentration of 80 mg L⁻¹. The concentration decays exponentially with a half‑life of 5 days (C = C₀·(½)^{t/5}). Residents drink 2 L of the river water per day, have an average body weight of 60 kg, and the reference dose (RfD) for the pollutant is 0.02 mg kg⁻¹ day⁻¹. The Hazard Index (HI) is defined as HI = (Dose ÷ RfD), where Dose = (C × 2 L) ÷ 60 kg. After how many whole days will the HI first fall below 1?
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About This Question
This is Waec Model Questions Vol1 2019 Geography Question 31. It is one of the objective questions from the 2019 Waec Model Questions Vol1 Geography examination.
Difficulty level: Hard .
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