Arsenic is released from an industrial stack at a rate of E=6 g/s. The effective height release is H = 50m. The mean wind speed is u = 3 m/s. Predict the ground-level arsenic concentrations 5 km downwind of the stack for two stability classes: B (moderately unstable) and E (slightly stable). If the RfD of arsenic is 3 x 10-4 mg/kg/day, and assuming an adsorption efficiency of 50%, is there an unsafe risk for an adult male breathing the air 5 km downwind of the stack in either stability class?