Consider sulfur dioxide at a concentration of 1 mg/m3 in the atmosphere. How much sulfur dioxide remains at the end of the trachea (10 cm length of a 2 cm diameter -cylindrical cross- section). Assume turbulence maintains a uniform concentration of sulfur dioxide across the trachea radially, that the membranes of the trachea are an infinite sink for sulfur dioxide and that the effective mass transfer coefficient to the trachea walls from the radially mixed air in the trachea is 100 cm/min. The volume of air being breathed is 20 m3/day