the USEPA assumes that each person breathes 20 cubic meters of air per day. If the air we breathe in has 50% relative humidity at 20 °C, and we breathe it out with 100% relative humidity at 37 °C, how many milliliters of water would we need to drink each day just to replace the water lost by breathing? The vapor pressure of water at 20 °C is 17.5 mmHg and at 37 °C it is 47.1 mmHg. Assume the volume of air
breathed in is the same as that breathed out.