Suppose a gaseous substance is emitted by an industrialfacility, outside of a city, and that this substance has a very lowinhalation LD50 value of 0.2 µg/kg/day.
a. Explain the meaning and units of LD50. Given the ‘very low’description, would you guess that the substance is generally toxicor non-toxic? Explain your answer.
b. A low-pressure system is sitting over the city. How willthis affect the transport of the pollutant relative to the citycenter, i.e., will it move towards or away the center, andwhy?
c. Assuming that city authorities do not know the source ofthe pollutant at first, suggest how monitoring equipment could beused/deployed around the city in order to determine the directionof the point source.
d. Suppose the industrial facility is in a rural area and hasplenty of land, and now needs to control a relatively smallvolumetric flow Q of the gaseous pollutant. What control technologywould you suggest and why? (Hint: there are two goodoptions.)
