An accident on a highway involving a tanker truck spilled 5000 gallons of 1,2-dichloroethene (DCA) forming a 2500-m2 pool. DCA has a vapor pressure of 0.1 atm at 298 K. The air temperature is 25 C and the wind speed averaged 4 m/s. The accident occurred on a sunny afternoon. Estimate the distance downwind of the spill that would exceed the worker standard exposure limit of 1 ppmv for DCA.