Because the real quench distance is only the minimum figure @ TDC (which is not the point of maximum risk), and there is measurable pumping loss getting those few molecules in and out of that small space, and as the clearance expands the loss is reduced.
Why is nonpoint source pollution potentially more harmful than point source pollution? a. Nonpoint source pollution disrupts the water cycle. b. Nonpoint source pollution is difficult to regulate. c. Nonpoint source pollution comes from more than one source. d. Nonpoint source pollution is more damaging to living organisms than point source pollution. Nonpoint source pollution generally results from land runoff, precipitation, atmospheric deposition, drainage, seepage or hydrologic modification.
Nonpoint source pollution. Non-point source (NPS) pollution includes both water and air pollution from diffuse sources. Non-point source water pollution affects a water body from sources such as polluted runoff from agricultural areas draining into a river, or wind-borne debris blowing out to sea. Non-point source air pollution affects air quality from sources such as smokestacks or car tailpipes. Although these pollutants have originated from a point source, the long-range transport ability and multiple sources of the pollutant make it a non-point source of pollution.