16.5 The California ambient air quality standard for visibility requires that the average σ e be less than 0.23 km - 1 when the relative humidity is less than 70%. To what visual range does this limit correspond? To what aerosol mass concentration does it correspond? To what aerosol mass concentration does it correspond? Assume that the particle size is 0.18 μm (SMD for the accumulation mode), the particle refractive index is 1.5, and ρp is 1000 kg /m 3 [1.0 g/cm3].