Among people affected by environmental harmful factors, due to the difference of individual exposure dose level and exposure time, there will be different degrees of influence in age, gender, physiological state and genetic susceptibility to harmful substances. Moreover, the effect of each grade accounts for a different proportion in the crowd. The distribution of different degrees of influence in the population is the health impact spectrum. At the bottom of the effect spectrum is the increase of physiological load, which does not cause changes in physiological function and biochemical metabolism, and this part of the population accounts for the largest proportion. So choose item e.