The latest report card for the US awards nothing but poor to very poor grades to all sectors where concrete dominates, with dams, roads, and aviation getting Ds and the overall average grade just D+.[102] This appraisal gives an inkling of what China might face (mass- and money-wise) by 2050. In contrast, the poorest countries need essential infrastructures and the most basic need in many homes in Africa and Asia is to replace mud floors with concrete floors in order to improve overall hygiene and to reduce the incidence of parasitic diseases by nearly 80 percent.[103]
