AbstractConcrete biodeterioration is defined as the damage that the products of microorganism metabolism, in particular sulfuric acid, do to hardened concrete. In Canada and in the northern part of the United States, sewer failures from concrete biodeterioration are almost unknown. In the southern part of the United States and in Mexico, however, it is a serious and expensive problem in sewage collection systems, which rapidly deteriorate. Also, leaking sewage systems result in the loss of groundwater resources particularly important in this arid region. Almost every city in the Mexican-American border region, who's combined population is more than 15 million people, faces this problem. The U.S. cities have made some provision to face these infrastructure problems, but the Mexican cities have made less effort. We recommend here the Mexican norm (NMX-C-414-ONNCCE-2004) [1] to be reviewed, or at least that a warning be issued as a key measure to avoid concrete biodeterioration.
Updated demographically adjusted norms for the Brief Visuospatial Memory Test-revised and Hopkins Verbal Learning Test-revised in Spanish-speakers from the U.S.-Mexico border region: The NP-NUMBRS project