PRINCIPLES OF TOXICOLOGY - Biology East Borneo

138 NEPHROTOXICITY: TOXIC RESPONSES OF THE KIDNEYestablished Threshold Limit Values (trademark) (TLVs) that are intended to protect against affects onthe kidney are given in Table 6.1. For these compounds, however, the renal system may not be the onlysystem the TLV is intended to protect.Two classes of environmentally or occupationally relevant chemicals that damage the kidney arethe heavy metals and halogenated hydrocarbons. The adverse effects of representative chemicals fromeach group are discussed below. Some occupations that have exposure to nephrotoxicants are given inTable 6.2.Cadmium The kidney is the organ most sensitive to the toxic effects of cadmium. Numerous factorshave been used as indicators of kidney damage by cadmium. One of the early indicators is the presenceof 2-microglobulin, a low-molecular-weight protein that is usually reabsorbed by the proximal tubules.Proximal tubule damage of the nephrons caused by cadmium is also evidenced by glycosuria,aminoaciduria, and the diminished ability of the kidney to secrete PAH. As damage increases, there isan increase in urinary excretion of low- and high-molecular-weight proteins, which predicts anacceleration of the decline in glomerular filtration rate. Workers in factories where nickel/cadmiumbatteries are manufactured and who are exposed to excessive amounts of cadmium oxide exhibitTABLE 6-1. Chemicals with ACGIH TLVs Specifically Set to Prevent Renal EffectsArsineMethyl tert-butyl etherCadmiumMethyl ChlorideChloroformMethyl Chloroform1-chloro-1-nitropropaneMethylcyclohexanolo-Chlorostyrene2-methyl cyclopentadienylHexavalent Chromium Compounds manganese tricarbanol(water soluble)4,4′-methylene bis(2-chloroaniline)Chromyl chlorideMethyl ethyl ketone peroxide†CyclohexaneMethyl isoamyl ketonep-dichlorobenzeneMethyl isobutyl ketone1,1-dichloroethaneNickel, elementalDiethanolamineNitrogen trifluoride1,4-dioxaneOxygen difluorideDiphenylamineParaquatDipropylketonePhenothiazineEpichlorohydrinPhosphorous (yellow)Ethyl bromidePicloramEthylene chlorohydrinPindoneEthylene dibromidePropargyl alcoholEthylene oxidePropylene dichlorideEthyl silicatePyridineHexachlorobutadieneStoddard SolventsHexachloroethane4,4′-thiobis(6-tert-butyl-m-cresol)Hexafluoroacetoneo-TolidineIndeneo-,m-, and p-toluideneIodoform1,2,3-trichloropropaneLeadUraniumLead ArsenateVinylidene chlorideMercury, aryl, inorganic, elementalXylidene (mixed isomers)Mesityl oxide†1998 Notice of Intended Changes includes kidney effects which were not listed previously