The cancer risks (CR) by oral ingestion, dermal absorption, and inhalation exposure of trihalomethanes (THM) from tap water of ten districts in Fortaleza, Brazil were estimated. The mean levels of THM compounds were obtained in Fortaleza tap water as follow: 63.9 microg L(-1) for chloroform (CHCl(3)), 40.0 microg L(-1) for bromodichloromethane (CHBrCl(2)), and 15.6 microg L(-1) for dibromochloromethane (CHBr(2)Cl). Bromoform (CHBr(3)) was not detected. The mean CR for THMs in tap water is 3.96 x 10(-4). The results indicate that Fortaleza residents have a higher CR by inhalation than dermal absorption and oral ingestion. The CR for CHCl(3) contributes with 68% as compared with the total CR, followed by CHBrCl(2) (21%), and CHBr(2)Cl (11%). The hazard index (HI) is about ten times lower than unity, not indicating non-cancer effects.

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The aim of this investigation is to evaluate the influence of glycerol (a nontoxic additive) on Zn-Mn coatings formed by electrochemical deposition. The influence of glycerol (GLY) on the electrodeposition of Zn-Mn alloys on Pt from acid baths was studied by cyclic voltammetry. The coatings were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The Zn-Mn alloys prepared in the absence or presence of this additive showed similar voltammograms except when using GLY and boric acid (BA) concentrations at 0.63 and 0.24 M, respectively. The current efficiency of the Zn-Mn electrodeposition process ranged from 5 to 41%, due to the lowest and highest concentrations of GLY and BA, respectively. SEM images of deposits obtained at -1.53 V from baths containing 0.08-0.48 M GLY were dendritic, while those formed in the presence of 0.63 M GLY showed that GLY acted as a brightener at this concentration. The XRD analysis showed that the electrodeposits contained Zn, Mn, oxides as well as alloys of various compositions. GLY acted as a grain refiner and inhibited the codeposition of Zn with Mn and the formation of oxides.

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