Evaluation of the Effects of Fluoride and Associated With Lead in Animal Model and Physical-Chemical Analysis of Public Supply Water and of the Sinos River in the South of Brazil

Abstract

Fluoride related to caries prevention is at the center of a scientific controversy. Studies show that fluoride causes damage to health and the environment, as well as reducing IQ in children. The fluoridation of drinking water, mandatory in Brazil, has repercussions over the whole society. One of our objectives was to know the concentrations of fluoride (F) and toxic metals of Sinos River, treated water and final consumers of the cities of Campo Bom (CB), Novo Hamburgo (NH) and São Leopoldo (SL), as well as the groundwater from Ivoti, located in southern Brazil. We also evaluated in rats the effects of F and, in association with lead (Pb), on thyroid hormones and the Total Antioxidant Capacity (TAC). Three groups of rats were exposed to different waters: G1-Control with distilled water (DW); G2-DW with 25ppm (F); G3-DW with 25ppm (F) + 30 ppm (Pb). The Sinos River has an average concentration of 0.0735 mg.L-1 of F. But the F of both the water treated by the ETA of SL as well as in the final consumers of SL had concentrations above 0.9 mg.L-1 (State Ordinance No. 10/1999). In addition, we verified the presence of Pb and Cr (VI) in all types of water. The results with the animals showed a significant difference in T3 (p=0.032) and in T4 (p=0.043) from G3 to G1. In TAC, the difference was significant from G2 to G1 and G3 (p=0.007), showing that F and F with Pb interfere with the endocrine and antioxidant functions of rats. In addition, the fact that there are water fluoridation failures shows that the population is exposed to health risks. We confirm that drinking water fluoridation needs to be demystified and reconsidered as a public health intervention.

Evaluation of Reversal and Transposition Generational Damages Caused by Manganese (II) in Zebrafish

“…Sporadically, manganese is also found in drinking water (Alvarez-Bastida et al 2018; Frisbie et al 2012; Krützmann et al 2020) because of the partial removal of this metal during conventional water treatment processes, causing manganese deposition in drinking water distribution systems (Zhou et al 2020). This deposition derives from the manganese concentration in the water source and subsequent transformations that occur in pipes and end up modifying the water color that consumers receive .…”

“…Being one of the main metals polluting the water, manganese occurs naturally in igneous, sedimentary, and metamorphic rocks, although it is also used in the manufacture of iron/steel alloys, batteries, glass, reworks, fertilizers, fungicides, varnishes, and animal supplementation (HSDB 2001; Mena 1980, Patil et al 2016. Due to its widespread use in the industry sector, manganese has been reported in the most varied water resources in Brazil and other countries in the range of mg L -1 (Bacquart et al 2015;Rietzler et al 2001;Kakkoi et al 2016;Krützmann et al 2020;Oliveira and Galvão 2019), mostly occurring in combination with carbonates, sulfates, chlorides, and phosphates, turning its detection di cult (Marsidi et al 2018).…”