Compendium of the most significant studies with reference to properties, intake, effects.

Srasra E, Bekri-Abbes I. Bentonite Clays for Therapeutic Purposes and Biomaterial Design. Curr Pharm Des. 2020;26(6):642-649. doi: 10.2174/1381612826666200203144034. 

Abstract. This review focuses on the promising potential of bentonite clays for biomaterial design and for therapeutic purposes.

Nagahashi E, Ogata F, Saenjum C, Nakamura T, Kawasaki N. Characteristics of Raw and Acid-Activated Bentonite and Its Application for Improving Electrical Conductivity of Tap Water. Chem Pharm Bull (Tokyo). 2021;69(1):92-98. doi: 10.1248/cpb.c20-00703.

Abstract. This study aimed to investigate the characteristics of acid-activated bentonite by focusing on its capability of improving the quality of tap water used during wire electrical discharge machining.

Shu S, Li Y, Zhu W, Wu S, Wu Y, Hou H. Comparing desorption properties of pollutants on bentonite particles and in compacted bentonite. Ecotoxicol Environ Saf. 2021 Mar 15;211:111940. doi: 10.1016/j.ecoenv.2021.111940.

Abstract.  To investigate differences in the desorption characteristics of different pollutants on clay particles and in compacted clay, batch and column desorption tests were conducted using cadmium chloride, fulvic acid, and sodium phosphate as the adsorbates and bentonite as the adsorbent.

Horky P, Gruberova HA, Aulichova T, Malyugina S, Slama P, Pavlik A, Skladanka J, Skoric M, Skalickova S. Protective effect of a new generation of activated and purified bentonite in combination with yeast and phytogenic substances on mycotoxin challenge in pigs. PLoS One. 2021 Oct 27;16(10):e0259132. doi: 10.1371/journal.pone.0259132.

Abstract. The study aimed to investigate the efficacy of new mycotoxin adsorbents based on purified and activated bentonites combined with yeast and phytogenic compounds in fattening pigs. The experiment involved 96 pigs (31.2±2.4 kg). 

Maxim LD, Niebo R, McConnell EE. Bentonite toxicology and epidemiology - a review. Inhal Toxicol. 2016 Nov;28(13):591-617. doi: 10.1080/08958378.2016.1240727. 

Abstract. Bentonite, a clay with numerous industrial and consumer applications, is mined and processed in many countries of the world. Its many beneficial uses also create the potential for widespread occupational and consumer exposure. The available studies on toxicity and epidemiology indicate that the principal exposure pathway of concern is inhalation of respirable dust by occupationally exposed cohorts. Bentonite itself is probably not more toxic than any other particulate not otherwise regulated and is not classified as a carcinogen by any regulatory or advisory body, but some bentonite may contain variable amounts of respirable crystalline silica, a recognized human carcinogen. Therefore, prudent management and adherence to occupational exposure limits is appropriate. This review summarizes the literature available on production, applications, exposure, toxicity, and epidemiology of bentonite and identifies data gaps and limitations.

Wang M, Hearon SE, Phillips TD. A high capacity bentonite clay for the sorption of aflatoxins. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2020 Feb;37(2):332-341. doi: 10.1080/19440049.2019.1662493.

Abstract. Previously a calcium bentonite clay (CB) has been shown to tightly bind aflatoxins in vitro, significantly reduce mortality and morbidity in animals, and decrease molecular biomarkers of aflatoxin exposure in humans and animals. Extensive studies have shown that CB is safe for human and animal consumption. In further work, we have investigated a highly active sodium bentonite (SB) clay (SB-E) with enhanced aflatoxin sorption efficacy compared to CB and other clays. 

Pereira JES, Silva AJF, Nascimento PFP, Ferreira RLS, Barros Neto EL. Carnauba straw powder treated with bentonite for copper adsorption in aqueous solution: isothermal, kinetic and thermodynamic study. Water Sci Technol. 2020 Nov;82(10):2178-2192. doi: 10.2166/wst.2020.491.

Abstract. In this work, the natural and modified carnauba powder from the addition of bentonite was evaluated for the adsorption of Cu(II) ions in synthetic solution. The results showed that the carnauba powder treated with bentonite (CPTB) showed a better percentage of removal of Cu(II) ions when compared to natural carnauba powder (NCP).

O'Neill OJ, Costello J, Sullivan J, Castellon L. Does exposure to bentonite dust during tunnel hyperbaric interventions increase health risks for compressed air workers? A prospective qualitative and quantitative safety assessment. Undersea Hyperb Med. 2019 Jun-Jul-Aug - Third Quarter;46(4):447-459. 

 Abstract. This work demonstrates that compressed-air workers (CAWs) performing tunnel hyperbaric interventions (HIs) may be at risk for hazards related to bentonite exposure, increasing the likelihood of developing harmful illnesses including cancer. Bentonite dust inhalation may result in respiratory levels of silica exceeding acceptable industrial hygiene standards.

Sukenik A, Viner-Mozzini Y, Tavassi M, Nir S. Removal of cyanobacteria and cyanotoxins from lake water by composites of bentonite with micelles of the cation octadecyltrimethyl ammonium (ODTMA). Water Res. 2017 Sep 1;120:165-173. doi: 10.1016/j.watres.2017.04.075. 

Abstract. Cyanobacteria and their toxins present potential hazard to consumers of water from lakes, reservoirs and rivers, thus their removal via water treatment is essential. The capacity of nano-composites of Octadecyltrimethyl-ammonium (ODTMA) complexed with clay to remove cyanobacterial and their toxins from laboratory cultures and from lake water, was evaluated.