Identification and Comparative Mammalian Cell Cytotoxicity of New Iodo-Phenolic Disinfection Byproducts in Chloraminated Oil and Gas Wastewaters

Abstract

Hydraulic fracturing wastewaters discharged to surface water have led to elevated bromide and iodide levels, as well as enhanced formation of brominated trihalomethanes, haloacetic acids, haloacetonitriles, and iodo-trihalomethanes at downstream drinking water treatment plants, in chlorinated effluent from wastewater treatment plants, and in controlled laboratory studies. This enhanced formation of brominated and iodinated disinfection byproducts (DBPs) raises concerns regarding human health, because they are much more toxic than chlorinated DBPs. This study represents the first nontarget, comprehensive analysis of iodinated DBPs formed in chloraminated produced waters associated with hydraulic fracturing of shale and conventional gas formations. Fifty-six iodo-phenolics were identified, comprising three homologous series of mono-, di-, and tri-iodinated phenols, along with two new classes of DBPs: iodomethylphenols and iododimethylphenols. Four iodo-phenolics (2-iodophenol, 4-iodophenol, 2,4,6-triiodophenol, and 4-iodo-2-methylphenol) were investigated for mammalian cell cytotoxicity. All were cytotoxic, especially 2,4,6-triiodophenol, which was more cytotoxic than all trihalomethanes and most haloacetic acids. In addition, geogenic organic compounds present in the oil and gas produced waters, including methylphenol and dimethylphenol, were found to be potential precursors to these iodo-DBPs.

Enzymatic assays for the assessment of toxic effects of halogenated organic contaminants in water and food. A review

“…Although more than 700 DBPs have been characterised chemically, determination of concentrations and study of their toxicological effects are limited by a lack of chemical standards. Notwithstanding, some of these iodinated compounds have been associated with strong cytotoxic and genotoxic effects in Chinese hamster ovary cell-lines (Duirk et al, 2011;Liberatore et al, 2017;Plewa et al, 2004;Richardson et al, 2008), Sprague-Dawley rat whole embryo culture (Hunter and Tugman, 1995), platynereis dumerilii embryos (Pan et al, 2016;Yang and Zhang, 2013) and Salmonella typhimurium cultures (Plewa et al, 2004). Their widespread presence in water systems and subsequent exposure to them, demands development of robust analytical methodologies for iodinated compounds as well as deeper knowledge about their potentially harmful effects.…”

Dual-Functioning Antibacterial Eugenol-Derived Plasticizers for Polylactide

“…This includes phenolic compounds that simultaneously also can act as antioxidants [ 31 , 32 ] and biocompatibilizers [ 33 ] in polymeric packaging materials. Nevertheless, some phenolic compounds have demonstrated cytotoxicity on mammalian cells and have aroused health concerns about their uses [ 34 , 35 , 36 ]. In addition to the mammalian toxicity, the biodegradation of plasticizers is another important issue when evaluating the full life-cycle of plastics.…”

Iodinated disinfection byproducts: Formation and concerns

“…Oil and gas produced wastewater also showed the potential to form a wide spectrum of iodo-phenols during chloramination reactions. Methylphenol and dimethylphenol, of geogenic origin, were identified as the main precursors of the iodo-phenols formed [15].…”

“…The list of iodo-DBPs being discovered in disinfected waters is continuously expanding due to the increasing availability of advanced sensitive analytical technologies based on high-resolution mass spectrometry [11]. Different approaches have been proposed in the literature for new iodo-DBP identification [10,[12][13][14][15][16].…”