Occurrence and Potential Human-Health Relevance of Volatile Organic Compounds in Drinking Water from Domestic Wells in the United States

Abstract

BackgroundAs the population and demand for safe drinking water from domestic wells increase, it is important to examine water quality and contaminant occurrence. A national assessment in 2006 by the U.S. Geological Survey reported findings for 55 volatile organic compounds (VOCs) based on 2,401 domestic wells sampled during 1985–2002.ObjectivesWe examined the occurrence of individual and multiple VOCs and assessed the potential human-health relevance of VOC concentrations. We also identified hydrogeologic and anthropogenic variables that influence the probability of VOC occurrence.MethodsThe domestic well samples were collected at the wellhead before treatment of water and analyzed for 55 VOCs. Results were used to examine VOC occurrence and identify associations of multiple explanatory variables using logistic regression analyses. We used a screening-level assessment to compare VOC concentrations to U.S. Environmental Protection Agency maximum contaminant levels (MCLs) and health-based screening levels.ResultsWe detected VOCs in 65% of the samples; about one-half of these samples contained VOC mixtures. Frequently detected VOCs included chloroform, toluene, 1,2,4-trimethylbenzene, and perchloroethene. VOC concentrations generally were < 1 μg/L. One or more VOC concentrations were greater than MCLs in 1.2% of samples, including dibromochloropropane, 1,2-dichloropropane, and ethylene dibromide (fumigants); perchloroethene and trichloroethene (solvents); and 1,1-dichloroethene (organic synthesis compound).ConclusionsDrinking water supplied by domestic wells is vulnerable to low-level VOC contamination. About 1% of samples had concentrations of potential human-health concern. Identifying factors associated with VOC occurrence may aid in understanding the sources, transport, and fate of VOCs in groundwater.

Simultaneous assessments of occurrence, ecological, human health, and organoleptic hazards for 77 VOCs in typical drinking water sources from 5 major river basins, China

“…Naphthalene is one of polycyclic aromatic hydrocarbons (PAHs), which was commonly detected in China (Guo et al, 2012;Liu and Zhou, 2011;Ma et al, 2014), while seldom detected in the USA (Carter et al, 2008;Moran et al, 2004;Rowe et al, 2007). For many years, naphthalene had been considered as a non-carcinogenic PAH, but in 2000, the US National Toxicology Program revealed clear evidence of the carcinogenic activity of naphthalene in rats (Preuss et al, 2003).…”

“…As the population and demand for safe drinking water increase, it is important to examine water quality and identify contaminants that occur in source water (Rowe et al, 2007), which are thought to be frequently exposed to large amounts of micropollutants originating from the discharge of anthropogenic activities and natural process (Cho et al, 2014). Volatile organic compounds (VOCs), one contaminant group of concern, could be originated from photochemical and microbial activities (Fink, 2007;Watson, 2004) and introduced to the aquatic environment by emission and combustion (Liu and Zhou, 2011).…”

“…This is not sufficient to identify the most concerned criteria and provide complete hazard information (Liu and Zhou, 2011). To gain a more comprehensive understanding of specific hazards of individual VOC, Rowe et al (2007) have selected candidate VOCs involving multiple criteria, including potential human cancer risks and non-cancer hazards, toxicity to and bioconcentration in aquatic organisms, physical properties and occurrence statistics, use or potential use, and so on. After that, related studies are focusing on ecological and human health risk assessments to evaluate the likelihood of adverse effects as a result of exposure to environmental contaminants (Du et al, 2013;Gao et al, 2012;Yang et al, 2014), especially the risks of natural water (Nganje et al, 2015;Zhu et al, 2015).…”

Effects of permissible maximum-contamination levels of VOC mixture in water on total DNA, antioxidant gene expression, and sequences of ribosomal DNA of Drosophila melanogaster

“…However, these studies generally have focused on the four most common VOC chemicals (benzene, xylene, toluene, and ethylbenzene), and relatively high concentrations were exposed by researchers in order to evaluate the results. Because analyses of drinking-water (Rowe et al 2007) and urine and venous blood samples have revealed that VOCs commonly occur as complex mixtures and that the concentrations of these substances are often very low (10-100 ppb), the purpose of this research was to investigate the genotoxic effects of very low concentrations of VOCs, currently permissible under drinking-water regulations, total DNA, the antioxidant gene expression, and basepair changes in ribosomal genes.…”

Lipid Peroxidation and Changes of Trace Elements in Mice Treated with Paradichlorobenzene

“…Due to its high volatility, a major fraction of pDCB used in the aforementioned products is emitted into the air [2][3][4][5]. Furthermore, trace amounts of pDCB have been found in marine and drinking water [6][7][8], food [9], and honey [10][11][12]. pDCB has also been detected in adipose tissues, blood, and maternal milk [13][14][15], indicating widespread human exposure to this compound.…”