Food Science and Preservation
The Korean Society of Food Preservation
Review

Trichloroethylene and tetrachloroethylene contamination: A review of toxicity, analytical methods, occurrence in foods, and risk assessment

Adebayo J. Akinboyehttps://orcid.org/0000-0003-0549-8867, Hyegyeong Leehttps://orcid.org/0009-0005-1670-4373, Joon-Goo Lee*https://orcid.org/0000-0003-3617-5518
Department of Food Science and Biotechnology, Seoul National University of Science and Technology, Seoul 01811, Korea
*Corresponding author Joon-Goo Lee, Tel: +82-2-970-6742, E-mail: jglee@seoultech.ac.kr

Citation: Akinboye AJ, Lee H, Lee JG. Trichloroethylene and tetrachloroethylene contamination: A review of toxicity, analytical methods, occurrence in foods, and risk assessment. Food Sci. Preserv., 31(3), 360-373 (2024)

Copyright © The Korean Society of Food Preservation. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Mar 03, 2024; Revised: May 07, 2024; Accepted: May 11, 2024

Published Online: Jun 30, 2024

Abstract

Polychlorinated hydrocarbons are continuously released into the environment from various industrial processes. Trichloroethylene (TCE) and tetrachloroethylene (perchloroethylene, PCE) are of primary concern because of their large-scale production, wide industrial application, poor biodegradability, and tendency to circulate in the air and water. The common routes of human exposure to these compounds include inhalation, ingestion, and dermal adsorption. Additionally, they have been detected in various plant foods. Prolonged exposure to these contaminants is associated with certain risks. They are carcinogenic and have other toxic effects, including gastrointestinal, developmental, neurological, and hematological toxicity. To analyze these contaminants, they are generally extracted from various matrices, followed by instrumental analysis. Gas chromatography, often in combination with different detectors, is the most widely used analytical method. This review covers the toxicity, analytical methods, occurrence in foods, and risk assessment of these contaminants.

Keywords: trichloroethylene; tetrachloroethylene; food; toxicity; analytical methods

1. Introduction

Polychlorinated organic compounds have since many years significantly been contributing to water and environmental pollution (Bruckner et al., 1989). Specifically, this issue has been linked to the widespread industrial usage of trichloroethylene (TCE) and tetrachloroethylene, also referred to as perchloroethylene (PCE) (Hughes et al., 1994; Jollow et al., 2009). TCE is a colorless, volatile liquid organic compound that smells like chloroform. It is primarily and most widely used in the degreasing of metal parts (ATSDR, 1997). People who work in the metal industries are therefore frequently exposed to TCE (Bakke et al., 2007). TCE is also employed in various other industries, such as the chemical, dry cleaning, textile, food, agricultural, electrical, and leather processing industries (Bakke et al., 2007; Khan et al., 2009). PCE is a highly volatile and lipophilic solvent that is frequently used in textile, metal, and dry-cleaning operations (Guyton et al., 2014).

Humans are frequently exposed to these substances through the ingestion of foods, breast milk, and plants, inhalation, groundwater contamination, occupational exposure, and other means (Doucette et al., 2007; Lan et al., 2010; Moran et al., 2007). Numerous reports regarding the hazardous properties of these substances have been published. For example, soybean oil meal extracted with TCE resulted in an outbreak of refractory and fatal hemorrhagic toxicity in cattle (Mckinney et al., 1955; Picken et al., 1955). TCE induced metabolic and biochemical transformations in rat tissues (Khan et al., 2009) and reportedly induces Parkinson’s disease (Liu et al., 2018). Exposure to PCE can cause reproductive and developmental defects (Bagnell and Ellenberger, 1977; Beliles, 2002; Bove et al., 2002; Kyyronen et al., 1989; Schwetz et al.1975), hematological toxicity (Seidei et al., 1992), acute and chronic toxicity (Richter et al., 1983), neurobehavioral toxicity (Seeber, 1989) and cardiopulmonary toxicity (Kobayashi et al., 1982). Both TCE and PCE are categorized as Group 2A carcinogens by the International Agency for Research on Cancer (IARC), indicating a potential risk for human cancer (IARC, 2014).

Chromatographic techniques (e.g., gas chromatography and high-performance liquid chromatography) are the most widely used to analyze these substances and their metablites in various media. Other methods include capillary electrophoresis (Ahrer and Buchberger, 1999), ion chromatography (Sarzanini et al., 1999), and high-field asymmetric waveform ion mobility spectrometry (Ells et al., 2000). Common detectors used in their analysis include mass spectrometry (MS) (Brashearl et al., 1997), flame ionization (Xu et al., 1996), electron capture (Forkert et al., 2003; Ketcha et al., 1996; Merdink et al., 1998), ultraviolet (Kim et al., 2001; Martınez et al., 1999), and conductivity (Narayanan et al., 1999) detectors. Common techniques to extract these substances and their metabolites from their matrix include liquid-liquid extraction (Ko et al., 2000), solid-phase microextraction (SPME) (Dehon et al., 2000; Xu et al., 1996), solid-phase extraction (Benanou et al., 1998; Calafat et al., 2003), and protein precipitation (Narayanan et al., 1999).

Several reports have documented the existence of TCE and PCE in various food items and food products, albeit at low concentrations. Furthermore, these harmful substances are associated with specific health hazards. This review aims to provide an overview of the relevant literature regarding the toxicity, analytical techniques, occurrence in foods, and risk assessment of these pollutants.

2. Toxicity

There are several publications concerning the harmful effects of TCE and PCE on experimental animals as well as humans. Some of these harmful effects are highlighted in Tables 1 and 2.

Table 1. Toxic effects of tetrachloroethylene
Subjects Toxic effects References
Mice Sperm head abnormalities Beliles et al. (1980)
Male California dry-cleaning workers Sperm abnormalities Eskenazi et al. (1991)
Pregnant Finnish dry-cleaning women Spontaneous abortion Kyyronen et al. (1989)
Teratology rats Increased resorptions Schwetz et al. (1975)
Two-generation rats Litters with dead pups Tinston (1994)
Two-year-old boy Death Garnier et al. (1996)
Rats Delayed behavioral changes and altered neurotransmitter levels Nelson et al. (1979)
Female dry-cleaning workers Neuropsychiatric tests Ferroni et al. (1992)
6-Year-old male child Severe depression Koppel et al. (1985)
Young male mice Hyperactivity Fredriksson et al. (1993)
Pregnant rats Reduced liver pup Narotsky and Kavlock (1995)
Download Excel Table
Table 2. Toxic effects of trichloroethylene
Subjects Toxic effects References
Male Wistar rats Brain, intestinal, and organ damage Khan et al. (2009)
Rats Central nervous system disturbance Honma et al. (1980b)
Human Permanent paresis of the olfactory nerves, gastric disturbance, liver degeneration, lung hemorrhage, death James (1963)
Human Cranial nerve palsies Buxton and Hayward (1967)
Mouse & rat Genotoxicity and mutagenicity Miller and Guengerich (1983)
Mazzullo et al. (1992)
Nelson and Bull (1988)
Walles (1986)
Human, rats Parkinson’s disease Gash et al. (2008)
Liu et al. (2010)
Guerl et al. (1999)
Human, rats Gastrointestinal effects Liotier et al. (2008)
Moritz et al. (2000)
Vattemi et al. (2005)
Byers et al. (1988)
Tucker et al. (1982)
Download Excel Table
2.1. Trichloroethylene

Male Wistar rats exposed to TCE had severe brain, intestinal, and organ (kidneys and liver) damage as well as altered carbohydrate metabolism and decreased antioxidant activity (Khan et al., 2009). Following the administration of 1,000 mg kg−1 day−1 TCE in corn oil to male Wistar rats for 25 days, urea blood nitrogen, serum creatinine, cholesterol, and alkaline phosphatase levels, which are indicators of liver and kidney toxicity, were increased, whereas serum glucose, inorganic phosphate, and phospholipid levels were decreased (Khan et al., 2009).

Honma et al. (1980b) determined the effects of TCE and PCE exposure on acetylcholine, dopamine, norepinephrine, and serotonin levles in the rat brain. Following exposure at 200, 400, and 800 ppm for 30 days, TCE increased dopamine levels in the striatum, albeit not significantly, whereas PCE had an opposite effect. Both chemicals significantly decreased acetylcholine levels in the striatum in a dose-dependent manner, with a significant effect at 800 ppm (p<0.05). TCE and PCE slightly increased norepinephrine levels in the hypothalamus, whereas TCE reduced norepinephrine levels in the cortex and hippocampus. As for serotonin, a non-significant increase was observed in the cortex and hippocampus following exposure to TCE and PCE (Honma et al., 1980b). These findings indicated that prolonged exposure to these chemicals may disturb the cholinergic neurons present in the central nervous system (Honma et al., 1980b). In a similar experiment, Honma et al. determined the free amino acid content in rat brains following exposure to TCE and PCE. They reported concentration-dependent increases in glutamine, threonine, and serine levels following exposure to PCE, whereas exposure to TCE induced significant increases in the levels of these amino acids at 800 ppm. Exposure to PCE decreased the glutamate content, whereas TCE exposure led to a significant decrease in glutamate at 800 ppm. No significant changes were observed in the contents of taurine, aspartate, and alanine (Honma et al., 1980a).

There is a risk of addiction to TCE inhalation following industrial exposure (James, 1963). Autopsy findings of a person with a TCE inhalation addiction disorder revealed that the addiction can result in permanent paresis of the olfactory nerves, gastric disturbance, fatty degeneration of the liver, lung hemorrhages and ultimately death (James, 1963). Buxton and Hayward (1967) reported that TCE may decompose into a toxic, irreversible substance that can cause cranial nerve palsies. They came to this conclusion based on the effects of inadvertent industrial exposure to TCE by four men, two of whom developed severe multiple cranial nerve palsies, leading to the death of one of them after 51 days (Buxton and Hayward, 1967).

There are numerous reports on the genotoxicity and mutagenicity of TCE. There is evidence that TCE metabolites can bind to and damage DNA (Mazzullo et al., 1992; Miller and Guengerich, 1983). Miller and Guengerich (1983) compared mice and rats exposed to TCE and found that mouse hepatocytes had significantly higher amounts of DNA adducts than hepatocytes. Mitotic recombination and aneuploidy are examples of mutational damage that can be induced by exposure to TCE (Cantelli-Forti and Bronzetti, 1988; Crebelli et al., 1985; Shahin and Von Borstel, 1977). In vivo examination of mouse and rat hepatic and kidney cells showed that TCE or its metabolites can bind to and induce single-strand breaks in DNA in these cells (Mazzullo et al., 1992; Nelson and Bull, 1988). The rate of DNA single-strand breaks differs depending on the species; low-level exposure to TCE more readily induced breaks in mice than in rats (Nelson and Bull, 1988; Walles, 1986).

Evidence suggests that exposure to TCE can induce Parkinson’s disease (Gash et al., 2008; Liu et al., 2010). When TCE was administered systemically to adult Fischer 344 rats, dopaminergic neurons in the substantia nigra pars compacta were lost in a dose-dependent manner, and the rats displayed abnormal rotarod behavior, a marked decrease in mitochondrial complex I activity, higher oxidative stress marker levels, and activated microglia in the nigral region (Liu et al., 2010). One clinical report linked the onset of Parkinson’s disease to occupational exposure to TCE (Guehl et al., 1999). In light of these findings, the authors exposed mice to TCE and measured tyrosine hydroxylase immunoreactivity to assess neuronal death; compared with control mice, those exposed to TCE a significant loss of dopaminergic neurons. (Guehl et al., 1999).

Gastrointestinal effects such as diarrhea, vomiting, and hemorrhagic gastritis can result from exposure to large amounts of TCE (Liotier et al., 2008; Moritz et al., 2000; Vattemi et al., 2005). A 47-year-old woman who intentionally consumed 500 mL of TCE and benzodiazepines suffere a fatal abdominal compartment syndrome, which resulted in multiple organ failure due to abdominal distension (Liotier et al., 2008). Complaints of people exposed to TCE and some other chlorinated hydrocarbons in Woburn, MA, USA included severe nausea, constipation, and diarrhea (Byers et al., 1988). In mice, exposed to 660 mg kg−1 day−1 TCE in water, gas pockets in the intestinal coating and blood in the intestines were observed (Tucker et al., 1982).

2.2. Tetrachloroethylene

To assess the hematological toxicity of PCE, Seidei et al. (1992) exposed mice to 270 and 135 ppm of PCE for 6 h per, 5 days per week, for 11.5 weeks (270 ppm) and 7.5 weeks (135 ppm), follwed by a 3-week exposure-free period. The experiment showed that, while nearly full regeneration occurred during the exposure-free period, peripheral blood neutrophil and lymphocyte counts decreased during the exposure period, and prolonged exposure led to hematopoietic failure in the myeloid and lymphoid cell lines (Seidel et al., 1992; Van Duuren et al., 1979).

Exposure to PCE during early pregnancy is associated with an increased risk of spontaneous abortion, according to a Finnish study in pregnant workers in the dry-cleaning industry (Kyyronen et al., 1989). Female rats exposed to PCE for two weeks (2 h day−1, 5 days week−1, N = 3) fewer fertilized oocytes after mating than control rats, indicating a connection between PCE exposure and fertility (Berger and Horner, 2003). Effects of PCE exposure on human sperm quality have been reported by Eskenazi et al. (1991). The effects included an increased proportion of round sperm, a reduced proportion of narrow sperm, and an increased amplitude of lateral head displacement, resulting in unsteady sperm movement. However, PCE exposure had no effect on the average percentage of motile or abnormally shaped sperm, the volume, number, and concentration of sperm, and did not increase the prevalence of azoospermia or oligospermia (Eskenazi et al., 1991). Some studies have reported decreased birth and fetal body weights as a result of exposure to PCE (Carney et al., 2006; Szakmary et al., 1997; Tinston, 1994).

Kobayashi et al. (1982) reported that PCE exerted cardiopulmonary toxicity in rabbits, cats, and dogs following an intravenous PCE injection. PCE increased the vulnerability of the ventricles to epinephrine-induced extrasystoles, bigeminal rhythms, and tachycardia, with mean threshold dosage levels of 10 mg kg−1, 24 mg kg−1, and 13 mg kg−1 in rabbits, cats, and dogs, respectively. Beyond the threshold dosage levels, the cats suffered acute pulmonary edema whereas the dogs experienced decreased left intraventricular dP/dt(max) (Kobayashi et al., 1982).

Schwetz et al. (1975) exposed Sprague-Dawley rats and Swiss-Webster mice to airborne PCE. The rats showed signs of embryotoxicity due to increased resorption, whereas the mice showed lower fetal body weights, delayed ossification of the skull bone, and increased subcutaneous edema (Schwetz et al., 1975). In another study, increased resorption occurred in pregnant Sprague-Dawley rats exposed to 1,800 ppm of PCE (Nelson et al., 1979).

Bagnell and Ellenberger (1977) reported that exposure to PCE through breast milk resulted in obstructive jaundice and hepatomegaly in a 6-week-old baby whose mother had been exposed to PCE after visiting a dry-cleaning service. After breast feeding was stopped, the baby’s health improved rapidly, and liver function normalized within two years following the exposure.

In Summary, both TCE and PCE are toxic to both humans and experimental animals. Their toxic effects include Parkinson’s disease, spontaneous abortion, reproductive and developmental issues, and cardiopulmonary and gastrointestinal disorders.

3. Analytical methods

TCE and PCE are frequently detected in tandem with other volatile organic chemicals or chlorinated hydrocarbons. Before instrumental analysis, these chemicals generally must be extracted from their matrix. TCE and PCE are mainly analyzed using chromatographic techniques. In particular, headspace GC is often used analytical technique. Common detectors used include electron capture, MS, ultraviolet, flame ionization, and conductivity detectors. Some common analytical methods used for TCE and PCE are summarized in Table 3.

Table 3. Method of analysis of trichloroethylene & tetrachloroethylene
Sample Analyte Sample preparation LOD/LOQ Instrumental analysis References
Food TCE, PCE Digestion, 20N H2SO4 10-50 ppb Headspace GC-ECD Entz and Hollifield (1982)
Food TCE, PCE Digestion, 20N H2SO4 Headspace GC-ECD, GC-MS Entz et al. (1982)
Water TCE, PCE Microextraction GC-FID Ilavský and Barloková (2017)
Food TCE, PCE Purge and trap GC-MS Fleming-Jones and Smith (2003)
Food TCE Solid-phase microextraction 0.035-4.8 ng g−1 GC-MS Cao et al. (2016)
Water TCE Solid-phase microextraction GC-FID Xu et al. (1996)
Water TCE Liquid-liquid extraction 5 ng mL−1 GC-MS Brown et al. (2003b)
Blood TCE Liquid-liquid extraction 5 ng mL−1 GC-MS Brown et al. (2003b)
Water TCE Purge and trap 5 ng mL−1 GC-MS Eichelberger et al. (1990)
Water TCE, PCE Liquid-liquid extraction 30 ng L−1 TCE
25 ng L−1 PCE
GC-ECD Russo et al. (2003)
Blood TCE Solid phase microextraction 1 ng mL−1 GC-MS Dixon et al. (2005)
Olive oil PCE Headspace equilibration 1 pg GC-ECD Van Rillaer and Beernaert (1989)
Olive oil PCE Direct injection 5 ppb Membrane Inlet mass spectrometer Kotiaho et al. (1995)
Fatty and non-fatty foods TCE, PCE Liquid extraction with isooctane, 20% acetone-5% sodium chloride in H3PO4 and isooctane GC-ECD
GC-Hall electrolytic conductivity detection (HECD)
Daft (1988)
Grain and grain-based foods TCE, PCE Purge & trap 0.5 ppb TCE
0.4 ppb PCE
GC-ECD
GC-HECD
Heikes and Hopper (1986)
Download Excel Table
3.1. Extraction and pretreatment

Some of the common extraction techniques used for TCE and PCE include liquid-liquid extraction, acid digestion, microextraction, solid-phase extraction and protein precipitation.

Liquid-liquid extraction is very helpful for extracting TCE and PCE from different matrices as they are lipophilic compounds. For the analysis of drinking water, an organic solvent is added to the sample to facilitate the transfer of TCE and PCE into the organic layer (Brown et al., 2003a; Dewulf and Langenhove, 1999; Russo et al., 2003; Song and Ho, 2003). However, this extraction method often requires large amounts of sometimes toxic solvents. A modified liquid-liquid extraction method involves using large a volume of water (10 L) with 10 ml of n-hexane (Zoccolillo et al., 2004) or room-temperature ionic liquids (Pandey, 2006) for extraction.

Solvent microextraction has received widespread interest as it is a more effective procedure and addresses some of the limitations of liquid-liquid extraction (Psillakis and Kalogerakis, 2003). It uses a lower volume of solvent (~1,000× less) than liquid-liquid extraction, and sample extraction, preconcentration, and introduction occur simultaneously (Dong et al., 2006; Tor and Aydin, 2006; Zhao et al., 2004). The two main types of this extraction technique are single-drop microextraction and liquid-phase microextraction. Dispersive liquid-liquid microextraction is a recent solvent microextraction method developed by Rezaee et al. (2006). This method is advantageous in that the extraction time is reduced because of the large surface area between the solvent and the aqueous phase.

SPME is another extraction technique. It requires an SPME fiber to be inserted into the sample headspace, or immersed in the sample (Kataoka et al., 2000). The analyte adsorbs and is concentrated on the fiber coating. Several studies have adopted SPME using polydimethylsiloxane fiber to analyze TCE in biological samples (Dehon et al. 2000; Dixon et al., 2005; Xu et al., 1996).

Solid phase extraction is commonly used as an alternative to liquid-liquid extraction because it requires less solvent. It is mostly utilized for semi-volatile organic compounds (Delinsky et al., 2005; Kot-Wasik et al., 2004; Santos and Galceran, 2002); very few studies have employed this extraction method for volatile organic compounds because of the possibility of analyte loss due to volatility (Delinsky et al., 2005).

3.2. Instrumental analysis

Skender et al. (1993) used headspace GC to identify TCE and PCE in urine and venous blood samples of 39 patients residing in Zagreb, Croatia, and in drinking water collected from a kitchen tap. The limit of detection (LOD) was 0.020 μg L−1 for TCE and 0.015 μg L−1 for PCE. Entz and Hollifield (1982) developed a similar method involving headspace chromatography and an electron capture detector (ECD) to analyze volatile hydrocarbons, including chloroform, TCE, and PCE in foods. Some samples were digested with 20 N H2SO4, shereas others were not pretreated. Using this technique, the authors found residues of TCE, PCE, and other volatile hydrocarbons in eight food samples, including fish, chocolate sauce, mayonnise, ice cream, and other processed foods (Entz et al., 1982). The GC technique involved the use of three different columns at different stages of the analysis; column 3 was used for initial identification and quantification of residues, column 1 was used for provisional GC confirmation, and column 2 was used for GC-MS confirmation.

Ilavský and Barloková (2012) analyzed TCE, PCE and other chlorinated hydrocarbons in water at concentrations of 1-30 μg L−1 using a microextraction technique that involved manual mixing of the water with 0.5 mL of n-pentane at 5-7°C for 5 min. The analysis was conducted using capillary GC with a flame ionization detector (FID) and ECD.

PCE is of high concern because it can readily transform into trichloroacetic acid, which is a persistent herbicide and a significant cause of forest decline (Frank and Frank, 1989; Frank et al., 1989). Frank and Frank (1989) determined PCE concentrations in spruce needles in southwest Germany. After hexane extraction and separation using capillary GC, detection was achieved using chemical ionization MS. Frank et al. (1989) analyzed one- and two-carbon halocarbons, including TCE and PCE in forest soil and air using thermodesorption, cryogenic trapping, GC on thick-film capillaries, ECD.

TCE and PCE can transition from the air into foods bcause they are major organic pollutants present in the air (Grob et al., 1990). The concentrations of these contaminants in foods and air have been analyzed using headspace techniques with column effluents being detected using an ECD for small quantities, and a FID for large quantities (Grob et al., 1990). Van Rillaer and Beernaert (1989) developed an analytical method to quantitatively determine PCE residues in olive oil samples and other products using headspace chromatography with an ECD. The authors reported the LOD of PCE to be 1 pg, and the concentration exceeded the proposed maximum level of 1 mg kg−1 in only one of the samples analyzed.

Kotiaho et al. (1995) developed a membrane-inlet MS method to rapidly determine styrene and PCE levels in olive oil. A peristatic pump was used to supply a clean stream of olive oil to the membrane inlet at a flow rate of 3.5 mL/min. The injection time was 2 or 3 min, and a wait time of 3-4 min was required after each sample injection, during which the signal returned to the base line level after clean olive oil was pumped through it. The LOD values for styrene and PCE were 100 and 5 ppb, respectively.

Fleming-Jones and Smith (2003) analyzed PCE, TCE, and other volatile organic compounds in 70 food samples using a purge-and-trap procedure in combination with GC-MS. They used a Tekmar 6,000 thermal desorber with 6016 autosampler and a Varian 3,400 GC interfaced with a Saturn II ion trap mas spectrometer for GC-MS.

In summary, this section describes the typical analytical processes for TCE and PCE in various food samples. Generally, instrumental analysis is preceded by an extraction process. Common of extraction methods include solvent microextraction, SPME, and SPE, whereas headspace GC is the most popular instrumental method for the analysis of these compounds.

4. Occurrence in foods

TCE and PCE are widely produced because of their usefulness and application potential in several industries. Because of their toxicity, they have been monitored in water, biological, environmental, and food samples. These chemicals have been detected in breast milk, coffee, yoghurt, margarine, olive oil and other food samples. Table 4 summarizes some studies that have detected these contaminants in various food sources.

Table 4. Occurrence of trichloroethylene & tetrachloroethylene in food samples
Analyte Foods Concentration References
TCE Yoghurt
Ice cream
Butter
Ground beef
Fresh pork
Lamb
Eggs
Poultry chicken/turkey
Fresh water fish
Shellfish
Coffee
Tea
Pizza
<0.34 μg kg−1
<0.92 μg kg−1
<4.1 μg kg−1
<0.61 μg kg−1
<0.42 μg kg−1
<0.83 μg kg−1
<0.34 μg kg−1
<0.25 μg kg−1
<0.30 μg kg−1
<0.43 μg kg−1
<0.05 μg kg−1
<0.06 μg kg−1
0.26 μg kg−1
Cao et al. (2016)
TCE Dairy products
Fats & oils
Ready-to-eat meals
Sugar & confectionary
0.3 μg kg−1
0.1 μg kg−1
0.1 μg kg−1
0.1 μg kg−1
Vinci et al. (2015)
PCE Non-alcoholic drinks
Sauces
Dairy products
Fruits & vegetables
Meat & meat products
Fish & fish products
Cereal products
Cookies and cakes
Fats & oils
Ready-to-eat meals
Sugar & confectionary
Egg
0.2 μg kg−1
3.4 μg kg−1
0.5 μg kg−1
1.8 μg kg−1
0.2 μg kg−1
1.7 μg kg−1
0.1 μg kg−1
2.3 μg kg−1
1.5 μg kg−1
1.7 μg kg−1
6.0 μg kg−1
0.7 μg kg−1
Vinci et al. (2015)
TCE Cakes
Juice
Lactic beverage
Ice cream
Plain yoghurt
Ice milk
0.8 μg kg−1
0.03 μg kg−1
0.03 μg kg−1
0.16 μg kg−1
0.03 μg kg−1
0.3 μg kg−1
Miyahara et al. (1995)
TCE Walnut
Apple
0.06-7.8 μg kg−1
10.9-103.6 μg kg−1
Doucette et al. (2007)
TCE Ground decaffeinated coffee
Brew and grounds from
decaffeinated ground coffee
41-44 μg kg−1
13 μg kg−1
Heikes (1987)
PCE Breast milk
Breast milk
13-75 μg kg−1
31 μg L−1 (after 1 month)
2.2 μg L−1 (after 4 months)
Schreiber et al. (2002)
PCE Breast milk 1.0 mg dL−1 after 24 hr
0.3 mg dL−1 after 44 hr
Bagnell and Ellenberger (1977)
PCE Wheat and wheat products
Corn and corn products
0-2.6 μg kg−1
0-1.8 μg kg−1
Heikes and Hopper (1986)
PCE Dairy products
Meat
Nuts
Fruit & vegetables
Margarine, oils & fats
Baked goods
5-102 μg kg−1
2-60 μg kg−1
7-54 μg kg−1
5-12 μg kg−1
3-42 μg kg−1
2-52 μg kg−1
Fleming-Jones and Smith (2003)
PCE Margarine 1-5 μg kg−1 Entz and Diachenko (1988)
PCE Cereals
Oils
Nuts
Fruit & vegetables
Baked goods
Meat
Dairy products
0-108 μg kg−1
0-21 μg kg−1
0-120 μg kg−1
0-14 μg kg−1
0-48 μg kg−1
0-124 μg kg−1
0-30 μg kg−1
Daft (1988)
Download Excel Table
4.1. Trichloroethylene

Cao et al. (2016) conducted a total diet stuies on the occurrence of volatile organic compounds in foods in Canada. They analyzed 153 composite food samples, and TCE was detected in 31 samples. The mean TCE concentration in the food samples was 0.53 ng g−1, and the highest TCE concentration of 4 ng g−1 was found in potato chips.

In a similar study on the presence of TCE and other volatile organic compounds in foods from markets in Belgium, 377 food samples representing 14 food groups were analyzed. TCE was detected in eight food groups, albeit at low concentrations. Among the total food samples analyzed, the highest percentage of occurrence of TCE (9%) was found for cookies and cakes. The total maximum concentration of TCE in all food categories analyzed was 0.2 μg kg−1, with an occurrence of 2% (Vinci et al., 2015).

Miyahara et al. (1995) detected volatile halogenated organic compounds in 13 food samples obtained from 20 families living in Tokyo. The concentration of TCE ranged from not detectible (ND) to 1.7 μg kg−1 in cakes, from ND to 0.6 μg kg−1 in juice, from ND to 0.5 μg kg−1 in lactic beverage, from ND to 1.3 μg kg−1 in ice cream, from ND to 0.6 μg kg−1 in plain yoghurt, and from ND to 1 μg kg−1 in ice milk. The mean TCE concentrations in cakes, juice, lactic beverage, ice cream, plain yoghurt, and ice milk were 0.8, 0.03, 0.03, 0.16, 0.03, and 0.3 μg kg−1, respectively.

A 3-year monitoring study by Doucette et al. (2007) revealed that TCE in groundwater can migrate into residential communities and be uptaken into vegetables and fruits. In 2001, TCE was detected in 167 fruit (0.4-17.9 μg kg−1) and fruit tree core (0.4-7.5 μg kg−1) samples collected from17 private residential areas. In 2002, TCE was not detected above the method detection limit (MDL) in 300 fruit and vegetables sampled, but it was found in a number of fruit tree cores. In 2003, samples were collected repeatedly from five locations over several months, and trends were the same as in 2002; TCE was not detected above the MDL in fruits, but it was detected in tree cores. TCE concentrations in tree cores during the 3-year study were in the range of 0.6-7.8 μg kg−1 in walnut and 10.9-103.6 μg kg−1 in apple.

Heikes (1987) detected residues of chlorinated solvents, including TCEc in decaffeinated coffees from nine commercial brands. TCE was detected at concentrations up to 44 μg kg−1 in ground decaffeinated coffee and up to 13 μg kg−1 in brews and grounds of decaffeinated ground coffee.

4.2. Tetrachloroethylene

Schreiber et al. (2002) detected PCE in breast milk samples of two nursing mothers who participated in a study to assess PCE exposure levels in residents of an apartment where dry-cleaning services were operated in the USA. Mean PCE concentration in the breast milk of the first mother who had been lactating for 6 weeks before sample collection were in the range of 13-75 μg L−1. The second mother was exposed to PCE throughout her pregnancy but breast milk samples were analyzed 1 and 4 months postpartum, after the dry-cleaning services were discontinued. The PCE concentrations in her breast milk samples were 31 μg L−1 after 1 month and 2.2 μg L−1 after 4 months. Similarly, Bagnell and Ellenberg (1977) detected PCE in the breast milk of a nursing mother 24 h after she was briefly exposed to PCE. The concentration after 24 h was 1.0 mg dL−1, but it decreased to 0.3 mg dL−1 after 48 h, suggesting a selective concentration of chlorinated hydrocarbons in milk.

Vinci et al. (2015) detected PCE alongside other volatile organic compounds in 377 food samples, representative of 14 food groups, from Belgian markets. PCE was detected at higher levels than TCE in 13 out of 14 groups. The only group in which PCE was not detected were alcoholic drinks. The highest maximum TCE concentration (6.0 μg kg−1) was found in the sugar and confectionary group, and the total maximum TCE concentration in all food categories analyzed was also 6.0 μg kg−1, with an occurrence of 24%.

Heikes and Hopper (1986) detected PCE and other compounds used as fumigants in whole grains, milled grain products, and intermediate grain-based foods. The PCE concentration was in the range of 0-2.6 μg kg−1 in wheat and wheat products and 0-1.8 μg kg−1 in corn and corn products.

In a 5-year study volatile organic compounds in 70 food samples, Fleming-Jones and Smith (2003) detected PCE at 5-102 μg kg−1 in dairy products, at 2-60 μg kg−1 in meat, at 7-54 μg kg−1 in nuts, at 5-12 μg kg−1 in fruit and vegetables, at 3-42 μg kg−1 in margarine, oils and fats, and at 2-52 μg kg−1 in baked goods.

Entz and Diachenko (1988) detected residues of PCE and other volatile halocarbons in 70 samples of stick, soft, and diet soft margarines in Washington, DC, USA, using headspace chromatography with ECD. The PCE concentration was in the range of 4-5,000 μg kg−1 in margarines from a store located next to a dry cleaner and 5- 50 μg kg−1 in margarines obtained directly from the producer. The highest concentration of PCE (1-5 μg kg−1) was detected in margarine obtained from a supermarket located next to a dry cleaner.

Daft (1988) analyzed residues of fumigants and industrial chemicals in food samples. In total 10 residues, including PCE, were analyzed in 213 food samples. The concentration range of PCE was in the range of 0-108 μg kg−1 in cereals, 0-21 μg kg−1 in oils, 0-120 μg kg−1 in nuts, 0-14 μg kg−1 in fruits and vegetables, 0-48 μg kg−1 in baked goods, 0-124 μg kg−1 in meat, and 0-30 μg kg−1 in dairy products.

Because of the wide production and use of TCE and PCE, these chemicals have been monitored and detected in numerous food samples. Grains, fruits, vegetables, breast milk, cakes, and dairy products have all been found to contain TCE and PCE at various concentration.

5. Risk assessment

Fan et al. (2009) assessed the risk from exposure to 14 volatile organic compounds in groundwater in Taiwan. Using the multimedia environmental pollutant assessment system, they calculated the specific cancer and non-cancer risks at a 1 μg L−1 exposure level for each of the compounds investigated. The investigators reported that PCE, along with other two compounds, was associated with the highest non-cancer risk, whereas the specific cancer risk of TCE did not exceed the general guidance value of 10−6. Water ingestion, indoor breathing, and skin absorption during bathing contributed the most to exposure risk, whereas with other absorption routes posed insignificant risks.

Metabolites of TCE and of other parent compounds that produce similar metabolites can exert certain health effects similar to those of TCE. Wu and Schaum (2000) reported that the common exposure route of the general population in the USA to TCE is water ingestion or direct inhalation. Average daily intake was estimated to be 2-20 μg day−1 via ingestion and 11-33 μg day−1 via inhalation.

Iritas et al. (2021) used methylated arginine biomarkers to assess the risk of cardiovascular diseases from exposure to TCE in 100 exposed and 98 control subjects. They found a strong correlation (r=0.453, p<0.01) between trichloroacetic acid, a urinary metabolite of TCE, and asymmetric dimethyl arginine, which is a classical risk factor and marker of cardiovascular diseases when present at increased levels. The author concluded that chronic exposure to TCE poses a risk of cardiovascular and other heart diseases.

Drinking water is a common route of exposure to PCE, and certain toxic effects in adults have been reported. Aschengrau et al. (2015) assessed the possible health risks in adults who had been exposed to PCE during gestation or early childhood. The study revealed a 1.8-fold increase in the incidence of cancer, particularly cervical cancer, and a 1.5-fold increase in the incidence of epilepsy in individuals exposed to PCE through contaminated drinking water early in life.

Although results from pharmacokinetic analyses can be inconsistent (lower resultant risks and higher permissible exposure), they have been used in calculations for risk assessment, and to assess the risk of PCE carcinogenicity in mice, rats, and humans (Bois et al., 1990). The median cancer risk estimate for humans exposed consistently to 1 ng L−1 of PCE in air was found to be 1.6 per million, and 0, 0.04, 2.8, and 6.8 per million for the 5th, 25th, 75th, and 95th percentiles, respectively, when considering the uncertainty in the model parameters (Bois et al., 1990).

6. Conclusions

TCE and PCE are polychlorinated volatile organic compounds that have wide industrial applications. As a result, they are common contaminants found in the environment particularly in the air, water, and foods. They have been categorized as carcinogenic, and have a wide range of other toxic effects. Following extraction from their matrix, chromatography is the most common method used to detect of detecting these contaminants. Humans typically come into contact with these toxins via direct inhalation or drinking water, both of which pose certain health risks. In this review, we assessed the toxicity and analytical methods of TCE and PCE, as well as their occurrence in foods and risk assessment.

Acknowledgements

None.

Conflict of interests

The authors declare no potential conflicts of interest.

Author contributions

Conceptualization: Lee JG. Methodology: Akinboye AJ. Formal analysis: Lee H. Writing - original draft: Akinboye AJ. Writing - review & editing: Lee JG.

Ethics approval

This article does not require IRB/IACUC approval because there are no human and animal participants.

Fundings

This research was supported by a grant (23192MFDS297) from the Ministry of Food and Drug Safety.

ORCID

Adebayo J. Akinboye (First author) https://orcid.org/0000-0003-0549-8867

Hyegyeong Lee https://orcid.org/0009-0005-1670-4373

Joon-Goo Lee (Corresponding author) https://orcid.org/0000-0003-3617-5518

References

1.

Agency for Toxic Substances and Diseases Registry (ATSDR) Toxicological Profile for Trichloroethylene Update.:11 1997;

2.

Ahrer W, Buchberger W. Determination of haloacetic acids by the combination of non-aqueous capillary electrophoresis and mass spectrometry. Fresenius J Anal Chem. 365:604-609 1999;

3.

Aschengrau A, Winter MR, Vieira VM, Webster TF, Janulewicz PA, Gallagher LG, Weinberg J, Ozonoff DM. Long-term health effects of early life exposure to tetrachloroethylene (PCE)-contaminated drinking water: A retrospective cohort study. Environ Health. 14:36 2015;

4.

Bagnell PC, Ellenberger HA. Obstructive jaundice due to a chlorinated hydrocarbon in breast milk. Can Med Assoc J. 117:1047-1048 1977;

5.

Bakke B, Stewart PA, Waters MA. Uses of and exposure to trichloroethylene in U.S. industry: A systematic literature review. J Occup Environ Hyg. 4:375-390 2007;

6.

Beliles RP. Concordance across species in the reproductive and developmental toxicity of tetrachloroethylene. Toxicol Ind Health. 18:91-106 2002;

7.

Beliles RP, Brusick DJ, Mecler FJ. Teratogenic-Mutagenic Risk of Workplace Contaminants: Trichloroethylene, Perchloroethylene, and Carbon Disulfide. Litton Bionetics, Incorporated. :210-277 1980;

8.

Benanou D, Acobas F, Sztajnbok P. Analysis of haloacetic acids in water by a novel technique: Simultaneous extraction-derivatization. Water Res. 32:2798-2806 1998;

9.

Berger T, Horner CM. In vivo exposure of female rats to toxicants may affect oocyte quality. Reprod Toxicol. 17:273-281 2003;

10.

Bois FY, Zeise L, Tozer TN. Precision and sensitivity of pharmacokinetic models for cancer risk assessment: Tetrachloroethylene in mice, rats, and humans. Toxicol Appl Pharmacol. 102:300-315 1990;

11.

Bove F, Shim Y, Zeitz P. Drinking water contaminants and adverse pregnancy outcomes: A review. Environ Health Perspect. 110:61-74 2002;

12.

Brashear WT, Bishop CT, Abbas R. Electrospray analysis of biological samples for trace amounts of trichloroacetic acid, dichloroacetic acid, and monochloroacetic acid. J Anal Toxicol. 21:330-334 1997;

13.

Brown SD, Dixon AM, Bruckner JV, Bartlett MG. A validated GC-MS assay for the quantitation of trichloroethylene (TCE) from drinking water. Int J Environ Anal Chem. 83:427-432 2003b;

14.

Brown SD, Muralidhara S, Bruckner JV, Bartlett MG. Trace level determination of trichloroethylene from liver, lung and kidney tissues by gas chromatography-magnetic sector mass spectrometry. J Chromatogr B. 783:319-325 2003a;

15.

Bruckner JV, Davis BD, Blancato JN. Metabolism, toxicity, and carcinogenicity of trichloroethylene. Crit Rev Toxicol. 20:31-50 1989;

16.

Buxton PH, Hayward M. Polyneuritis cranialis associated with industrial trichloroethylene poisoning. J Neurol Neurosurg Psychiatry. 30:511-518 1967;

17.

Byers VS, Levin AS, Ozonoff DM, Baldwin RW. Association between clinical symptoms and lymphocyte abnormalities in a population with chronic domestic exposure to industrial solvent-contaminated domestic water supply and a high incidence of leukemia. Cancer Immunol Immunother. 27:77-81 1988;

18.

Calafat AM, Kuklenyik Z, Caudill SP, Ashley DL. Urinary levels of trichloroacetic acid, a disinfection by-product in chlorinated drinking water, in a human reference population. Environ Health Perspect. 111:151-154 2003;

19.

Cantelli-Forti G, Bronzetti G. Mutagenesis and carcinogenesis of halogenated ethylenes. Ann N Y Acad Sci. 534:679-693 1988;

20.

Cao XL, Sparling M, Dabeka R. Occurrence of 13 volatile organic compounds in foods from the Canadian total diet study. Food Addit Contam Part A. 33:373-382 2016;

21.

Carney EW, Thorsrud BA, Dugard PH, Zablotny CL. Developmental toxicity studies in Crl:CD (SD) rats following inhalation exposure to trichloroethylene and perchloroethylene. Birth Defects Res B Dev Reprod Toxicol. 77:405-412 2006;

22.

Crebelli R, Conti G, Conti L, Carere A. Mutagenicity of trichloroethylene, trichloroethanol and chloral hydrate in Aspergillus nidulans. Mutat Res. 155:105-111 1985;

23.

Daft JL. Rapid determination of fumigant and industrial chemical residues in food. J Assoc Off Anal Chem. 71:748-760 1988;

24.

Dehon B, Humbert L, Devisme L, Stievenart M, Mathieu D, Houdret N, Lhermitte M. Tetrachloroethylene and trichloroethylene fatality: Case report and simple headspace SPME-capillary gas chromatographic determination in tissues. J Anal Toxicol. 24:22-26 2000;

25.

Delinsky AD, Bruckner JV, Bartlett MG. A review of analytical methods for the determination of trichloroethylene and its major metabolites chloral hydrate, trichloroacetic acid and dichloroacetic acid. Biomed Chromatogr. 19:617-639 2005;

26.

Dewulf J, Langenhove HV. Anthropogenic volatile organic compounds in ambient air and natural waters: A review on recent developments of analytical methodology, performance and interpretation of field measurements. J Chromatogr A. 843:163-177 1999;

27.

Dixon AM, Brown SD, Muralidhara S, Bruckner JV, Bartlett MG. Optimization of SPME for analysis of trichloroethylene in rat blood and tissues by SPME-GC/MS. Instrum Sci Technol. 33:175-186 2005;

28.

Dong L, Shen X, Deng C. Development of gas chromatography-mass spectrometry following headspace single-drop microextraction and simultaneous derivatization for fast determination of the diabetes biomarker, acetone in human blood samples. Anal Chim Acta. 569:91-96 2006;

29.

Doucette WJ, Chard JK, Fabrizius H, Crouch C, Petersen MR, Carlsen TE, Chard BK, Gorder K. Trichloroethylene uptake into fruits and vegetables: Three-year field monitoring study. Environ Sci Technol. 41:2505-2509 2007;

30.

Eichelberger JW, Bellar TA, Donnelly JP, Budde WL. Determination of volatile organics in drinking water with USEPA Method 524.2 and the ion trap detector. J Chromatogr Sci. 28:460-467 1990;

31.

Ells B, Barnett DA, Purves RW, Guevremont R. Detection of nine chlorinated and brominated haloacetic acids at part-per-trillion levels using ESI-FAIMS-MS. Anal Chem. 72:4555-4559 2000;

32.

Entz RC, Diachenko GW. Residues of volatile halocarbons in margarines. Food Addit Contam. 5:267-276 1988;

33.

Entz RC, Hollifield HC. Headspace gas chromatographic analysis of foods for volatile halocarbons. J Agric Food Chem. 30:84-88 1982;

34.

Entz RC, Thomas KW, Diachenko GW. Residues of volatile halocarbons in foods using headspace gas chromatography. J Agric Food Chem. 30:846-849 1982;

35.

Eskenazi B, Wyrobek AJ, Fenster L, Katz DF, Sadler M, Lee J, Hudes M, Rempel DM. A study of the effect of perchloroethylene exposure on semen quality in dry cleaning workers. Am J Ind Med. 20:575-591 1991;

36.

Fan C, Wang GS, Chen YC, Ko CH. Risk assessment of exposure to volatile organic compounds in groundwater in Taiwan. Sci Total Environ. 407:2165-2174 2009;

37.

Ferroni C, Selis L, Mutti A, Folli D, Bergamaschi E, Franchini I. Neurobehavioral and neuroendocrine effects of occupational exposure to perchloroethylene. Neurotoxicology. 13:243-247 1992;

38.

Fleming-Jones ME, Smith RE. Volatile organic compounds in foods: A five-year study. J Agric Food Chem. 51:8120-8127 2003;

39.

Forkert PG, Lash L, Tardif R, Tanphaichitr N, Vandevoort C, Moussa M. Identification of trichloroethylene and its metabolites in human seminal fluid of workers exposed to trichloroethylene. Drug Metab Dispos. 31:306-311 2003;

40.

Frank H, Frank W. Uptake of airborne tetrachloroethene by spruce needles. Environ Sci Technol. 23:365-367 1989;

41.

Frank H, Frank W, Thiel D. C1- and C2-halocarbons in soil-air of forests. Atmos Environ. 23:1333-1335 1989;

42.

Fredriksson A, Danielsson BR, Eriksson P. Altered behaviour in adult mice orally exposed to tri-and tetrachloroethylene as neonates. Toxicol Lett. 66:13-19 1993;

43.

Garnier R, Bedouin J, Pepin G, Gaillard Y. Coin-operated dry-cleaning machines may be responsible for acute tetrachloroethylene poisoning: Report of 26 cases including one death. J Toxicol Clin Toxicol. 34:191-197 1996;

44.

Gash DM, Rutland K, Hudson NL, Sullivan PG, Bing G, Cass WA, Pandya JD, Liu M, Choi DY, Hunter RL, Gerhardt GA, Smith CD, Slevin JT, Prince TS. Trichloroethylene: Parkinsonism and complex 1 mitochondrial neurotoxicity. Ann Neurol. 63:184-192 2008;

45.

Grob K, Frauenfelder C, Artho A. Uptake by foods of tetrachloroethylene, trichloroethylene, toluene, and benzene from air. Z Lebensm Unters Forsch. 191:435-441 1990;

46.

Guehl D, Bezard E, Dovero S, Boraud T, Bioulac B, Gross C. Trichloroethylene and parkinsonism: A human and experimental observation. Eur J Neurol. 6:609-611 1999;

47.

Guyton KZ, Hogan KA, Scott CS, Cooper GS, Bale AS, Kopylev L, Barone S, Makris SL, Glenn B, Subramaniam RP, Gwinn MR, Dzubow RC, Chiu WA. Human health effects of tetrachloroethylene: Key findings and scientific issues. Environ Health Perspect. 122:325-334 2014;

48.

Heikes DL. Determination of residual chlorinated solvents in decaffeinated coffee by using purge and trap procedure. J Assoc Off Anal Chem. 70:176-180 1987;

49.

Heikes DL, Hopper ML. Purge and trap method for determination of fumigants in whole grains, milled grain products, and intermediate grain-based foods. J Assoc Off Anal Chem. 69:990-998 1986;

50.

Honma T, Hasegawa H, Sato M, Sudo A. Changes of free amino acid content in rat brain after exposure to trichloroethylene and tetrachloroethylene. Ind Health. 18:1-7 1980a;

51.

Honma T, Sudo A, Miyagawa M, Sato M, Hasegawa H. Effects of exposure to trichloroethylene and tetrachloroethylene on the contents of acetylcholine, dopamine, norepinephrine and serotonin in rat brain. Ind Health. 18:171-178 1980b;

52.

Hughes K, Meek ME, Windle W. Trichloroethylene: evaluation of risks to health from environmental exposure in Canada. J Environ Sci Health Part C. 12:527-543 1994;

53.

International Agency for Research on Cancer (IARC) Trichloroethylene, tetrachloroethylene, and some other chlorinated agents. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. 106 2014;

54.

Ilavsky J, Barlokova D. Analysis of trichloro-and tetrachloro-ethylene in water. Food Environ Saf. 11:29-38 2017;

55.

Iritas SB, Dip A, Gunduzoz M, Tutkun L, Turksoy VA, Deniz S, Tekin G, Oztan O, Unlu A. Assessment of potential cardiovascular risk in trichloroethylene exposure by serum methylated arginine levels. Int J Environ Health Res. 31:63-74 2021;

56.

James WR. Fatal addiction to trichloroethylene. Occup Environ Med. 20:47-49 1963;

57.

Jollow DJ, Bruckner JV, McMillan DC, Fisher JW, Hoel DG, Mohr LC. Trichloroethylene risk assessment: A review and commentary. Crit Rev Toxicol. 39:782-797 2009;

58.

Kataoka H, Lord HL, Pawliszyn J. Applications of solid-phase microextraction in food analysis. J Chromatogr A. 880:35-62 2000;

59.

Ketcha MM, Stevens DK, Warren DA, Bishop CT, Brashear WT. Conversion of trichloroacetic acid to dichloroacetic acid in biological samples. J Anal Toxicol. 20:236-241 1996;

60.

Khan S, Priyamvada S, Khan SA, Khan W, Farooq N, Khan F, Yusufi ANK. Effect of trichloroethylene toxicity on the enzymes of carbohydrate metabolism, brush border membrane and oxidative stress in kidney and other rat tissues. Food Chem Toxicol. 47:1562-1568 2009;

61.

Kim DH, Choi JO, Kim M, Lee DW. Determination of haloacetic acids in tap water by capillary electrophoresis with direct UV detection. J Liq Chromatogr Relat Technol. 24:47-55 2001;

62.

Ko YW, Gremm TJ, Abbt-Braun G, Frimmel FH, Chiang PC. Determination of dichloroacetic acid and trichloroacetic acid by liquid-liquid extraction and ion chromatography. Fresenius J Anal Chem. 366:244-248 2000;

63.

Kobayashi S, Hutcheon DE, Regan J. Cardiopulmonary toxicity of tetrachloroethylene. J Toxicol Environ Health Sci. 10:23-30 1982;

64.

Koppel C, Arndt I, Arendt U, Koeppe P. Acute tetrachloroethylene poisoning-blood elimination kinetics during hyperventilation therapy. J Toxicol Clin Toxicol. 23:103-115 1985;

65.

Kotiaho T, Gylling S, Landing A, Lauritsen FR. Direct determination of styrene and tetrachloroethylene in olive oil by membrane inlet mass spectrometry. J Agric Food Chem. 43:928-930 1995;

66.

Kot-Wasik A, Debska J, Namiesnik J. Monitoring of organic pollutants in coastal waters of the Gulf of Gdansk, Southern Baltic. Mar Pollut Bull. 49:264-276 2004;

67.

Kyyronen P, Taskinen H, Lindbohm ML, Hemminki K, Heinonen OP. Spontaneous abortion and congenital malformations among women exposed to tetrachloroethylene in dry cleaning. J Epidemiol Community Health. 43:346-351 1989;

68.

Lan Q, Zhang L, Tang X, Shen M, Smith MT, Qiu C, Ge Y, Ji Z, Xiong J, He J, Reiss B. Occupational exposure to trichloroethylene is associated with a decline in lymphocyte subsets and soluble CD27 and CD30 markers. Carcinogenesis. 31:1592-1596 2010;

69.

Liotier J, Barbier M, Plantefeve G, Duale C, Deteix P, Souweine B, Coudore F. A rare cause of abdominal compartment syndrome: acute trichlorethylene overdose. Clin Toxicol. 46:905-907 2008;

70.

Liu M, Choi DY, Hunter RL, Pandya JD, Cass WA, Sullivan PG, Kim HC, Gash DM, Bing G. Trichloroethylene induces dopaminergic neurodegeneration in Fisher 344 rats. J Neurochem. 112:773-783 2010;

71.

Liu M, Shin EJ, Dang DK, Jin CH, Lee PH, Jeong JH, Park SJ, Kim YS, Xing B, Xin T, Bing G, Kim HC. Trichloroethylene and Parkinson’s disease: Risk assessment. Mol Neurobiol. 55:6201-6214 2018;

72.

Martınez D, Borrull F, Calull M. Evaluation of different electrolyte systems and on-line preconcentrations for the analysis of haloacetic acids by capillary zone electrophoresis. J Chromatogr A. 835:187-196 1999;

73.

Mazzullo M, Bartoli S, Bonora B, Colacci A, Lattanzi G, Niero A, Silingardi P, Grilli S. In vivo and in vitro interaction of trichloroethylene with macromolecules from various organs of rat and mouse. Res Commun Chem Pathol Pharmacol. 76:192-208 1992;

74.

Mckinney LL, Uhing EH, White JL, Picken JC. Vegetable oil extraction, autoxidation products of trichloroethylene. J Agric Food Chem. 3:413-419 1955;

75.

Merdink JL, Gonzalez-Leon A, Bull RJ, Schultz IR. The extent of dichloroacetate formation from trichloroethylene, chloral hydrate, trichloroacetate, and trichloroethanol in B6C3F1 mice. Toxicol Sci. 45:33-41 1998;

76.

Miller RE, Guengerich FP. Metabolism of trichloroethylene in isolated hepatocytes, microsomes, and reconstituted enzyme systems containing cytochrome P-450. Cancer Res. 43:1145-1152 1983;

77.

Miyahara M, Toyoda M, Ushijima K, Nose N, Saito Y. Volatile halogenated hydrocarbons in foods. J Agric Food Chem. 43:320-326 1995;

78.

Moran MJ, Zogorski JS, Squillace PJ. Chlorinated solvents in groundwater of the United States. Environ Sci Technol. 41:74-81 2007;

79.

Moritz F, De La Chapelle A, Bauer F, Leroy JP, Goulle JP, Bonmarchand G. Esmolol in the treatment of severe arrhythmia after acute trichloroethylene poisoning. Intensive Care Med. 26:256 2000;

80.

Narayanan L, Moghaddam AP, Taylor AG, Sudberry GL, Fisher JW. Sensitive high-performance liquid chromatography method for the simultaneous determination of low levels of dichloroacetic acid and its metabolites in blood and urine. J Chromatogr B Biomed Sci Appl. 729:271-277 1999;

81.

Narotsky MG, Kavlock RJ. A multidisciplinary approach to toxicological screening: II. Developmental toxicity. J Toxicol Env Heal A. 45:145-171 1995;

82.

Nelson BK, Taylor BJ, Setzer JV, Hornung RW. Behavioral teratology of perchloroethylene in rats. J Environ Pathol Toxicol Oncol. 3:233-250 1979;

83.

Nelson MA, Bull RJ. Induction of strand breaks in DNA by trichloroethylene and metabolites in rat and mouse liver in vivo. Toxicol Appl Pharmacol. 94:45-54 1988;

84.

Pandey S. Analytical applications of room-temperature ionic liquids: A review of recent efforts. Anal Chim Acta. 556:38-45 2006;

85.

Picken JC, Jacobson NL, Allen RS, Biester HE, Bennett PC, Mckinney LL, Cowan JC. Vegetable oil extraction, toxicity of trichloroethylene-extracted soybean oil meal. J Agric Food Chem. 3:420-424 1955;

86.

Psillakis E, Kalogerakis N. Developments in liquid-phase microextraction. Trac-Trend Anal Chem. 22:565-574 2003;

87.

Rezaee M, Assadi Y, Hosseini MRM, Aghaee E, Ahmadi F, Berijani S. Determination of organic compounds in water using dispersive liquid-liquid microextraction. J Chromatogr A. 1116:1-9 2006;

88.

Richter JE, Peterson SF, Kleinert CF. Acute and chronic toxicity of some chlorinated benzenes, chlorinated ethanes, and tetrachloroethylene to Daphnia magna. Arch Environ Contam Toxicol. 12:679-684 1983;

89.

Russo MV, Campanella L, Avino P. Identification of halocarbons in the Tiber and Marta rivers by static headspace and liquid-liquid extraction analysis. J Sep Sci. 26:376-380 2003;

90.

Santos FJ, Galceran MT. The application of gas chromatography to environmental analysis. TrAc-Trends Anal Chem. 21:672-685 2002;

91.

Sarzanini C, Bruzzoniti MC, Mentasti E. Preconcentration and separation of haloacetic acids by ion chromatography. J Chromatogr A. 850:197-211 1999;

92.

Schreiber JS, Kenneth Hudnell H, Geller AM, House DE, Aldous KM, Force MS, Langguth K, Prohonic EJ, Parker JC. Apartment residents’ and day care workers’ exposures to tetrachloroethylene and deficits in visual contrast sensitivity. Environ Health Perspect. 110:655-664 2002;

93.

Schwetz BA, Leong BKJ, Gehring PJ. The effect of maternally inhaled trichloroethylene, perchloroethylene, methyl chloroform, and methylene chloride on embryonal and fetal development in mice and rats. Toxicol Appl Pharmacol. 32:84-96 1975;

94.

Seeber A. Neurobehavioral toxicity of long-term exposure to tetrachloroethylene. Neurotoxicol Teratol. 11:579-583 1989;

95.

Seidei HJ, Weber L, Barthel E. Hematological toxicity of tetrachloroethylene in mice. Arch Toxicol. 66:228-230 1992;

96.

Shahin MM, Von Borstel RC. Mutagenic and lethal effects of a-benzene hexachloride, dibutyl phthalate and trichloroethylene in Saccharomyces cerevisiae. Mutat Res-Fundam Mol Mech Mutagen. 48:173-180 1977;

97.

Skender L, Karacic V, Bosner B, Prpic-Majic D. Assessment of exposure to trichloroethylene and tetrachloroethylene in the population of Zagreb, Croatia. Int Arch Occup Environ Health. 65:S163-S165 1993;

98.

Song JZ, Ho JW. Simultaneous detection of trichloroethylene alcohol and acetate in rat urine by gas chromatography-mass spectrometry. J Chromatogr B. 789:303-309 2003;

99.

Szakmary E, Ungvary G, Tatrai E. The offspring-damaging effect of tetrachloroethylene in rats, mice and rabbits. Cent Eur J Med. 3:31-39 1997;

100.

Tinston DJ. Perchloroethylene: A Multigeneration Inhalation Study in the Rat. Zeneca Centr Toxicol Lab. Cheshire, UK. 1994

101.

Tor A, Aydin ME. Application of liquid-phase microextraction to the analysis of trihalomethanes in water. Anal Chim Acta. 575:138-143 2006;

102.

Tucker AN, Sanders VM, Barnes DW, Bradshaw TJ, White KL, Sain LE, Borzelleca JF, Munson AE. Toxicology of trichloroethylene in the mouse. Toxicol Appl Pharmacol. 62:351-357 1982;

103.

Van Duuren BL, Goldschmldt BM, Loewengart G, Smith AC, Melchlonne S, Seldman I, Roth D. Carcinogenicity of halogenated olefinic and aliphatic hydrocarbons in mice. J Natl Cancer Inst. 63:1433-1439 1979;

104.

Van Rillaer W, Beernaert H. Determination of residual tetrachloroethylene in olive oil by headspace-gas chromatography. Z Lebensm-Unters Forsch. 188:221-222 1989;

105.

Vattemi GN, Tonin P, Filosto M, Rizzuto N, Tomelleri G, Perbellini L, Iacovelli W, Petrucci N. Human skeletal muscle as a target organ of trichloroethylene toxicity. JAMA. 294:554-556 2005;

106.

Vinci RM, Jacxsens L, De Meulenaer B, Deconink E, Matsiko E, Lachat C, de Schaetzen T, Canfyn M, Van Overmeire I, Kolsteren P, Van Loco J. Occurrence of volatile organic compounds in foods from the Belgian market and dietary exposure assessment. Food Control. 52:1-8 2015;

107.

Walles SAS. Induction of single-strand breaks in DNA of mice by trichloroethylene and tetrachloroethylene. Toxicol Lett. 31:31-35 1986;

108.

Wu C, Schaum J. Exposure assessment of trichloroethylene. Environ Health Perspect. 108:359-363 2000;

109.

Xu N, Vandegrift S, Sewell GW. Determination of chloroethenes in environmental biological samples using gas chromatography coupled with solid phase micro extraction. Chromatographia. 42:313-317 1996;

110.

Zhao RS, Lao WJ, Xu XB. Headspace liquid-phase microextraction of trihalomethanes in drinking water and their gas chromatographic determination. Talanta. 62:751-756 2004;

111.

Zoccolillo L, Abete C, Amendola L, Ruocco R, Sbrilli A, Termine M. Halocarbons in aqueous matrices from the Rennick Glacier and the Ross Sea (Antarctica). Int J Environ Anal Chem. 84:513-522 2004;