Identification of plasticizers in medical products by a combined direct thermodesorption--cooled injection system and gas chromatography--mass spectrometry

Legacy and Emerging Plasticizers and Stabilizers in PVC Floorings and Implications for Recycling

Hazardous chemicals in building and construction plastics can lead to health risks due to indoor exposure and may contaminate recycled materials. We systematically sampled new polyvinyl chloride floorings on the Swiss market (n = 151). We performed elemental analysis by X-ray fluorescence, targeted and suspect gas chromatography-mass spectrometry analysis of ortho-phthalates and alternative plasticizers, and bioassay tests for cytotoxicity and oxidative stress, and endocrine, mutagenic, and genotoxic activities (for selected samples). Surprisingly, 16% of the samples contained regulated chemicals above 0.1 wt %, mainly lead and bis(2-ethylhexyl) phthalate (DEHP). Their presence is likely related to the use of recycled PVC in new flooring, highlighting that uncontrolled recycling can delay the phase-out of hazardous chemicals. Besides DEHP, 29% of the samples contained other ortho-phthalates (mainly diisononyl and diisodecyl phthalates, DiNP and DiDP) above 0.1 wt %, and 17% of the samples indicated a potential to cause biological effects. Considering some overlap between these groups, they together make up an additional 35% of the samples of potential concern. Moreover, both suspect screening and bioassay results indicate the presence of additional potentially hazardous substances. Overall, our study highlights the urgent need to accelerate the phase-out of hazardous substances, increase the transparency of chemical compositions in plastics to protect human and ecosystem health, and enable the transition to a safe and sustainable circular economy.

Leaching of Phthalates from Medical Supplies and Their Implications for Exposure

In this study, 72 single-use medical products, grouped into four categories, namely, creams/liquids (n = 8), medical devices (n = 46; 15 of 46 labeled "di(2-ethylhexyl)phthalate (DEHP)-free"), first aid products (n = 13), and intravenous (IV) infusion/irrigation fluids (n = 5), were collected from an intensive care unit in a hospital in New York State in 2015 and analyzed for the migration of 10 phthalates in ethanol/water (1:1) mixture for 1 h. The total phthalate concentration (Σ_phthalates) leached from medical products ranged from 0.04 to 54,600 μg. DEHP was the major phthalate found in 99% of the samples analyzed, with the highest amount leached from respiratory support devices (median: 6560 μg). DEHP was also found at notable concentrations in products labeled as "DEHP-free". Direct exposure to phthalates from the use of medical devices and first aid supplies and dermal intake from the use of creams/lotions were calculated. The highest DEHP exposure dose of 730 μg/kg bw/day was determined from the use of cannula for neonates. This is the first study to document the amount of phthalates leached from various medical supplies and associated exposures.

Volatile compounds in human breath: critical review and meta-analysis

Volatile compounds contained in human breath reflect the inner workings of the body. A large number of studies have been published that link individual components of breath to disease, but diagnostic applications remain limited, in part due to inconsistent and conflicting identification of breath biomarkers. New approaches are therefore required to identify effective biomarker targets. Here, volatile organic compounds have been identified in the literature from four metabolically and physiologically distinct diseases and grouped into chemical functional groups (e.g. - methylated hydrocarbons or aldehydes; based on known metabolic and enzymatic pathways) to support biomarker discovery and provide new insight on existing data. Using this functional grouping approach, principal component analysis doubled explanatory capacity from 19.1% to 38% relative to single individual compound approaches. Random forest and linear discriminant analysis reveal 93% classification accuracy for cancer. This review and meta-analysis provides insight for future research design by identifying volatile functional groups associated with disease. By incorporating our understanding of the complexities of the human body, along with accounting for variability in methodological and analytical approaches, this work demonstrates that a suite of targeted, functional volatile biomarkers, rather than individual biomarker compounds, will improve accuracy and success in diagnostic research and application.

Testicular dysgenesis syndrome and phthalate exposure: A review of literature

Endocrine disruptors are chemicals that interfere with the body's endocrine system and cause adverse effects in biological systems. Phthalates are a group of man-made chemicals which are mainly used as plasticizers and classified as endocrine disruptors. They are also used in cosmetic and personal care products as color or smell fixators. Moreover, phthalates are present in inks, adhesives, sealants, automobile parts, tools, toys, carpets, medical tubing and blood storage bags, and food packages. Pathological condition known as "testicular dysgenesis syndrome" (TDS) or "phthalate syndrome" is usually linked to phthalate exposure and is coined to describe the rise in alterations in reproductive health in men, such as reduced semen quality (decrease in sperm counts, sperm motility and increase in abnormal sperms), hypospadias, cryptorchidism, reduced anogenital distance and early-life testicular cancer. Phthalates are suggested to cause direct effect on gonadal and non-gonadal tissues, impair the differentiation and morphogenesis of seminiferous tubules and accessory sex organs and testicular cells (both Sertoli and Leydig cells), alter estradiol and/or testosterone levels, decrease insulin-like 3 (INSL3) peptide production, impair spermatogenesis and lead to epigenetic alterations, all of which may lead to TDS. This review will mainly focus on phthalates as causes of TDS and their mechanisms of action.

Risk assessment for humans using physiologically based pharmacokinetic model of diethyl phthalate and its major metabolite, monoethyl phthalate

Diethyl phthalate (DEP) belongs to phthalates with short alkyl chains. It is a substance frequently used to make various products. Thus, humans are widely exposed to DEP from the surrounding environment such as food, soil, air, and water. As previously reported in many studies, DEP is an endocrine disruptor with reproductive toxicity. Monoethyl phthalate (MEP), a major metabolite of DEP in vivo, is a biomarker for DEP exposure assessment. It is also an endocrine disruptor with reproductive toxicity, similar to DEP. However, toxicokinetic studies on both MEP and DEP have not been reported in detail yet. Therefore, the objective of this study was to evaluate and develop physiologically based pharmacokinetic (PBPK) model for both DEP and MEP in rats and extend this to human risk assessment based on human exposure. This study was conducted in vivo after intravenous or oral administration of DEP into female (2 mg/kg dose) and male (0.1-10 mg/kg dose) rats. Biological samples consisted of urine, plasma, and 11 different tissues. These samples were analyzed using UPLC-ESI-MS/MS method. For DEP, the tissue to plasma partition coefficient was the highest in the kidney, followed by that in the liver. For MEP, the tissue to plasma partition coefficient was the highest in the liver. It was less than unity in all other tissues. Plasma, urine, and fecal samples were also obtained after IV administration of MEP (10 mg/kg dose) to male rats. All results were reflected in a model developed in this study, including in vivo conversion from DEP to MEP. Predicted concentrations of DEP and MEP in rat urine, plasma, and tissue samples using the developed PBPK model fitted well with observed values. We then extrapolated the PBPK model in rats to a human PBPK model of DEP and MEP based on human physiological parameters. Reference dose of 0.63 mg/kg/day (or 0.18 mg/kg/day) for DEP and external doses of 0.246 μg/kg/day (pregnant), 0.193 μg/kg/day (fetus), 1.005-1.253 μg/kg/day (adults), 0.356-0.376 μg/kg/day (adolescents), and 0.595-0.603 μg/kg/day (children) for DEP for human risk assessment were estimated using Korean biomonitoring values. Our study provides valuable insight into human health risk assessment regarding DEP exposure.

Biologically Active Contaminants of Intravenous Saline in PVC Packaging: Australasian, European, and North American Samples

We have previously found evidence of contaminants in 0.9% saline packaged in polyvinyl chloride (PVC) for clinical use. For this current study we asked two questions: (1) what are the organic chemical contaminants in solutions packaged in PVC? and (2) do the contaminants vary in bags manufactured in different countries? We studied samples of 0.9% saline packaged in PVC from Australasia, Europe, and North America. We analysed the saline solutions with high-resolution capillary gas chromatography – mass spectrometry. Components of the Australasian and European bags were also analysed using thermodesorption followed by gas chromatography and mass spectrometry. In three pairs of samples we found twenty-four different organic contaminants of the saline solutions. Diethylhexyl phthalate (DEHP) was found in all solutions; the concentrations were greater than 10 μg/l in the Australasian and European samples. All samples contained 2-ethyl hexanol (>50 μg/l), a DEHP breakdown product. The Australasian and North American samples contained cyclohexanone at concentrations of about 1000 μg/l. The cyclohexanone probably originated in joints at the bases of the bags. Both the Australasian and European bags contained t-butyl cyclohexanol (>500 μg/l) and t-butyl cyclohexanone (>50 μg/l). Printing ink on the outside of the bags was the most likely source for both of these contaminants. Several of the contaminants are toxic to animals. Little is known about the toxicity of combinations of contaminants.

Investigation of Drug-Packaging Interactions with Mass Spectroscopy Detectors: A Meta-Synthesis of the Literature

Background

The production of hospital-compounded medicines with a longer shelf life raises questions about drug-packaging interactions, especially desorption events involving extractables and leachables (E/L). A meta-synthesis of the literature was performed to describe which mass spectrometer is suitable for identifying and quantifying E/L.

Methods

A meta-synthesis of studies focused on the identification or quantification of E/L published between January 1997 and December 2017 was performed. Inclusion criteria were E/L studies dealing with pharmaceutical products, in which mass spectrometry (MS) coupled to liquid chromatography (LC) or gas chromatography (GC) was used. The full-text articles had to be available and written in English. Articles about food packaging, environmental contamination, counterfeit compounds, pharmacokinetics, or process-related impurity studies were excluded. Two researchers independently assessed the papers according to a score based on a seven-item questionnaire.

Results

In total, 32 papers matched our criteria and were included in the meta-synthesis. For qualitative analysis with LC, quadrupole time-of-flight (QTOF; n=4) and ion trap (n=4) mass detectors were used the most; and with GC, single quadrupole (n=8). For quantification studies with LC, QTOF (n=3) and triple quadrupole (n=2) were used the most; and with GC, single quadrupole (n=7).

Conclusions

For simultaneous qualitative and quantitative analysis of E/L with LC, QTOF or Orbitrap is a suitable detector. For quantitative analysis with LC only, triple quadrupole is suitable. For qualitative and quantitative analysis with GC, single quadrupole can be used.

Evaluation of repeated exposure systemic toxicity test of PVC with new plasticizer on rats via dual parenteral routes

Systemic toxicity caused by repeated exposure to both polar and nonpolar leachables of di(2-ethylhexyl)-1,2-cyclohexane plasticized polyvinyl chloride (PVC) was evaluated with dual routes of parenteral administration method on rats in the study. Experimental group and control group were designed by researchers. Tail intravenous injection with 0.9% sodium chloride injection extracts and intraperitoneal injection with corn oil extracts were conducted to the experimental rats while tail intravenous injection with 0.9% sodium chloride Injection and intraperitoneal injection with corn oil were conducted to the control rats. After 14 days, blood specimens were collected for clinical pathology (hematology and clinical chemistry) analysis. Selected organs were weighed and a histopathological examination was conducted. As a result, compared with the control animals, there were no toxicity-related changes on the parameters above. The results show that the rats do not show obvious systemic toxicity reaction caused by repeated exposure with dual routes of parenteral administration method on rats after administration with both polar and nonpolar exacts of di(2-ethylhexyl)-1,2-cyclohexane plasticized PVC simultaneously up for 14 days.

Development and Validation of Gas Chromatography-Triple Quadrupole Mass Spectrometric Method for Quantitative Determination of Regulated Plasticizers in Medical Infusion Sets

A method for the quantitative determination of dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), bis(2-ethylhexyl) adipate (DEHA), bis(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DNOP), dioctyl terephthalate (DOTP), diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP) in medical infusion sets was developed and validated using gas chromatography coupled with triple quadrupole mass spectrometry (GC-MS/MS) in the multiple reaction monitoring (MRM) mode. Solvent extraction with polymer dissolution for sample preparation was employed prior to GC-MS/MS analysis. Average recoveries of the eight target analytes are typically in the range of 91.8-122% with the relative standard deviations of 1.8-17.8%. The limits of quantification (LOQs) of the analytical method were in the ranges of 54.1 to 76.3 ng/g. Analysis using GC-MS/MS provided reliable performance, as well as higher sensitivity and selectivity than GC-MS analysis, especially for the presence of minority plasticizers at different concentrations.

Co-liquefaction with acetone and GC analysis of volatile compounds in exhaled breath as lung cancer biomarkers

Introduction: A simple, rapid and low cost method for enrichment of volatile organic compounds (VOCs) from exhaled breath (EB) is presented.

Methods: A 1000 mL home-made extraction device was filled with EB. The VOCs were extracted and condensed in 0.5 mL acetone. Recognition of volatiles in the real studied EB samples was performed by a GC-MS.

Results: The method displays an extraction efficiency of >86% with the enrichment factor of 1929 for octanal. Limits of detection and quantification, and linear dynamic range were 0.008, 0.026 and 0.026-400 ng/mL respectively. Analysis of real samples showed the existence of more than 100 compounds in EB of healthy volunteers and patients with lung cancer before and after treatment. Exhaled octanal concentration was significantly higher in lung cancer patient than in healthy volunteers and lung cancer patient after treatment.

Conclusion: Having used the proposed approach, high extraction recovery (up to 86%) was attained for the lung cancer marker, octanal, as an important biomarker. Our findings on smaples of EB of healthy controls and patients with lung cancer before and after treatment provide complelling evidence upon the effectiveness of the developed method.

The insect repellents: A silent environmental chemical toxicant to the health

In recent years, a large number of insect repellents have been developed with the idea of consumer benefits. In addition to already known advantageous application of insect repellents, there is increasing concern about the potential toxicity in environment leading to health caused by random use of these compounds. An increasing number of evidence suggests that insect repellents may trigger undesirable hazardous interactions with biological systems with a potential to generate harmful effects including intermediate metabolites. Biotransformation followed by bioaccumulation (vice e versa) may be an important phenomenon for toxic response of this chemicals. In this review, we have summarized the current state of knowledge on the insect repellent toxicity, including biochemical pathway alteration under in vitro and in vivo conditions considering different classes of organisms, from lower to higher vertebrate. Furthermore, we have tried to incorporate the effects of insect repellent in light of some clinical reports. We hope this review would provide useful information on potential side effects of uncontrolled use of insect repellents.

Synthetic phenolic antioxidants, including butylated hydroxytoluene (BHT), in resin-based dental sealants

Resin-based dental sealants (also referred to as pit-and-fissure sealants) have been studied for their contribution to bisphenol A (BPA) exposure in children. Nevertheless, little attention has been paid to the occurrence of other potentially toxic chemicals in dental sealants. In this study, the occurrence of six synthetic phenolic antioxidants (SPAs), including 2,6-di-tert-butyl-4-hydroxytoluene (BHT), 2,6-di-tert-butyl-4-(hydroxyethyl)phenol (BHT-OH), 3,5-di-tert-butyl-4-hydroxy-benzaldehyde (BHT-CHO), 2,6-di-tert-butylcyclohexa-2,5-diene-1,4-dione (BHT-Q), 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH) and 2-tert-butyl-4-methoxyphenol (BHA), was examined in 63 dental sealant products purchased from the U.S. market. BHT was found in all dental sealants at median and maximum concentrations of 56.8 and 1020µg/g, respectively. The metabolites of BHT and BHA were detected in 39-67% of samples, at concentration ranges of <LOQ to 242µg/g. BHT is likely used in sealants to inhibit oxidative reactions, remove free radicals, and inhibit potential polymerization, which would eventually prolong the shelf-life of the products. The estimated daily intake (EDI) of BHT, following sealant placement, based on a worst-case scenario (application on eight teeth at 8mg each tooth), was 930 and 6510ng/kg bw/d for adults and children, respectively. The EDI of BHT from dental sealants was several orders of magnitude lower than the current acceptable daily intake (ADI) proposed by the European Food Safety Authority (EFSA).

Non-destructive plasticizer screening using a direct inlet probe-atmospheric pressure chemical ionization source and ion trap mass spectrometry

RATIONALE

In recent years, several ambient ionization techniques, where solid and/or liquid samples are brought directly into the ion source without any sample preparation and chromatographic separation, have been introduced for mass spectrometric (MS) analyses. Using the direct inlet probe-atmospheric pressure chemical ionization (DIP-APCI)-MS and DIP-APCI-MS(n) methods presented here, a non-destructive screening analysis for plasticizers directly from plastic articles can be performed.

METHODS

The DIP-APCI ion source developed in our laboratory uses a temperature-programmed push rod to introduce solid or liquid samples into a homemade APCI ion source. The DIP-APCI ion source was coupled to an ion trap (IT) mass spectrometer and selected source parameters were optimized. To enable a screening analysis for plasticizers, standards substances of several phthalates and other plasticizers were analyzed and their fragmentation behavior during collision-induced dissociation (CID) was studied.

RESULTS

Using DIP-APCI-ITMS, plasticizers can be detected directly from plastic articles and identification is possible through MS(n) experiments. For example, the isomeric phthalates di(2-ethylhexyl) phthalate and di-n-octyl phthalate can be differentiated according to their fragmentation behavior.

CONCLUSIONS

There are several advantages of the DIP-APCI source in comparison to many other ambient desorption ion sources: (i) well-defined gas phase matrix, (ii) precisely adjustable reagent gases (e.g. O2 for negative APCI), (iii) well-defined probe temperature, and (iv) fully automated operation.

Determination of phthalate esters in cow milk samples using dispersive liquid-liquid microextraction coupled with gas chromatography followed by flame ionization and mass spectrometric detection

A simple and economic method for the analysis of phthalate esters, dimethyl phthalate, diethyl phthalate, di-iso-butyl phthalate, di-n-butyl phthalate, and di-2-ethylhexyl phthalate in cow milk samples by means of gas chromatography-flame ionization detection and gas chromatography-mass spectrometry has been developed. In this work, NaCl and ACN were added to 5 mL of the milk sample as the salting out agent and extraction solvent, respectively. After manual shaking, the mixture was centrifuged. In the presence of NaCl, a two-phase system was formed: upper phase - acetonitrile containing phthalate esters -and lower phase - aqueous phase containing soluble compounds and the precipitated proteins. After the extraction of phthalate esters from milk, a portion of supernatant phase (acetonitrile) was removed, mixed with 1,2-dibromoethane at microliter level and injected by syringe into NaCl solution. After the extraction of the selected phthalate esters into 1,2-dibromoethane, phase separation was performed by centrifugation and the enriched analytes in the sedimented phase were determined by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. Under the optimum extraction conditions, low limits of detection and quantification between 1.5-3 and 2.5-11 ng/mL, respectively was observed. Enrichment factors were in the range of 397-499. The relative standard deviations for the extraction of 100 ng/mL of each phthalate ester were in the range of 3-4% (n = 6). Finally, some milk samples were successfully analyzed using the proposed method and two analytes, di-n-butyl phthalate and di-2-ethylhyxel phthalate, were determined in them in nanogram per milliliter level.

Presence of phthalate esters in intravenous solution evaluated using gas chromatography-mass spectrometry method

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the production of poly-(vinyl) chloride (PVC) materials. It is a reproductive and developmental toxicant in animals and a suspected endocrine modulator in humans. DEHP is not covalently bound within the PVC molecule, which is why migration into a suitable medium can be expected. Since application of infusion solutions is one of the most common medical treatments, the objective of this study was to determine the migration of phthalates from softened PVC storage bags into infusion solution in different time periods within one year from date of production using a gas chromatography-mass spectrometry method. The measured values of DEHP ranged between 0.22 and 14.00 µg l(-1) , but the unexpected presence of other phthalate esters was also detected. It was concluded that values obtained in infusion solutions match the reference data and represent a minor risk for the patient. The presence of other phthalate esters leads to the conclusion that the pharmacopeic requirement for polymer cleanness was not fully met. Since phthalate esters are among the most extensively used industrial chemicals and are widely distributed in the environment, special precautions and further monitoring should be conducted to minimize any possible health risks.

Effect of phthalate esters on the secretion of prostaglandins (F2alpha and E2) and oxytocin in cultured bovine ovarian and endometrial cells

The influence of phthalate esters di-2-ethylhexyl phthalate (DEHP) and mono-2-ethylhexyl phthalate (MEHP) on uterine prostaglandin (PGF2alpha and PGE2) and ovarian oxytocin secretion was investigated. Endometrial, granulosa, and luteal cells from cows on days 8-12 of the estrous cycle were treated with DEHP or MEHP (0.1, 1, or 10 ng/mL). We found that DEHP and MEHP stimulated (P < 0.05) secretion of PGF2alpha and inhibited (P < 0.001) secretion of PGE2 from endometrial cells. The ratio of PGF2alpha to PGE2 was markedly altered. The endocrine disrupting chemicals also enhanced secretion of oxytocin (P < 0.05) from ovarian cells. Our results indicated that DEHP and its metabolite MEHP could affect the process of the estrous cycle by impairing secretion of prostaglandin from the uterus and oxytocin from the ovary.

Breath gas aldehydes as biomarkers of lung cancer

There is experimental evidence that volatile substances in human breath can reflect presence of neoplasma. Volatile aldehydes were determined in exhaled breath of 12 lung cancer patients, 12 smokers and 12 healthy volunteers. Alveolar breath samples were collected under control of expired CO(2). Reactive aldehydes were transformed into stable oximes by means of on-fiber-derivatization (SPME-OFD). Aldehyde concentrations in the ppt and ppb level were determined by means of gas chromatography-mass spectrometry (GC-MS). Exhaled concentrations were corrected for inspired values. Exhaled C(1)-C(10) aldehydes could be detected in all healthy volunteers, smokers and lung cancer patients. Concentrations ranged from 7 pmol/l (161 pptV) for butanal to 71 nmol/l (1,582 ppbV) for formaldehyde. Highest inspired concentrations were found for formaldehyde and acetaldehyde (0-55 nmol/l and 0-13 nmol/l, respectively). Acetaldehyde, propanal, butanal, heptanal and decanal concentrations showed no significant differences for cancer patients, smokers and healthy volunteers. Exhaled pentanal, hexanal, octanal and nonanal concentrations were significantly higher in lung cancer patients than in smokers and healthy controls (p(pentanal) = 0.001; p(hexanal) = 0.006; p(octanal) = 0.014; p(nonanal) = 0.025). Sensitivity and specificity of this method were comparable to the diagnostic certitude of conventional serum markers and CT imaging. Lung cancer patients could be identified by means of exhaled pentanal, hexanal, octanal and nonanal concentrations. Exhaled aldehydes reflect aspects of oxidative stress and tumor-specific tissue composition and metabolism. Noninvasive recognition of lung malignancies may be realized if analytical skills, biochemical knowledge and medical expertise are combined into a joint effort.

The indoor air pollutant 2-ethyl-hexanol activates CD4 cells

It has been reported that the numbers of people suffering from occupational asthma and skin rashes triggered by various chemicals in indoor air have increased markedly. Two-ethyl-hexanol (2-EH) is known to be an indoor air pollutant and its influence on health is of great concern. However, there are only a few reports regarding its effect on immune cells. Thus, we investigated the effects of 2-EH on immune responses in vitro with respect to effects on regulation of transcription factors as well as on 2-EH induced proliferation of spleen cells in vitro. The production of interleukin (IL)-6 and immunoglobulin were not induced by 2-EH. To characterize the effector cells of 2-EH, we prepared CD4-positive, CD8-positive, and peritoneal exudate cells (PEC). IL-2 was induced by 2-EH in CD4 cells, but not in CD8 cells. CD3-induced IL-2 expression was enhanced by 2-EH in CD4 cells, but not in CD8 cells. Moreover, IL-6 production was not induced by 2-EH in PEC. Nuclear factor-kappa B, nuclear factor of activated T, and signal transducer and activator of transcription-5 were activated by 2-EH in CD4 cells. Taken together, 2-EH activated CD4 cells, where this was accompanied by the activation of transcription factors. This suggested that the indoor pollutant 2-EH could function as a modulator of immune response.

Toxicity study of maternal transfer of polychlorinated biphenyls and diethyl phthalate to 21-day-old male and female weanling pups of Wistar rats

Polychlorinated biphenyls (PCBs) are environmental pollutants known to act as xenoestrogens. PCBs and diethylphthalate (DEP) are ubiquitous environmental pollutants because both are used as plasticizers and in various other industrial applications. Therefore, a study was undertaken to evaluate the interactive toxicity of DEP and PCB in 21-day-old male and female pups of Wistar rats. Healthy young male and female albino rats of Wistar strain weighing 75-100g (6-7 weeks old) were randomly assigned to four groups of six each. Group I male and female rats were fed a normal diet and water ad libitum. Group II and III male and female rats were given PCB (Clophen A60) and DEP dissolved in corn oil mixed with the diet at 50 mg/kg of the diet (2.85 mg/kg body wt) individually to each group. Group IV male and female rats received a mixture of DEP and PCB (Clophen A60), each dissolved in corn oil mixed with the diet at 50 mg/kg of the diet (2.85 mg/kg body wt). Hundred days after the treatment, females were mated with males for 10 days. Exposure to DEP and PCB was continued throughout mating, gestation until termination at weaning, which was 150 days of total treatment period of adults. The pups from each group were then segregated on the basis of their sex. Six male and female pups each (approx. 21 days old) from each group were chosen randomly and were killed for toxicity study. Liver-to-body weight ratio showed significant increase in the male and female pups of PCB- and PCB+DEP-treated rats, whereas male pups of DEP alone treated rats showed significant increase and female pups showed significant decrease as compared to controls and other treated groups. Significant increase in liver and serum lactate dehydrogenase (LDH) and acid phosphatase (ACP) activity in the male and female pups of the three treated groups was observed. Alkaline phosphatase (ALP) activity was significantly increased only in the serum of male and female pups of the three treated groups, whereas significant decrease in the liver of male pups of the three treated groups. In the female pups, significant decrease in liver ALP was observed only PCB- and PCB+DEP-treated groups. Histology of liver showed severe vacuolation and steatosis in the hepatocytes of PCB-treated male and female pups and in PCB+DEP-treated group, vacuolation, and steatosis was much more predominant as compared to the PCB and DEP alone treated groups. DEP alone treated groups, both male and female pups showed mild vacuolations in the liver. A synergistic interactive toxic effect of PCB and DEP was evident in both male and female pups in the following study.

Chronic toxicity of diethyl phthalate-A three generation lactational and gestational exposure study on male Wistar rats

Diethyl phthalate (DEP) is widely used in the perfume industry as a vehicle for fragrances and in personal care products making human exposure of DEP significant to adults as well as neonatals, as confirmed by levels recorded in blood as well as breast milk samples of human populations in some parts of the world. Therefore, a study was undertaken to understand the toxic effect of DEP over three generations in male Wistar rats. Healthy male and female albino rats of Wistar strain weighing 75-100g (6-7 weeks old) were randomly assigned to two groups of six each. Group I (Control) male and female rats were fed on normal diet and water ad libitum. Group II (DEP) male and female rats were given DEP dissolved in corn oil mixed with the diet at 50mg/kg of the diet/day. Hundred days after the treatment, females were mated with males for 10 days. Exposure to DEP was continued throughout mating, gestation until termination at weaning, which was 150 days of total treatment period of the parental generation. The F1 and F2 generation pups were then segregated on the basis of their sex and six male and female pups of both generations were allowed to grow till they were 75-100g in weight. The treatment was then carried out similar to the parental generation but with reduced dose of 25mg/kg of the diet/day for F1 generation and 10mg/kg of the diet/day for F2 generation. Hundred days after the treatment, females were mated with males for 10 days. Exposure to DEP was continued throughout mating, gestation (21 days) until termination at weaning (21 days), which was 150 days of total treatment period of the F1 and F2 generation. Liver and serum ALT, AST and triglycerides were significantly increased over the three generations, which was much more significant in the F2 generation DEP treated group. The serum cholesterol and liver glutathione and glutathione reductase showed a significant decrease over the three generations, which was much more significant in the F2 generation DEP treated group as compared to the parental and F1 generation DEP treated rats. Histology of the liver showed remarkably enhanced fatty degeneration in the F2 generation DEP treated rats as compared to parental and F1 generation DEP treated rats. Vacuolations were much more significant in the F1 generation DEP treated rats as compared to the controls and F2 generation DEP treated rats. It can be concluded from this study, that continuous exposure through food, gestation and lactation over three generation's inspite of dose reduction of DEP leads to an enhanced toxic effect in the latter generations.

Studies of uptake, elimination, and late effects in Atlantic salmon (Salmo salar) dietary exposed to Di-2-ethylhexyl phthalate (DEHP) during early life

The phthalate esters are a group of industrial chemicals considered to have endocrine-disrupting properties. The most common tonnage product among these, di-2-ethylhexyl phthalate (DEHP), is widely spread in the environment. The objectives with the present work were to study uptake and metabolism of orally administered DEHP and its major metabolite mono-2-ethyl hexyl phthalate (MEHP) and to evaluate the impact of early life exposure on sex differentiation in Atlantic salmon. The feeding with contaminated diet started immediately after yolk sac resorption and continued for 4 weeks. Nominal concentrations of DEHP in the diet were 400 (measured 359), 800 (measured 827), and 1500 (measured 1648) mg DEHP/kg and a control group was fed food mixed with solvent. After the exposure period, fish were fed non-contaminated diet until final sampling 4 months post-exposure. There were no effects on growth or survival of the fish and no late effects on hepatosomatic index or sex ratio. However, the histological examination of gonads from fish exposed to 1500 mg DEHP/kg revealed a small but significant incidence (3%) of intersex fish (ovo-testis). Chemical residues of DEHP and MEHP were analyzed weekly during the first 3 months of the post-exposure period. Both DEHP and MEHP were rapidly eliminated to near background levels within one week post exposure. The study indicates that exposure of Atlantic salmon to relatively high concentrations of DEHP during a sensitive part of the life cycle may interfere with gonad differentiation.

A two-generation chronic mixture toxicity study of Clophen A60 and diethyl phthalate on histology of adrenal cortex and thyroid of rats

This study was undertaken to observe the type of interaction that exists between polychlorinated biphenyls (Clophen A60) and diethyl phthalate (DEP) on the adrenal and thyroid glands of male and female Wistar rats. Animals were divided into four groups of six animals each, group I male and female rats were fed on a normal diet and water ad libitum. Groups II, III and IV male and female rats were given Clophen A60, DEP, or mixture of Clophen A60 and DEP, respectively, each dissolved in corn oil mixed with the diet at 50mg/kg of the diet/day. One hundred days after treatment, females were mated with males for 10 days. Exposure to the pollutants was continued throughout mating, gestation (21 days) until termination at weaning (21 days), which was 150 days of total treatment period of the parental generation. When the F1-generation pups (six males and six females of each group) were 75-100g in weight, they were treated in a similar manner to the parental generation, again for a period of 150 days, with the dose reduced to 25mg/kg of the diet/day in all treated groups. After 150 days of treatment, animals were sacrificed and histology of the adrenal and thyroid glands was asessed. An antagonistic interactive effect of treatment was seen in male parental and F1-generation rats, while an inhibitory type of interactive effect was observed in female rats. In the zona fasciculata region of the adrenal cortex of treated rats of both generations, vacuolations and degeneration were seen in samples from male animals and intracellular vacuolations in samples from females. A synergistic interactive toxic effect to the thyroid gland was observed in treated parental generation male rats, and mild changes in F1-generation-treated male rats, showing follicular shrinkage, loss of thyroglobulin and fibrosis of the interfollicular epithelium. In females, an antagonistic effect to the thyroid gland was observed in both parental and F1-generation-treated rats, showing similar effects as observed in males. From this study, we can conclude that combined administration of Clophen A60 and DEP shows an enhanced toxic effect on adrenal glands of F1-generation male and female rats, but the effect is much more marked in the thyroid gland of F1-generation male rats, and seen to a lesser extent in F1-generation female rats.

Chronic toxicity of diethyl phthalate in male Wistar rats—A dose–response study

Diethyl phthalate (DEP) is widely used in personal care products, plastics and medical devices at various concentrations, but its information is limited on its toxicity associated with exposure at high as well as low doses for a prolonged period. Therefore, a study was undertaken to understand the dose-response toxic effect of DEP in male Wistar rats. Control rats were fed on normal diet and water ad libitum. Rats were given DEP dissolved individually in corn oil mixed with the diet at 10, 25 and 50 mg/kg of the diet/day, which is equal to 0.57, 1.425 and 2.85 mg/kg body wt/day. After 5 months of treatment animals were sacrificed, enzymes and other biochemical parameters in the serum and liver were assessed. Liver weight to body weight ratio showed a significant increase only in 10 ppm DEP treated rats. A significant increase was observed in the serum ACP, LDH, ALT enzyme levels of 10 mg/kg treated rats as compared to control, 25 and 50 mg/kg treated rats. Other biochemical parameters like glycogen, total cholesterol, total triglycerides and lipid peroxidation were also increased in the liver of all the three treated groups. In the 10 and 50 mg/kg diet/day treated rats, there was a significant decrease in liver total GSH as compared to controls and 25 mg/kg treated rats. Histology of liver showed severe vacuolations, fatty degeneration and loss of hepatic architecture in the 10mg/kg treated rats, whereas in the 25 and 50 mg/kg treated rats only loss of hepatic architecture and granular deposits in the hepatocytes was predominant. Histology of liver by electron micrographs showed a significant dose-dependent proliferation of mitochondria in the hepatocytes, while the 10mg/kg treated rats showed increased number of peroxisomes in the hepatocytes. It is evident from this study that treatment with higher concentrations of DEP results in mitochondrial proliferation as well as accumulation of glycogen, cholesterol and triglycerides within the liver, but exposure to lower concentrations for longer periods results in increase in peroxisome numbers leading to severe hepatocellular changes which can be confirmed by significantly increased liver weights, elevated enzyme levels in the serum and liver and impaired metabolism of glycogen, cholesterol and triglyceride as well as altered liver histology.

Combined and individual administration of diethyl phthalate and polychlorinated biphenyls and its toxicity in female Wistar rats

Polychlorinated biphenyls (PCBs) are persistent environmental pollutants and known to act as xenoestrogens. PCBs and diethyl phthalate (DEP) are ubiquitous environmental pollutants because both are used as plasticizers and in various other industrial applications. Therefore, a study was undertaken to evaluate the interactive toxicity of DEP and PCBs in young female Wistar rats. Healthy young female albino rats of Wistar strain weighing 100g (7-8 weeks old) were randomly assigned to five groups of six each. Group I female rats were fed on normal diet and water ad libitum. Group II female rats were maintained on normal diet mixed with corn oil at 16.5mg/kg diet/day and 0.94mg/kg body weight/day as oil control. Groups III and IV female rats were given Clophen A60 and DEP dissolved in corn oil mixed with the diet at 50mg/(kgdietday), which is approximately equal to 2.85mg/(kgbodyweightday), individually to each group. Group V female rats received a mixture of DEP and Clophen A60, each dissolved in corn oil mixed with the diet at 50mg/(kgdietday), which is approximately equal to 2.85mg/(kgbodyweightday). Treatment was carried out for 150 days and after the completion of treatment, serum and liver enzymes and other biochemical parameters in the serum and liver were assessed. Liver weight to body weight ratio showed significant increase in Clophen A60 and Clophen A60+DEP treated rats. In the three treated groups, there was significant decrease in liver glutathione (GSH) and glutathione reductase (GR). Alanine amino transferase (ALT) was significantly increased in the liver of the three treated groups and in the serum of Clophen A60 and DEP alone treated groups and significant decrease only in the serum of Clophen A60+DEP treated rats. Significant increase in liver and serum lactate dehydrogenase (LDH) and acid phosphatase (ACP) activity was observed in the three treated groups. Alkaline phosphatase (ALP) activity was significantly increased only in the serum of the Clophen A60 and Clophen A60+DEP treated rats, whereas significant decrease in the serum and liver of DEP alone treated rats was observed. Aspartate aminotransferase (AST) activity and cholesterol levels were highly significant in the liver and serum of DEP treated rats. In addition, cholesterol level was significantly increased in the liver and serum of Clophen A60 treated rats and only in the liver of Clophen A60+DEP treated rats. Succinate dehydrogenase (SDH) activity was significantly increased in the liver of Clophen A60 and Clophen A60+DEP treated rats and highly significant increase in the serum of Clophen A60+DEP treated rats. There was significant increase in triglyceride levels in the liver and serum of Clophen A60 and Clophen A60+DEP treated rats, whereas significant increase in triglyceride levels in the serum of DEP alone treated rats was observed. Glycogen levels were significantly increased in the liver of Clophen A60+DEP treated rats, whereas serum glucose levels showed significant decrease, but in Clophen A60 alone treated rats showed significant increase in liver glycogen and serum glucose, whereas DEP alone treated rats showed significant increase in only serum glucose levels. Lipid peroxidation was increased in the liver of DEP treated rats, which was highly significant, compared to significant increase in Clophen A60 and Clophen A60+DEP treated rats. Histology of liver showed severe vacuolation, loss of hepatic architecture and granular deposits in the hepatocytes of DEP and Clophen A60+DEP treated rats, whereas in Clophen A60 alone treated rats, hepatocytes showed hyper pigmentation mild loss of hepatic architecture in centrilobular and periportal area.

Automated solid phase extraction and quantitative analysis of human milk for 13 phthalate metabolites

While the demonstrated benefits associated with breastfeeding are well recognized, breast milk is one possible route of exposure to environmental chemicals, including phthalates, by breastfeeding infants. Because of the potential health impact of phthalates to nursing children, determining whether phthalates are present in breast milk is important. We developed a sensitive method for measuring 13 phthalate metabolites in breast milk using automated solid phase extraction (SPE) coupled to isotope dilution-high-performance liquid chromatography (HPLC)-negative ion electrospray ionization-tandem mass spectrometry. We used D(4)-phthalate diesters to unequivocally establish the presence in human breast milk of enzymes capable of hydrolyzing the ubiquitous phthalate diesters to their respective monoesters. The analytical method involves acid-denaturation of the enzymes after collection of the milk to avoid hydrolysis of contaminant phthalate diesters introduced during sampling, storage, and analysis. The method shows good reproducibility (average coefficient of variations range between 4 and 27%) and accuracy (spiked recoveries are approximately 100%). The detection limits are in the low ng/ml range in 1ml of breast milk. We detected several phthalate metabolites in pooled human breast milk samples, suggesting that phthalates can be incorporated into breast milk and transferred to the nursing child.

4-Heptanone is a metabolite of the plasticizer di(2-ethylhexyl) phthalate (DEHP) in haemodialysis patients

BACKGROUND

There is an ongoing discussion about the risks of di(2-ethylhexyl) phthalate (DEHP) exposure for the general population as well as for specific subgroups in various medical settings. Haemodialysis patients certainly belong to the group with the highest exposure taking into account the repeated treatments over a long period of time. Many studies have shown that DEHP metabolites are more active with regard to cellular responses than DEHP itself. Although 4-heptanone has been shown to be a DEHP metabolite in rats, this has never been tested in humans. On the other hand, 4-heptanone was reported to be associated with diabetes mellitus.

METHODS

After establishing analytical methods for all postulated metabolites, we analysed (i) plasma samples from 50 patients on haemodialysis and 50 controls; (ii) urine samples from 100 diabetic patients and 100 controls; and (iii) urine samples from 10 controls receiving DEHP intravenously.

RESULTS

4-Heptanone concentrations in urine did not differ between controls (128.6+/-11.4 micro g/l, mean+/- SEM) and diabetic patients (131.2+/-11.6 micro g/l) but were significantly elevated in plasma from haemodialysis patients (95.9+/-9.6 micro g/l) compared with controls (10.4+/-0.5 micro g/l). Exposure to DEHP led to a significant increase (P<0.001) of the metabolite 4-heptanone and all the proposed intermediates in urine of healthy persons within 24 h.

CONCLUSIONS

These studies show that 4-heptanone is not associated with diabetes but is a major DEHP metabolite in humans. Studies concerning the toxicity of DEHP in haemodialysis patients and other highly exposed groups should therefore include 4-heptanone together with DEHP and its primary metabolites mono(2-ethylhexyl) phthalate (MEHP) and 2-ethylhexanol.

Exposure to di-(2-ethylhexyl) phthalate among premature neonates in a neonatal intensive care unit

OBJECTIVE

Premature neonates who spend time in a neonatal intensive care unit may be at increased risk of adverse health effects from exposure to di-(2-ethylhexyl) phthalate (DEHP) because of their increased risk of high exposure, their small body size, and their physical condition. DEHP, a reproductive toxicant in animals, is a major component in polyvinyl chloride (PVC) plastics, which are frequently used in medical tubing and blood storage bags. DEHP is not covalently bound to PVC, and it may be easily released from the PVC medical devices. The objective of this study was to determine whether premature infants who undergo medical procedures, such as blood transfusions, intravenous therapy, enteral and parenteral nutrition support, and dialysis, are at increased risk of exposure to DEHP than the general population. Because of their smaller size, children and especially premature and small infants may receive a larger dose of DEHP on a milligram per kilogram basis than adults when the same-size medical device is used for all ages.

METHODS

Premature neonates who seemed to have the potential to be on intravenous infusion for >2 weeks and were expected to survive were eligible for enrollment in the study. We assessed exposure to DEHP in 6 premature newborns by measuring in 41 urine samples the levels of 3 DEHP metabolites: mono-(2-ethylhexyl) phthalate (mEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (mEHHP), and mono-(2-ethyl-5-oxohexyl) phthalate (mEOHP).

RESULTS

mEHHP and mEOHP were detected in all 41 urine samples, and mEHP was detected in 33. Because only 33 of the samples had detectable amounts for all 3 metabolites, statistical analyses were limited to those 33. The levels of all 3 DEHP metabolites varied widely, and the urinary mean and median concentrations of mEOHP and mEHHP were 1 order of magnitude higher than those for mEHP. Furthermore, the geometric mean urinary concentrations of mEOHP (1617 ng/mL), mEHHP (2003 ng/mL), and mEHP (100 ng/mL) in these 6 premature infants who underwent intensive therapeutic interventions were found to be severalfold higher than in the US general population (for mEHP, geometric mean in those 6 years and older was 3.43 ng/mL).

CONCLUSIONS

This study provides the first quantitative evidence confirming that newborns who undergo intensive therapeutic medical interventions are exposed to higher concentrations of DEHP than the general population. Although the overall benefits of medical procedures using PVC devices outweigh the risks associated with exposure to DEHP, more research is needed to determine whether infants and children who undergo intensive therapeutic interventions using DEHP-containing devices are at higher risk for altered health outcomes than infants and children who undergo similar treatments but are not potentially exposed to DEHP.

Gas chromatography-mass spectrometry determination of the migration of phthalate plasticisers from polyvinyl chloride toys and childcare articles

Two laboratory-based linear horizontal agitation methods for determining a range of phthalate esters from soft polyvinyl chloride (PVC) toys are presented in compliance with EU legislation. Both of these methods were validated through interlaboratory trials using a PVC reference disc and four soft PVC toy/childcare articles intended or likely to be mouthed. Two of these commercial samples contained diisononyl phthalate (DINP), one diisodecyl phthalate (DIDP) and one bis(2-ethylhexyl) phthalate (DEHP). Acceptable repeatability (r, within-laboratory) and reproducibility (R, between-laboratory) data were demonstrated for both the analytical detection technique (GC-MS) (r = 9.8% and R = 8.1%) and agitation/extraction procedure (r=21.9% and R = 35.3% at 37 degrees C; r = 22.7% and R = 31.1% at 65 degrees C) for DINP. This was achieved through the participation of six laboratories. The remaining three phthalates from the EU Scientific Committee for Toxicity, Ecotoxicity and the Environment (CSTEE) list--dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and di-n-octyl phthalate (DnOP)--were not tested due to the unavailability of suitable materials.

Headspace solid-phase microextraction profiling of volatile compounds in urine: application to metabolic investigations

Volatile compounds contribute substantially to the metabolic pool in man. Their analysis in body fluids is problematic. We investigated headspace solid-phase microextraction (HS-SPME) with Carboxen-polydimethylsiloxane fibres and gas chromatography-mass spectrometry for profiling urinary volatile components. These fibres were more sensitive for very volatile and sulfur compounds than three other phases tested. We detected a wide range of compounds in normal urine at acid and alkaline pH. Profiles presented for five individuals with metabolic disturbances demonstrate abnormal accumulation of sulfur compounds, fatty acids and plasticisers. HS-SPME can complement profiling of non-volatile compounds in metabolic investigations and could be a useful extension of the diagnostic repertoire.

Urine 4-heptanone: a beta-oxidation product of 2-ethylhexanoic acid from plasticisers

4-Heptanone is a common volatile constituent of human urine and is of unknown origin. We hypothesised that it arises from in vivo beta-oxidation of 2-ethylhexanoic acid (EHA) from plasticisers, similar to formation of 3-heptanone from valproic acid. We investigated urine from individuals with normal and increased plasticiser exposure. Using GC/MS, solvent-extracted organic acids were analysed as trimethylsilyl (TMS) derivatives and heptanone with headspace solid-phase microextraction. We identified 3-oxo-2-ethylhexanoic acid, the beta-oxidation product of EHA, as an enol in all samples. This is the first report of its TMS mass spectrum. We also found 2-ethyl-1,6-hexanedioic acid and 5-hydroxyEHA, omega- and omega-1-oxidation products of EHA, respectively, and 2-ethylhexanoylglucuronide, but only in trace amounts in some plasticiser samples. These compounds have not been reported in human urine, nor has the TMS mass spectrum of 5-hydroxyEHA. The median concentrations of 3-oxoethylhexanoic acid and total 4-heptanone of seven plasticiser samples were around 30--175-fold higher than normal samples. 4-Heptanone was barely detectable and 3-oxoethylhexanoic acid was not increased in an eighth plasticiser sample, from a baby with deficiency of 2-methylbranched-chain acyl-CoA dehydrogenase. beta-Oxidation is a major catabolic pathway of EHA in man, and might be involved in the metabolism of other branched-chain drugs and environmental pollutants.