Studies of migration of potentially genotoxic compounds into water stored in pet bottles

Insights into Solar Disinfection Enhancements for Drinking Water Treatment Applications

Poor access to drinking water, sanitation, and hygiene has always been a major concern and a main challenge facing humanity even in the current century. A third of the global population lacks access to microbiologically safe drinking water, especially in rural and poor areas that lack proper treatment facilities. Solar water disinfection (SODIS) is widely proven by the World Health Organization as an accepted method for inactivating waterborne pathogens. A significant number of studies have recently been conducted regarding its effectiveness and how to overcome its limitations, by using water pretreatment steps either by physical, chemical, and biological factors or the integration of photocatalysis in SODIS processes. This review covers the role of solar disinfection in water treatment applications, going through different water treatment approaches including physical, chemical, and biological, and discusses the inactivation mechanisms of water pathogens including bacteria, viruses, and even protozoa and fungi. The review also addresses the latest advances in different pre-treatment modifications to enhance the treatment performance of the SODIS process in addition to the main limitations and challenges.

Screening of estrogenic endocrine-disrupting chemicals in meat products based on the detection of vitellogenin by enzyme-linked immunosorbent assay

Vitellogenin (VTG) is typically produced by females but when present in males can indicate contamination with estrogenic endocrine-disrupting chemicals (EDCs). Here we used primary hepatocytes isolated from male crucian carp uncontaminated with estrogenic EDCs as a culture model. Nine EDCs were used for validation, and an enzyme-linked immunosorbent assay (ELISA) was used to quantify VTG production by primary hepatocytes. The lower limit of detection of 17β-E2, DES, and HES using the method was 10^-12 M. Fresh pork was roasted, and non-hydrolytic acetonitrile-vortexing was used to extract potential estrogenic EDCs. The extracted substances were separated by thin-layer chromatography (TLC), and dimethyl terephthalate present in roast pork was found to induce high VTG concentrations. Therefore, the detection of VTG by ELISA provides a sensitive and reliable method for detecting known and unknown estrogenic EDCs in food products.

Enhancing solar disinfection (SODIS) with the photo-Fenton or the Fe2+/peroxymonosulfate-activation process in large-scale plastic bottles leads to toxicologically safe drinking water

Solar disinfection (SODIS) in 2-L bottles is a well-established drinking water treatment technique, suitable for rural, peri‑urban, or isolated communities in tropical or sub-tropical climates. In this work, we assess the enlargement of the treatment volume by using cheap, large scale plastic vessels. The bactericidal performance of SODIS and two solar-Fe²⁺ based enhancements, namely photo-Fenton (light/H₂O₂/Fe²⁺) and peroxymonosulfate activation (light/PMS/Fe²⁺) were assessed in 19-L polycarbonate (PC) and 25-L polyethylene terephthalate (PET) bottles, in ultrapure and real water matrices (tap water, lake Geneva water). Although SODIS always reached total (5-logU) inactivation, under solar light, enhancement by or both Fe²⁺/H₂O₂ or Fe²⁺/PMS was always beneficial and led to an increase in bacterial elimination kinetics, as high as 2-fold in PC and PET bottles with tap water for light/H₂O₂/Fe²⁺, and 8-fold in PET bottles with Lake Geneva water. The toxicological safety of the enhancements and their effects on the plastic container materials was assessed using the E-screen assay and the Ames test, after 1-day or 1-week exposure to SODIS, photo-Fenton and persulfate activation. Although the production of estrogenic compounds was observed, we report that no treatment method, duration of exposure or material resulted in estrogenicity risk for humans, and similarly, no mutagenicity risk was measured. In summary, we suggest that SODIS enhancement by either HO^•- or SO₄^•--based advanced oxidation process is a suitable enhancement of bacterial inactivation in large scale plastic bottles, without any associated toxicity risks.

Evaluation of the Suitability of Mammalian In Vitro Assays to Assess the Genotoxic Potential of Food Contact Materials

Background: Non-targeted screening of food contact materials (FCM) for non-intentionally added substances (NIAS) reveals a great number of unknown and unidentified substances present at low concentrations. In the absence of toxicological data, the application of the threshold of toxicological concern (TTC) or of EU Regulation 10/2011 requires methods able to fulfill safety threshold criteria. In this review, mammalian in vitro genotoxicity assays are analyzed for their ability to detect DNA-damaging substances at limits of biological detection (LOBD) corresponding to the appropriate safety thresholds. Results: The ability of the assays to detect genotoxic effects varies greatly between substance classes. Especially for direct-acting mutagens, the assays lacked the ability to detect most DNA reactive substances below the threshold of 10 ppb, making them unsuitable to pick up potential genotoxicants present in FCM migrates. However, suitability for the detection of chromosomal damage or investigation of other modes of action makes them a complementary tool as part of a standard test battery aimed at giving additional information to ensure safety. Conclusion: improvements are necessary to comply with regulatory thresholds to consider mammalian genotoxicity in vitro assays to assess FCM safety.

Value and limitation of in vitro bioassays to support the application of the threshold of toxicological concern to prioritise unidentified chemicals in food contact materials

Some of the chemicals in materials used for packaging food may leak into the food, resulting in human exposure. These include so-called Non-intentionally Added Substances (NIAS), many of them being unidentified and toxicologically uncharacterized. This raises the question of how to address their safety. An approach consisting of identification and toxicologically testing all of them appears neither feasible nor necessary. Instead, it has been proposed to use the threshold of toxicological concern (TTC) Cramer class III to prioritise unknown NIAS on which further safety investigations should focus. Use of the Cramer class III TTC for this purpose would be appropriate if amongst others sufficient evidence were available that the unknown chemicals were not acetylcholinesterase inhibitors or direct DNA-reactive mutagens. While knowledge of the material and analytical chemistry may efficiently address the first concern, the second could not be addressed in this way. An alternative would be use of a bioassay capable of detecting DNA-reactive mutagens at very low levels. No fully satisfactory bioassay was identified. The Ames test appeared the most suitable since it specifically detects DNA-reactive mutagens and the limit of biological detection of highly potent genotoxic carcinogens is low. It is proposed that for a specific migrate, the evidence for absence of mutagenicity based on the Ames test, together with analytical chemistry and information on packaging manufacture could allow application of the Cramer class III TTC to prioritise unknown NIAS. Recommendations, as well as research proposals, have been developed on sample preparation and bioassay improvement with the ultimate aim of improving limits of biological detection of mutagens. Although research is still necessary, the proposed approach should bring significant benefits over the current practices used for safety evaluation of food contact materials.

Mutagenicity assessment of food contact material migrates with the Ames MPF assay

A major challenge in the safety assessment of food contact materials (FCM) is the evaluation of unknown non-intentionally added substances (NIAS). Even though consumer exposure levels may be quantitatively low, these substances are considered to be of high toxicological concern if they act as DNA reactive mutagens. From a safety assessment perspective, it is therefore important to detect their presence in FCM migrates. The present study applied the Ames MPF assay to assess the mutagenicity of migrates obtained from 30 food contact material samples out of 3 categories: plastics, composite materials and coatings. As a food simulant, 95% ethanol (EtOH) had a superior performance to less volatile simulants when evaluating recovery rates of representative model substances in different volatility categories. To monitor possible interference of the FCM matrix with Ames MPF results, migrates were spiked with reference substances and recovery rates were established. Out of 30 samples tested, two caused significant inhibition of revertant formation in the presence of the spiking control. Overall detection limits of the applied test method were estimated by determination of the lowest effective concentrations (LEC) for 10 Ames-positive substances. Even though the current limits of detection are not sufficient to entirely fulfil regulatory and safety requirements, three out of 30 FCMs showed evidence of dose-dependent effects in the Ames MPF assay. Overall, the data obtained supported the relevance of testing FCM migrates for DNA reactive contaminants and showed the value of the Ames MPF assay for the safety assessment of FCMs.

Suitability of the Ames test to characterise genotoxicity of food contact material migrates

Non-intentionally added substances (NIAS) are chemical impurities which can migrate from packaging materials (FCM) into food. Safety assessment of NIAS is required by European law, but currently there is no comprehensive testing strategy available. In this context, one key element is to get insight on the potential presence of genotoxic NIAS in FCM migrates. This raises questions about the limit at which genotoxins can be detected in complex mixtures such as FCM migrates, and if such limits of detection (LOD) would be compatible with safety. In this context, the present review assesses the suitability of the Ames assay to address genotoxicity of FCM migrates. Lowest effective concentrations of packaging-related and other chemicals in test media were retrieved from scientific literature and used as surrogates of LODs to be benchmarked against a value of 0.01 mg kg^-1 (10 ppb) in migrates. This is a pragmatic threshold used in FCM safety evaluation to prioritise substances requiring proper identification and risk assessment. The analysis of the data shows that only potent genotoxins can theoretically be detectable at a level of 0.01 mg kg^-1 in migrates or food. Only a minority (10%) of genotoxic chemicals reported to be associated with FCMs could be picked up at a level of 0.01 mg kg^-1 or lower. Overall, this review shows that the Ames test in its present form cannot be used as standalone method for evaluating the genotoxic potential of FCM migrates, but must be used together with other information from analytical chemistry and FCM manufacturing.

In Vitro Toxicity Testing of Food Contact Materials: State-of-the-Art and Future Challenges

Currently, toxicological testing of food contact materials (FCMs) is focused on single substances and their genotoxicity. However, people are exposed to mixtures of chemicals migrating from food contact articles (FCAs) into food, and toxic effects other than genotoxic damage may also be relevant. Since FCMs can be made of more than 8 thousand substances, assessing them one-by-one is very resource-consuming. Moreover, finished FCAs usually contain non-intentionally added substances (NIAS). NIAS toxicity can only be tested if a substance's chemical identity is known and if it is available as a pure chemical. Often, this is not the case. Nonetheless, regulations require safety assessments for all substances migrating from FCAs, including NIAS, hence new approaches to meet this legal obligation are needed. Testing the overall migrate or extract from an FCM/FCA is an option. Ideally, such an assessment would be performed by means of in vitro bioassays, as they are rapid and cost-effective. Here, we review the studies using in vitro bioassays to test toxicity of FCMs/FCAs. Three main categories of in vitro assays that have been applied include assays for cytotoxicity, genotoxicity, and endocrine disruption potential. In addition, we reviewed studies with small multicellular animal-based bioassays. Our overview shows that in vitro testing of FCMs is in principle feasible. We discuss future research needs and FCM-specific challenges. Sample preparation procedures need to be optimized and standardized. Further, the array of in vitro tests should be expanded to include those of highest relevance for the most prevalent human diseases of concern.

Exposure to the polyester PET precursor--terephthalic acid induces and perpetuates DNA damage-harboring non-malignant human breast cells

Accurate assessment of the biological impact of xenoestrogens could assist breast cancer prevention. Effects on DNA integrity of breast epithelium, which might be missed in common chemical test screens, underscore the importance of endpoints beyond estrogen receptor interaction and cell proliferation.

Identification of early perturbations induced in cells from non-cancerous breast tissue is critical for understanding possible breast cancer risk from chemical exposure. We have demonstrated previously that exposure to the ubiquitous xenoestrogens, bisphenol A (BPA) and methyl paraben, promotes the hallmarks of cancer in non-malignant human high-risk donor breast epithelial cells (HRBECs) isolated from several donors. Here we show that terephthalic acid (TPA), a major chemical precursor of polyethylene terephthalate (PET) containers used for the storage of food and beverages, increased the ERα: ERβ ratio in multiple HRBEC samples, suggesting an estrogenic effect. Although, like BPA and methyl paraben, TPA also promoted resistance to tamoxifen-induced apoptosis, unlike these chemicals instead of inducing an increased S-phase fraction, TPA treatment arrested cell proliferation. DNA-PK, ATM and members of the MRN complex, known to be involved in DNA damage sensor and effector proteins, were elevated indicating induction of DNA strand breaks. Early DNA damage checkpoint response, mediated through p53/p21, led to G₁ arrest in TPA-exposed cells. Removal of TPA from the growth medium resulted in the rapid induction of BCL2, increasing the ratio of anti-: pro-apoptotic proteins, together with overexpression of Cyclin A/CDK2 proteins. Consequently, despite elevated p53^pSer15 and H2AX^pSer139, indicating sustained DNA damage, TPA exposed cells resumed robust growth rates seen prior to TPA exposure. The propensity for the perpetuation of DNA aberrations that activate DNA damage pathways in non-malignant breast cells justifies careful consideration of human exposure to TPA, particularly at vulnerable life stages.

Safety Assessment of Modified Terephthalate Polymers as Used in Cosmetics

The safety of 6 modified terephthalate polymers as cosmetic ingredients was assessed. These ingredients mostly function as exfoliants, bulking agents, hair fixatives, and viscosity-increasing agents—nonaqueous. Polyethylene terephthalate (PET) is used in leave-on products up to 100% and in rinse-off products up to 2%. The Cosmetic Ingredient Review Expert Panel (Panel) considered that the PET used in cosmetics is chemically equivalent to that used in medical devices. The Panel determined that the Food and Drug Administration’s determination of safety of PET in several medical devices, which included human and animal safety data, can be used as the basis for the determination of safety of PET and related polymers used in cosmetics. Use studies of cosmetic eye products that contain PET demonstrated no ocular irritation or dermal sensitization. The Panel concluded that modified terephthalate polymers were safe as cosmetic ingredients in the practices of use and concentration described in this safety assessment.

Impact of temperature and storage duration on the chemical and odor quality of military packaged water in polyethylene terephthalate bottles

The impact of temperature and storage time on military packaged water (MPW) quality was examined at four temperatures (23.0 °C to 60.0 °C) for 120 days. Polyethylene terephthalate (PET) bottles were filled in California and Afghanistan with unbuffered water treated by reverse osmosis. The US military's water pH long-term potability standard was exceeded, and US Food and Drug Administration (USFDA) and US Environmental Protection Agency (USEPA) drinking water pH and odor intensity limits were also exceeded. During a 70 day exposure period, Port Hueneme MPW total organic carbon and total trihalomethane levels increased from < 0.25mg/L to 2.0 ± 0.0mg/L and <0.05 μg/L to 51.5 ± 2.1 μg/L, respectively. PET released organic contaminants into MPW and residual disinfectant generated trihalomethane contaminants. After 14 days at 37.7 °C and 60.0 °C, Afghanistan MPW threshold odor number values were 8.0 and 8.6, respectively. Total organic carbon concentration only increased with exposure duration at 60.0 °C. Acetaldehyde and formaldehyde contaminants were not detected likely due to the high method detection limits applied in this study. Phthalate contaminants detected and their maximum levels were butylbenzylphthalate (BBP) 0.43 μg/L, di-n-butylphthalate (DnBP) 0.38 μg/L, di(2-ethylhexyl)phthalate (DEHP) 0.6 μg/L, and diethylphthalate (DEP) 0.32 μg/L. Antimony was only detected in 60.0 °C Afghanistan MPW on Day 28 and beyond, and its maximum concentration was 3.6 ± 0.3 μg/L. No antimony was found in bottles exposed to lesser temperatures. Environmental health, PET synthesis and bottle manufacturers, and bottle users can integrate results of this work to improve health protective decisions and doctrine.

Factors affecting the quality of bottled water

The ever-increasing popularity of bottled water means that it is important to analyze not only its mineral content but also, above all, its content of possible contaminants, especially the organic ones. In this respect, bottled waters are a special case, because apart from organic chemical contaminants derived from the well from which they were acquired, their secondary contamination is always possible, during treatment or storage or transport in unsuitable conditions (sunlight and elevated temperature). This paper describes how various factors, from the area around the well, and the method of drawing and treating water, to the manner in which the finished product is stored and transported may affect the quality of bottled waters. It also summarizes literature information on the levels of organic contaminants in various kinds of bottled water samples.

Chemical compounds and toxicological assessments of drinking water stored in polyethylene terephthalate (PET) bottles: A source of controversy reviewed

A declaration of conformity according to European regulation No. 10/2011 is required to ensure the safety of plastic materials in contact with foodstuffs. This regulation established a positive list of substances that are authorized for use in plastic materials. Some compounds are subject to restrictions and/or specifications according to their toxicological data. Despite this, the analysis of PET reveals some non-intentionally added substances (NIAS) produced by authorized initial reactants and additives. Genotoxic and estrogenic activities in PET-bottled water have been reported. Chemical mixtures in bottled water have been suggested as the source of these toxicological effects. Furthermore, sample preparation techniques, such as solid-phase extraction (SPE), to extract estrogen-like compounds in bottled water are controversial. It has been suggested that inappropriate extraction methods and sample treatment may result in false-negative or positive responses when testing water extracts in bioassays. There is therefore a need to combine chemical analysis with bioassays to carry out hazard assessments. Formaldehyde, acetaldehyde and antimony are clearly related to migration from PET into water. However, several studies have shown other theoretically unexpected substances in bottled water. The origin of these compounds has not been clearly established (PET container, cap-sealing resins, background contamination, water processing steps, NIAS, recycled PET, etc.). Here, we surveyed toxicological studies on PET-bottled water and chemical compounds that may be present therein. Our literature review shows that contradictory results for PET-bottled water have been reported, and differences can be explained by the wide variety of analytical methods, bioassays and exposure conditions employed.

Toxicological review and oral risk assessment of terephthalic acid (TPA) and its esters: A category approach

Polyethylene terephthalate, a copolymer of terephthalic acid (TPA) or dimethyl terephthalate (DMT) with ethylene glycol, has food, beverage, and drinking water contact applications. Di-2-ethylhexyl terephthalate (DEHT) is a plasticizer in food and drinking water contact materials. Oral reference doses (RfDs) and total allowable concentrations (TACs) in drinking water were derived for TPA, DMT, and DEHT. Category RfD and TAC levels were also established for nine C(1)-C(8) terephthalate esters. The mode of action of TPA, and of DMT, which is metabolized to TPA, involves urinary acidosis, altered electrolyte elimination and hypercalciuria, urinary supersaturation with calcium terephthalate or calcium hydrogen terephthalate, and crystallization into bladder calculi. Weanling rats were more sensitive to calculus formation than dams. Calculi-induced irritation led to bladder hyperplasia and tumors in rats fed 1000 mg/kg-day TPA. The lack of effects at 142 mg/kg-day supports a threshold for urine saturation with calcium terephthalate, a key event for calculus formation. Chronic dietary DMT exposure in rodents caused kidney inflammation, but not calculi. Chronic dietary DEHT exposure caused general toxicity unrelated to calculi, although urine pH was reduced suggesting the TPA metabolite was biologically-active, but of insufficient concentration to induce calculi. Respective oral reference doses of 0.5, 0.5, and 0.2 mg/kg-day and total allowable drinking water concentrations of 3, 3, and 1 mg/L were derived for TPA, DMT, and DEHT. An oral RfD of 0.2 mg/kg-day for the terephthalate category chemicals corresponded to a drinking water TAC of 1 mg/L.

Development of a test system for homeopathic preparations using impaired duckweed (Lemna gibba L.)

OBJECTIVES

A bioassay with arsenic-stressed duckweed (Lemna gibba L.) was developed to study potentially regulative effects of homeopathic preparations. We compared potentized substances (nine different potency levels between 17 x and 33 x ) with two controls (unsuccussed and succussed water) regarding their influence on number- and area-related growth rate and color of fronds (leaves). Screening included 11 potentized substances: Arsenicum album, gibberellic acid, nosode, arsenic(V), phosphorus, Conchae, Acidum picrinicum, Argentum nitricum, Crotalus horridus, Hepar sulfuris, and Mercurius vivus naturalis.

DESIGN

Duckweed was stressed with arsenic(V) for 48 hours. Afterwards, plants grew in either potentized substances or water controls for 6 days. Growth rate and color of fronds were determined with a computerized image analysis system for different time intervals (days 0-2, 2-6, 0-6). A systematic negative control experiment with unsuccussed water was used to investigate the stability of the bioassay. All experiments were randomized and blinded.

RESULTS

Arsenicum album and nosode potencies increased frond number-related growth rate compared to controls (succussed water controls or pooled water controls [succussed and unsuccussed], p < 0.05, t test). Regarding color classification, no effects were observed.

CONCLUSIONS

The experimental setup with L. gibba stressed by arsenic(V) provides a valuable tool to investigate regulative effects of potentized substances. In order to verify the effects of Arsenicum album and nosode potencies, further independent replication experiments are necessary.

INFLUÊNCIA DO PROCESSO DE TRANSFORMAÇÃO NA GERAÇÃO DE ACETALDEÍDO E NÍVEIS RESIDUAIS EM EMBALAGENS DE POLI (ETILENO TEREFTALATO) (PET) E EM BEBIDAS - ARTIGO DE REVISÃO

O principal objetivo deste texto é reunir informações relativas à presença do composto acetaldeído,sua formação, reações químicas, formas pelas quais se manifesta em bebidas e fontes decontaminação provenientes de diferentes caminhos nos sistemas de produção, embalagem eambiente. Trata-se de um trabalho de revisão bibliográfica comentada e discutida, onde o autorinsere sua experiência em tecnologia de transformação de resinas de PET, bem como embalagenspara diversos produtos acondicionados e também fundamentos teóricos e práticos das etapas doprocesso relacionadas à formação de acetaldeído.

Acetaldehyde residue in polyethylene terephthalate (PET) bottles

A simple sample preparation technique was developed for rapid analysis of acetaldehyde residue in Polyethylene Terephthalate (PET) bottles. A laboratory-built heating system was used and coupled with gas chromatography-flame ionization detector (GC-FID) at optimized conditions. The results were a tremendous reduction of the sample preparation time from 24 hours, for the conventional method, to only one hour. The analysis took only 1.5 min with other good analytical performances i.e. a low detection limit, 0.3 ng mL(- 1) and a wide linear dynamic range, 0.3 ng mL(- 1) to 6.6 microg mL(- 1) with R(2) > 0.99. Acetaldehyde residue in freshly blown bottles were analyzed and found in the range of 0.4 to 1.1 ng mL(- 1). The results were good agreement with the conventional 24-hour airspace method (P < 0.01). The PET-bottle sampling technique was also developed to minimize the complication of sample transportation and pre-concentration. A purge and trap technique was found to be the most suitable. Then, it was implemented and compared, the results showed no significant difference (P < 0.01) with and without purge and trap.

Migration of a UV stabilizer from polyethylene terephthalate (PET) into food simulants

The migration characteristics of the UV stabilizer Tinuvin 234 (2-(2H-benzotriazol-2-yl)-4,6-bis (1-methyl-1-phenylethyl)phenol) into food simulants has been measured from polyethylene terephthalate (PET) using HPLC with UV detection. Ethanol/ water, isooctane and a fractionated coconut oil simulant (Miglyol) were used as food simulating solvents. The migration characteristics were measured at temperatures in the range of 40-70 degrees C. Diffusion coefficients were determined to be in the range of 1 x 10(-14) cm2 s(-1) to 1 x 10(-18) cm2 s(-1). At 40 degrees C, the amount of migration into 95% ethanol after 10 days was 2 microg dm(-2). Isooctane is determined to be a good fatty food simulant that provides similar results for PET to those of fatty foods.

Toxicological evaluation of commercial mineral water bottled in polyethylene terephthalate: a cytogenetic approach with Allium cepa

The aim of this study was to ascertain the possible toxicological effects of chemicals released into mineral water packaged in polyethylene terephthalate (PET) bottles. Two commercial mineral waters, bottled both in PET and glass and stored under different conditions, were examined using the Allium cepa test. The influence of the water samples on macroscopic (root length, colour and form) and microscopic (root tip mitotic index, chromosome aberrations) parameters was examined. The water samples were analysed after: (A) controlled-condition storage (no direct light exposure and 18 +/- 2 degrees C), (B) storage at 40 degrees C for 10 days, in the dark (migration test in accordance with 82/711/EEC), and (C) exposure to sunlight and varying temperatures (18-38 degrees C, mean temperature 25 +/- 3 degrees C). The two water samples bottled in PET induced cytogenetic aberrations regardless of the storage conditions. These signs of toxicity were evident even only 8 weeks after bottling, which is well within the recommended expiry date. Storage conditions were very important, as is suggested by the finding that chromosomal aberrations were particularly apparent after exposure to direct sunlight. However, as plant systems are not considered as primary screening tools by current international guidelines for mammalian systems, extrapolation of the results from this test system to other systems and, eventually, to human beings should be based on results from a battery of assays covering various metabolic pathways.