Project description:Relatively little is known about the exposure of nail technicians to semivolatile organic compounds (SVOCs) in nail salons. We collected preshift and postshift urine samples and silicone wrist bands (SWBs) worn on lapels and wrists from 10 female nail technicians in the Boston area in 2016-17. We analyzed samples for phthalates, phthalate alternatives, and organophosphate esters (OPEs) or their metabolites. Postshift urine concentrations were generally higher than preshift concentrations for SVOC metabolites; the greatest change was for a metabolite of the phthalate alternative di(2-ethylhexyl) terephthalate (DEHTP): mono(2-ethyl-5-carboxypentyl) terephthalate (MECPTP) more than tripled from 11.7 to 36.6 μg/g creatinine. DEHTP biomarkers were higher in our study participants' postshift urine compared to 2015-2016 National Health and Nutrition Examination Survey females. Urinary MECPTP and another DEHTP metabolite were moderately correlated (r = 0.37-0.60) with DEHTP on the SWBs, suggesting occupation as a source of exposure. Our results suggest that nail technicians are occupationally exposed to certain phthalates, phthalate alternatives, and OPEs, with metabolites of DEHTP showing the largest increase across a work day. The detection of several of these SVOCs on SWBs suggests that they can be used as a tool for examining potential occupational exposures to SVOCs among nail salon workers.
Project description:Phthalate esters (PAEs) are plasticizers associated with multiple toxicities; however, no strict regulations have been implemented to restrict their use in medical applications in Lebanon. Our study aimed at assessing the potential risks correlated with phthalate exposure from IV bags manufactured in Lebanon. GC-MS analysis showed that di-(2-ethylhexyl) phthalate (DEHP) is the predominant phthalate found in almost all samples tested with values ranging from 32.8 to 39.7% w/w of plastic. DEHP concentrations in the IV solutions reached up to 148 µg/L, as measured by SPME-GC-MS/MS, thus resulting in hazard quotients greater than 1, specifically in neonates. The toxicity of DEHP is mainly attributed to its metabolites, most importantly mono-(2-ethylhexyl) phthalate (MEHP). The IV bag solution with the highest content in DEHP was therefore used to extrapolate the amounts of urinary MEHP. The highest concentrations were found in neonates having the lowest body weight, which is concerning, knowing the adverse effects of MEHP in infants. Our study suggests that the use of IV bags manufactured in Lebanon could pose a significant risk in hospitalized patients, especially infants in neonatal care. Therefore, Lebanon, as well as other countries, should start imposing laws that restrict the use of phthalates in medical IV bags and substitute them with less toxic plasticizers.
Project description:Despite efforts to develop effective upconverting nanoparticle (UCNP) synthesis methods, there is still a need for approaches that are accessible and up-scalable while reproducibly providing fine control of UCNP size, crystallinity, and luminescence. This work presents a one-pot microwave-assisted strategy for synthesizing NaYF4:Yb3+/Er3 UCNPs. A premixed rare earth (RE) solution in oleic acid (OA) was used to enhance repeatability while testing various synthesis conditions. The stock solution aliquots were mixed with OA and bis(2-ethylhexyl) adipate (BEHA), a polycarboxylic ester with a high boiling point, high thermal stability, and moderately polar character that facilitated rapid microwave heating at an average rate (room temperature to 300 °C) up to 60 °C min-1. Combinations of BEHA concentration and high-temperature reaction time were identified for consistently producing cubic and hexagonal UCNPs with narrow size distributions in the tens and hundreds of nanometers. After washing, the resulting UCNPs were dispersible in aqueous media without further processing. This straightforward, accessible, and repeatable microwave-assisted synthesis method holds potential for scaling up the production of UCNPs with well-defined size and crystallinity.
Project description:Beer is one of the most popular beverages worldwide. As a product of variable agricultural ingredients and processes, beer has high molecular complexity. We used DIA/SWATH-MS to investigate the proteomic complexity and diversity of 23 commercial Australian beers. While the overall complexity of the beer proteome was modest, with contributions from barley and yeast proteins, we uncovered a very high diversity of post-translational modifications (PTMs), especially proteolysis, glycation, and glycosylation. Proteolysis was widespread throughout barley proteins, but showed clear site-specificity. Oligohexose modifications were common on lysines in barley proteins, consistent with glycation by maltooligosaccharides released from starch during malting or mashing. O-glycosylation consistent with oligomannose was abundant on secreted yeast glycoproteins. We developed and used data analysis pipelines to efficiently extract and quantify site-specific PTMs from SWATH-MS data, and showed incorporating these features into proteomic analyses extended analytical precision. We found that the key differentiator of the beer glyco/proteome was the brewery, with beer from independent breweries having a distinct profile to beer from multinational breweries. Within a given brewery, beer styles also had distinct glyco/proteomes. Targeting our analyses to beers from a single brewery, Newstead Brewing Co., allowed us to identify beer style-specific features of the glyco/proteome. Specifically, we found that proteins in darker beers tended to have low glycation and high proteolysis. Finally, we objectively quantified features of foam formation and stability, and showed that these quality properties correlated with the concentration of abundant surface-active proteins from barley and yeast.
Project description:The worldwide regulatory demand for the elimination of non-phthalate compounds for poly(vinyl chloride) (PVC) plasticization has intensified the search for alternatives. Concomitantly, sustainability concerns have highlighted sugar-based 2,5-furandicarboxylic acid as one key renewable-chemical for the development of several products, namely di(2-ethylhexyl) 2,5-furandicarboxylate (DEHF) plasticizer. This study addresses the use of DEHF under a realistic scenario of the co-existence of both DEHF and entirely fossil-based plasticizers. More precisely, original PVC blends using mixtures of non-toxic DEHF and di(2-ethylhexyl) terephthalate ester (DEHT) were designed. The detailed structural, thermal, and mechanical characterization of these materials showed that they all have a set of interesting properties that are compatible with those of commercial DEHT, namely a low glass transition (19.2-23.8 °C) and enhanced elongation at break (up to 330%). Importantly, migration tests under different daily situations, such as for example exudation from food/beverages packages and medical blood bags, reveal very low weight loss percentages. For example, in both distilled water and phosphate buffered saline (PBS) solution, weight loss does not exceed ca. 0.3% and 0.2%, respectively. Viability tests show, for the first time, that up to 500 μM of DEHF, a promising cytotoxic profile is observed, as well as for DEHT. Overall, this study demonstrates that the combination of DEHF and DEHT plasticizers result in a noticeable plasticized PVC with an increased green content with promising cytotoxic results.
Project description:Introduction: A physiologically based biokinetic model for di (2-ethylhexyl) adipate (DEHA) based on a refined model for di-(2-propylheptyl) phthalate (DPHP) was developed to interpret the metabolism and biokinetics of DEHA following a single oral dosage of 50 mg to two male and two female volunteers. Methods: The model was parameterized using in vitro and in silico methods such as, measured intrinsic hepatic clearance scaled from in vitro to in vivo and algorithmically predicted parameters such as plasma unbound fraction and tissue:blood partition coefficients (PCs). Calibration of the DEHA model was achieved using concentrations of specific downstream metabolites of DEHA excreted in urine. The total fractions of ingested DEHA eliminated as specific metabolites were estimated and were sufficient for interpreting the human biomonitoring data. Results: The specific metabolites of DEHA, mono-2-ethyl-5-hydroxyhexyl adipate (5OH-MEHA), mono-2-ethyl-5-oxohexyl adipate (5oxo-MEHA), mono-5-carboxy-2-ethylpentyl adipate (5cx-MEPA) only accounted for ∼0.45% of the ingested DEHA. Importantly, the measurements of adipic acid, a non-specific metabolite of DEHA, proved to be important in model calibration. Discussion: The very prominent trends in the urinary excretion of the metabolites, 5cx-MEPA and 5OH-MEHA allowed the important absorption mechanisms of DEHA to be modelled. The model should be useful for the study of exposure to DEHA of the general human population.
Project description:Allergic rhinitis (AR) is a common chronic inflammatory disease of the upper respiratory tract. Di(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer and belongs to environmental endocrine disruptors (EDCs). It can be entered the human body which is harmful to health. The relationship between DEHP and AR is still inconclusive. This study aims to investigate the effect of environmental pollutants DEHP on AR. By examining DEHP metabolites in the urine of AR patients and building an AR model. 24 BALB/c mice were used as the study subjects, and ovalbumin (OVA) and DEHP (3 mg/kg/body) were used for intragastric administration. They were divided into control group, DEHP group, OVA group and OVA + DEHP group. Examination, behavioral scoring, inflammatory factor testing, oxidative stress testing, detection of aryl hydrocarbon receptor (AhR) and signaling pathways CYP1A1 and CYP1B1 related proteins and mRNA. The concentrations of 3 metabolites of DEHP (MEHHP, MEOHP, and MEHP) in urine of AR patients were higher. And HE-staining showed that for the control group, many chronic inflammatory cell infiltration and nasal mucosal destruction were observed in the OVA + DEHP group and were more severe than the OVA group. Allergic symptom scores were obtained from sneezing, scratching, number of scratching, and nose flow. The scores of the OVA group and the OVA + DEHP group were higher than 7 points. Serum ELISA and nasal mucosal oxidative stress tests are more serious in the OVA + DEHP group. The expression of AhR protein and its mRNA was increased in the DEHP group, OVA group and OVA + DEHP group. The OVA + DEHP group was more significant in the OVA group and DEHP group. And the mRNAs of the AhR-related signaling pathways CYP1A1 and CYP1B1 were also more prominent in the OVA + DEHP group. DEHP may aggravate its inflammatory response through the AhR pathway closely related to the environment. When combined with OVA, DEHP can further aggravate the OVA-induced nasal inflammatory response and make the nasal cavity have undergone severe changes, and many inflammatory cells have infiltrated. DEHP has shown an adjuvant effect, and the AhR-related signaling pathways CYP1A1 and CYP1B1 may be critical.
Project description:A growing number of studies point to reduced fertility upon chronic exposure to endocrine-disrupting chemicals (EDCs) such as phthalates and plasticizers. These toxins are ubiquitous and are often found in food and beverage containers, medical devices, as well as in common household and personal care items. Animal studies with EDCs, such as phthalates and bisphenol A have shown a dose-dependent decrease in fertility and embryo toxicity upon chronic exposure. However, limited research has been conducted on the acute effects of these EDCs on male fertility. Here we used a murine model to test the acute effects of four ubiquitous environmental toxins: bisphenol A (BPA), di-2-ethylhexyl phthalate (DEHP), diethyl phthalate (DEP), and dimethyl phthalate (DMP) on sperm fertilizing ability and pre-implantation embryo development. The most potent of these toxins, di-2-ethylhexyl phthalate (DEHP), was further evaluated for its effect on sperm ion channel activity, capacitation status, acrosome reaction and generation of reactive oxygen species (ROS). DEHP demonstrated a profound hazardous effect on sperm fertility by producing an altered capacitation profile, impairing the acrosome reaction, and, interestingly, also increasing ROS production. These results indicate that in addition to its known chronic impact on reproductive potential, DEHP also imposes acute and profound damage to spermatozoa, and thus, represents a significant risk to male fertility.
Project description:The purpose of this study was to determine the origin, presence, and fate of the endocrine disruptor di-ethylhexil phthalate (DEHP) during tequila production. For this, three tequila factories (small, medium, and large) were monitored. DEHP concentrations in water, agave, additives, lubricating greases, neoprene seals, and materials of each stage process were analyzed using gas chromatography/mass spectrometry. DEHP mass balances were performed to identify the processes with significant changes in the inputs/outputs. DEHP was detected in agave at up to 0.08 ± 0.03 mg kg-1, water 0.02 ± 0.01 mg kg-1, lubricant greases 131.05 ± 2.80 mg kg-1, and neoprene seals 369.11 ± 22.52 mg kg-1. Whereas, tequila produced in the large, medium, and small factories contained 0.05 ± 0.01, 0.24 ± 0.04, and 1.43 ± 0.48 mg kg-1 DEHP, respectively. Furthermore, in waste materials (vinasses and bagasse) released, 534.26 ± 349.02, 947.18 ± 65.84, and 5222.60 ± 2836.94 mg of DEHP was detected for every 1000 L of tequila produced. The most significant increase in DEHP occurred during the sugar extraction and distillation stages. Results demonstrate that main raw materials, such as agave and water, contain DEHP, but lubricant greases and neoprene seals are the major sources of DEHP contamination. Identification of the contamination sources can help the tequila industry to take actions to reduce it, protect consumer health and the environment, and prevent circular contamination.
Project description:Di(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer found in a variety of polyvinyl chloride (PVC) medical products. The results of studies in experimental animals suggest that DEHP leached from flexible PVC tubing may cause health problems in some patient populations. While the cancerogenic and reproductive effects of DEHP are well recognized, little is known about the potential adverse impact of phthalates on the heart. This study examined the effects of clinically relevant concentrations of DEHP on neonatal rat cardiomyocytes. It was found that application of DEHP to a confluent, synchronously beating cardiac cell network, leads to a marked, concentration-dependent decrease in conduction velocity and asynchronous cell beating. The mechanism behind these changes was a loss of gap junctional connexin-43, documented using Western blot analysis, dye-transfer assay and immunofluorescence. In addition to its effect on electrical coupling, DEHP treatment also affected the mechanical movement of myocyte layers. The latter was linked to the decreased stiffness of the underlying fibroblasts, as the amount of triton-insoluble vimentin was significantly decreased in DEHP-treated samples. The data indicate that DEHP, in clinically relevant concentrations, can impair the electrical and mechanical behavior of a cardiac cell network. Applicability of these findings to human patients remains to be established.