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The goal of this study was to describe environmental tobacco smoke (ETS) exposure using urinary biomarkers and its correlation with parent report, among children presenting to emergency room. This is a case control study among children aged 3 to 12 years at a tertiary pediatric emergency department in Israel. Children with respiratory (case) or gastrointestinal (control) symptoms were recruited and their accompanying parent completed a short survey. Urine samples were obtained and analyzed for nicotine, cotinine trans-3'-hydroxycotine. Clinical data were extracted from medical records. We compared tobacco exposure using urinary biomarkers, parent report, and Pearson's product-moment correlation, including 95% confidence intervals, between cases and controls. Forty-nine cases with respiratory symptoms and 96 controls with gastrointestinal symptoms were enrolled in the study. Parent-reported ETS exposure in the previous month was higher in the cases compared to control (71.4% vs 57.3%), although the difference was not statistically significant. The mean values of detectable biomarkers did not differ by between cases and controls. However, there was a correlation between urinary biomarkers and reported ETS exposure (0.278–0.460 for various biomarkers) only among cases. The majority of children in this study had detectable nicotine urinary biomarkers, regardless of their symptoms. However, correlation between parental report and urinary biomarkers was only found among children with symptoms potentially related to ETS. These findings imply that parents of children without respiratory symptoms may underestimate exposure. Efforts to educate parents and caregivers on the risks associated with exposure to ETS should be intensified, regardless of illness. [ABSTRACT FROM AUTHOR]

The combustion characteristics of ethanol/Jet A-1 fuel droplets having three different proportions of ethanol (10%, 30%, and 50% by vol.) are investigated in the present study. The large volatility differential between ethanol and Jet A-1 and the nominal immiscibility of the fuels seem to result in combustion characteristics that are rather different from our previous work on butanol/Jet A-1 droplets (miscible blends). Abrupt explosion was facilitated in fuel droplets comprising lower proportions of ethanol (10%), possibly due to insufficient nucleation sites inside the droplet and the partially unmixed fuel mixture. For the fuel droplets containing higher proportions of ethanol (30% and 50%), micro-explosion occurred through homogeneous nucleation, leading to the ejection of secondary droplets and subsequent significant reduction in the overall droplet lifetime. The rate of bubble growth is nearly similar in all the blends of ethanol; however, the evolution of ethanol vapor bubble is significantly faster than that of a vapor bubble in the blends of butanol. The probability of disruptive behavior is considerably higher in ethanol/Jet A-1 blends than that of butanol/Jet A-1 blends. The Sauter mean diameter of the secondary droplets produced from micro-explosion is larger for blends with a higher proportion of ethanol. Both abrupt explosion and micro-explosion create a large-scale distortion of the flame, which surrounds the parent droplet. The secondary droplets generated from abrupt explosion undergo rapid evaporation whereas the secondary droplets from micro-explosion carry their individual flame and evaporate slowly. The growth of vapor bubble was also witnessed in the secondary droplets, which leads to the further breakup of the droplet (puffing/micro-explosion). [ABSTRACT FROM AUTHOR]

Global profiling of xenobiotics in human matrices in an untargeted mode is gaining attention for studying the environmental chemical space of the human exposome. Defined as the study of a comprehensive inclusion of environmental influences and associated biological responses, human exposome science is currently evolving out of the metabolomics science. In analogy to the latter, the development and applications of high resolution mass spectrometry (HRMS) has shown potential and promise to greatly expand our ability to capture the broad spectrum of environmental chemicals in exposome studies. HRMS can perform both untargeted and targeted analysis because of its capability of full- and/or tandem-mass spectrum acquisition at high mass accuracy with good sensitivity. The collected data from target, suspect and non-target screening can be used not only for the identification of environmental chemical contaminants in human matrices prospectively but also retrospectively. This review covers recent trends and advances in this field. We focus on advances and applications of HRMS in human biomonitoring studies, and data acquisition and mining. The acquired insights provide stepping stones to improve understanding of the human exposome by applying HRMS, and the challenges and prospects for future research. [ABSTRACT FROM AUTHOR]

Human exposures to bisphenol A (BPA) has attained considerable global health attention and represents one of the leading environmental contaminants with potential adverse health effects including endocrine disruption. Current practice of measuring of exposure to BPA includes the measurement of unconjugated BPA (aglycone) and total (both conjugated and unconjugated) BPA; the difference between the two measurements leads to estimation of conjugated forms. However, the measurement of BPA as the end analyte leads to inaccurate estimates from potential interferences from background sources during sample collection and analysis. BPA glucuronides (BPAG) and sulfates (BPAS) represent better candidates for biomarkers of BPA exposure, since they require in vivo metabolism and are not prone to external contamination. In this work, the primary focus was to review the current state of the art in analytical methods available to quantitate BPA conjugates. The entire analytical procedure for the simultaneous extraction and detection of aglycone BPA and conjugates is covered, from sample pre-treatment, extraction, separation, ionization, and detection. Solid phase extraction coupled with liquid chromatograph and tandem mass spectrometer analysis provides the most sensitive detection and quantification of BPA conjugates. Discussed herein are the applications of BPA conjugates analysis in human exposure assessment studies. Measuring these potential biomarkers of BPA exposure has only recently become analytically feasible and there are limitations and challenges to overcome in biomonitoring studies. [ABSTRACT FROM AUTHOR]

A novel efficient transdermal (TD) lidocaine (LD) delivery device based on chitosan (CS) and hyaluronic acid (HA) was successfully developed in the present investigation. CS was grafted with glycidyl methacrylate (GMA) and butyl methacrylate (BMA) to fabricate a versatile material with improved adhesion and mechanical properties. HA was hydrophobically modified by covalently conjugating 3-(dimethylamino)-1-propylamine (DMPA) to encapsulate poorly water soluble LD and was uniformly dispersed in modified CS matrix. The prepared materials were characterized through FTIR, NMR, XRD, SEM, TEM and tensile assay. The dispersion of amine functionalized HA (AHA) on modified CS matrix offered strong matrix – filler interaction, which improved the mechanical properties and drug retention behavior of the device . In vitro skin permeation study of LD was performed with modified Franz diffusion cell using rat skin and exhibited controlled release. The influence of storage time on release profile was investigated and demonstrated that after the initial burst, LD release profile of the device after 30 and 60 days storage was identical to that of a device which was not stored. In vivo skin adhesion test and skin irritation assay in human subjects, water vapor permeability and environmental fitness test was performed to judge its application in biomedical field. All results displayed that the fabricated device is a potential candidate for TD LD administration to the systemic circulation. [ABSTRACT FROM AUTHOR]

The high reactivity of bisphenol A (BPA) with disinfectant chlorine is evident in the instantaneous formation of chlorinated BPA derivatives (Cl x BPA) in various environmental media that show increased estrogen-activity when compared with that of BPA. The documented health risks associated with BPA exposures have led to the gradual market entry of BPA structural analogs, such as bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), etc. A suite of exposure sources to Cl x BPA and BPA analogs in the domestic environment is anticipated to drive the nature and range of halogenated BPA derivatives that can form when residual BPA comes in contact with disinfectant in tap water and/or consumer products. The primary objective of this review was to survey all available studies reporting biomonitoring protocols of Cl x BPA and structural BPA analogs (BPS, BPF, BPB, etc.) in human matrices. Focus was paid on describing the analytical methodologies practiced for the analysis of Cl x BPA and BPA analogs using hyphenated chromatography and mass spectrometry techniques, because current methodologies for human matrices are complex. During the last decade, an increasing number of ecotoxicological, cell-culture and animal-based and human studies dealing with Cl x BPA exposure sources and routes of exposure, metabolism and toxicity have been published. Up to date findings indicated the association of Cl x BPA with metabolic conditions, such as obesity, lipid accumulation, and type 2 diabetes mellitus, particularly in in-vitro and in-vivo studies. We critically discuss the limitations, research needs and future opportunities linked with the inclusion of Cl x BPA and BPA analogs into exposure assessment protocols of relevant epidemiological studies. [ABSTRACT FROM AUTHOR]

Gradually-changing shocks associated with potable water quality deficiencies are anticipated for urban drinking-water distribution systems (UDWDS). The impact of structural UDWDS features such as, the number of pipe leaking incidences on the formation of water trihalomethanes (THM) at the geocoded household level has never been studied before. The objectives were to: (i) characterize the distribution of water THM concentrations in households from two district-metered areas (DMAs) with contrasting UDWDS characteristics sampled in two seasons (summer and winter), and (ii) assess the within- and between-household, spatial variability of water THM accounting for UDWDS characteristics (household distance from chlorination tank and service pipe leaking incidences). A total of 383 tap water samples were collected from 193 households located in two DMAs within the UDWDS of Nicosia city, Cyprus, and analyzed for the four THM species. The higher intraclass correlation coefficient (ICC) values for water tribromomethane (TBM) (0.75) followed by trichloromethane (0.42) suggested that the two DMAs differed with respect to these analytes. On the other hand, the low ICC values for total THM levels between the two DMAs suggested a large variance between households. The effect of households nested under each DMA remained significant ( p < 0.05) for TBM (not for the rest of the THM species) in the multivariate mixed-effect models, even after inclusion of pipe network characteristics. Our results could find use by water utilities in overcoming techno-economic difficulties associated with the large spatiotemporal variability of THM, while accounting for the influence of UDWDS features at points of water use. [ABSTRACT FROM AUTHOR]

Abstract: With the exception of chloroform, the rest of trihalomethanes (THM), the so-called brominated THM (Br-THM) are composed of bromine-substituted molecules with increased lipophilicity and potency to biological tissues. The THM are formed within disinfected tap water and their health effects, under research, range from cancer to adverse reproductive outcomes. However, the association between human exposures to Br-THM and the risk of developing type II diabetes mellitus (T2DM) and metabolic co-morbidities, such as obesity and non-alcoholic steatohepatitis has never been previously explored. The objective of this exploratory analysis was to address obesity-mediated associations between urinary concentrations of brominated THM and incidences of T2DM in a Cypriot adult population (n=326). First morning urine voids were collected once during summer and another time during winter while a detailed questionnaire was administered to participants. Creatinine-adjusted urinary Br-THM analyte concentrations were significantly (p <0.05) higher in T2DM cases when compared with those in healthy individuals. Multivariate logistic regression models adjusted for potential confounders showed that participants with ?30kgm?2 BMI were at a higher T2DM risk (OR=8.42, 95% CI: 1.97, 45.5; p <0.01) when compared with that of normal weight participants (<25kgm?2). About 4 times higher risk for developing T2DM was observed for individuals in the upper tertile of urinary Br-THM levels (OR=3.99, 95% CI: 1.07, 19.7; p <0.05) when compared with the lower tertile participants. Among the participants with BMI?25kg m?2, urinary Br-THM levels were significantly (p<0.001) higher in diabetics than in healthy individuals. Ingestion and non-ingestion exposures to Br-THM deserve careful consideration in relevant epidemiological studies, as a possible environmental risk factor of T2DM. [Copyright &y& Elsevier]

Abstract: Changes in disinfectant type could trigger a cascade of reactions releasing pipe-anchored metals/metalloids into finished water. However, the effect of pre-formed disinfection by-products on the release of sorbed contaminants (arsenic-As in particular) from drinking water distribution system pipe scales remains unexplored. A bench-scale study using a factorial experimental design was performed to evaluate the independent and interaction effects of trihalomethanes (TTHM) and haloacetic acids (HAA) on arsenic (As) release from either scales-only or scale-biofilm conglomerates (SBC) both anchored on asbestos/cement pipe coupons. A model biofilm (Pseudomonas aeruginosa) was allowed to grow on select pipe coupons prior experimentation. Either TTHM or HAA individual dosing did not promote As release from either scales only or SBC, detecting <6μg AsL−1 in finished water. In the case of scales-only coupons, the combination of the highest spike level of TTHM and HAA significantly (p<0.001) increased dissolved and total As concentrations to levels up to 16 and 95μgL−1, respectively. Similar treatments in the presence of biofilm (SBC) resulted in significant (p <0.001) increase in dissolved and total recoverable As up to 20 and 47μgL−1, respectively, exceeding the regulatory As limit. Whether or not, our laboratory-based results truly represent mechanisms operating in disinfected finished water in pipe networks remains to be investigated in the field. [Copyright &y& Elsevier]

Abstract: Water contamination and noise have been consistently the least assessed environmental/lifestyle exposures in pregnancy–birth cohorts (PBC). Water quality surveillance data collected during the past decade within urban drinking-water distribution systems call for re-evaluation of water and health issues in the developed world. The objectives of this scientific commentary were to (i) highlight the extent of appraisal of water contamination in exposure assessment studies of PBC, worldwide, and (ii) propose recommendations to increase awareness of emerging water-related risks through their improved representation into PBC study designs in urban centers. Three scientific literature databases (Scopus, PubMed, and Web of Science) were used for a systematic search on worldwide PBC and their publications that considered water contamination and health outcomes. Publicly-available e-databases (ENRIECO, BIRTHCOHORTS, and CHICOS) were also employed for detailed exploration of existing European Union (EU)-based PBC. Out of the 76 PBC identified in the EU territory, only 12 of them incorporated water contamination into their study designs. Among which only 6 PBC published scientific articles that either included data on water contamination and/or water intake estimates. Trihalomethanes but not other disinfection by-products were mostly studied in the PBC around the globe, while fluoride, atrazine, perfluorinated compounds, tetrachloroethylene, and lead were studied to a lesser extent as water contaminants. It appears that chemical-based water contamination and corresponding human exposures represent a largely underappreciated niche of exposure science pertaining to pregnant mother and children's health in PBC. Future PBC studies should grasp this opportunity to substantially reform elements of water contamination in their exposure assessment protocols and effectively combine them with their epidemiological study designs. [Copyright &y& Elsevier]

Abstract: Non-carcinogenic effects in low-level (<100μgL−1) arsenic (As)-impacted populations, such as the development and progression of type-2 diabetes mellitus (T2DM), are often neglected given the primary emphasis of public health authorities on As carcinogenicity. We gathered studies reporting urinary biomarkers of As exposure (U-As) and biomarkers associated with T2DM and its complications (U-T2DM), such as renal damage, oxidation stress, low-grade inflammation, and endothelial damage. Studied U-T2DM biomarkers were: 8-hydroxy-2′deoxyguanosine, N-acetyl-β-d-glucosaminidase, β2-microglobulin, and albumin. Data was expressed as: either arithmetic means and standard deviations, or geometric means and geometric standard deviations, or correlation coefficients of U-As and U-T2DM. Urinary As concentrations were consistently associated with the aforementioned biomarkers of T2DM pathologic complications. Despite the limited selectivity of the selected T2DM biomarkers, a per unit change in As exposure level was reflected in the corresponding T2DM biomarker urinary concentrations. Our systematic review provides new evidence on the role of environmental As exposures influencing the T2DM disease process. Additional epidemiologic studies onto the association between As and T2DM should incorporate both urinary As and T2DM biomarkers, as suggested in this study, in order to evaluate subclinical effects of low-level As exposures. [Copyright &y& Elsevier]

Abstract: A fast-growing bottled water market is occasionally challenged by reports calling for contaminant leaching from water-contact materials (plastics). Our focus was on leaching of antimony (Sb) and brominated compounds expressed by total soluble bromine (Br) measurements, including those of polybrominated diphenyl ethers (PBDE). Studies are lacking on concomitant leaching of two or more inorganic plastic constituents from the same bottle. A market-representative basket survey of bottled water was initiated in Boston, USA supermarkets. Bottled water classes sampled were: i) non-carbonated (NCR), ii) carbonated (CR), and iii) non-carbonated and enriched (NCRE). Plastic bottle materials sampled were: polyethylene terephthalate (PET), high-density polyethylene (HDPE), polystyrene (PS), and polycarbonate (PC). Storage conditions for the 31 bottled water samples were: 23°C temperature, no-shaking and 12h/12h light/dark for 60days of equilibration. Average Br and Sb concentrations after 60-days of storage followed the order of NCR

Abstract: Microbial-, and chemical-based burden of disease associated with lack of access to safe water continues to primarily impact developing countries. Cost-effective health risk-mitigating measures, such as of solar disinfection applied to microbial-contaminated water stored in plastic bottles have been increasingly tested in developing countries adversely impacted by epidemic water-borne diseases. Public health concerns associated with chemical leaching from water packaging materials led us to investigate the magnitude and variability of antimony (Sb) and bromine (Br) leaching from reused plastic containers (polyethylene terephthalate, PET; and polycarbonate, PC) subject to UV and/or temperature-driven disinfection. The overall objective of this study was to determine the main and interactive effects of temperature, UV exposure duration, and frequency of bottle reuse on the extent of leaching of Sb and Br from plastic bottles into water. Regardless of UV exposure duration, frequency of reuse (up to 27 times) was the major factor that linearly increased Sb leaching from PET bottles at all temperatures tested (13–47 °C). Leached Sb concentrations (∼360 ng L−1) from the highly reused (27 times) PET bottles (minimal Sb leaching from PC bottles, <15 ng L−1) did not pose a serious risk to human health according to current daily Sb acceptable intake estimates. Leached Br concentrations from both PET and PC containers (up to ∼15 μg L−1) did not pose a consumer health risk either, however, no acceptable daily dose estimates exist for oral ingestion of organo-brominated, or other plasticizers/additives compounds if they were to be found in bottled water at much lower concentrations. Additional research on potential leaching of organic chemicals from water packaging materials is deemed necessary under relevant environmental conditions. [Copyright &y& Elsevier]

Concentrated animal feeding operations around the globe generate large amounts of nitrous oxide (N2O) in the surrounding atmosphere. Liquid animal waste systems have received little attention with respect to N2O emissions. We hypothesized that the solution chemistry of animal waste aqueous suspensions would promote conditions that lead to N2O supersaturation at the liquid/air interface. The concentration of dissolved N2O in poultry litter (PL) aqueous suspensions at 25 °C was 0.36 μg N2O mL−1, at least an order of magnitude greater than that measured in water in equilibrium with ambient air, suggesting N2O supersaturation. There was a nonlinear increase in the N2O Henry constants of PL from 2810 atm/mole fraction at 35 °C to 17 300 atm/mole fraction at 41 °C. The extremely high N2O Henry constants were partially ascribed to N2O complexation with aromatic moieties. Complexed N2O structures were unstable at temperatures > 35 °C, supplying the headspace with additional free N2O concentrations. [Copyright &y& Elsevier]

Ethylenediamene tetraacetic acid (EDTA) has been used to mobilize soil lead (Pb) and enhance plant uptake for phytoremediation. Chelant bound Pb is considered less toxic compared to free Pb ions and hence might induce less stress on plants. Characterization of possible Pb complexes with phytochelatins (PC n , metal-binding peptides) and EDTA in plant tissues will enhance our understanding of Pb tolerance mechanisms. In a previous study, we showed that vetiver grass (Vetiveria zizanioides L.) can accumulate up to 19,800 and 3350mg Pb kg−1 dry weight in root and shoot tissues, respectively; in a hydroponics set-up. Following the basic incubation study, a greenhouse experiment was conducted to elucidate the efficiency of vetiver grass (with or without EDTA) in remediating Pb-contaminated soils from actual residential sites where Pb-based paints were used. The levels of total thiols, PC n , and catalase (an antioxidant enzyme) were measured in vetiver root and shoot following chelant-assisted phytostabilization. In the presence of 15mM kg −1 EDTA, vetiver accumulated 4460 and 480mg Pb kg−1 dry root and shoot tissue, respectively; that are 15- and 24-fold higher compared to those in untreated controls. Despite higher Pb concentrations in the plant tissues, the amount of total thiols and catalase activity in EDTA treated vetiver tissues was comparable to chelant unamended controls, indicating lowered Pb toxicity by chelation with EDTA. The identification of glutathione (referred as PC1) (m/z 308.2), along with chelated complexes like Pb–EDTA (m/z 498.8) and PC1–Pb–EDTA (m/z 805.3) in vetiver root tissue using electrospray tandem mass spectrometry (ES-MS) highlights the possible role of such species towards Pb tolerance in vetiver grass. [Copyright &y& Elsevier]

Abstract: Animal wastewater lagoons nearby concentrated animal feeding operations (CAFOs) represent the latest tendency in global animal farming, severely impacting the magnitude of greenhouse gas emissions, including nitrous oxide (N2O). We hypothesized that lagoon wastewater could be supersaturated with N2O as part of incomplete microbial nitrification/denitrification processes, thereby regulating the N2O partitioning in the gaseous phase. The objectives of this study were: (i) to investigate the magnitude of dissolved N2O concentrations in the lagoon; and (ii) to determine the extent to which supersaturation of N2O occurs in wastewater lagoons. Dissolved N2O concentrations in the wastewater samples were high, ranging from 0.4 to 40.5μg N2O mL−1. Calculated dissolved N2O concentrations from the experimentally measured partition coefficients were much greater than those typically expected in aquatic systems (<∼0.6μg N2O mL−1). Knowledge of the factors controlling the magnitude of N2O supersaturation could potentially bridge mass balance differences between in situ measurements and global N2O models. [Copyright &y& Elsevier]

Abstract: Chelation of metals is an important factor in enhancing solubility and hence, availability to plants to promote phytoremediation. We compared the effects of two chelants, namely, ethylenediaminetetraacetic acid (EDTA) and ethylenediaminedisuccinic acid (EDDS) in enhancing mobilized lead (Pb) in Pb-based paint contaminated residential soils collected from San Antonio, Texas and Baltimore, Maryland. Batch incubation studies were performed to investigate the effectiveness of the two chelants in enhancing mobilized Pb, at various concentrations and treatment durations. Over a period of 1 month, the mobilized Pb pool in the San Antonio study soils increased from 52mgkg−1 to 287 and 114mgkg−1 in the presence of 15mMkg−1 EDTA and EDDS, respectively. Stepwise linear regression analysis demonstrated that pH and organic matter content significantly affected the mobilized Pb fraction. The regression models explained a large percentage, from 83 to 99%, of the total variation in mobilized Pb concentrations. [Copyright &y& Elsevier]

Inconsistent dosage of insulin (INS) for type 2 diabetes patients lead to severe adverse effects like limb amputation, blindness and fatal hypo or hyper glycaemia. Hence, a drug delivery system (DDS) capable of consistent INS release by sensing changes in blood glucose level is essential. Herein, we report a glucose responsive DDS comprised of oleic acid-grafted-aminated beta cyclodextrin (OA-g-ACD) copolymer, coated with a dispersion of glucose oxidase (GOx) and catalase (CAT). The prepared DDS was characterised using FTIR, Optical Microscopy, H 1 NMR, DLS and SEM. Hydrophobicity and drug loading capacity was ascertained using contact angle measurements and confocal laser scanning microscopy (CLSM) respectively. Extent of swelling was observed to be a function of glucose concentration. INS release profile showed a cumulative release of 78.0 % after 240 min. Flow cytometry studies revealed greater population of INS on HeLa cells indicating application of DDS as potential candidate for the intravenous administration of INS. [ABSTRACT FROM AUTHOR]

Non-iodo-containing trihalomethanes (TTHM) are frequently detected in chlorinated tap water and currently regulated against their carcinogenic potential. Iodinated THM (ITHM) may also form in disinfected with chlorine waters that are high in iodine content, but little is known about their magnitude and variability within the drinking-water pipe distribution network of urban areas. The main objective of this study was to determine the magnitude and variability of ITHM and TTHM levels and their corresponding daily intake estimates within the drinking water distribution systems of Limassol and Nicosia cities of Cyprus, using tap samples collected from individual households (n = 37). In Limassol, mean household tap water ITHM and TTHM levels was 0.58 and 38 μg L − 1 , respectively. Dichloroiodomethane (DCIM) was the dominant species of the two measured ITHM compounds accounting for 77% of total ITHM and in the range of 0.032 and 1.65 μg L − 1 . The range of DCIM concentrations in Nicosia tap water samples was narrower (0.032 – 0.848 μg L − 1 ). Mean total iodine concentration in tap water samples from the seaside city of Limassol was 15 μg L − 1 and approximately twice to those observed in samples from the mainland Nicosia city. However, iodine concentrations did not correlate with the ITHM levels. The calculated chronic daily intake rates of ITHM were low when compared with those of TTHM, but because of their widespread occurrence in tap water and their enhanced mammalian cell toxicity, additional research is warranted to assess the magnitude and variability of human ITHM exposures. [ABSTRACT FROM AUTHOR]

• A molecularly imprinted conducting polymer was developed for the detection of Chlorpyrifos. • Polythiophenes covalently grown on the surface of Multiwalled carbon nanotubes as imprinting substrate. • Low limit of detection (LOD) of 4.0 × 10-12 M was obtained. Molecular imprinting technique (MIT) with electrochemical sensing provides an attractive tool for the fabrication of sensors. Incorporation of conducting copolymer and surface imprinting strategies in the sensing device improves the conducting properties and poor template accessibility, slow binding kinetics at the same time. Here, this technique was employed with conducting polymers with multi-walled carbon nanotubes (MWCNT) to build an electrochemical sensor for detecting Chlorpyrifos (CPF) in vegetable sample solutions. In this work, we aimed at synthesizing a copolymer of 3-thiophene acetic acid and 3,4-ethylene dioxythiophene on the surface of MWCNT. We further constructed a polymer drop-casted glassy carbon electrode sensor for ultrasensitive detection CPF. Under optimal conditions, the sensor exhibited a very low limit of detection (LOD) of 4.0 × 10-12 M for CPF. Due to the excellent repeatability and reusability of the materials, this study and findings have potential applications in the monitoring of pesticides from vegetable samples. [ABSTRACT FROM AUTHOR]

The burden of pediatric asthma and other allergic diseases is not evenly distributed among United States populations. To determine whether urinary biomarkers are associated with asthma morbidity, and if associations vary by child race, ethnicity and sex. This study includes n = 152 children with physician-diagnosed asthma who participated in the School Inner-City Asthma Intervention Study (SICAS-2). Metabolites of phenol, paraben, polycyclic aromatic hydrocarbons, and phthalate analytes were analyzed from urine samples collected at baseline. Asthma symptom days over the past 2 weeks were dichotomized to no asthma symptom days or any asthma symptom days. Cross-sectional regression models were adjusted for age, sex, number of colds, household income, prescription control, race and ethnicity, body mass index (BMI) percentile, and smoke exposure. Weighted quantile sum regression was used to analyze each chemical class and a total mixture effect, controlling for the same covariates. Analyses were conducted with the assistance of the National Institute of Environmental Health Sciences Children's Health Exposure Analysis Resource (CHEAR). Participants were mostly Hispanic/Latino and low income with an average age of 7.83 years and the average maximum asthma symptom days over the past two weeks of 2.13 (standard deviation: 3.56). The maximum concentrations indicate extreme values for several chemicals, including bisphenol-3, 2,5-dichlorophenol, propyl and methyl parabens, triclosan, methyl paraben and cotinine. We found a significant interaction effect and differing contributions of analytes for children with allergen sensitivity versus those that did not. For stratified analyses assessing effect modification by child race and ethnicity, weighted quantile sum interaction models showed reduced odds of asthma symptoms to a greater magnitude in children of other races and ethnicities compared to Black, Non-Hispanic children. Preliminary analyses of the association between environmental chemical exposure and asthma symptoms among inner-city children revealed an inverse association, which may be due to personal care and medication use and can be understood further in future analyses. Beneficial effects were detected for most of the chemicals. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA)-free plastic products are widely available. Transient BPA release has been reported in Tritan drinking bottles. This study assessed the effectiveness of common consumer washing methods in removing BPA contamination in Tritan bottles using both ELISA and HPLC-MS/MS assays. BPA release was detected in 2 out of 10 kinds of Tritan drinking bottles tested. Average BPA level was 0.493 μg/L in water samples from a type of Tritan kid drinking bottle following 24-h incubation at room temperature, corresponding to a release rate of 0.015 ng/cm2/h. Of the common consumer cleaning methods identified in an informal survey, dishwashing was the most effective method that significantly reduced, even eliminated BPA release from the tested BPA-positive Tritan bottles, while rinsing with water and handwashing with soap and water were ineffective. The bioactivity of the leached BPA was confirmed using a rodent cardiac myocyte acute exposure model and an invertebrate 7-day exposure model. The BPA release is possibly the result of surface contamination in the manufacturing process. As a case study, our result may be informative for general consumer practice and for better quality control by the manufactures. • Transient BPA release from some Tritan drinking bottles was detected. • BPA release was likely due to surface contamination in the manufacturing process. • The released BPA was bioactive as assessed using two independent bioassays. • Effect of common consumer cleaning methods in removing BPA contamination was assessed. • Dishwashing, but not rinsing or handwashing, was effective in elimination BPA release. [ABSTRACT FROM AUTHOR]

• We dermally administered deuterated BPA to 10 subjects at 100 µg/kg over 12 h. • We conducted blood and urine analysis from the beginning of dosing through 3–6 days. • We present time-course serum and urine concentrations of total and free d6-BPA. • Free d6-BPA was a greater percentage of total serum BPA when compared to oral data. • Dermal exposure resulted in a longer half-life when compared to oral data. • Approximately 2.2% of the dermal dose became systemically available. Human exposures to bisphenol A (BPA) are widespread. The current study addresses uncertainties regarding human pharmacokinetics of BPA following dermal exposure. To examine the absorption, distribution, metabolism and excretion of BPA in humans following dermal administration. We dermally administered deuterated BPA (d6-BPA) to 10 subjects (6 men and 4 women) at a dose of 100 µg/kg over a 12-hour period and conducted blood and urine analysis from the beginning of dosing through a three- or six-day period. We present time-course serum and urine concentrations of total and unconjugated ("free") d6-BPA and used this information to calculate terminal half-life and area under the curve. Detectable serum levels of total d6-BPA were observed at 1.4 h after the start of dosing, and a maximum serum concentration (C max) of 3.26 nM was observed. Free d6-BPA was detectable in serum 2.8 h after start of dermal administration, with C max of 0.272 nM. Beginning at approximately seven hours and continuing to 12 h (which corresponds to cessation of exposure), the concentration of free and total serum d6-BPA plateaued. The terminal half-lives of total d6-BPA and free d6-BPA in the body were 21.4 ± 9.81 h and 17.6 ± 7.69 h, respectively. Elimination from the body was rate-limited by kinetics in the dermal compartment. Free d6-BPA was a greater percentage of the area under the curve of total serum BPA (8.81%) compared to the 0.56% observed in our previously published oral study. Recovery of total d6-BPA in urine was <2% of the applied dose after six days. Analysis of the area under the curve for dermal and oral administration revealed that 2.2% of the dermal dose became systemically available. These data are in line with prior studies indicating how pharmacokinetics of BPA differ following oral and dermal exposures. Dermal exposure resulted in a longer apparent half-life and higher free:total d6-BPA ratio compared to oral. [ABSTRACT FROM AUTHOR]

Bronchopulmonary dysplasia (BPD) is a serious yet common morbidity of preterm birth. Although prior work suggests a possible role for phthalate exposure in the development of BPD, no study has rigorously evaluated this. Our objective was to determine whether hospital-based phthalate exposure is associated with the development of BPD and to identify developmental windows sensitive to exposure. Study Design: This is a prospective multicenter cohort study of 360 preterm infants born at 23–33 weeks gestation participating in the Developmental Impact of NICU Exposures (DINE) cohort. 939 urine specimens collected during the NICU stay were analyzed for biomarkers of phthalate exposure by liquid chromatography with tandem mass spectrometry. The modified Shennan definition was used to diagnose bronchopulmonary dysplasia. Reverse distributed-lag modeling identified developmental windows sensitive to specific phthalate exposure, controlling for relevant covariates including sex and respiratory support. Thirty-five percent of participants were diagnosed with BPD. Exposure to specific phthalate mixtures at susceptible points in preterm infant development are associated with later diagnosis of BPD in models adjusted for use of respiratory support. The weighted influence of specific phthalate metabolites in the mixtures varied by sex. Metabolites of di(2-ethylhexyl) phthalate, a phthalate previously linked to neonatal respiratory support equipment, drove this association, particularly among female infants, at 26- to 30-weeks post-menstrual age. This is the largest and only multi-site study of NICU-based phthalate exposure and clinical impact yet reported. In well-constructed models accounting for infant sex and respiratory support, we found a significant positive association between ultimate diagnosis of BPD and prior exposure to phthalate mixtures with DEHP predominance at 26- to 30-weeks PMA or 34–36-weeks PMA. This information is critically important as it identifies a previously unrecognized and modifiable contributing factor to BPD. [ABSTRACT FROM AUTHOR]

Phthalates are a class of widely used synthetic chemicals found in commonly used materials and products. Epidemiological studies suggest phthalate exposure is associated with asthma outcomes, though most studies have not investigated phthalates as triggers of exacerbations in children diagnosed with asthma. This study used data from the Home Air in Agriculture Pediatric Intervention Trial (HAPI) to examine relationships between phthalate exposure and outcomes related to childhood asthma exacerbation. We used measures of phthalate metabolites and respiratory health measures including fractional exhaled nitric oxide (FENO), the Asthma Control Test (ACT), caregiver report of symptoms, and urinary leukotriene E4 (uLTE4) to estimate longitudinal associations using mixed effects models, adjusted for covariates. For 100% (i.e., doubling) increases in mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono-2-ethylhexyl phthalate (MEHP), and mono-ethyl phthalate (MEP), concentrations of FENO increased by 8.7% (95% CI: 0.7-17.3), 7.2% (95% CI: 0.0-14.9), and 6.4% (95% CI: 0.0-13.3), respectively. All phthalate metabolites demonstrated associations with uLTE4, effect sizes ranging from an 8.7% increase in uLTE4 (95% CI: 4.3-12.5) for a 100% increase in MEHP to an 18.1% increase in uLTE4 (95% CI: 13.3-23.1) for a 100% increase in MNBP. In models of caregiver report of symptoms, no phthalate metabolites were significantly associated in primary models. No phthalate metabolites were associated with standardized ACT score. Our results suggest urinary phthalate metabolites are significant predictors of inflammatory biomarkers related to asthma exacerbation in children but not child and caregiver report of airway symptomatology. [ABSTRACT FROM AUTHOR]

A consortium of laboratories established under the Children's Health Exposure Analysis Resource (CHEAR) used a multifaceted quality assurance program to promote measurement harmonization for trace organics analyses of human biospecimens that included: (1) participation in external quality assurance (EQA)/proficiency testing (PT) programs; (2) analyses of a urine-based CHEAR common quality control (QC) pool with each analytical batch across all participating laboratories; (3) method validation against NIST Standard Reference Materials® (SRMs); and (4) analyses of blinded duplicates and other project-specific QC samples. The capability of five CHEAR laboratories in organic chemical analysis increased across the 4-year period, and performance in the external PT program improved over time - recent challenges reporting >90% analytes with satisfactory performance. The CHEAR QC pools were analyzed for several classes of organic chemicals including phthalate metabolites and environmental phenols by the participating laboratories with every batch of project samples, which provided a rich source of measurement data for the assessment of intra- and inter-laboratory variance. Within-laboratory and overall variabilities in measurements across laboratories were calculated for target chemicals in urine QC pools; the coefficient of variation (CV) was generally below 25% across batches, studies and laboratories and indicated acceptable analytical imprecision. The suite of organic chemicals analyzed in the CHEAR QC pool was broader than those reported for commercially available reference materials. The accuracy of each of the laboratories' methods was verified through the analysis of several NIST SRMs and was, for example, 97 ± 5.2% for environmental phenols and 95 ± 11% for phthalates. Analysis of blinded duplicate samples showed excellent agreement and reliability of measurements. The intra-class correlation coefficients (ICC) for phthalate metabolites analyzed in various batches across three CHEAR laboratories showed excellent reliability (typically >0.90). Overall, the multifaceted quality assurance protocols followed among the CHEAR laboratories ensured reliable and reproducible data quality for several classes of organic chemicals. Increased participation in external PT programs through inclusion of additional target analytes will further enhance the confidence in data quality. [ABSTRACT FROM AUTHOR]