Are We Justified in Modeling Human Exposure to Chlorinated Paraffin Mixtures Using the Average Properties of Congeners and Homologues?

Concern over human exposure to chlorinated paraffin (CP) mixtures keeps increasing. The absence of a comprehensive understanding of how human exposure varies with the physicochemical properties of CP constituents has hindered the ability to determine at what level of aggregation exposure to CPs should be assessed. We answer this question by comparing exposure predicted with either a "complex" method that utilizes isomer-specific properties or "simplified" methods that rely on median properties of congener, homologue, or short-/medium-/long-chain CP groups. Our results demonstrate the wide range of physicochemical properties across CP mixtures and their dependence on molecular structures. Assuming unit emissions in the environment, these variances translate into an extensive disparity in whole-body concentrations predicted for different isomers, spanning ∼11 orders of magnitude. CPs with 13-19 carbons and 6-10 chlorines exhibit the highest human exposure potential, primarily owing to moderate to high hydrophobicity and slow environmental degradation and biotransformation. Far-field exposure is dominant for most CP constituents. Our study underscores that using average properties of congener, homologue, or S/M/LCCP groups yields results that are consistent with those derived from isomer-based modeling, thus offering an efficient and practical framework for future risk assessments and human exposure studies of CPs and other complex chemical mixtures.

Identification and yield of metabolites of chlorinated paraffins incubated with chicken liver microsomes: Assessment of their potential to convert into metabolites.

Chlorinated paraffins (CPs) are emerging environmental pollutants. Although metabolism has been shown to affect the differential accumulation of short-chain (SCCPs), medium-chain (MCCPs) and long-chain (LCCPs) CPs in birds, CP metabolites have rarely been reported and the extent to which they are formed is still unclear. In this study, single and mixed CP standards were incubated with chicken liver microsomes in vitro to study the generation of CP metabolites. Putative aldehyde/ketone and carboxylic acid metabolites identified by mass spectroscopy data were shown to be false positive results. Phase I metabolism of CPs first formed monohydroxylated ([M-Cl+OH]) and then dihydroxylated ([M-2Cl+2OH]) products. The yields of monohydroxylated metabolites of CPs decreased with increasing carbon chain length and chlorine content at the initial stage of reaction. Notably, the yield of monohydroxylated metabolites of SCCPs with 51.5% Cl content reached 21%, and that of 1,2,5,6,9,10-hexachlorodecane (C10H16Cl6) was as high as 71%. Thus, monohydroxy metabolites of CPs in birds should not be ignored, especially those of SCCPs. This study provides important data that could support improvements to the ecological/health risk assessment of CPs.

Short-chain chlorinated paraffin (SCCP) pollution from a CP production plant in China: Dispersion, congener patterns and health risk assessment.

China is the largest chlorinated paraffin (CP) producer in the world. Given that CP production is a major source of short-chain CP (SCCP) pollution in China, the effects of CP production on the environment inside and outside of CP production plants are worth revealing. The concentrations and specific congener group patterns of SCCPs in various environmental matrices, such as air, soil and dust, inside and outside of a chosen CP production plant surrounded by farmlands and villages were analyzed to explore SCCP pollution and transportation behaviors. SCCP concentrations in air (129-1442 ng/m3) and soil (28-554 µg/g) samples inside the CP production plant were dramatically higher than those in air (91-333 ng/m3) and soil (102-441 ng/g) samples outside the CP production plant. Based on the congener abundance patterns among these samples, lighter groups (C10-11 and Cl5-6) were dominant in atmospheric environment, with greater long-range transport potential, whereas heavier groups (C12-13 and Cl7-10) were inclined toward deposition. It was clear that substantial amounts of SCCPs were released from the CP production plant, which contaminated the environment inside and outside of the plant. The daily occupational SCCP exposure of employees in the production hall (21.8 µg/day-kg) exceeded the tolerable daily intake (TDI, 10 µg/day-kg) given by Canadian Environmental Protection Act, suggesting that production employees were confronted with high health risk from SCCP exposure; while daily SCCP exposure of employees in office areas (0.57 µg/day-kg) and residents near the CP plant (1.22-25.5 × 10-2 µg/day-kg) were significantly lower, representing low health risk.

Short-chain chlorinated paraffins in soil, paddy seeds (Oryza sativa) and snails (Ampullariidae) in an e-waste dismantling area in China: Homologue group pattern, spatial distribution and risk assessment.

Short-chain chlorinated paraffins (SCCPs) in multi-environmental matrices are studied in Taizhou, Zhejiang Province, China, which is a notorious e-waste dismantling area. The investigated matrices consist of paddy field soil, paddy seeds (Oryza sativa, separated into hulls and rice unpolished) and apple snails (Ampullariidae, inhabiting the paddy fields). The sampling area covered a 65-km radius around the contamination center. C10 and C11 are the two predominant homologue groups in the area, accounting for about 35.7% and 33.0% of total SCCPs, respectively. SCCPs in snails and hulls are generally higher than in soil samples (30.4-530 ng/g dw), and SCCPs in hulls are approximate five times higher than in corresponding rice samples (4.90-55.1 ng/g dw). Homologue pattern analysis indicates that paddy seeds (both hull and rice) tend to accumulate relatively high volatile SCCP homologues, especially the ones with shorter carbon chain length, while snails tend to accumulate relatively high lipophilic homologues, especially the ones with more substituted chlorines. SCCPs in both paddy seeds and snails are linearly related to those in the soil. The e-waste dismantling area, which covers a radius of approximate 20 km, shows higher pollution levels for SCCPs according to their spatial distribution in four matrices. The preliminary assessment indicates that SCCP levels in local soils pose no significant ecological risk for soil dwelling organisms, but higher risks from dietary exposure of SCCPs are suspected for people living in e-waste dismantling area.

Copy number analysis by low coverage whole genome sequencing using ultra low-input DNA from formalin-fixed paraffin embedded tumor tissue.

Unlocking clinically translatable genomic information, including copy number alterations (CNA), from formalin-fixed paraffin-embedded (FFPE) tissue is challenging due to low yields and degraded DNA. We describe a robust, cost-effective low-coverage whole genome sequencing (LC WGS) method for CNA detection using 5 ng of FFPE-derived DNA. CN profiles using 100 ng or 5 ng input DNA were highly concordant and comparable with molecular inversion probe (MIP) array profiles. LC WGS improved CN profiles of samples that performed poorly using MIP arrays. Our technique enables identification of driver and prognostic CNAs in archival patient samples previously deemed unsuitable for genomic analysis due to DNA limitations.

Occurrences, sources and risk assessment of short- and medium-chain chlorinated paraffins in sediments from the middle reaches of the Yellow River, China.

Chlorinated paraffins (CPs), one class of hydrophobic and toxic compounds, are easily adsorbed into sediments and then pose potential risks to the ecosystem and human health. However, few researches on short- and medium-chain CPs (SCCPs and MCCPs) in sediments have been performed. In order to comprehensively investigate the spatial distributions, sources, and ecological risks of CPs, sediments collected from the middle reaches of the Yellow River were analyzed by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS). The concentrations of SCCPs and MCCPs ranged from 11.6 to 9.76 × 103 ng/g dry weight (dw) and from 8.33 to 168 ng/g dw, respectively. No significant correlation was found between total organic carbon (TOC) and CP concentrations (P > 0.05). The spatial distributions showed that contamination levels of CPs were relevant to human activities. In addition, two types of sediment samples were classified by hierarchical cluster analysis (HCA) and results indicated the predominant congener groups were C10Cl6-7 for SCCPs and C14Cl7-8 for MCCPs. Principal component analysis (PCA) revealed that SCCPs and MCCPs in the sediments may have different sources, and SCCPs are likely to come from the production and use of CP-42 and CP-52. Moreover, complex environmental processes, including long-range transportation via the atmosphere and/or river, deposition and degradation of CPs, resulted in increased abundances of short chain and low chlorinated congeners in sediment samples compared with commercial mixtures, and different homolog patterns among samples. The significant negative correlation between SCCP concentrations and MCCP/SCCP ratios could be related to long-range transport of CPs. A preliminary risk assessment indicated that CPs at current levels posed no significant ecological risk.

MCNP SIMULATION OF THE HP(10) ENERGY RESPONSE OF A BRAZILIAN TLD ALBEDO NEUTRON INDIVIDUAL DOSEMETER, FROM THERMAL TO 20 MeV.

The Brazilian Instituto de Radioproteção e Dosimetria (IRD) runs a neutron individual monitoring system with a home-made TLD albedo dosemeter. It has already been characterised and calibrated in some reference fields. However, the complete energy response of this dosemeter is not known, and the calibration factors for all monitored workplace neutron fields are difficult to be obtained experimentally. Therefore, to overcome such difficulties, Monte Carlo simulations have been used. This paper describes the simulation of the HP(10) neutron response of the IRD TLD albedo dosemeter using the MCNPX transport code, for energies from thermal to 20 MeV. The validation of the MCNPX modelling is done comparing the simulated results with the experimental measurements for ISO standard neutron fields of (241)Am-Be, (252)Cf, (241)Am-B and (252)Cf(D2O) and also for (241)Am-Be source moderated with paraffin and silicone. Bare (252)Cf are used for normalisation.

The Italian external quality assessment for RAS testing in colorectal carcinoma identifies methods-related inter-laboratory differences.

BACKGROUND: In 2014 the European Medicines Agency included exon 2, 3 and 4 KRAS and NRAS testing for the selection of metastatic colorectal cancer (mCRC) patients eligible for the therapy with anti-EGFR monoclonal antibodies. The Italian Association of Medical Oncology (AIOM) and the Italian Society of Pathology and Cytology (SIAPEC) organized an external quality assessment (EQA) scheme for CRC to evaluate inter-laboratory consistency and to ensure standardization of the results in the transition from KRAS to all-RAS testing. METHODS: Ten formalin fixed paraffin embedded specimens including KRAS/NRAS (exons 2, 3, 4) and BRAF (codon 600) mutations were validated by three referral laboratories and sent to 88 participant centers. Molecular pathology sample reports were also requested to each laboratory. A board of assessors from AIOM and SIAPEC evaluated the results according to a predefined scoring system. The scheme was composed of two rounds. RESULTS: In the first round 36% of the 88 participants failed, with 23 centers having at least one false positive or false negative while 9 centers did not meet the deadline. The genotyping error rate was higher when Sanger sequencing was employed for testing as compared with pyrosequencing (3 vs 1.3%; p = 0.01; Pearson Chi Square test). In the second round, the laboratories improved their performance, with 23/32 laboratories passing the round. Overall, 79/88 participants passed the RAS EQA scheme. Standardized Human Genome Variation Society nomenclature was incorrectly used to describe the mutations identified and relevant variations were noticed in the genotype specification. CONCLUSION: The results of the Italian RAS EQA scheme indicate that the mutational analyses are performed with good quality in many Italian centers, although significant differences in the methods used were highlighted. The relatively high number of centers failing the first round underlines the fundamental role in continued education covered by EQA schemes.

Parafilm-M®, An Available Cost-Effective Alternative for Immuno-blot Pouches.

Commercially available standard immuno-blot pouches do play an efficient role in antibody incubation in performing an immuno-blot, but are not readily available in the laboratory and have to be specifically ordered. We have developed an equally efficient technique to make an immune-blot more cost-effective with more conservation of antibodies by using a common and readily available laboratory product Parafilm-M(®). Parafilm-M(®) which serves as a sealant for various items of laboratory equipment can be used for antibody incubation. Manually made Parafilm-M(®) pouch has a clear advantage over standard immuno-blot pouches in terms of availability, cost-effectiveness, and consumption of antibodies that ultimately reduces the cost of an immuno-blot. We have performed a series of experiments to check the efficacy of both the techniques. Samples with equal amount of protein were analyzed on separate SDS PAGE gels. The proteins were transferred electrophoretically to the nitrocellulose membrane using Trans-Blot(®) Turbo™ Mini Nitrocellulose Transfer Pack. Antibody incubation was done using standard immuno-blot pouch, standard container and Parafilm-M(®) sealed pouch. The expression of protein was determined and the results of immuno-blots were compared. We found that antibodies are binding the membrane in Parafilm-M(®) pouches as efficiently as in container method or in standard immuno-blot pouches. By restricting the membrane, the surface area of the manually made Parafilm-M(®) pouch can be reduced, less diluent is required to cover the membrane as a result less antibodies are consumed. We also calculated that each immuno-blot pouch cost around $0.1906, whereas the cost for Parafilm-M(®) pouch is 0.0695 which is almost one-third the price of an immuno-blot pouch. Thus, Parafilm-M(®) method distinctly provides a cost-effective solution for antibody incubation.

Technical reproducibility of single-nucleotide and size-based DNA biomarker assessment using DNA extracted from formalin-fixed, paraffin-embedded tissues.

DNA extracted from formalin-fixed, paraffin-embedded (FFPE) tissues has been used in the past to analyze genetic polymorphisms. We evaluated the technical reproducibility of different types of assays for gene polymorphisms using DNA extracted from FFPE material. By using the MassARRAY iPLEX system, we investigated polymorphisms in DPYD (rs1801159 and rs3918290), UMPS (rs1801019), ERCC1 (rs11615), ERCC1 (rs3212986), and ERCC2 (rs13181) in 56 FFPE DNA samples. By using PCR, followed by size-based gel electrophoresis, we also examined TYMS 5' untranslated region 2R/3R repeats and GSTT1 deletions in 50 FFPE DNA samples and 34 DNAs extracted from fresh-frozen tissues and cell lines. Each polymorphism was analyzed by two independent runs. We found that iPLEX biomarker assays measuring single-nucleotide polymorphisms provided consistent concordant results. However, by using FFPE DNA, size-based PCR biomarkers (GSTT1 and TYMS 5' untranslated region) were discrepant in 32.7% (16/49, with exact 95% CI, 19.9%-47.5%; exact binomial confidence limit test) and 4.2% (2/48, with exact 95% CI, 0.5%-14.3%) of cases, respectively, whereas no discrepancies were observed using intact genomic DNA. Our findings suggest that DNA from FFPE material can be used to reliably test single-nucleotide polymorphisms. However, results based on size-based PCR biomarkers, and particularly GSTT1 deletions, using FFPE DNA need to be interpreted with caution. Independent repeated assays should be performed on all cases to assess potential discrepancies.

Microfluidic paper-based analytical devices fabricated by low-cost photolithography and embossing of Parafilm®.

Microfluidic paper-based analytical devices (µPADs) attract tremendous attention as an economical tool for in-field diagnosis, food safety and environmental monitoring. We innovatively fabricated 2D and 3D µPADs by photolithography-patterning microchannels on a Parafilm® and subsequently embossing them to paper. This truly low-cost, wax printer and cutter plotter independent approach offers the opportunity for researchers from resource-limited laboratories to work on paper-based analytical devices.

High quality genomic copy number data from archival formalin-fixed paraffin-embedded leiomyosarcoma: optimisation of universal linkage system labelling.

Most soft tissue sarcomas are characterized by genetic instability and frequent genomic copy number aberrations that are not subtype-specific. Oligonucleotide microarray-based Comparative Genomic Hybridisation (array CGH) is an important technique used to map genome-wide copy number aberrations, but the traditional requirement for high-quality DNA typically obtained from fresh tissue has limited its use in sarcomas. Although large archives of Formalin-fixed Paraffin-embedded (FFPE) tumour samples are available for research, the degradative effects of formalin on DNA from these tissues has made labelling and analysis by array CGH technically challenging. The Universal Linkage System (ULS) may be used for a one-step chemical labelling of such degraded DNA. We have optimised the ULS labelling protocol to perform aCGH on archived FFPE leiomyosarcoma tissues using the 180k Agilent platform. Preservation age of samples ranged from a few months to seventeen years and the DNA showed a wide range of degradation (when visualised on agarose gels). Consistently high DNA labelling efficiency and low microarray probe-to-probe variation (as measured by the derivative log ratio spread) was seen. Comparison of paired fresh and FFPE samples from identical tumours showed good correlation of CNAs detected. Furthermore, the ability to macro-dissect FFPE samples permitted the detection of CNAs that were masked in fresh tissue. Aberrations were visually confirmed using Fluorescence in situ Hybridisation. These results suggest that archival FFPE tissue, with its relative abundance and attendant clinical data may be used for effective mapping for genomic copy number aberrations in such rare tumours as leiomyosarcoma and potentially unravel clues to tumour origins, progression and ultimately, targeted treatment.

Safety assessment of isoparaffins as used in cosmetics.

The safety of isoparaffins as used in cosmetic products is reviewed in this safety assessment. These ingredients function mostly as solvents and also function as emollients in the 0001% to 90% concentration range. The Cosmetic Ingredient Review (CIR) Expert Panel has reviewed relevant animal and clinical data and concluded that these ingredients are safe in the present practices of use and concentration described in this safety assessment.

Molecular risk assessment of BIG 1-98 participants by expression profiling using RNA from archival tissue.

BACKGROUND: The purpose of the work reported here is to test reliable molecular profiles using routinely processed formalin-fixed paraffin-embedded (FFPE) tissues from participants of the clinical trial BIG 1-98 with a median follow-up of 60 months. METHODS: RNA from fresh frozen (FF) and FFPE tumor samples of 82 patients were used for quality control, and independent FFPE tissues of 342 postmenopausal participants of BIG 1-98 with ER-positive cancer were analyzed by measuring prospectively selected genes and computing scores representing the functions of the estrogen receptor (eight genes, ER_8), the progesterone receptor (five genes, PGR_5), Her2 (two genes, HER2_2), and proliferation (ten genes, PRO_10) by quantitative reverse transcription PCR (qRT-PCR) on TaqMan Low Density Arrays. Molecular scores were computed for each category and ER_8, PGR_5, HER2_2, and PRO_10 scores were combined into a RISK_25 score. RESULTS: Pearson correlation coefficients between FF- and FFPE-derived scores were at least 0.94 and high concordance was observed between molecular scores and immunohistochemical data. The HER2_2, PGR_5, PRO_10 and RISK_25 scores were significant predictors of disease free-survival (DFS) in univariate Cox proportional hazard regression. PRO_10 and RISK_25 scores predicted DFS in patients with histological grade II breast cancer and in lymph node positive disease. The PRO_10 and PGR_5 scores were independent predictors of DFS in multivariate Cox regression models incorporating clinical risk indicators; PRO_10 outperformed Ki-67 labeling index in multivariate Cox proportional hazard analyses. CONCLUSIONS: Scores representing the endocrine responsiveness and proliferation status of breast cancers were developed from gene expression analyses based on RNA derived from FFPE tissues. The validation of the molecular scores with tumor samples of participants of the BIG 1-98 trial demonstrates that such scores can serve as independent prognostic factors to estimate disease free survival (DFS) in postmenopausal patients with estrogen receptor positive breast cancer.

Dual resolution cone beam breast CT: a feasibility study.

PURPOSE: In this study, the authors investigated the feasibility of a dual resolution volume-of-interest (VOI) cone beam breast CT technique and compared two implementation approaches in terms of dose saving and scatter reduction. METHODS: With this technique, a lead VOI mask with an opening is inserted between the x-ray source and the breast to deliver x-ray exposure to the VOI while blocking x rays outside the VOI. A CCD detector is used to collect the high resolution projection data of the VOI. Low resolution cone beam CT (CBCT) images of the entire breast, acquired with a flat panel (FP) detector, were used to calculate the projection data outside the VOI with the ray-tracing reprojection method. The Feldkamp-Davis-Kress filtered backprojection algorithm was used to reconstruct the dual resolution 3D images. Breast phantoms with 180 microm and smaller microcalcifications (MCs) were imaged with both FP and FP-CCD dual resolution CBCT systems, respectively. Two approaches of implementing the dual resolution technique, breast-centered approach and VOI-centered approach, were investigated and evaluated for dose saving and scatter reduction with Monte Carlo simulation using a GEANT4 package. RESULTS: The results showed that the breast-centered approach saved more breast absorbed dose than did VOI-centered approach with similar scatter reduction. The MCs in fatty breast phantom, which were invisible with FP CBCT scan, became visible with the FP-CCD dual resolution CBCT scan. CONCLUSIONS: These results indicate potential improvement of the image quality inside the VOI with reduced breast dose both inside and outside the VOI.

Field evaluation of a passive sampler of polycyclic aromatic hydrocarbons (PAHs) in an urban atmosphere (Bologna, Italy).

A simple device consisting of a Petri dish containing cellulose paper soaked with paraffin oil (hereinafter defined "artificial leaf", AL) was deployed in a typical urban site and partitioning of a set of PAHs between the atmosphere and AL was investigated. Gas-phase PAHs rapidly equilibrate with AL, thus rendering it a promising cost-effective tool for spatial and temporal trends studies of air quality.

Mechanism of migration from agglomerated cork stoppers. Part 2: Safety assessment criteria of agglomerated cork stoppers for champagne wine cork producers, for users and for control laboratories.

Producers of cork for champagne and wine have to be certain the corks meet the requirements of the European Union Framework Directive, and comply with the evaluations of chemicals carried out in the European Union. To identify chemicals in cork with the potential to migrate, the different synthetic products on the market were classified based on their technical role and of the chemistry involved. The potential migrants in each class (adhesive for cork bodies, adhesive for cork disks, lubricants and surface treatments) were analysed spectroscopically and chromatographically. A general approach was proposed for the evaluation of each commercial chemical: the detailed composition was supplied and verified mainly by infrared spectroscopy, proton nuclear magnetic resonance spectroscopy ((1)H-NMR) and GC-MS. A procedure to determine primary aromatic amines, specifically for cork migrates, based on GC-MS was developed. These techniques focussed on migrants below 1000 g mol(-1), as higher molecular weight chemicals are not likely to pose a problem for public health. The products were also tested after polymerization. The analytical scheme included an analytical check of synthetic product formulation and identification of potential migrants, solvent extraction and analysis of cork extracts.

Assessment of the acute pulmonary toxicity of lamp oil aspiration in the isolated perfused rat lung.

Mainly among children incidental ingestion of conventional lamp oils (paraffin oil) is responsible for casual intoxications with severe pulmonary toxicity and fatal consequences. On the basis of the isolated blood-free perfused rat lung we developed a model to study the acute toxic effects of lamp oil. Three oils were studied: conventional paraffin lamp oil (kinematic viscosity 1.62 10(-6) m(2)/sec), the methyl ester Edenor ME C12 70 (2.7 10(-6) m(2)/s) and another ester Edenor LPL (4.5 10(-6) m(2)/s). The oils were instilled into the trachea of isolated rat lungs and the changes in lung mechanics (tidal volume, pulmonary compliance and pulmonary conductance) as well as edema formation (increase in lung weight) studied. Instillation of as little as 10 microl paraffin oil caused complete failure of lung functions within 20 min and even 2 microl caused noticeable edema. Similar results were obtained with Edenor ME C12 70, which appeared to be even more toxic than paraffin oil, while Edenor LPL was less toxic. We conclude that tracheal instillation of oils into isolated perfused rat lungs may be a useful model to study the toxicity of lamp oils in vitro. Our findings further suggest that Edenor LPL may be a safer alternative for use as a lamp oil than paraffin oil.

Assessment of problems in diagnostic and research immunohistochemistry associated with epitope instability in stored paraffin sections.

Loss of antigenicity or epitope instability, especially after tissue sections have been prepared, may affect immunohistochemical staining results. To obtain insight into the magnitude of this problem, we conducted a systematic investigation. A total of 20 monoclonal and 12 polyclonal antibodies were used for immunohistochemistry using formalin-fixed, paraffin-embedded sections that were stored for periods ranging from 15 to 360 days at temperatures of 4 degrees C, 21 degrees C, and 37 degrees C. After 1 year of storage. immunohistochemical results appeared to be impaired with four antibodies at 4 degrees C, 11 antibodies at 21 degrees, and 16 antibodies at 37 degrees C. It was found that staining results using polyclonal antisera are affected to the same extent by this phenomenon compared to antibodies of monoclonal origin. No indication was found that antigen retrieval could restore the effect of epitope instability. An additional experiment, in which the influence of section adhesives on epitope instability was investigated, revealed that none of the applied adhesives hampers immunohistochemical reactivity for a storage time of up to 6 months.