Assessing the biological reactivity of organic compounds on volcanic ash: implications for human health hazard

Exposure to volcanic ash is a long-standing health concern for people living near active volcanoes and in distal urban areas. During transport and deposition, ash is subjected to various physicochemical processes that may change its surface composition and, consequently, bioreactivity. One such process is the interaction with anthropogenic pollutants; however, the potential for adsorbed, deleterious organic compounds to directly impact human health is unknown. We use an in vitro bioanalytical approach to screen for the presence of organic compounds of toxicological concern on ash surfaces and assess their biological potency. These compounds include polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dlPCBs). Analysis of ash collected in or near urbanised areas at five active volcanoes across the world (Etna, Italy; Fuego, Guatemala; Kelud, Indonesia; Sakurajima, Japan; Tungurahua, Ecuador) using the bioassay inferred the presence of such compounds on all samples. A relatively low response to PCDD/Fs and the absence of a dlPCBs response in the bioassay suggest that the measured activity is dominated by PAHs and PAH-like compounds. This study is the first to demonstrate a biological potency of organic pollutants associated with volcanic ash particles. According to our estimations, they are present in quantities below recommended exposure limits and likely pose a low direct concern for human health

Impact of disease outcomes on the Assessment of SpondyloArthritis International Society Health Index (ASAS HI): a Bayesian network analysis of the DESIR cohort

Objective The objective of this study is to build a structural model visualising and quantifying the interrelationships of different disease outcomes with the Assessment of SpondyloArthritis International Society Health Index (ASAS HI) in patients with axial spondyloarthritis (axSpA).Methods Cross-sectional data collected at month 72 of the Devenir des Spondylarthropathies Indifferénciées Récentes cohort was analysed. Combining prior knowledge and observed data, probabilistic Bayesian network modelling was used to study how the interplay of different disease outcomes affects the ASAS HI, which measures disease-specific overall functioning and health. Disease outcomes comprised, among others, the Ankylosing Spondylitis (AS) Disease Activity Score (ASDAS) and the Bath AS Functional Index (BASFI).Results Data of 384 patients were analysed. The obtained structure suggests that ASAS HI is determined by both patient-reported physical function (BASFI) and disease activity (ASDAS). The parameters of the structural model show that an increase of ASDAS or BASFI by 1 unit corresponds to an increase of ASAS HI by 0.70 or 1.25 units, respectively. Moreover, the model suggests that disease activity has an indirect impact on ASAS HI via BASFI. No relationship between spinal mobility or structural damage and ASAS HI was found.Conclusions This is the first structural model developed to better understand the construct and the interplay between clinically relevant outcomes related to ASAS HI in axSpA patients. It shows that disease activity and physical function have a strong impact on ASAS HI, confirming it to be a valid construct of overall functioning and health in axSpA patients

Qualitative analysis of dental material ingredients, composite resins and sealants using liquid chromatography coupled to quadrupole time of flight mass spectrometry

Since 2011, the World Health Organization has encouraged a global phase-down of the use of dental amalgam and actively supported the use of alternative, resin-based dental materials. The resins consist of (meth)acrylate monomers derived from Bisphenol A (BPA), such as Bisphenol A glycidyl methacrylate (BisGMA) and Bisphenol A ethoxylate methacrylate (BisEMA) or triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA) which lack the BPA backbone. Besides monomers, other compounds such as photoinitiators and stabilizing agents can be present in the dental resin matrices. The current study consists in the development of an analytical method for the separation and identification of dental material components using LC-QTOF-MS. The developed method was applied on several dental material ingredients, unpolymerized composite resins, and a common dental sealant. The acquired high resolution accurate-mass data was analyzed using suspect screening with an in-house developed library. Next to the main components, various isomers and impurities related to the production of the main component have been detected and identified in the dental material ingredients. In total, 39 chemicals have been identified in the analyzed dental materials. On average 15 chemicals have been identified. Major components, such as BisEMA, BisGMA and TEGDMA were identified although they were not always stated in the material safety data sheets. Minor components included photoinitiators, such as ethyl 4-dimethyl aminobenzoate (EDMAB) and (meth)acrylates impurities originating from production of main ingredients.status: publishe

Assessment of hazards and risks associated with dietary exposure to mineral oil for the Belgian population

Recently collected dietary exposure data on mineral oil saturated (MOSH) and aromatic (MOAH) hydrocarbons were used to evaluate the risks associated with exposure to mineral oil through food for the Belgian population. For MOSH, the no observed adverse effect level (NOAEL) value of 19&nbsp;mg&nbsp;kg−1&nbsp;bw day−1&nbsp;based on the hepatic inflammation-associated granulomas found in a 90-day oral study in F-344 rats was used as point of departure (PoD). Due to existing toxicological uncertainties, the margin of exposure (MOE) approach was applied. In all investigated scenarios, the MOE values were well above 100, indicating that there is no direct health concern related to MOSH exposure for the Belgian population. Nevertheless, more appropriate risk assessment approaches for MOSH based on adequate PoD are needed. For dietary exposure to MOAH, which are potentially genotoxic and carcinogenic, no MOE values could be calculated due to the lack of adequate dose-response carcinogenicity data. In two investigated worst-case scenarios, a health concern related to MOAH exposure could not be excluded, highlighting that more data are needed to perform an adequate risk assessment. The possibility to use&nbsp;in vitro&nbsp;bioassays to collect such additional toxicological information for MOAH present in food samples was also&nbsp;investigated.</p

Degradation products of resin-based materials detected in saliva in vivo

Abstract: ObjectivesDental composites remain under scrutiny regarding their (long-term) safety. In spite of numerous studies on the release of monomers both in vitro and in vivo, only limited quantitative data exist on the in vivo leaching of degradation products from monomers and additives. The aim of this observational study was for the first time to quantitatively and qualitatively monitor the release of parent compounds and their degradation products in saliva from patients undergoing multiple restorations.Materials and methodsFive patients in need of multiple large composite restorations (minimally 5 up to 28 restorations) due to wear (attrition, abrasion, and erosion) were included in the study, and they received adhesive restorative treatment according to the standard procedures in the university clinic for Restorative Dentistry. Saliva was collected at different time points, starting before the restoration up until 24 h after the treatment with composite restorations. Saliva extracts were analyzed by liquid chromatography-mass spectrometry.ResultsLeaching of monomers and degradation products was highest within 30 min after the placement of the restorations. The highest median concentrations of monomers were recorded for UDMA, BisEMA-3, and TEGDMA; yet, besides BisEMA-3 and TEGDMA, no monomers could be detected after 24 h. Mono- and demethacrylated degradation products remained present up to 24 h and concentrations were generally higher than those of monomers. In patients with multiple restorations, degradation products were still present in the sample taken before the next operation, several weeks after the previous operation.ConclusionsExposure to residual monomers and degradation products occurs in the first hours after restoration. Monomers are present in saliva shortly after restoration, but degradation products can be detected weeks after the restoration confirming a long-term release.Clinical significanceFuture research should focus more on the release of degradation products from monomers and additives from resin-based materials given their prolonged presence in saliva after restoration