Solubility is a critical component of physicochemical characterisation engineered nanomaterials (ENMs) and an important parameter in their risk assessments. Standard testing methodologies are needed to estimate the dissolution behaviour biodurability (half-life) ENMs biological fluids. The effect pH, particle size crystal form on zinc metal, ZnO TiO2 was investigated using simple 2 h solubility assay at body temperature (37 °C) two pH conditions (1.5 7) approximately frame range found human...

Vacuum samples were collected from 1025 randomly selected urban Canadian homes to investigate bioaccessible Pb (PbS) concentrations in settled house dust. Results indicate a polymodal frequency distribution, consisting of three lognormally distributed subpopulations defined as "urban background" (geomean 58 μg g–1), "elevated" 447 and "anomalous" 1730 g–1). Dust PbS 924 (90%) fall into the category. The elevated anomalous predominantly consist older located central core areas cities....

This study investigated relationships between element concentrations in settled indoor dust and airborne particulate matter (PM), characterized fine (PM2.5) coarse (PM10-2.5) modes of indoor, outdoor personal microenvironments. Concentrations house correlated significantly (99% CI) with PM10 for 11 out 17 studied elements: Ag, Al, As, B, Cu, Fe, Mn, Pb, U, V Zn. Five elements showed significant correlations dust, at 99% CI As; 95% Mn Sb. These dust- were observed non-smokers' homes Windsor,...

ABSTRACT This study examines factors affecting oral bioaccessibility of metals in household dust, particular metal speciation, organic carbon content, and particle size, with the goal addressing risk assessment information requirements. Investigation copper (Cu) zinc (Zn) speciation two size fractions dust (< 36 μ m 80–150 m) using synchrotron X-ray absorption spectroscopy (XAS) indicates that are bound to different components dust: Cu is predominately associated phase while Zn mineral...

Abstract Solubility is a key criterion used in the hazard assessment of metal oxide–engineered nanomaterials (ENMs). The present study investigated solubility CuO, NiO, and TiO 2 ENMs compared with their bulk analogues two aqueous media: water Dulbecco’s modified Eagle’s medium (DMEM). Particle size distributions were characterized using dynamic light scattering (DLS) tunable resistive pulse sensing (TRPS). After centrifugal separation, dissolved fraction was quantified inductively coupled...

Toxicological effects of metal-oxide-engineered nanomaterials (ENMs) are closely related to their distinct physical-chemical properties, especially solubility and surface reactivity. The present study used five metal-oxide ENMs (ZnO, MnO2, CeO2, Al2O3, Fe2O3) investigate how various biologically relevant media influenced dissolution behaviour. In both water cell culture medium (DMEM), the were more soluble than bulk analogues, with exception that bulk-MnO2 was slightly in nano-MnO2 Fe2O3...

Nationally representative baseline data are presented for rare earth elements (REE), thorium (Th) and uranium (U) in house dust sampled from 1025 urban homes, units of concentrations (μg g-1 ), loadings m-2 loading rates (ng d-1 ). Spearman rank correlations indicate that, addition to outdoor sources, consumer products building materials can influence indoor REE, Th, U. Correlations (P<.01) with numbers occupants, dogs, cats suggest soil track-in. hardwood floors release REE additives used...

Indoor exposures to metals arise from a wide variety of indoor and outdoor sources. This study investigates the impact humid conditions on bioaccessibility Zn in dust, transformation species during weathering. House dust samples were subjected an oxygenated, highly atmosphere closed chamber for 4 5 months. Zinc before after experiment was determined using simulated gastric acid extraction. Bulk micro X-ray absorption structure (XAS) spectroscopy used speciate dust. Exposure led significant...

ABSTRACT The bioaccessibility of arsenic, cadmium, chromium, copper, lead, nickel, and zinc in four National Institute Standards Technology (NIST) standard reference materials two Canadian dust samples as determined using the Solubility/Bioavailability Research Consortium (SBRC) vitro procedure ranged from a low 1.8% for chromium material NIST 2711 to high 95.2% cadmium 2584. SBRC data were compared generated modified EN-71 Toy Safety protocol conducted at different laboratories. Results...

Humidity increases the bioaccessibility of Pb and Zn in dust that collects damp microenvironments (such as window troughs).

Wipe sampling is the USA regulatory protocol for determination of "dust lead loadings" in residential environments. Few studies have applied wipe method to metals other than (Pb) purpose exposure assessments. This study was undertaken develop and expand quantifying additional metal(loid)s including arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), antimony (Sb); provide information on typical background loadings these urban Canadian homes. A total 932 samples, 220 field...

This study investigated the use of metal impurities in single-wall carbon nanotubes (SWCNT) as potential tracers to distinguish engineered nanomaterials from background aerosols. TEM and SEM were used characterize parent material aerosolized agglomerates collected on PTFE filters using a cascade impactor. image analysis indicated that SWCNT contained about 45% amorphous backscatter electron concentrated within component. Two elements present (Y Ni) selected appropriate this case their...

Oral bioaccessibility estimates for six metals which are prevalent as contaminants in Canada (zinc, lead, cadmium, copper, nickel, and chromium) investigated house dust using the simple gastric phase versus two-phase physiologically-based extraction technique (PBET). The purpose is to determine whether a complete gastrointestinal (GI) assay yields more conservative (i.e., higher) estimate of metal than alone (G-alone). study samples include household vacuum collected from 33 homes Montreal,...

A simple single-step ultrasonic dissolution procedure for low mass (<1 mg) particulate matter (PM) filter samples using HNO3–HF acid solution is proposed multi-element determination ICP-MS. The PM-loaded PTFE are inserted directly into disposable centrifuge tubes extraction digestion (UD). Potential interferences owing to contamination and element loss minimized. Key factors influencing recoveries investigated, including composition, concentration, temperature, matrix interferences....

Residual metal impurities in carbon nanotubes (CNTs) provide a means to distinguish CNT from non-CNT sources of elemental environmental samples. A practical and cost-effective analytical approach is needed support routine surface monitoring tracers using wipe sampling. Wipe sampling for considered qualitative indicator the presence CNTs, not quantitative exposure metric. In this study, two digestion approaches (microwave-assisted nitric acid/H 2 O ultrasonic nitric/HF acid digestion)...

Abstract Eight metal oxides were obtained to investigate the dissolution behaviour of engineered nanomaterials (ENMs) dispersed in biologically relevant media. Identities oxide compounds, and their crystal form size checked using powder X-ray diffraction (XRD). Methods for sonication nanoparticles optimized achieve stable stock dispersions, methods separation dissolved ions from evaluated. The results optimization experiments showed that each ENM required a different combination time power...

Trends in the elemental composition of fine particulate matter (PM2.5) collected from indoor, outdoor, and personal microenvironments were investigated using two metrics: ng/m3 mg/kg. Pearson correlations that positive one metric commonly disappeared or flipped to become negative when other was applied same dataset. For example, correlation between Mo S outdoor microenvironment (p < 0.05) but mg/kg 0.05). In general, concentrations (mg/kg) within PM2.5 decreased significantly as (µg/m3)...

This study investigates the application of Aerosol-to-Liquid Particle Extraction System (ALPXS), which uses wet electrostatic precipitation to collect airborne particles, for multi-element indoor stationary monitoring. Optimum conditions are determined capturing particles metal determination by inductively coupled plasma–mass spectrometry (ICP-MS), measuring field blanks, and calculating limits detection (LOD) quantification (LOQ). Due relatively high flow rate (300 L min−1), a sampling...

Road dust is enriched with a range of metals and metalloids human health concern, including technology-critical elements, such as the automotive exhaust catalysts platinum (Pt), palladium (Pd) rhodium (Rh). To date, inhalable road particle size fractions have not been fully characterized in terms their elemental composition or bioaccessibility upon uptake lung. The goal this study was to examine group element (PGE) enrichment patterns physiological relevance for respiratory exposures (<10...