Influence of sebum proportion in synthetic sweat on dermal bioaccessibility and on permeation of metal(loid)s from contaminated soils.

Even if dermal exposure to metal(loid)s from contaminated soils has received less attention than oral and inhalation exposure, the human health risk can be significant for some contaminants and exposure scenarios. The purpose of this study was to assess the influence of sebum proportion (1% v/v and 3% v/v) in two synthetic sweat formulations (EN 1811, pH 6.5 (sweat A) and NIHS 96-10, pH 4.

Metal(loid) speciation in dermal bioaccessibility extracts from contaminated soils and permeation through synthetic skin.

Dermal exposure to metal(loid)s from contaminated soils can contribute to health risk. Metal(loid) speciation will influence their bioaccessibility in sweat and subsequent permeation across the skin. Therefore, the speciation of the bioaccessible fraction of metal(loid)s in two synthetic sweat formulations (sweat A (pH 6.

Occurrence of metals in e-cigarette liquids: Influence of coils on metal leaching and exposure assessment.

Electronic cigarettes are generally recognized as a safer alternative than conventional cigarettes. Nevertheless, previous research suggests metal (loid) leaching due to coil contact, potentially transferring to the e-liquid and its aerosolized form. In this study, Cr, Cd, Ni, and Pb levels were measured by inductively coupled plasma mass spectrometry (ICP-MS) on 17 samples of e-liquids with different chemical properties (e.

Incorporating oral, inhalation and dermal bioaccessibility into human health risk characterization following exposure to Chromated Copper Arsenate (CCA)-contaminated soils.

Exposure to potentially toxic metal(loid)s (PTMs) in soil may happen via ingestion, inhalation, and dermal pathway. A more accurate risk characterization should consider PTM bioavailability. Using ten soil samples collected in the Montreal area (Canada) near CCA-treated utility poles, this study aims to characterize non-carcinogenic and carcinogenic human health risks associated with As, Cr, Cu, Pb, and Zn through a multi-pathway exposure approach.

Comparison of Synthetic Sweat and Influence of Sebum in the Permeation of Bioaccessible Metal(loid)s from Contaminated Soils through a Synthetic Skin Membrane.

Dermal exposure to metal(loid)s from contaminated soils has received less attention than oral and inhalation exposure. Still, it can be a relevant pathway for some contaminants. Comparison of synthetic sweats (donor solutions), the influence of sebum, and the characterization of diffusion parameters through a synthetic membrane (acting as skin surrogate) in the permeation of metal(loid)s (As, Cr, Cu, Ni, Pb, and, Zn) from polluted soils is missing.

Removal of nickel from neutral mine drainage using peat-calcite, compost, and wood ash in column reactors.

The effectiveness of compost, peat-calcite, and wood ash to remove Ni from a circum-neutral-contaminated mine water was tested in continuous flow experiments. Materials were compared in 4.8-L columns at hydraulic residence times (HRT) of ∼ 16.

Oral and inhalation bioaccessibility of metal(loid)s in chromated copper arsenate (CCA)-contaminated soils: Assessment of particle size influence.

Soil samples adjacent to ten CCA-treated utility poles were collected, sieved into four fractions (<2 mm, 250-90 μm, 90-20 μm and <20 μm), and characterized for their total metal(loid) (As, Cu, Cr, Pb, and Zn) content and physico-chemical properties. Oral bioaccessibility tests were performed using In Vitro Gastrointestinal (IVG) method for fractions 250-90 μm and 90-20 μm. Inhalation bioaccessibility tests were performed in particle size fraction <20 μm using two simulated lung fluids: artificial lysosomal fluid (ALF) and Gamble's solution (GS).

Treatment efficiency of iron-rich acid mine drainage in a tri-unit pilot system.

Treatment efficiency of iron-rich acid mine drainage (AMD; pH 3, and 2 and 4 g/L Fe) was tested in a laboratory tri-unit pilot-scale reactor (2.65 m) for 1 year. The first unit consisted of a passive biochemical reactor (PBR1), filled with reactive mixture (50% of manure, sawdust, maple chips, compost, urea, sediment, and sand; 50% of calcite), with the aim to neutralize acidity and to partially remove metals.

Salinity and low temperature effects on the performance of column biochemical reactors for the treatment of acidic and neutral mine drainage.

Passive biochemical reactors (PBRs) represent a promising option for the treatment of mine drainage. In this study, the influence of temperature (22 and 5 °C), salinity (0 and 20 g/L) and hydraulic retention time (HRT) on the efficiency of PBRs for the treatment of acidic and neutral mine drainage (AMD and NMD) was evaluated. To do so, eight 11 L PBRs were set-up and operated with vertically upward flow.

Comparison of five artificial skin surface film liquids for assessing dermal bioaccessibility of metals in certified reference soils.

Dermal exposure to metals has previously received less attention than oral/inhalation exposure. Nonetheless, human health risk is significant for certain contaminants and exposure scenarios. The present study aims to (1) characterize two certified reference soils (SQC001, BGS 102); and (2) assess Cr, Ni, Pb, and Zn dermal bioaccessibility via in vitro assays using three synthetic sweat formulations (EN 1811, pH 6.

Metal(loid)s inhalation bioaccessibility and oxidative potential of particulate matter from chromated copper arsenate (CCA)-contaminated soils.

Field-collected chromated copper arsenate (CCA)-contaminated soils and associated particulate matter (PM) were characterized for their total metal(loid)s content (As, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and physicochemical properties. Copper, Ni, Pb and Zn fractionation (using sequential extraction) and inhalation bioaccessibility (using two lung fluids) of trace elements were assessed in PM samples. In Gamble's solution (GS), low average bioaccessibility (up to 12%) was observed for As, Cu, Mn, and Ni.

Modeling of the clogging in a MgO column used to treat a Ni- and Co-contaminated water and performance prediction for a centripetal radial column.

A geochemical model was established to predict the chemical and hydraulic performances of MgO columns used to treat a nickel- and cobalt-contaminated groundwater. Using the PHREEQC software, an advection-reaction simulation was carried out to re-create the outlet concentrations observed during a previous axial column laboratory test. Reaction kinetics were introduced to calculate the rates of brucite dissolution as well as iron and manganese oxidation.

Centripetal filtration of groundwater to improve the lifetime of an MgO recycled refractory filter: observations and technical challenges.

In the context of improving permeable reactive barrier (PRB) filters, axial and a centripetal column tests were performed to compare their evolution in terms of chemical and hydraulic performances. For both tests, the MgO reactive media, made of crushed (< 10 mm) spent MgO-C refractory bricks was used to treat water contaminated with Co and Ni by raising the pH and promoting hydroxide precipitation. As opposed to the traditional cylindrical axial configuration, the centripetal column consists of an annulus of reactive media through which the water flows from the outer radius towards the inner radius.

Removal efficiency of As(V) and Sb(III) in contaminated neutral drainage by Fe-loaded biochar.

Performance of raw and two Fe-loaded biochars, produced either by evaporation (E-product, 26.9% Fe) or precipitation (P-product, 12.6% Fe), was evaluated in batch and column testing for As(V) and Sb(III) removal from contaminated neutral drainage (CND).

Spent MgO-carbon refractory bricks as a material for permeable reactive barriers to treat a nickel- and cobalt-contaminated groundwater.

Spent magnesia (MgO)-carbon refractory bricks were repurposed as a permeable reactive barrier reactive media to treat a nickel (5 mg l)- and cobalt (0.3 mg l)-contaminated groundwater. MgO has been used for decades as a heavy metal precipitating agent as it hydrates and buffers the pH in a range of 8.

Performance assessment of laboratory and field-scale multi-step passive treatment of iron-rich acid mine drainage for design improvement.

Multi-step passive systems for the treatment of iron-rich acid mine drainage (Fe-rich AMD) perform satisfactorily at the laboratory scale. However, their field-scale application has revealed dissimilarities in performance, particularly with respect to hydraulic parameters. In this study, the assessment of factors potentially responsible for the variations in performance of laboratory and field-scale multi-step systems was undertaken.

Metals and metalloids treatment in contaminated neutral effluents using modified materials.

Circumneutral surface water and groundwater can contain hazardous concentrations of metals and metalloids that can threaten organisms in surrounding ecosystems. Extensive research has been conducted over the past two decades to prevent, limit, and treat water pollution. Among the currently available treatment options is the use of natural and residual materials, which is generally regarded as effective and inexpensive.

In vitro dermal bioaccessibility of selected metals in contaminated soil and mine tailings and human health risk characterization.

Dermal exposure to contaminated sites has generally received less attention than oral/inhalation exposure due to limited exposure scenarios and less perceived potential for toxicity, however, the risk can be significant for specific contaminants and scenarios. The present study aims to (1) measure Cr, Ni, Pb, and Zn contamination in soil and mine tailings samples (n = 7), (2) determine the dermal bioaccessibility of these metals via in vitro tests using two synthetic sweat formulations (EN 1811; NIHS 96-10), and (3) obtain dermal absorbed doses (DADs) for children's and adults' exposure scenarios and compare them to derived dermal reference values. The NIHS 96-10 formulation yielded higher bioaccessibility values for all metals than EN 1811, possibly due to its lower pH.

Determination of point of zero charge of natural organic materials.

This study evaluates different methods to determine points of zero charge (PZCs) on five organic materials, namely maple sawdust, wood ash, peat moss, compost, and brown algae, used for the passive treatment of contaminated neutral drainage effluents. The PZC provides important information about metal sorption mechanisms. Three methods were used: (1) the salt addition method, measuring the PZC; (2) the zeta potential method, measuring the isoelectric point (IEP); (3) the ion adsorption method, measuring the point of zero net charge (PZNC).

Iron removal in highly contaminated acid mine drainage using passive biochemical reactors.

Passive biochemical reactors (PBRs) are a viable alternative to neutralization plants for the treatment of acid mine drainage (AMD) because they require lower investment costs and use residual materials. However, high iron (Fe) concentrations (≥0.5 g/L) in AMD are challenging for their long-term efficiency.

Lung bioaccessibility of As, Cu, Fe, Mn, Ni, Pb, and Zn in fine fraction (<20μm) from contaminated soils and mine tailings.

The present study aims (1) to characterize contaminated soils (n=6) and mine tailings samples (n=3) for As, Cu, Fe, Mn, Ni, Pb, and Zn content; and (2) to assess elemental lung bioaccessibility in fine fraction (d<20μm which might contribute to airborne particulate matter (PM) and thus be inhaled) by means of in vitro tests using Gamble's solution (GS) and an artificial lysosomal fluid (ALF). Elemental concentrations were high in the majority of samples, particularly for As (up to 2040mg·kg), Fe (up to 30.7%), Mn (up to 4360mg·kg), and Zn (up to 4060mg·kg); and elemental concentrations (As, Cu, and Ni) in the sieved fraction (d<20μm) obtained from contaminated soils were significantly higher than in the bulk fraction (<160μm).

Recovery and reuse of sludge from active and passive treatment of mine drainage-impacted waters: a review.

The treatment of mine drainage-impacted waters generates considerable amounts of sludge, which raises several concerns, such as storage and disposal, stability, and potential social and environmental impacts. To alleviate the storage and management costs, as well as to give the mine sludge a second life, recovery and reuse have recently become interesting options. In this review, different recovery and reuse options of sludge originating from active and passive treatment of mine drainage are identified and thoroughly discussed, based on available laboratory and field studies.

Lung bioaccessibility of contaminants in particulate matter of geological origin.

Human exposure to particulate matter (PM) has been associated with adverse health effects. While inhalation exposure to airborne PM is a prominent research subject, exposure to PM of geological origin (i.e.