The variability of selenium and sulphur and the impact of creatinine in blood and urine of humans.

Background: Intake of selenium (Se) and sulphur (S) is mainly through meat and fish. This is also the case for creatine, which is broken down into creatinine (Crea).

Objectives: Objectives were to assess variability of Se and S in urine and blood, assess diurnal variation and associations with Crea in urine (U-Crea).

Characterization of particle exposure during tunnel excavation by tunnel boring machines.

Tunnel boring machines (TBMs) are used to excavate tunnels in a manner where the rock is constantly penetrated with rotating cutter heads. Fine particles of the rock minerals are thereby generated. Workers on and in the vicinity of the TBM are exposed to particulate matter (PM) consisting of bedrock minerals including α-quartz.

Job function as determinant of clinker exposure at workplaces during cement production.

Objectives: In the cement production industry, exposure to airborne particulate matter is associated with a decline in lung function and increased airway symptoms. Exposure to clinker-the major constituent of cement and supposedly the cause of the observed adverse health effects-was determined recently in 15 cement production plants located in 8 different countries (Estonia, Greece, Italy, Norway, Sweden, Switzerland, Spain, Turkey). It was shown that the median clinker abundance in the thoracic fraction varied between approximately 20% and 70% for individual plants.

Content of clinker and other materials in personal thoracic aerosol samples from cement plants estimated by scanning electron microscopy and energy-dispersive X-ray microanalysis.

Objectives: To estimate the composition and exposure to clinker and other specific components in personal thoracic dust samples of cement production workers.

Methods: A procedure for the classification of airborne particles in cement production plants was developed based on classification trees. For this purpose, the chemical compositions of 27,217 particles in 29 material samples (clinker, limestone, gypsum, clay, quartz, bauxite, iron source, coal fly ash, and coal) were determined automatically by scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDX).

The variability of arsenic in blood and urine of humans.

Background: Humans are exposed to inorganic and organic arsenic. The total arsenic (As) concentration in urine is a commonly used biomarker of exposure. However, little is known about variability of As in biological fluids and the diurnal variation of As excretion.

Urinary iodine excretion and optimal time point for sampling when estimating 24-h urinary iodine.

Iodine deficiency may cause thyroid dysfunction. The iodine intake in a population is measured by urinary iodine concentration (UIC) in spot samples or 24-h urinary iodine excretion (24UIE). 24UIE is considered the gold standard and may be estimated using an equation including UIC, urinary creatinine concentration, sex and age (e24UIE).

Exhaust and non-exhaust contributions from road transport to PM at a Southern European traffic site.

It is a well - established fact that road traffic is one of the main contributors to ambient levels of airborne particulate matter (APM). This study was carried out at a traffic site in which the PM levels are monitored all year round. A trend analysis of these levels revealed that over a decade there was no discernible trend, with the PM concentrations normally hovering around the EU limit values.

Physicochemical characterization of particulate matter in a cement production plant.

Employees working in cement production plants are exposed to airborne particulate matter (PM) which may lead to lung function impairments and airway symptoms. The PM consists of raw materials, clinker and additives which vary depending on cement blend. The aim of this work was to characterize the thoracic fraction of PM with regard to size, phase composition and mixing state.

Variability of lead in urine and blood in healthy individuals.

Background: Lead is a non-essential toxic trace element. Lead in blood (BPb) is the most common biomarker of lead exposure but lead in urine (UPb) has also been used. There is, however, limited data on the variability of UPb in the general population and the association with BPb.

Particle characterisation and bioaccessibility of manganese in particulate matter in silico- and ferromanganese smelters.

The aim of this study was to characterise particulate matter (PM) collected in the furnace area during SiMn and high carbon (HC)-FeMn production in terms of single particle analysis and to determine the bioaccessibility of Mn in the PM in a simulated lung fluid. Airborne PM was collected with Sioutas cascade impactors and respirable cyclones in the breathing zone of tappers and crane operators. Stationary samples were collected from the furnace area with a nanoMOUDI cascade impactor and an ESPnano electrostatic particle collector.

Normal variability of 22 elements in 24-hour urine samples - Results from a biobank from healthy non-smoking adults.

Background: Urine is often used for biomonitoring the exposure to elements. However, most studies report concentrations in spot urine samples, which may not accurately mirror the "gold standard" of complete 24-h (24 h) urine samples. There are relatively few data published for 24 h samples, and little information on the within- and between person variability.

Investigating the plausibility of a PMF source apportionment solution derived using a small dataset: A case study from a receptor in a rural site in Apulia - South East Italy.

Results of a methodological study on the use of Positive Matrix Factorization (PMF) with smaller datasets are being reported in this work. This study is based on 29 PM and 33 PM samples from a receptor in a rural setup in Apulia (Southern Italy). Running PMF on the two size fractions separately resulted in the model not functioning correctly.

On the bio-accessibility of 14 elements in welding fumes.

The bio-accessibility of 14 elements in welding fume particulate matter was investigated in 325 personal air samples collected during welding in two shipyards and one factory producing heavy machinery. The apparent solubility in a synthetic lung lining fluid (Hatch's solution) was used as proxy for the bio-accessibility. The Hatch solubility of the different elements was highly variable with a median < 1% for Al, Fe, Pb, Ti, between 4 and 6% for Co, Cr, Ni, V, W, between 13 and 27% for Cd, Cu, Mn, Zn, and 41% for Mo.

Comparison of operator- and computer-controlled scanning electron microscopy of particles from different atmospheric aerosol types.

Individual aerosol particles from an urban background site in Mainz (Germany), a traffic hotspot site in Essen (Germany), the free troposphere in the Swiss Alps (high altitude research station Jungfraujoch), a rural background/marine site on Cyprus (Cyprus Atmospheric Observatory) and a rural background site in the forested area of Odenwald (Germany) were characterised with two different scanning electron microscopy techniques, operator controlled (opSEM) and computer controlled (ccSEM). For all samples, about 500 particles were investigated by opSEM, and between 1103 and 6940 particles by ccSEM. Large systematic differences (in some cases a factor up to ~ 20) in the abundance of the various particle groups are observed in the results of the two techniques.

Size distribution and single particle characterization of airborne particulate matter collected in a silicon carbide plant.

The global SiC market is projected to grow in the coming years, and research on potential health effects as well as epidemiological studies is therefore of importance. A detailed characterization in terms of the phase composition, morphology and mixing state of airborne PM is still missing, though highly necessary to identify sources and to understand the risk factors in this industry. Particles in the size range of 10 nm to 10 µm were collected with a 13-stage NanoMOUDI impactor in the Acheson Furnace Hall as well as in processing departments during two sampling campaigns.

Characterization of air contaminants emitted during laser cutting of carbon fiber-reinforced composite materials.

The emission of ultrafine carbonaceous particles during the laser cutting of fiber-reinforced polymer (CFRP) composite materials was investigated. The study was based on characterization of air contaminants emitted during laser cutting of an epoxy-based CFRP material with respect to particle size distribution, particle morphology, and chemical composition. Results indicate that about 90% of the total particulate mass is present as fine particulate matter with an aerodynamic cut-off diameter of 0.

Estimation of the contributions of the sources driving PM levels in a Central Mediterranean coastal town.

Receptor modelling techniques are widely used in order to identify the main natural and anthropogenic processes driving aerosol levels at a receptor. In this work, Positive Matrix Factorization (PMF) was used to apportion PM levels at a traffic site (Msida) located in a coastal town. 180 filters collected throughout a yearly sampling campaign conducted in 2016, were chemically characterized by light absorbance analysis, x-ray fluorescence and ion chromatography in order to determine the concentrations of black carbon, 17 elements and 5 ions, respectively.

Phase identification of individual crystalline particles by combining EDX and EBSD: application to workplace aerosols.

This paper discusses the combined use of electron backscatter diffraction (EBSD) and energy dispersive X-ray microanalysis (EDX) to identify unknown phases in particulate matter from different workplace aerosols. Particles of α-silicon carbide (α-SiC), manganese oxide (MnO) and α-quartz (α-SiO) were used to test the method. Phase identification of spherical manganese oxide particles from ferromanganese production, with diameter less than 200 nm, was unambiguous, and phases of both MnO and MnO were identified in the same agglomerate.

Essential and non-essential trace elements among working populations in Ghana.

Background: Lead battery repair workers (LBRW) and electronic repair workers (ERW) may be exposed to inorganic components during work. This study aimed at determining essential and non-essential trace elements in male LBRW, ERW, referents and a group of female petty traders (FPT) in Kumasi (Ghana), taking into account iron status and inflammation.

Methods: Altogether 64 LBRW, 64 ERW, 65 referents and 26 FPT were investigated in this cross-sectional study.

Morphology, chemical composition and nanostructure of single carbon-rich particles studied by transmission electron microscopy: source apportionment in workroom air of aluminium smelters.

Sources of C-rich particles at work places in two aluminium smelters in Norway were studied by transmission electron microscopy and energy-dispersive X-ray microanalysis. Based on morphology, nanostructure and chemistry, three different types of C-rich particles are distinguished: (a) chain-like agglomerates (70-100% by number, relative to the sum of C-rich particles) consisting of primary particles with typical onion-shell structure of graphene layers, (b) multi-walled carbon nanotube particles (≈3%) and (c) spheres or agglomerates of amorphous C-rich particles (0-30%). Chain-like agglomerates are interpreted as diesel soot in accordance with literature data on primary particle diameter, chemical composition and nanostructure of primary particles.

Electron microscopy of particles deposited in the lungs of nickel refinery workers.

The size, morphology, and chemical composition of particles deposited in the lungs of two nickel refinery workers were studied by scanning and transmission electron microscopy. The particles were extracted from the lung tissue by low-temperature ashing or by dissolution in tetramethylammonium hydroxide. The suitability of both sample preparation techniques was checked with reference materials.

Involvement of IL-1 genes in the cellular responses to carbon nanotube exposure.

The interleukin-1 (IL-1) family has been implicated in cellular responses to nanoparticles including carbon nanotubes (CNTs). IL-1α and β are key proinflammatory cytokines important in inflammatory and oxidative stress responses. The aim of this study was to characterize the role of IL-1 in cellular responses of CNTs in cells from IL-1α/β wild type (IL1-WT) mice and cells with reduced inflammatory potential from IL-1α/β deficient (IL1-KO) mice.