Air pollution is a foremost public health problem worldwide. The pulmonary effects of air pollution have been well established for decades, and substantial epidemiological evidence is consistently showing that both acute and chronic exposure to air pollution is linked to cardiovascular morbidity and mortality. The underlying cause for this link is, however, still unknown, and many questions remain open. Most of the epidemiological studies focusing on health consequences of exposure to urban air used data from air monitoring stations or—when applying personal sampling or monitoring—measured a limited number of components to assess the exposure. On the other hand, studies conducting a decent exposure characterization and measuring a relatively large number of components with personal sampling had little or no focus on the effects and investigated only a few biomarkers. The number of research studies on this topic is huge, but at the same time, it seems as if there was no need for a comprehensive examination of the effects of urban air pollution on health. Researchers and research supporting organizations, in their fascination with the search for “novelty” and “beyond state-of-the-art”, do not seem to be aware of that they will never be able to assemble the whole picture from the puzzle pieces of research activities focusing only on certain aspects. Without a comprehensive investigation, we might never be able to answer such questions as (i) which of the urban air pollutants are forerunners in causing health effects, especially cardiovascular effects? (ii) Which biomarkers have the best predictor performance in early effects? (iii) Are there biomarkers or combinations of biomarkers that can help determine the degree of individual susceptibility and sensitivity and the dependence of these by different factors (e.g., age, gender, and physical activity)? The authors of this article aim to go through the already investigated—at the same time, essential—elements of the topic and propose a more comprehensive study, which, of course, can be expanded, debated, and improved.

The aims of this study were to assess serum concentrations of per- and polyfluoroalkyl substances (PFASs) in selected populations from Ghana, including workers engaged in the repair of electronic equipment (ERWs), and to elucidate PFAS concentrations in relation to blood mercury concentrations (B-Hg) as a biomarker of seafood consumption. In all, 219 participants were recruited into the study, of which 26 were women and 64 were ERWs. Overall, the PFAS concentrations were low. The most abundant components were perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonic acid (PFHxS). Women had generally lower PFAS concentration than men. The ERWs had statistically significantly higher concentrations of perfluorooctanoate (PFOA), which was associated with the concentration of tin in urine. This could indicate exposure during soldering. The concentration of B-Hg was associated with several of the PFASs such as PFOA, PFOS and perfluoroheptane sulfonate (PFHpS). Additionally, the concentrations of perfluorodecanoic acid (PFDA) and perfluoroundecanoate (PFUnDA) were highly associated with the concentrations of B-Hg. It is noteworthy that the linear isomer of PFHxS was strongly associated with B-Hg while the branched isomers of PFHxS were not. In conclusion, the PFAS concentrations observed in the present study are low compared to other populations previously investigated, which also reflects a lower PFAS exposure within the Ghanaian cohorts. ERWs had significantly higher PFOA concentrations than the other participants. Several PFASs were associated with B-Hg, indicating that seafood consumption may be a source of PFAS exposure.

While exposure to air contaminants from metal arc welding at workplaces has been intensively investigated over the last five decades, other hot work processes, such as flame and plasma cutting, air carbon arc gouging, and surface grinding have not received as much attention. Exposures to particulate matter (PM) during selected hot work processes, such as metal active gas (MAG) and manual metal arc (MMA) welding, flame and plasma cutting, air carbon arc gouging, and surface grinding were measured. Respirable, inhalable, and “total” fractions of the PM were collected with different air samplers in the workers’ breathing zone. Concentrations of PM, chromium (Cr), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), copper (Cu), and lead (Pb) were determined in the samples by using gravimetric analysis and plasma-based analytical atomic spectrometry techniques. Bio-accessibility of the elements was investigated by using a synthetic lung lining fluid (Hatch´s solution) for the leaching of soluble metal compounds in the collected samples. Short term (15–75 min) workplace air concentrations of PM, Cr, Fe, Mn, Ni and Cu in the workers´ breathing zone during hot work processes were found to be high compared to the current 8-hr time-weighted average (TWA) exposure limit values (ELVs) in use in many countries. The short-term median concentrations of PM during the different hot work processes varied between 6.0 and 88.7 mg m⁻³ and between 15.1 and 193 mg m⁻³ in the respirable and inhalable fractions, respectively. The highest median concentration of Fe (107 mg m⁻³) and Mn (28.7 mg m⁻³) was found in the inhalable fraction during plasma cutting and air carbon arc gouging, respectively. More than 40% of the inhalable PM generated during flame and plasma cutting, air carbon arc gouging and surface grinding was present in the respirable fraction. There was large variation in the bio-accessibility of the elements in PM collected during the different hot work processes.

Elemental carbon (EC) and nitrogen dioxide (NO2) in air as markers for diesel exhaust (DE) emission exposure were measured in selected work environments in Norway where diesel-powered engines are in use. Two hundred and ninety personal full-shift air samples were collected in primary aluminium production, underground and open-pit mining, road tunnel finishing, transport of ore, and among airport baggage handlers. EC was determined in the samples by a thermo-optical method, while NO2 was determined by ion chromatography. Highest EC air concentrations (geometric mean, GM) were found in aluminium smelters (GM = 45.5 μg m-3) followed by road tunnel finishing (GM = 37.8 μg m-3) and underground mining activities (GM = 18.9 μg m-3). Low EC air concentrations were measured for baggage handling at an international airport (GM = 2.7 μg m-3) and in an open-pit mine (GM = 1.2 μg m-3). Air concentrations of NO2 were similar in road tunnel finishing (GM = 128 μg m-3) and underground mining (GM = 108 μg m-3). Lower NO2 values were observed in open-pit mining (GM = 50 μg m-3), at the airport (GM = 37 μg m-3), and in the aluminium smelters (GM = 27 μg m-3). Highly significant (P < 0.001) positive correlations between NO2 and EC air concentrations in underground mining (r = 0.54) and road tunnel finishing (r = 0.71) indicate a common source of these pollutants. NO2 and EC were also correlated (P < 0.01) positively at the airport. However, due to the complex air chemistry and a potential contribution of various sources, the correlation between EC and NO2 cannot be regarded as unambiguous hint for a common source. The association between EC and NO2 was not of statistical significance in open-pit mining. In the aluminium smelters, EC and NO2 were negatively correlated, although not reaching statistical significance. The substantial differences in NO2/EC ratios across the investigated industries, ranging from around 0.2 in the primary aluminium production to around 25 during spring at the airport, clearly show that exposure to DE cannot be estimated based on NO2 concentrations, at least for outdoor environments. Results in the primary aluminium production suggest that the measured EC concentrations are related to DE emissions, although the NO2 concentrations were low. Further studies are required to assess the magnitude of exposure in primary aluminium production.

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. Both stationary and personal impactors were used to collect size-fractionated samples in a cement production plant in Norway. Stationary samples were measured with aerosol particle counters and collected with a 13-stage cascade impactor, which were stationed at three locations of the cement production plant: at the raw meal mill, clinker conveyor belt and cement mill. Sioutas cascade impactors, and thoracic and respirable dust samplers were used in parallel for personal sampling. Additionally, particles for electron microscopy were collected with the stationary cascade impactor for size-fractionated single particle characterization. Gravimetric measurements and element compositions of the samples from the stationary impactors show that the PM mass is dominated by calcium-rich particles of size >1 μm. The size distribution results of stationary and personal impactors were similar. Characterization of single particles reveals that limestone is the dominating material in the raw meal mill, whereas clinker and limestone dominate at the clinker conveyor belt and at the cement mill. The element composition of clinker PM did not change with particle size. The PM collected on impactor stages with aerodynamic diameter cut-offs below 0.56 μm was dominated by soot and volatile secondary particles at the three locations. The number of ultrafine particles of the cement related compounds was low. Air concentrations of PM in personal respirable and thoracic samples ranged from 0.14–10 mg m⁻³ to 0.37–9.5 mg m⁻³, respectively. Considerable local variations exist, both in composition and air concentration of the PM.