Airborne Aluminum as an Underestimated Source of Human Exposure: Quantification of Aluminum in 24 Human Tissue Types Reveals High Aluminum Concentrations in Lung and Hilar Lymph Node Tissues.

Aluminum (Al) is the most abundant metal in the earth's crust, and humans are exposed to Al through sources like food, cosmetics, and medication. So far, no comprehensive data on the Al distribution between and within human tissues were reported. We measured Al concentrations in 24 different tissue types of 8 autopsied patients using ICP-MS/MS (inductively coupled plasma-tandem mass spectrometry) under cleanroom conditions and found surprisingly high concentrations in both the upper and inferior lobes of the lung and hilar lymph nodes. Al/Si ratios in lung and hilar lymph node samples of 12 additional patients were similar to the ratios reported in urban fine dust. Histological analyses using lumogallion staining showed Al in lung erythrocytes and macrophages, indicating the uptake of airborne Al in the bloodstream. Furthermore, Al was continuously found in PM2.5 and PM10 fine dust particles over 7 years in Upper Austria, Austria. According to our findings, air pollution needs to be reconsidered as a major Al source for humans and the environment.

The COVID-19 Pandemic: Quantification of Temporal Variations in Air Pollutants Before, During and Post the Lockdown in Jeddah City, Saudi Arabia.

The government of Saudi Arabia imposed a strict lockdown between March and July 2020 to stop the spread of the coronavirus disease (COVID-19), which has led to a sharp decline in economic activities. The daily temporal variations of PM10, PM2.5, carbon monoxide (CO), nitrogen dioxide (NO2), and ozone (O3) were used to investigate the changes in air quality in response to COVID-19 lockdown control measures from January to December 2020 in Jeddah, Saudi Arabia. Meteorological parameters (wind speed, direction, temperature, relative humidity) were also analyzed to understand the changes during the pandemic. As a result, significant reductions in the concentrations of NO2 (- 44.5%), CO (- 41.5%), and PM2.5, PM10 (- 29.5%, each) were measured in the capital city of Jeddah during the quarantine compared to the pre-lockdown average. In contrast, the lockdown caused a significant increase in O3 by 41%. The changes in air quality during the COVID-19 outbreak by comparing the average pollutant concentration before lockdown (January 1-March 21, 2020) and the following 12 weeks during the partial lockdown (March 22-July 28, 2020), reveal a very significant decrease in pollutants, and consequently a significant improvement in air quality. Observed differences are attributable to changes in point source emissions associated with changes in localized activities, possibly related to decreased economic and industrial activity in response to the lockdown. The results of the present study show during the study period indicated a positive response to lockdown during the COVID-19 pandemic. Furthermore, the results can be used to establish future control measures and strategies to improve air quality.

Channeled PM10, PM2.5 and PM1 Emission Factors Associated with the Ceramic Process and Abatement Technologies.

A sampling methodology and a mathematical data treatment were developed that enable to determine not only total suspended particulates (TSP) emitted at channeled sources but also the PM10, PM2.5, and PM1 mass fractions (w10, w2.5, and w1) and emission factors (E.F.), using a seven-stage cascade impactor. Moreover, a chemical analysis was performed to identify the elements present in these emissions. The proposed methodology was applied to different stages of the ceramic process, including ambient temperature (milling, shaping, glazing) and medium-high-temperature (spray-drying, drying, firing, and frit melting) stages. In total, more than 100 measurements were performed (pilot scale and industrial scale), which leads to a measurement time of 1500 h. Related to the mass fractions, in general, the mean values of w10 after the fabric filters operated at high performance are high and with little dispersion (75-85%), and it is also observed that they are practically independent of the stage considered, i.e., they are not significantly dependent on the initial PSD of the stream to be treated. In the case of the fine fraction w2.5, the behavior is more complex (w2.5: 30-60%), probably because the only variable is not the cleaning system, but also the nature of the processed material. Regarding abatement measures, the use of high-efficiency cleaning systems considerably reduces the emission factors obtained for fractions PM10, PM2.5, and PM1. In reference to chemical analysis, the presence of ZrO2 and Ni in the spray-drying and pressing stages, the significant concentration of ZrO2 in the glazing stage, the presence of Pb, As, and Zn in the firing stage, and the presence of Zn, Pb, Cd, and As compounds in the frits manufacturing should all be highlighted. Nevertheless, it should be pointed out that the use of some compounds, such as cadmium and lead, has been very limited in the last years and, therefore, presumably, the presence of these elements in the emissions should have been also reduced in the same way.

Metabolomic profiling identifies plasma sphingosine 1-phosphate levels associated with welding exposures.

BACKGROUND: Despite a number of known health hazards of welding fume exposure, it is unclear how exposure affects the human metabolome. OBJECTIVE: We assessed the metabolic profiles of welders before and after a 6-hour welding shift, controlling for circadian rhythm of metabolism on a non-welding day. METHODS: Welders were recruited from a training centre in Quincy, Massachusetts, in 2006 and 2010-2012 and donated blood samples on a welding shift day before and after work, as well as on a non-welding day spent in an adjacent classroom. In total, we collected 509 samples from 74 participants. Liquid chromatography-mass spectrometry quantified 665 metabolites from thawed plasmas. Metabolites with significant time (afternoon compared with morning) and day (welding/classroom) interactions were identified by two-way analysis of variance, and the overnight changes were evaluated. RESULTS: Sphingosine 1-phosphate (S1P) and sphingasine 1-phosphate (SA1P) exhibited significant interaction effects between day and time with false discovery rate-adjusted p values of 0.03 and <0.01, respectively. S1P, SA1P and sphingosine shared similar trends over time: high relative levels in the morning of a non-welding day declining by afternoon, but with lower starting levels on a welding day and no decline. There was no obvious pattern related to current smoking status. CONCLUSION: S1P and SA1P profiles were different between welding day and classroom day. The S1P pathway was disrupted on the day of welding exposure. The levels of S1P, SA1P and sphingosine were highly correlated over time. S1P is a signalling lipid with many vital roles; thus, the underlying mechanism and clinical implications of this alteration need further investigation.

Evaluation of particulate matter concentrations according to cooking activity in a residential environment.

This study aimed to determine the ventilation conditions required for suitable indoor air quality management during cooking in a typical South Korean residential home. We measured the concentrations of particulate matter (PM10) and fine particulate matter (PM2.5) under different ventilation conditions during the cooking of different food materials in the kitchen of a multi-family house, which is the representative residential space in South Korea. Pork belly and mackerel, which are the staple meat and fish products of Korean people, were prepared (200 g of each) and cooked via roasting. The PM10 and PM2.5 concentrations were measured three times for 1 h at 1 min intervals under twelve ventilation conditions. To investigate the PM10 and PM2.5 concentration distribution characteristics and the reduction effect according to ventilation condition, the ratio of the concentration during cooking to the initial concentration was calculated for each condition. Factors causing the emission of PM10 and PM2.5 for each food material and under each ventilation condition were analyzed using principal component analysis and verified using one-way analysis of variance and post hoc analysis. The PM10 and PM2.5 concentrations generated during the cooking of pork belly and mackerel reached their maximum values when no ventilation was used. Under this condition, PM10 concentrations were 246.27 and 1227.71 µg/m3 while the PM2.5 concentrations were 161.93 and 760.82 µg/m3 for pork belly and mackerel cooking, respectively. The PM10 and PM2.5 concentrations were also found to be high when a range hood and air cleaner were used, indicating that it is necessary to improve the performance of ventilation devices and to use appropriate ventilation methods. The use of natural ventilation exhibited a high PM10 and PM2.5 reduction effect compared with the ventilation conditions that used ventilation devices. Using natural ventilation together with ventilation devices was found to be the most effective method of reducing the PM10 and PM2.5 generated during cooking. In conclusion, PM10 and PM2.5 concentrations generated during the cooking of pork belly and mackerel varied depending on the ventilation condition, but they were high when inappropriate ventilation methods were used. Therefore, using appropriate ventilation conditions is effective in reducing PM10 and PM2.5 generated during cooking.

Temporal Changes in Air Quality According to Land-Use Using Real Time Big Data from Smart Sensors in Korea.

This study analyzed the changes in particulate matter concentrations according to land-use over time and the spatial characteristics of the distribution of particulate matter concentrations using big data of particulate matter in Daejeon, Korea, measured by Private Air Quality Monitoring Smart Sensors (PAQMSSs). Land-uses were classified into residential, commercial, industrial, and green groups according to the primary land-use around the 650-m sensor radius. Data on particulate matter with an aerodynamic diameter <10 µm (PM10) and <2.5 µm (PM2.5) were captured by PAQMSSs from September‒October (i.e., fall) in 2019. Differences and variation characteristics of particulate matter concentrations between time periods and land-uses were analyzed and spatial mobility characteristics of the particulate matter concentrations over time were analyzed. The results indicate that the particulate matter concentrations in Daejeon decreased in the order of industrial, housing, commercial and green groups overall; however, the concentrations of the commercial group were higher than those of the residential group during 21:00-23:00, which reflected the vital nighttime lifestyle in the commercial group in Korea. Second, the green group showed the lowest particulate matter concentration and the industrial group showed the highest concentration. Third, the highest particulate matter concentrations were in urban areas where commercial and business functions were centered and in the vicinity of industrial complexes. Finally, over time, the PM10 concentrations were clearly high at noon and low at night, whereas the PM2.5 concentrations were similar at certain areas.

Combustion in the future: The importance of chemistry.

Combustion involves chemical reactions that are often highly exothermic. Combustion systems utilize the energy of chemical compounds released during this reactive process for transportation, to generate electric power, or to provide heat for various applications. Chemistry and combustion are interlinked in several ways. The outcome of a combustion process in terms of its energy and material balance, regarding the delivery of useful work as well as the generation of harmful emissions, depends sensitively on the molecular nature of the respective fuel. The design of efficient, low-emission combustion processes in compliance with air quality and climate goals suggests a closer inspection of the molecular properties and reactions of conventional, bio-derived, and synthetic fuels. Information about flammability, reaction intensity, and potentially hazardous combustion by-products is important also for safety considerations. Moreover, some of the compounds that serve as fuels can assume important roles in chemical energy storage and conversion. Combustion processes can furthermore be used to synthesize materials with attractive properties. A systematic understanding of the combustion behavior thus demands chemical knowledge. Desirable information includes properties of the thermodynamic states before and after the combustion reactions and relevant details about the dynamic processes that occur during the reactive transformations from the fuel and oxidizer to the products under the given boundary conditions. Combustion systems can be described, tailored, and improved by taking chemical knowledge into account. Combining theory, experiment, model development, simulation, and a systematic analysis of uncertainties enables qualitative or even quantitative predictions for many combustion situations of practical relevance. This article can highlight only a few of the numerous investigations on chemical processes for combustion and combustion-related science and applications, with a main focus on gas-phase reaction systems. It attempts to provide a snapshot of recent progress and a guide to exciting opportunities that drive such research beyond fossil combustion.

Aerosols chemical composition, light extinction, and source apportionment near a desert margin city, Yulin, China.

Daily PM10and PM2.5 sampling was conducted during four seasons from December 2013 to October 2014 at three monitoring sites over Yulin, a desert margin city. PM10 and PM2.5 levels, water soluble ions, organic carbon (OC), and elemental carbon (EC) were also analyzed to characterize their chemical profiles. b ext (light extinction coefficient) was calculated, which showed the highest in winter with an average of 232.95 ± 154.88 Mm-1, followed by autumn, summer, spring. Light extinction source apportionment results investigated (NH4)2SO4 and NH4NO3 played key roles in the light extinction under high RH conditions during summer and winter. Sulfate, nitrate and Ca2 + dominated in PM10/PM2.5 ions. Ion balance results illustrated that PM samples were alkaline, and PM10 samples were more alkaline than PM2.5. High SO4 2-/K+ and Cl-/K+ ratio indicated the important contribution of coal combustion, which was consistent with the OC/EC regression equation intercepts results. Principal component analysis (PCA) analyses results showed that the fugitive dust was the most major source of PM, followed by coal combustion & gasoline vehicle emissions, secondary formation and diesel vehicle emissions. Potential contribution source function (PSCF) results suggested that local emissions, as well as certain regional transport from northwesterly and southerly areas contributed to PM2.5 loadings during the whole year. Local government should take some measures to reduce the PM levels.

Accelerated lung function decline in an aluminium manufacturing industry cohort exposed to PM2.5: an application of the parametric g-formula.

OBJECTIVE: Occupational dust exposure has been associated with accelerated lung function decline, which in turn is associated with overall morbidity and mortality. In the current study, we assess potential benefits on lung function of hypothetical interventions that would reduce occupational exposure to fine particulate matter (PM2.5) while adjusting for the healthy worker survivor effect. METHODS: Analyses were performed in a cohort of 6485 hourly male workers in an aluminium manufacturing company in the USA, followed between 1996 and 2013. We used the parametric g-formula to assess lung function decline over time under hypothetical interventions while also addressing time-varying confounding by underlying health status, using a composite risk score based on health insurance claims. RESULTS: A counterfactual scenario envisioning a limit on exposure equivalent to the 10th percentile of the observed exposure distribution of 0.05 mg/m3 was associated with an improvement in forced expiratory volume in one second (FEV1) equivalent to 37.6 mL (95% CI 13.6 to 61.6) after 10 years of follow-up when compared with the observed. Assuming a linear decrease and (from NHANES reference values), a 20 mL decrease per year for a 1.8 m-tall man as they age, this 37.6 mL FEV1 loss over 10 years associated with observed exposure would translate to approximately a 19% increase to the already expected loss per year from age alone. CONCLUSIONS: Our results indicate that occupational PM2.5 exposure in the aluminium industry accelerates lung function decline over age. Reduction in exposure may mitigate accelerated loss of lung function over time in the industry.

Functional, inflammatory and interstitial impairment due to artificial stone dust ultrafine particles exposure.

OBJECTIVE: Artificial stone dust (ASD) contains high levels of ultrafine particles (UFP <1 µm) which penetrate deeply into the lungs. This study aimed to demonstrate the direct effect of UFP in the lungs of ASD-exposed workers on functional inflammatory and imaging parameters. METHODS: 68 workers with up to 20 years of ASD exposure at the workplace were recruited from small enterprises throughout the country and compared with 48 non-exposed individuals. Pulmonary function test (PFT), CT, induced sputum (IS) and cytokine analyses were performed by conventional methods. The CT scans were evaluated for features indicative of silicosis in three zones of each lung. UFP were quantitated by the NanoSight LM20 system (NanoSight, Salisbury) using the Nanoparticle Tracking Analysis. Interleukin (IL)-6, IL-8 and tumour necrosis factor alpha (TNF-α) levels were measured by Luminex (R&D Systems). RESULTS: Thirty-four patients had CT scores between 0 and 42, and 29 of them were diagnosed with silicosis. Content of the UFP retrieved from IS supernatants correlated negatively with the PFT results (total lung capacity r=-0.347, p=0.011; forced expiratory volume in 1 s r=-0.299, p=0.046; diffusion lung carbon monoxide in a single breath r=-0.425, p=0.004) and with the CT score (r=0.378, p=0.023), and with the inflammatory cytokines IL-8 (r=0.336, p=0.024), IL-6 (r=0.294, p=0.065) and TNF-α (r=0.409, p=0.007). Raw material of ASD was left to sedimentate in water for <15 min, and 50% of the floating particles were UFP. A cut-off of 8×106 UFP/mL in IS samples had a sensitivity of 77% to predict pulmonary disease. CONCLUSIONS: This is the first demonstration of an association between UFP-related decreased PFT results, worsening of CT findings and elevation of inflammatory cytokines, which may be attributed to high-dose inhalation of UFP of ASD at the workplace.

Acute effects of air pollutants on spontaneous pregnancy loss: a case-crossover study.

OBJECTIVE: To investigate the relationship between acute exposure to air pollutants and spontaneous pregnancy loss. DESIGN: Case-crossover study from 2007 to 2015. SETTING: An academic emergency department in the Wasatch Front area of Utah. PATIENT(S): A total of 1,398 women who experienced spontaneous pregnancy loss events. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Odds of spontaneous pregnancy loss. RESULT(S): We found that a 10-ppb increase in 7-day average levels of nitrogen dioxide was associated with a 16% increase in the odds of spontaneous pregnancy loss (odds ratio [OR] = 1.16; 95% confidence interval [CI] 1.01-1.33; P=.04). A 10-µg/m3 increase in 3-day and 7-day averages of fine particulate matter were associated with increased risk of spontaneous pregnancy loss, but the associations did not reach statistical significance (OR3-day average = 1.09; 95% CI 0.99-1.20; P=.05) (OR7-day average = 1.11; 95% CI 0.99-1.24; P=.06). We found no evidence of increased risk for any other metrics of nitrogen dioxide or fine particulate matter or any metric for ozone. CONCLUSIONS: We found that short-term exposure to elevated levels of air pollutants was associated with higher risk for spontaneous pregnancy loss.

Carcinogenic Potency of Airborne Polycyclic Aromatic Hydrocarbons in Relation to the Particle Fraction Size.

Polycyclic aromatic hydrocarbons (PAHs) that are bound to particulate matter can have adverse effects on human health. Particle size plays an important role in assessing health risks. The aim of this study was to compare concentrations of PAHs bound to particle fractions PM10, PM2.5, and PM1, as well as to estimate their carcinogenic potency and relative contributions of the individual PAHs to the carcinogenic potency in relation to the size of the particle. Measurements of ten PAHs were carried out in 2014 at an urban location in the northern part of Zagreb, Croatia. 24-h samples of the PM10, PM2.5, and PM1 particle fraction were collected over forty days per season. Carcinogenic potency of PAHs was estimated by calculating benzo(a)pyrene equivalent concentrations while using three different toxic equivalence factor (TEF) schemes. The total carcinogenic potency (TCP) and percentage contributions differed significantly depending on the TEF scheme used. The lowest PAH mass concentrations and TCPs were in summer and the highest in winter. The contributions of individual PAHs to the sum of PAH mass concentrations remained similar in all fractions and seasons, while in fractions PM10⁻2.5 and PM2.5⁻1 they varied significantly. Road traffic represented the important source of PAHs in all fractions and throughout all seasons. Other sources (wood and biomass burning, petroleum combustion) were also present, especially during winter as a consequence of household heating. The highest contribution to the TCP came from benzo(a)pyrene, dibenzo(ah)antrachene, indeno(1,2,3,cd)pyrene, and benzo(b)fluoranthene (together between 87% and 96%) in all fractions and seasons. In all cases, BaP showed the highest contribution to the TCP regardless relatively low contributions to the mass of total PAHs and it can be considered as a good representative for assessing the carcinogenicity of the PAH mixture. When comparing the TCP of PAHs in PM10 and PM2.5 fractions, it was found that about 21⁻26% of carcinogenic potency of the PAH mixture belonged to the PM2.5 fraction. Comparison of TCP in PM2.5 and PM1 showed that about 86% of carcinogenic potency belonged to the PM1 fraction, regardless of the TEF scheme used.

Effectiveness of face masks used to protect Beijing residents against particulate air pollution.

OBJECTIVES: Many residents in Beijing use disposable face masks in an attempt to protect their health from high particulate matter (PM) concentrations. Retail masks may be certified to local or international standards, but their real-life performance may not confer the exposure reduction potential that is marketed. This study aimed to evaluate the effectiveness of a range of face masks that are commercially available in China. METHODS: Nine masks claiming protection against fine PM (PM2.5) were purchased from consumer outlets in Beijing. The masks' filtration efficiency was tested by drawing airborne diesel exhaust through a section of the material and measuring the PM2.5 and black carbon (BC) concentrations upstream and downstream of the filtering medium. Four masks were selected for testing on volunteers. Volunteers were exposed to diesel exhaust inside an experimental chamber while performing sedentary tasks and active tasks. BC concentrations were continuously monitored inside and outside the mask. RESULTS: The mean per cent penetration for each mask material ranged from 0.26% to 29%, depending on the flow rate and mask material. In the volunteer tests, the average total inward leakage (TIL) of BC ranged from 3% to 68% in the sedentary tests and from 7% to 66% in the active tests. Only one mask type tested showed an average TIL of less than 10%, under both test conditions. CONCLUSIONS: Many commercially available face masks may not provide adequate protection, primarily due to poor facial fit. Our results indicate that further attention should be given to mask design and providing evidence-based guidance to consumers.

Enfermedad meningocóccica en la Región Metropolitana de Chile y su correlación con factores ambientales / Meningococcal disease in the Metropolitan Region of Chile and its correlation with environmental factors

Introduction: Meningococcal disease (MD) is a public health problem worldwide, due to its high morbidity and mortality. Most cases occur in sub-Saharan Africa, where there is a marked seasonal pattern with predominance during the dry season. Objectives: To describe the morbidity of MD in the Metropolitan Region (MR) of Chile and explore whether there is a correlation between the number of cases with the levels of atmospheric particulate matter PM 10 and PM 2.5, relative humidity (RH), temperature and total environmental pollen. Materials and Methods: Ecological time series study, statistical analysis with R 3.0.1, graphics with Excel 2013. Results: Between 2010 and 2013, 234 MD cases were reported in the MR with an increasing trend. There is a seasonal pattern with an increase of cases from August to October, and a decrease from March to April. There is no correlation with the levels of PM10 and PM2.5. There is a slight positive correlation with RH and a slight negative correlation with temperature. There is a moderate positive correlation with the levels of total environmental pollens. Discussion: Overcrowding and the winter viral infections could explain the increased incidence of MD and the slight correlation with RH and temperature. The moderate correlation with the pollens could be explained by an effect of irritation of the upper airway. Conclusions: More epidemiological studies whose designs allow a greater causal inference are required.

Introducción: La enfermedad meningocóccica (EM) constituye un problema de salud pública mundial debido a su alta morbi-mortalidad. La mayor cantidad de casos ocurre en África subsahariana, donde existe un marcado patrón estacional en la estación seca. Objetivos: Describir la morbilidad de la EM en la Región Metropolitana (RM) de Chile y explorar si existe correlación entre el número de casos con PM 10, PM 2,5 humedad relativa (HR), temperatura y pólenes ambientales totales. Materiales y Métodos: Estudio ecológico tipo series de tiempo, análisis estadístico con R 3.0.1, gráficos con Excel 2013. Resultados: En el período 2010-2013 se notificaron 234 casos de EM en la RM, con una tendencia al alza. Se observa un patrón estacional con aumento de casos entre agosto y octubre y una disminución entre marzo y abril. No existe correlación con los niveles de PM 10 ni de PM 2,5. Se describe una correlación positiva leve con la HR y negativa leve con la temperatura. Existe correlación moderada positiva con los niveles de pólenes totales ambientales. Discusión: El hacinamiento y las infecciones virales de invierno podrían explicar el aumento de casos de EM y la correlación leve con la HR y la temperatura. La correlación moderada con los pólenes podría explicarse por un efecto de irritación de la vía aérea superior. Conclusiones: Se requieren más estudios epidemiológicos cuyos diseños permitan una mayor inferencia causal.

Associations between ambient air pollution and daily mortality among elderly persons in Montreal, Quebec.

BACKGROUND: Persons with underlying health conditions may be at higher risk for the short-term effects of air pollution. We have extended our original mortality time series study in Montreal, Quebec, among persons 65 years of age and older, for an additional 10 years (1990-2003) to assess whether these associations persisted and to investigate new health conditions. METHODS AND RESULTS: We created subgroups of subjects diagnosed with major health conditions one year before death using billing and prescription data from the Quebec Health Insurance Plan. We used parametric log-linear Poisson models within the distributed lag non-linear models framework, that were adjusted for long-term temporal trends and daily maximum temperature, for which we assessed associations with NO2, O3, CO, SO2, and particles with aerodynamic diameters 2.5 µm in diameter or less (PM2.5). We found positive associations between daily non-accidental mortality and all air pollutants but O3 (e.g., for a cumulative effect over a 3-day lag, with a mean percent change (MPC) in daily mortality of 1.90% [95% confidence interval: 0.73, 3.08%] for an increase of the interquartile range (17.56 µg m(-3)) of NO2). Positive associations were found amongst persons having cardiovascular disease (cumulative MPC for an increase equal to the interquartile range of NO2=2.67%), congestive heart failure (MPC=3.46%), atrial fibrillation (MPC=4.21%), diabetes (MPC=3.45%), and diabetes and cardiovascular disease (MPC=3.50%). Associations in the warm season were also found for acute and chronic coronary artery disease, hypertension, and cancer. There was no persuasive evidence to conclude that there were seasonal associations for cerebrovascular disease, acute lower respiratory disease (defined within 2 months of death), airways disease, and diabetes and airways disease. CONCLUSIONS: These data indicate that individuals with certain health conditions, especially those with diabetes and cardiovascular disease, hypertension, atrial fibrillation, and cancer, may be susceptible to the short-term effects of air pollution.