| 1. |
- Beko, Gabriel, et al.
(author)
-
Contribution of various microenvironments to the daily personal exposure to ultrafine particles: Personal monitoring coupled with GPS tracking
- 2015
-
In: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 110, s. 122-129
-
Journal article (peer-reviewed)abstract
- Exposure to ultrafine particles (UFP) may have adverse health effects. Central monitoring stations do not represent the personal exposure to UFP accurately. Few studies have previously focused on personal exposure to UFP. Sixty non-smoking residents living in Copenhagen, Denmark were asked to carry a backpack equipped with a portable monitor, continuously recording particle number concentrations (PN), in order to measure the real-time individual exposure over a period of similar to 48 h. A GPS logger was carried along with the particle monitor and allowed us to estimate the contribution of UFP exposure occurring in various microenvironments (residence, during active and passive transport, other indoor and outdoor environments) to the total daily exposure. On average, the fractional contribution of each microenvironment to the daily integrated personal exposure roughly corresponded to the fractions of the day the subjects spent in each microenvironment. The home environment accounted for 50% of the daily personal exposure. Indoor environments other than home or vehicles contributed with similar to 40%. The highest median UFP concentration was obtained during passive transport (vehicles). However, being in transit or outdoors contributed 5% or less to the daily exposure. Additionally, the subjects recorded in a diary the periods when they were at home. With this approach, 66% of the total daily exposure was attributable to the home environment. The subjects spent 28% more time at home according to the diary, compared to the GPS. These results may indicate limitations of using diaries, but also possible inaccuracy and miss-classification in the GPS data. (C) 2015 Elsevier Ltd. All rights reserved.
|
|
| 2. |
- Bekö, Gabriel, et al.
(author)
-
Ultrafine Particles: Exposure and Source Apportionment in 56 Danish Homes
- 2013
-
In: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 47:18, s. 10240-10248
-
Journal article (peer-reviewed)abstract
- ABSTRACT: Particle number (PN) concentrations (10−300 nm in size) were continuously measured over a period of ∼45 h in 56 residences of nonsmokers in Copenhagen, Denmark. The highest concentrations were measured when occupants were present and awake (geometric mean, GM: 22.3 × 103 cm−3), the lowest when the homes were vacant (GM: 6.1 × 103 cm−3) or the occupants were asleep (GM: 5.1 × 103 cm−3). Diary entries regarding occupancy and particle related activities were used to identify source events and apportion the daily integrated exposure among sources. Source events clearly resulted in increased PN concentrations and decreased average particle diameter. For a given event, elevated particle concentrations persisted for several hours after the emission of fresh particles ceased. The residential daily integrated PN exposure in the 56 homes ranged between 37 × 103 and 6.0 × 106 particles per cm3·h/day (GM: 3.3 × 105 cm−3·h/day). On average, ∼90% of this exposure occurred outside of the period from midnight to 6 a.m. Source events, especially candle burning, cooking, toasting, and unknown activities, were responsible on average for ∼65% of the residential integrated exposure (51% without the unknown activities). Candle burning occurred in half of the homes where, on average, it was responsible for almost 60% of the integrated exposure.
|
|
| 3. |
|
|
| 4. |
- Bräuner, Elvira Vaclavik, et al.
(author)
-
Exposure to ambient concentrations of particulate air pollution does not influence vascular function or inflammatory pathways in young healthy individuals.
- 2008
-
In: Particle and fibre toxicology. - : Springer Science and Business Media LLC. - 1743-8977. ; 5
-
Journal article (peer-reviewed)abstract
- ABSTRACT: BACKGROUND: Particulate air pollution is associated with increased risk of cardiovascular events although the involved mechanisms are poorly understood. The objective of the present study was to investigate the effects of controlled exposure to ambient air fine and ultrafine particles on microvascular function and biomarkers related to inflammation, haemostasis and lipid and protein oxidation. METHODS: Twenty-nine subjects participated in a randomized, two-factor crossover study with or without biking exercise for 180 minutes and with 24 hour exposure to particle rich (number concentrations, NC: 11600 +/- 5600 per cm3, mass concentrations: 13.8 +/- 7.4 mug/m3 and 10.5 +/- 4.8 mug/m3 for PM10-2.5 and PM2.5, respectively) or particle filtered (NC: 555 +/- 1053 per cm3) air collected above a busy street. Microvascular function was assessed non-invasively by measuring digital peripheral artery tone following arm ischemia. Biomarkers included haemoglobin, red blood cells, platelet count, coagulation factors, C-reactive protein, fibrinogen, interleukin-6, tumour necrosis factor alpha, lag time to copper-induced oxidation of plasma lipids and protein oxidation measured as 2-aminoadipic semialdehyde in plasma. RESULTS: No statistically significant differences were observed on microvascular function or the biomarkers after exposure to particle rich or particle filtered air. CONCLUSION: This study indicates that exposure to air pollution particles at outdoor concentrations is not associated with detectable systemic inflammation, lipid or protein oxidation, altered haemostasis or microvascular function in young healthy participants.
|
|
| 5. |
- Bräuner, Elvira Vaclavik, et al.
(author)
-
Indoor particles affect vascular function in the aged: an air filtration-based intervention study.
- 2008
-
In: American journal of respiratory and critical care medicine. - 1535-4970. ; 177:4, s. 419-25
-
Journal article (peer-reviewed)abstract
- RATIONALE: Exposure to particulate matter is associated with risk of cardiovascular events, possibly through endothelial dysfunction, and indoor air may be most important. OBJECTIVES: We investigated effects of controlled exposure to indoor air particles on microvascular function (MVF) as the primary endpoint and biomarkers of inflammation and oxidative stress as secondary endpoints in a healthy elderly population. METHODS: A total of 21 nonsmoking couples participated in a randomized, double-blind, crossover study with two consecutive 48-hour exposures to either particle-filtered or nonfiltered air (2,533-4,058 and 7,718-12,988 particles/cm(3), respectively) in their homes. MEASUREMENTS AND MAIN RESULTS: MVF was assessed noninvasively by measuring digital peripheral artery tone after arm ischemia. Secondary endpoints included hemoglobin, red blood cells, platelet count, coagulation factors, P-selectin, plasma amyloid A, C-reactive protein, fibrinogen, IL-6, tumor necrosis factor-alpha, protein oxidation measured as 2-aminoadipic semialdehyde in plasma, urinary 8-iso-prostaglandin F(2alpha), and blood pressure. Indoor air filtration significantly improved MVF by 8.1% (95% confidence interval, 0.4-16.3%), and the particulate matter (diameter < 2.5 mum) mass of the indoor particles was more important than the total number concentration (10-700 nm) for these effects. MVF was significantly associated with personal exposure to iron, potassium, copper, zinc, arsenic, and lead in the fine fraction. After Bonferroni correction, none of the secondary biomarkers changed significantly. CONCLUSIONS: Reduction of particle exposure by filtration of recirculated indoor air for only 48 hours improved MVF in healthy elderly citizens, suggesting that this may be a feasible way of reducing the risk of cardiovascular disease.
|
|
| 6. |
|
|
| 7. |
- Danielsen, Pernille Hogh, et al.
(author)
-
Oxidatively damaged DNA and its repair after experimental exposure to wood smoke in healthy humans.
- 2008
-
In: Mutation research. - : Elsevier BV. - 0027-5107. ; 642:1-2, s. 37-42
-
Journal article (peer-reviewed)abstract
- Particulate matter from wood smoke may cause health effects through generation of oxidative stress with resulting damage to DNA. We investigated oxidatively damaged DNA and related repair capacity in peripheral blood mononuclear cells (PBMC) and measured the urinary excretion of repair products after controlled short-term exposure of human volunteers to wood smoke. Thirteen healthy adults were exposed first to clean air and then to wood smoke in a chamber during 4h sessions, 1 week apart. Blood samples were taken 3h after exposure and on the following morning, and urine was collected after exposure, from bedtime until the next morning. We measured the levels of DNA strand breaks (SB), oxidized purines as formamidopyrimidine-DNA-glycosylase (FPG) sites and activity of oxoguanine glycosylase 1 (hOGG1) in PBMC by the comet assay, whereas mRNA levels of hOGG1, nucleoside diphosphate linked moiety X-type motif 1 (hNUDT1) and heme oxygenase 1 (hHO1) were determined by real-time RT-PCR. The excretion of 8-oxo-7,8-dihydro-oxoguanine (8-oxoGua) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in urine was measured by high performance liquid chromatography purification followed by gas chromatography with mass spectrometry. The morning following exposure to wood smoke the PBMC levels of SB were significantly decreased and the mRNA levels of hOGG1 significantly increased. FPG sites, hOGG1 activity, expression of hNUDT1 and hHO1, urinary excretion of 8-oxodG and 8-oxoGua did not change significantly. Our findings support that exposure to wood smoke causes systemic effects, although we could not demonstrate genotoxic effects, possibly explained by enhanced repair and timing of sampling.
|
|
| 8. |
|
|
| 9. |
- Haghdoost, Siamak, 1968-
(author)
-
Biomarkers of oxidative stress and their application for assessment of individual radiosensitivity
- 2005
-
Doctoral thesis (other academic/artistic)abstract
- Radiotherapy is one of the most common therapeutic methods for treatment of many types of cancer. Despite many decades of development and experience there is much to improve, both in efficacy of treatment and to decrease the incidences of adverse healthy tissue reactions. Around 20 % of the radiotherapy patients show a broad range in the severity of normal tissue reactions to radiotherapy, and dose limits are governed by severe reactions in the most radiosensitive patients (< 5 %). Identification of patients with low, moderate or high clinical radiosensitivity before commencing of radiotherapy would allow individual adaptation of the maximum dose with an overall increase in the cure rate. Characterization of factors that may modify the biological effects of ionizing radiation has been a subject of intense research efforts. Still, there is no assay currently available that can reliably predict the clinical radiosensitivity. The aim of this work has been to investigate the role of oxidative stress in individual radiosensitivity and evaluate novel markers of radiation response, which could be adapted for clinical use.8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG), a general marker of oxidative stress, is one of the major products of interaction of ionizing radiation with DNA and the nucleotide pool of the cell. As 8-oxo-dG is highly mutagenic due to incorrect base pairing with deoxyadenosine, various repair mechanisms recognize and remove 8-oxo-dG. The repaired lesions are released from cells to the extracellular milieu (serum, urine and cell culture medium) where they can be detected as markers for free radical reactions with the nucleic acids.Significant variations in background levels as well as in radiation induced levels of 8-oxo-dG in urine have been demonstrated in breast cancer patients (paper 1). Two major patterns were observed: high background and no therapy-related increase vs. low background and significant increase during radiotherapy for the radiosensitive and non radiosensitive patients respectively.Studies in paper 2 indicated major contribution of the nucleotide pool to the extracellular 8-oxo-dG levels. The results also implicated induction of prolonged endogenous oxidative stress in the irradiated cells. RNA “knock-down” experiments on the nucleotide pool sanitization enzyme hMTH1 in paper 3 lend further experimental evidence to this assumption.The applicability of 8-oxo-dG as a diagnostic marker of oxidative stress was demonstrated in paper 4. Studies on dialysis patients revealed a good correlation between inflammatory responses (known to be associated with persistent oxidative stress) and extracellular 8-oxo-dG.In summary, our results confirm that extracellular 8-oxo-dG is a sensitive in vivo biomarker of oxidative stress, primarily formed by oxidative damage of dGTP in the nucleotide pool with a potential to become a clinical tool for prediction of individual responses to radiotherapy.
|
|
| 10. |
- Hemmingsen, Jette Gjerke, et al.
(author)
-
Controlled exposure to diesel exhaust and traffic noise - Effects on oxidative stress and activation in mononuclear blood cells.
- 2015
-
In: Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis. - : Elsevier BV. - 1879-2871 .- 0027-5107. ; 775, s. 66-71
-
Journal article (peer-reviewed)abstract
- Particulate air pollution increases risk of cancer and cardiopulmonary disease, partly through oxidative stress. Traffic-related noise increases risk of cardiovascular disease and may cause oxidative stress. In this controlled random sequence study, 18 healthy subjects were exposed for 3h to diesel exhaust (DE) at 276μg/m(3) from a passenger car or filtered air, with co-exposure to traffic noise at 48 or 75dB(A). Gene expression markers of inflammation, (interleukin-8 and tumor necrosis factor), oxidative stress (heme oxygenase (decycling-1)) and DNA repair (8-oxoguanine DNA glycosylase (OGG1)) were unaltered in peripheral blood mononuclear cells (PBMCs). No significant differences in DNA damage levels, measured by the comet assay, were observed after DE exposure, whereas exposure to high noise levels was associated with significantly increased levels of hOGG1-sensitive sites in PBMCs. Urinary levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine were unaltered. In auxiliary ex vivo experiments whole blood was incubated with particles from the exposure chamber for 3h without effects on DNA damage in PBMCs or intracellular reactive oxygen species production and expression of CD11b and CD62L adhesion molecules in leukocyte subtypes.
|
|
| 11. |
- Johnsen, Nina Fans, et al.
(author)
-
Physical activity and risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort
- 2009
-
In: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 125:4, s. 902-908
-
Journal article (peer-reviewed)abstract
- The evidence concerning the possible association between physical activity and the risk of prostate cancer is inconsistent and additional data are needed. We examined the association between risk of prostate cancer and physical activity at work and in leisure time in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. In our study, including 127,923 men aged 20-97 years from 8 European countries, 2,458 cases of prostate cancer were identified during 8.5 years of followup. Using the Cox proportional hazards model, we investigated the associations between prostate cancer incidence rate and occupational activity and leisure time activity in terms of participation in sports, cycling, walking and gardening; a metabolic equivalent (MET) score based on weekly time spent on the 4 activities; and a physical activity index. MET hours per week of leisure time activity, higher score in the physical activity index, participation in any of the 4 leisure time activities, and the number of leisure time activities in which the participants were active were not associated with prostate cancer incidence. However, higher level of occupational physical activity was associated with lower risk of advanced stage prostate cancer (p(trend) = 0.024). In conclusion, our data support the hypothesis of an inverse association between advanced prostate cancer risk and occupational physical activity, but we found no support for an association between prostate cancer risk and leisure time physical activity. (C) 2009 UICC
|
|
| 12. |
|
|
| 13. |
- Kyrø, Cecilie, et al.
(author)
-
Intake of whole grains from different cereal and food sources and incidence of colorectal cancer in the Scandinavian HELGA cohort
- 2013
-
In: Cancer Causes and Control. - : Springer Science and Business Media LLC. - 0957-5243 .- 1573-7225. ; 24:7, s. 1363-1374
-
Journal article (peer-reviewed)abstract
- A high intake of whole grains has been associated with a lower incidence of colorectal cancer, but few studies are available on the association with whole grains from different cereals, for example, wheat, rye and oats, and none has addressed these separately. The objective of this study was to investigate the association between whole-grain intake and colorectal cancer. We used data from the large population-based Scandinavian cohort HELGA consisting of 108,000 Danish, Swedish, and Norwegian persons, of whom 1,123 developed colorectal cancer during a median of 11 years of follow-up. Detailed information on daily intake of whole-grain products, including whole-grain bread, crispbread, and breakfast cereals, was available, and intakes of total whole grains and specific whole-grain species (wheat, rye, and oats) were estimated. Associations between these whole-grain variables and the incidence of colorectal cancer were investigated using Cox proportional hazards models. Intake of whole-grain products was associated with a lower incidence of colorectal cancer per 50-g increment (incidence rate ratio [IRR], 0.94; 95 % confidence interval [CI], 0.89, 0.99), and the same tendency was found for total whole-grain intake (IRR pr. 25-g increment, 0.94; 95 % CI, 0.88, 1.01). Intake of whole-grain wheat was associated with a lower incidence of colorectal cancer (IRR for highest versus lowest quartile of intake, 0.66; 95 % CI, 0.51, 0.85), but no statistical significant linear trend was observed (p for trend: 0.18). No significant association was found for whole-grain rye or oats. Whole-grain intake was associated with a lower incidence of colorectal cancer.
|
|
| 14. |
- Kyrø, Cecilie, et al.
(author)
-
Plasma alkylresorcinol concentrations, biomarkers of whole-grain wheat and rye intake, in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort
- 2014
-
In: British Journal of Nutrition. - : Cambridge University Press. - 0007-1145 .- 1475-2662. ; 111:10, s. 1881-1890
-
Journal article (peer-reviewed)abstract
- Whole-grain intake has been reported to be associated with a lower risk of several lifestyle-related diseases such as type 2 diabetes, CVD and some types of cancers. As measurement errors in self-reported whole-grain intake assessments can be substantial, dietary biomarkers are relevant to be used as complementary tools for dietary intake assessment. Alkylresorcinols (AR) are phenolic lipids found almost exclusively in whole-grain wheat and rye products among the commonly consumed foods and are considered as valid biomarkers of the intake of these products. In the present study, we analysed the plasma concentrations of five AR homologues in 2845 participants from ten European countries from a nested case-control study in the European Prospective Investigation into Cancer and Nutrition. High concentrations of plasma total AR were found in participants from Scandinavia and Central Europe and lower concentrations in those from the Mediterranean countries. The geometric mean plasma total AR concentrations were between 35 and 41nmol/l in samples drawn from fasting participants in the Central European and Scandinavian countries and below 23nmol/l in those of participants from the Mediterranean countries. The whole-grain source (wheat or rye) could be determined using the ratio of two of the homologues. The main source was wheat in Greece, Italy, the Netherlands and the UK, whereas rye was also consumed in considerable amounts in Germany, Denmark and Sweden. The present study demonstrates a considerable variation in the plasma concentrations of total AR and concentrations of AR homologues across ten European countries, reflecting both quantitative and qualitative differences in the intake of whole-grain wheat and rye.
|
|
| 15. |
- Kyrø, Cecilie, et al.
(author)
-
Plasma Alkylresorcinols, Biomarkers of Whole-Grain Wheat and Rye Intake, and Incidence of Colorectal Cancer
- 2014
-
In: Journal of the National Cancer Institute. - : Oxford University Press. - 0027-8874 .- 1460-2105. ; 106:1, s. djt352-
-
Journal article (peer-reviewed)abstract
- Background Few studies have investigated the association between whole-grain intake and colorectal cancer. Because whole-grain intake estimation might be prone to measurement errors, more objective measures (eg, biomarkers) could assist in investigating such associations. Methods The association between alkylresorcinols, biomarkers of whole-grain rye and wheat intake, and colorectal cancer incidence were investigated using prediagnostic plasma samples from colorectal cancer case patients and matched control subjects nested within the European Prospective Investigation into Cancer and Nutrition. We included 1372 incident colorectal cancer case patients and 1372 individual matched control subjects and calculated the incidence rate ratios (IRRs) for overall and anatomical subsites of colorectal cancer using conditional logistic regression adjusted for potential confounders. Regional differences (Scandinavia, the Mediterranean, Central Europe) were also explored. Results High plasma total alkylresorcinol concentration was associated with lower incidence of distal colon cancer; the adjusted incidence rate ratio of distal colon cancer for the highest vs lowest quartile of plasma total alkylresorcinols was 0.48 (95% confidence interval [CI] = 0.28 to 0.83). An inverse association between plasma total alkylresorcinol concentrations and colon cancer was found for Scandinavian participants (IRR per doubling = 0.83; 95% CI = 0.70 to 0.98). However, plasma total alkylresorcinol concentrations were not associated with overall colorectal cancer, proximal colon cancer, or rectal cancer. Plasma alkylresorcinols concentrations were associated with colon and distal colon cancer only in Central Europe and Scandinavia (ie, areas where alkylresorcinol levels were higher). Conclusions High concentrations of plasma alkylresorcinols were associated with a lower incidence of distal colon cancer but not with overall colorectal cancer, proximal colon cancer, and rectal cancer.
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
- Löndahl, Jakob, et al.
(author)
-
Experimentally Determined Human Respiratory Tract Deposition of Airborne Particles at a Busy Street
- 2009
-
In: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 43:13, s. 4659-4664
-
Journal article (peer-reviewed)abstract
- Traffic is one of the major sources of harmful airborne particles worldwide. To relate exposure to adverse health effects it is important to determine the deposition probability of the inhaled particles in the human respiratory tract. The size-dependent deposition of 12-580 nm particles was measured with a novel setup in 9 healthy subjects breathing by mouth on the windward side of a busy street in Copenhagen, Denmark. The aerosol was characterized both at the curbside and, to obtain the background concentration, at rooftop level. Particle hygroscopicity, a key parameter affecting respiratory tract deposition, was also measured at the same time of exposure. The total deposition fraction of the curbside particles in the range 12-580 nm was 0.60 by number, 0.29 by surface area, and 0.23 by mass. The deposition fractions of the "traffic exhaust" contribution, calculated as the hydrophobic fraction of the curbside particles, was 0.68, 0.35, and 0.28 by number, surface area, and mass, respectively. The deposited amount of traffic exhaust particles was 16 times higher by number and 3 times higher by surface area compared to the deposition of residential biofuel combustion particles investigated previously (equal inhaled mass concentrations). This was because the traffic exhaust particles had both a higher deposition probability and a higher number and surface area concentration per unit mass. To validate the results, the respiratory tract deposition was estimated by using the well-established ICRP. model. Predictions were in agreement with experimental results when the effects of particle hygroscopicity were considered in the model.
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
- Löndahl, Jakob, et al.
(author)
-
Size-Resolved Respiratory Tract Deposition of Fine and Ultrafine Hydrophobic and Hygroscopic Aerosol Particles during Rest and Exercise
- 2007
-
In: Inhalation Toxicology. - : Informa UK Limited. - 0895-8378 .- 1091-7691. ; 19:2, s. 109-116
-
Journal article (peer-reviewed)abstract
- Airborne ultrafine particles (diameter <100 nm) are ubiquitous in the environment and have been associated with adverse health effects. The respiratory-tract deposition of these particles is fundamentally influenced by their hygroscopicity: their ability to grow by condensation of water in the humid respiratory system. Ambient particles are typically hygroscopic, to varying degrees. This article investigates the influence of hygroscopicity, exercise level, gender, and intersubject variability on size-dependent deposition of fine and ultrafine particles during spontaneous breathing. Using a novel and well-characterized setup, respiratory-tract deposition in the range 12-320 nm has been measured for 29 healthy adults (20 men, 9 women). Each subject completed four sessions: rest and light exercise on an ergometer bicycle while inhaling both hydrophobic (diethylhexylsebacate) and hygroscopic (NaCl) particles. The deposited fraction (DF) based on dry diameters was two to four times higher for the hydrophobic ultrafine particles than for the hygroscopic. The DF of hygroscopic ultrafine particles could be estimated by calculating their equilibrium size at 99.5% relative humidity. The differences in average DF due to exercise level and gender were essentially less than 0.03. However, the minute ventilation increased fourfold during exercise and was 18-46% higher for the men than for the women. Consequently the deposited dose of particles was fourfold higher during exercise and considerably increased for the male subjects. Some individuals consistently had a high DF in all four sessions. As an example, the results show that an average person exposed to 100-nm hydrophobic particles during exercise will receive a 16 times higher dose than a relaxed person exposed to an equal amount of hygroscopic (NaCl) particles.
|
|
| 26. |
|
|
| 27. |
|
|
| 28. |
|
|
| 29. |
- Olsen, Yulia, et al.
(author)
-
Vascular and lung function related to ultrafine and fine particles exposure assessed by personal and indoor monitoring: a cross-sectional study
- 2014
-
In: Environmental Health. - 1476-069X. ; 13
-
Journal article (peer-reviewed)abstract
- Background: Exposure to ambient air particulate matter (PM) has been linked to decline in pulmonary function and cardiovascular events possibly through inflammation. Little is known about individual exposure to ultrafine particles (UFP) inside and outside modern homes and associated health-related effects. Methods: Associations between vascular and lung function, inflammation markers and exposure in terms of particle number concentration (PNC; d = 10-300 nm) were studied in a cross-sectional design with personal and home indoor monitoring in the Western Copenhagen Area, Denmark. During 48-h, PNC and PM2.5 were monitored in living rooms of 60 homes with 81 non-smoking subjects (30-75 years old), 59 of whom carried personal monitors both when at home and away from home. We measured lung function in terms of the FEV1/FVC ratio, microvascular function (MVF) and pulse amplitude by digital artery tonometry, blood pressure and biomarkers of inflammation including C-reactive protein, and leukocyte counts with subdivision in neutrophils, eosinophils, monocytes, and lymphocytes in blood. Results: PNC from personal and stationary home monitoring showed weak correlation (r = 0.15, p = 0.24). Personal UFP exposure away from home was significantly inversely associated with MVF (1.3% decline per interquartile range, 95% confidence interval: 0.1-2.5%) and pulse amplitude and positively associated with leukocyte and neutrophil counts. The leukocyte and neutrophil counts were also positively and pulse amplitude negatively associated with total personal PNC. Indoor PNC and PM2.5 showed positive association with blood pressure and inverse association with eosinophil counts. Conclusions: The inverse association between personal exposure away from home and MVF is consistent with adverse health effects of UFP from sources outside the home and might be related to increased inflammation indicated by leukocyte counts, whereas UFP from sources in the home could have less effect.
|
|
| 30. |
- Rissler, Jenny, et al.
(author)
-
Effective Density and Mixing State of Aerosol Particles in a Near-Traffic Urban Environment.
- 2014
-
In: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 48:11, s. 6300-6308
-
Journal article (peer-reviewed)abstract
- In urban environments, airborne particles are continuously emitted, followed by atmospheric aging. Also, particles emitted elsewhere, transported by winds, contribute to the urban aerosol. We studied the effective density (mass-mobility relationship) and mixing state with respect to the density of particles in central Copenhagen, in wintertime. The results are related to particle origin, morphology, and aging. Using a differential mobility analyzer-aerosol particle mass analyzer (DMA-APM), we determined that particles in the diameter range of 50-400 nm were of two groups: porous soot aggregates and more dense particles. Both groups were present at each size in varying proportions. Two types of temporal variability in the relative number fraction of the two groups were found: soot correlated with intense traffic in a diel pattern and dense particles increased during episodes with long-range transport from polluted continental areas. The effective density of each group was relatively stable over time, especially of the soot aggregates, which had effective densities similar to those observed in laboratory studies of fresh diesel exhaust emissions. When heated to 300 °C, the soot aggregate volatile mass fraction was ∼10%. For the dense particles, the volatile mass fraction varied from ∼80% to nearly 100%.
|
|
| 31. |
|
|
| 32. |
|
|
| 33. |
|
|
| 34. |
- Sehlstedt, Maria, 1979-
(author)
-
Respiratory effects of particulate matter air pollution : studies on diesel exhaust, road tunnel, subway and wood smoke exposure in human subjects
- 2011
-
Doctoral thesis (other academic/artistic)abstract
- Background: Ambient air pollution is associated with adverse health effects, but the sources and components, which cause these effects is still incompletely understood. The aim of this thesis was to investigate the pulmonary effects of a variety of common air pollutants, including diesel exhaust, biomass smoke, and road tunnel and subway station environments. Healthy non-smoking volunteers were exposed in random order to the specific air pollutants and air/control, during intermittent exercise, followed by bronchoscopy. Methods and results: In study I, exposures were performed with diesel exhaust (DE) generated at transient engine load and air for 1 hour with bronchoscopy at 6 hours post-exposure. Immunohistochemical analyses of bronchial mucosal biopsies showed that DE exposure significantly increased the endothelial adhesion molecule expression of p-selectin and VCAM-1, together with increased bronchoalveolar lavage (BAL) eosinophils. In study II, the subjects were exposed for 1 hour to DE generated during idling with bronchoscopy at 6 hours. The bronchial mucosal biopsies showed significant increases in neutrophils, mast cells and lymphocytes together with bronchial wash neutrophils. Additionally, DE exposure significantly increased the nuclear translocation of the aryl hydrocarbon receptor (AhR) and phosphorylated c-jun in the bronchial epithelium. In contrast, the phase II enzyme NAD(P)H-quinone oxidoreductase 1 (NQO1) decreased after DE. In study III, the 2-hour exposures took place in a road tunnel with bronchoscopy 14 hours later. The road tunnel exposure significantly increased the total numbers of lymphocytes and alveolar macrophages in BAL, whereas NK cell and CD56+/T cell numbers significantly decreased. Additionally, the nuclear expression of phosphorylated c-jun in the bronchial epithelium was significantly increased after road tunnel exposure. In study IV, the subjects were exposed to metal-rich particulate aerosol for 2 hours at a subway station with bronchial biopsy and BAL sampling at 14 hours. The subway exposure significantly increased the concentration of glutathione disulphide (GSSG) in BAL, with no airway inflammatory responses. In contrast, the number of neutrophils in the bronchial mucosa and the nuclear expression of phosphorylated c-jun in the bronchial epithelium tended to decrease after the subway exposure. In study V, the exposure to biomass smoke lasted 3 hours. Bronchoscopy was conducted 24 hours post exposure. The investigated biomass combustion emissions resulted in a significant increase in total glutathione and reduced glutathione in BAL, without any evident acute airway inflammatory responses. Conclusion: The present thesis presents data from exposures of healthy subjects to a variety of common air pollutants, as compared with an air reference. Oxidative as well as bronchial mucosal and bronchoalveolar responses differed between these air pollutants, with the most pronounced airway effects seen after exposure to diesel exhaust. This may be due to differences in pulmonary deposition, physicochemical characteristics, toxicological pathways and potency. Additional studies will assist in addressing dose-response and time kinetic aspects of the airway responses.
|
|
| 35. |
|
|
| 36. |
-
- 2019
-
Journal article (peer-reviewed)
|
|
