| 1. |
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| 2. |
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| 3. |
- Adlard, B., et al.
(författare)
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Future directions for monitoring and human health research for the Arctic Monitoring and Assessment Programme
- 2018
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Ingår i: Global Health Action. - : Taylor & Francis. - 1654-9716 .- 1654-9880. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- For the last two and a half decades, a network of human health experts under the Arctic Monitoring and Assessment Program (AMAP) has produced several human health assessment reports. These reports have provided a base of scientific knowledge regarding environmental contaminants and their impact on human health in the Arctic. These reports provide scientific information and policy-relevant recommendations to Arctic governments. They also support international agreements such as the Stockholm Convention on Persistent Organic Pollutants (POPs) and the Minamata Convention on Mercury. Key topics discussed in this paper regarding future human health research in the circumpolar Arctic are continued contaminant biomonitoring, health effects research and risk communication. The objective of this paper is to describe knowledge gaps and future priorities for these fields.
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| 4. |
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| 5. |
- Barany, E, et al.
(författare)
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Mercury and selenium in whole blood and serum in relation to fish consumption and amalgam fillings in adolescents
- 2003
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Ingår i: Journal of Trace Elements in Medicine and Biology. - 1878-3252 .- 0946-672X. ; 17:3, s. 165-170
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Tidskriftsartikel (refereegranskat)abstract
- Mercury and selenium in whole blood and serum of 245 17-year old Swedish adolescents were analysed. The relationships between these elements' concentrations and the consumption of fish as well as the number of dental amalgam fillings were studied. The geometric means (GM) of the mercury concentrations were 1.1 mug/L in blood and 0.43 mug/L in serum. The mean selenium concentration in blood was 110 mug/L and the GM of the serum selenium concentration 110 mug/L. Fish species with dietary restrictions due to elevated mercury Levels (i.e. pike, perch, pikeperch, burbot, eel and halibut) were consumed on average 0.7 times/month and fish species without such restrictions 4.1 times/month. Despite this comparatively Low fish consumption, the adolescents' blood mercury concentrations were positively correlated with fish consumption. Of the adolescents, 39% had amalgam fillings (mean 2 +/- 1.5). Serum mercury was influenced by the number of amalgam fittings, by fish consumption, blood and serum levels of selenium and the residential area. Blood and serum selenium concentrations were not influenced by fish consumption, but were positively associated with the serum mercury concentration.
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| 6. |
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| 8. |
- Amilon, Sofia, 1982, et al.
(författare)
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How common are refractures in childhood? a study based on 40,000 paediatric fractures from the Swedish Fracture Register
- 2023
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Ingår i: Bone & Joint Journal. - 2049-4394. ; 105B:8, s. 928-934
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Tidskriftsartikel (refereegranskat)abstract
- Aims The aim of this study was to describe the incidence of refractures among children, follow-ing fractures of all long bones, and to identify when the risk of refracture decreases. Methods All patients aged under 16 years with a fracture that had occurred in a bone with ongo-ing growth (open physis) from 1 May 2015 to 31 December 2020 were retrieved from the Swedish Fracture Register. A new fracture in the same segment within one year of the pri-mary fracture was regarded as a refracture. Fracture localization, sex, lateral distribution, and time from primary fracture to refracture were analyzed for all long bones. Results Of 40,090 primary fractures, 348 children (0.88%) sustained a refracture in the same long bone segment. The diaphyseal forearm was the long bone segment most commonly affected by refractures (n = 140; 3.4%). The median time to refracture was 147 days (inter-quartile range 82 to 253) in all segments of the long bones combined. The majority of the refractures occurred in boys (n = 236; 67%), and the left side was the most common side to refracture (n = 220; 62%). The data in this study suggest that the risk of refracture decreas-es after 180 days in the diaphyseal forearm, after 90 days in the distal forearm, and after 135 days in the diaphyseal tibia. Conclusion Refractures in children are rare. However, different fractured segments run a different threat of refracture, with the highest risk associated with diaphyseal forearm fractures. The data in this study imply that children who have sustained a distal forearm fracture should avoid hazardous activities for three months, while children with a diaphyseal forearm fracture should avoid these activities for six months, and for four and a half months if they have sustained a diaphyseal tibia fracture.
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| 9. |
- Barany, E, et al.
(författare)
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Relationships between trace element concentrations in human blood and serum
- 2002
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Ingår i: Toxicology Letters. - 1879-3169 .- 0378-4274. ; 134:1-3, s. 177-184
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Tidskriftsartikel (refereegranskat)abstract
- Trace element interactions can affect the absorption, metabolism, or effects of elements. Also, different elements may derive from the same source. Associations in biological media between element concentrations may indicate such phenomena. A large number of correlations were found between 13 trace elements (Co, Cu, Zn, Se, Rb, Rh, Pd, Cd, W, Pt, Hg, Tl, and Pb) in human blood and/or serum, as investigated in 372 Swedish adolescents. Notably, serum Se correlated with blood Ph and blood Hg and Cu and Zn were correlated to each other in both blood and serum. The elements Pt, Pd and Rh, spread in the environment through use of catalytic converters in cars, were closely correlated in both blood and serum. Apart from the correlations with a probable biological or exposure-related explanation, several other correlations, of yet unknown importance and origin, were found.
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| 10. |
- Barany, E, et al.
(författare)
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Trace element levels in whole blood and serum from Swedish adolescents
- 2002
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Ingår i: Science of the Total Environment. - 1879-1026 .- 0048-9697. ; 286:1-3, s. 129-141
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Tidskriftsartikel (refereegranskat)abstract
- Blood and serum samples from 372 15-year-old adolescents were collected in two cities in Sweden and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The objective was to (1) determine the levels of 13 elements in blood and serum from the teenagers; and (2) for each element, investigate the correlation between the concentrations in blood and serum. The concentrations in blood and serum were generally in line with that usually reported for the essential elements Co, Cu, Zn and Se, and generally low for the 'non-essential' elements Cd, Hg, Pb. The median concentrations were in blood and serum, respectively: of Co 031 and 0.48 mug/l, Cu 0.92 and 1.0 mg/l, Zn 6.1 and 0.99 mg/l, Se 110 and 100 mug/l, Rb 2.8 and 0.24 mg/l, Hg 1.1 and 0.44 mug/l, Pb 16 and 0.33 mug/l. The median concentration of W in blood was < 0.2 mug/l (below the detection limit) and in serum 0.087 mug/l. The median concentrations of Cd, Rh, Pd, Pt and TI were below the detection limits. Statistically significant correlations were found between the concentrations in blood and serum for Co, Cu, Zn, Se, Rb, W, Hg and Pb. The levels presented in this study constitute baseline levels or levels generally not exceeded in adolescents for 13 elements, including essential, ubiquitous toxic, and rare elements.
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| 11. |
- Barany, E, et al.
(författare)
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Trace elements in blood and serum of Swedish adolescents: Relation to gender, age, residential area, and socioeconomic status
- 2002
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Ingår i: Environmental Research. - : Elsevier BV. - 1096-0953 .- 0013-9351. ; 89:1, s. 72-84
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Tidskriftsartikel (refereegranskat)abstract
- The influence of gender, age, residential area, and socioeconomic status on the blood and serum levels of 13 trace elements was studied in boys and girls living in two Swedish cities with different socioeconomic and environmental characters. The same groups of adolescents were sampled twice, at ages 15 (n = 372) and 17 (n = 294) years. All the investigated factors were shown to be of importance. Age was important for most elements; e.g., copper levels in both blood and serum increased in girls, and selenium increased in serum from both genders. Lead decreased approximately 10%, in blood from the first to the second sampling, and cadmium increased in blood, however not in nonsmokers. The age factor may also reflect temporal changes in environmental exposure, especially for nonessential elements. Girls had higher levels of cobalt and copper, while lead in blood was higher in boys. Smoking girls had higher copper levels than nonsmoking girls. Residential area influenced all elements. The teenagers with university-educated mothers had higher levels of cadmium in blood than those with only primary school-educated mothers.
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| 12. |
- Bergdahl, Ingvar A, et al.
(författare)
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Plasma-lead concentration: investigations into its usefulness for biological monitoring of occupational lead exposure.
- 2006
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Ingår i: American journal of industrial medicine. - New York : Wiley. - 0271-3586 .- 1097-0274. ; 49:2, s. 93-101
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The lead concentration in plasma is correlated to that in whole blood with a two to fourfold variation. It has never been investigated if this variation is inter-individual. METHODS: Lead and hemoglobin were determined in blood and plasma from 13 lead workers with a history of relatively high blood-lead concentrations, sampled three times during 1 day. The variation in the distribution of lead between cells and plasma was studied, but not the variation in the lead concentrations as such. RESULTS: Blood hemoglobin decreased with rising plasma lead (0.9-3.0 microg/L). Regarding the distribution of lead, no effect of current exposure during the day or of recent meals appeared. As much as 84% of the overall variance of the distribution of lead between cells and plasma could be attributed to individual factors. After adjustment for erythrocyte volume fraction this decreased to 67%. Plasma samples with elevated hemoglobin concentrations (due to in vitro hemolysis) had somewhat elevated lead concentrations. CONCLUSIONS: Plasma lead is not significantly altered by variation in a single day's exposure and, therefore, the choice of time of the day is not critical for sampling. However, plasma lead is negatively correlated to blood hemoglobin and mild hemolysis (not visible by the eye) in a sample may increase plasma lead with up to 30%. Finally, plasma provides lead exposure information that differs from whole blood, but it is not clear which one of these is the biomarker with the closest relation to exposure and/or effects.
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| 13. |
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| 14. |
- Choong, Oi Kuan, 1985, et al.
(författare)
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SARS-CoV-2 replicates and displays oncolytic properties in clear cell and papillary renal cell carcinoma
- 2023
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- The SARS-CoV-2 virus is currently causing a global pandemic. Infection may result in a systemic disease called COVID-19, affecting primarily the respiratory tract. Often the gastrointestinal tract and kidneys also become involved. Angiotensin converting enzyme 2 (ACE2) serves as the receptor for SARS-CoV-2. The membrane proteins, Transmembrane serine protease 2 (TMPRSS2) and Neuropilin 1 (NRP1) are accessory proteins facilitating the virus entry. In this study we show that the human proximal kidney tubules, express these factors. We hypothesized that cancers derived from proximal tubules as clear cell (CCRCC) and papillary renal cell carcinoma (PRCC), retain the expression of the SARS-CoV-2 entry factors making these cancers susceptible to SARS-CoV-2 infection. We used bioinformatics, western blotting, and assessment of tissue micro arrays (TMA) including 263 cases of CCRCC, 139 cases of PRCC and 18 cases of chromophobe RCC to demonstrate that the majority of CCRCC and PRCC cases retained the RNA and protein expression of the entry factors for SARS-CoV-2. We furthermore show that SARS-CoV-2 virus propagated robustly in primary cultures of CCRCC and PRCC cells with a visible virus cytopathogenic effect correlating with viral RNA expression levels. We also noted that the delta-variant of SARS-CoV-2 causes cancer cells to form syncytia in-vitro. This phenomenon was also identified histologically in CCRCC tissue from a patient that had been hospitalized for COVID-19, twelve months prior to nephrectomy. Our data provide insights into SARS-CoV-2 infectivity in renal cell carcinoma and that the virus causes a distinct cytopathogenic effect.
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| 15. |
- Ek, Weronica E., et al.
(författare)
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Tea and coffee consumption in relation to DNA methylation in four European cohorts
- 2017
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Ingår i: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 26:16, s. 3221-3231
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Tidskriftsartikel (refereegranskat)abstract
- Lifestyle factors, such as food choices and exposure to chemicals, can alter DNA methylation and lead to changes in gene activity. Two such exposures with pharmacologically active components are coffee and tea consumption. Both coffee and tea has been suggested to play an important role in modulating disease-risk in humans by suppressing tumour progression, decreasing inflammation and influencing estrogen metabolism. These mechanisms may be mediated by changes in DNA methylation.To investigate if DNA methylation in blood is associated with coffee and tea consumption we performed a genome-wide DNA methylation study for coffee and tea consumption in four European cohorts (N = 3,096). DNA methylation was measured from whole blood at 421,695 CpG sites distributed throughout the genome and analysed in men and women both separately and together in each cohort. Meta-analyses of the results and additional regional-level analyses were performed.After adjusting for multiple testing, the meta-analysis revealed that two individual CpG-sites, mapping to DNAJC16 and TTC17, were differentially methylated in relation to tea consumption in women. No individual sites were associated in men or in the sex-combined analysis for tea or coffee. The regional analysis revealed that 28 regions were differentially methylated in relation to tea consumption in women. These regions contained genes known to interact with estradiol metabolism and cancer. No significant regions were found in the sex-combined and male-only analysis for either tea or coffee consumption.
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| 16. |
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| 17. |
- Gaudet, Mia M, et al.
(författare)
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Blood Levels of Cadmium and Lead in Relation to Breast Cancer Risk in Three Prospective Cohorts.
- 2019
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Ingår i: International Journal of Cancer. - : Wiley-Blackwell. - 0020-7136 .- 1097-0215. ; 144:5, s. 1010-1016
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Tidskriftsartikel (refereegranskat)abstract
- Cadmium and lead have been classified as carcinogens by the International Agency for Research on Cancer. However, their associations with breast cancer risk are unknown despite their persistence in the environment and ubiquitous human exposure. We examined associations of circulating levels of cadmium and lead with breast cancer risk in three case-control studies nested within the Cancer Prevention Study-II (CPS-II) LifeLink Cohort, European Prospective Investigation into Cancer and Nutrition - Italy (EPIC-Italy), and the Northern Sweden Health and Disease Study (NSHDS) cohorts. Metal levels were measured in stored erythrocytes from 1,435 cases and 1,433 controls using inductively coupled plasma-mass spectrometry. Summary relative risks (RR) and 95% confidence intervals (CI) were calculated using random-effects models with each study result weighted by the within- and between-study variances. I2 values were calculated to estimate proportion of between study variation. Using common cut-points, cadmium levels were not associated with breast cancer risk in the CPS-II cohort (continuous RR=1.01, 95% CI 0.76 - 1.34), but were inversely associated with risk in the EPIC- Italy (continuous RR=0.80, 95% CI 0.61 - 1.03) and NSHDS cohorts (continuous RR=0.73, 95% CI 0.54 - 0.97). The inverse association was also evident in the meta-analysis (continuous RR=0.84, 95% CI 0.69 - 1.01) with low between-study heterogeneity. Large differences in lead level distributions precluded a meta-analysis of their association with breast cancer risk; no associations were found in the three studies. Adult cadmium and lead levels were not associated with higher risk of breast cancer in our large meta-analysis.
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| 18. |
- Jakobsson, Rasmus, 1987, et al.
(författare)
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Family History and Risk of Renal Cell Carcinoma: A National Multiregister Case-Control Study
- 2024
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Ingår i: The Journal of urology. - 1527-3792. ; 211:1, s. 71-79
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Our purpose was to investigate the association between family history of renal cell carcinoma (RCC) and RCC risk. MATERIALS AND METHODS: RCC cases diagnosed in Sweden between 2005 and 2014 and 10 matched controls were identified using the Renal Cell Cancer Database Sweden, with linkage to the Multigeneration Register and the Swedish Cancer Registry. The association between a family history of RCC and RCC was investigated, overall and by sex and age groups. RESULTS: Among 9416 RCC cases, 294 (3.1%) had 1 or more parent or sibling (first-degree relative [FDR]) with RCC. Median age at diagnosis for cases with an affected FDR was 65 years (IQR 59-71) and 68 years (IQR 60-75) for all cases. The proportion of women was significantly higher among familial RCC compared to sporadic RCC (44.6% vs 38.5%, P = .035). RCC was twice as likely with 1 or more FDR with RCC (OR 1.9; CI 1.65-2.16). Stratified analysis showed an OR of 2.4 for women (CI 1.93-2.92) and 1.6 for men (CI 1.35-1.93). Two or more FDRs was associated with a sixfold increased risk (95% CI 2.37-15.5). Familial RCC was strongly associated with bilateral and multifocal tumors (OR 5.5; CI 2.36-13.0, OR 3.5; CI 1.89-6.49). CONCLUSIONS: In this Swedish data set, 3.1% of RCC patients have 1 or more FDR diagnosed with RCC. There was no statistical difference in median age between sporadic RCC and familial RCC. Having 1 or more FDR with RCC approximately doubles the risk of RCC with a higher risk increase for women than for men. People with 2 FDRs with RCC constitute a small high-risk group that may benefit from screening.
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| 19. |
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| 20. |
- Kumar, B, et al.
(författare)
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Upregulated TRPC1 Channel in Vascular Injury In Vivo and Its Role in Human Neointimal Hyperplasia.
- 2006
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Ingår i: Circulation Research. - 0009-7330. ; 98:4, s. 557-563
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Tidskriftsartikel (refereegranskat)abstract
- Occlusive vascular disease is a widespread abnormality leading to lethal or debilitating outcomes such as myocardial infarction and stroke. It is part of atherosclerosis and is evoked by clinical procedures including angioplasty and grafting of saphenous vein in bypass surgery. A causative factor is the switch in smooth muscle cells to an invasive and proliferative mode, leading to neointimal hyperplasia. Here we reveal the importance to this process of TRPC1, a homolog of Drosophila transient receptor potential. Using 2 different in vivo models of vascular injury in rodents we show hyperplasic smooth muscle cells have upregulated TRPC1 associated with enhanced calcium entry and cell cycle activity. Neointimal smooth muscle cells after balloon angioplasty of pig coronary artery also express TRPC1. Furthermore, human vein samples obtained during coronary artery bypass graft surgery commonly exhibit an intimal structure containing smooth muscle cells that expressed more TRPC1 than the medial layer cells. Veins were organ cultured to allow growth of neointimal smooth muscle cells over a 2-week period. To explore the functional relevance of TRPC1, we used a specific E3-targeted antibody to TRPC1 and chemical blocker 2-aminoethoxydiphenyl borate. Both agents significantly reduced neointimal growth in human vein, as well as calcium entry and proliferation of smooth muscle cells in culture. The data suggest upregulated TRPC1 is a general feature of smooth muscle cells in occlusive vascular disease and that TRPC1 inhibitors have potential as protective agents against human vascular failure.
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| 21. |
- Lampa, Erik G., et al.
(författare)
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Optimizing occupational exposure measurement strategies when estimating the log-scale arithmetic mean value : An example from the reinforced plastics industry
- 2006
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Ingår i: Annals of Occupational Hygiene. - Oxford : Pergamon Press. - 0003-4878 .- 1475-3162. ; 50:4, s. 371-377
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Tidskriftsartikel (refereegranskat)abstract
- When assessing occupational exposures, repeated measurements are in most cases required. Repeated measurements are more resource intensive than a single measurement, so careful planning of the measurement strategy is necessary to assure that resources are spent wisely. The optimal strategy depends on the objectives of the measurements. Here, two different models of random effects analysis of variance (ANOVA) are proposed for the optimization of measurement strategies by the minimization of the variance of the estimated log-transformed arithmetic mean value of a worker group, i.e. the strategies are optimized for precise estimation of that value. The first model is a one-way random effects ANOVA model. For that model it is shown that the best precision in the estimated mean value is always obtained by including as many workers as possible in the sample while restricting the number of replicates to two or at most three regardless of the size of the variance components. The second model introduces the ‘shared temporal variation’ which accounts for those random temporal fluctuations of the exposure that the workers have in common. It is shown for that model that the optimal sample allocation depends on the relative sizes of the between-worker component and the shared temporal component, so that if the between-worker component is larger than the shared temporal component more workers should be included in the sample and vice versa. The results are illustrated graphically with an example from the reinforced plastics industry. If there exists a shared temporal variation at a workplace, that variability needs to be accounted for in the sampling design and the more complex model is recommended.
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| 22. |
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| 23. |
- Pettersson-Strömbäck, Anita E, 1965-, et al.
(författare)
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When and why do experts perform exposure measurements? : An exploratory study of safety engineers, work environment inspectors, and occupational hygienists.
- 2006
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Ingår i: Journal of Occupational and Environmental Hygiene. - : Informa UK Limited. - 1545-9624 .- 1545-9632. ; 3:12, s. 713-717
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to describe experts' decision processes leading to measurements of occupational chemical exposure. Safety engineers, clinical occupational hygienists, and work environment inspectors (four from each group) were interviewed according to a semistructured scheme. We analyzed: (i) perceived triggers for measurements, (ii) the experts' decision criteria for performing measurements when there was a trigger, and (iii) sampling strategy. Regarding triggers, all safety engineers reported a “request” from, for example, an employer; all work environment inspectors reported “legal demands;” and all clinical occupational hygienists reported “symptoms among workers.” As a decision criterion, all the interviewees reported that they measured only if they expected sufficiently high levels. The results of the present study highlight factors that trigger measurements and are of importance in determining whether measurements will be performed. These factors appear to be related to the expert's professional role and may bias the assessment of exposure. Thus, when using data from routine measurements done by experts, the possibility of a bias needs to be considered.
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| 24. |
- Shirdel, Mariam, et al.
(författare)
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A pilot study : the UNC passive aerosol sampler in a working environment
- 2017
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press. - 2398-7308 .- 2398-7316. ; 61:8, s. 1029-1034
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Dust is generally sampled on a filter using air pumps, but passive sampling could be a cost-effective alternative. One promising passive sampler is the University of North Carolina passive aerosol sampler (UNC sampler). The aim of this study is to characterize and compare the UNC sampler’s performance with PM10 and PM2.5 impactors in a working environment.Methods: Area sampling was carried out at different mining locations using UNC samplers in parallel with PM2.5 and PM10 impactors. Two different collection surfaces, polycarbonate (PC) and carbon tabs (CT), were employed for the UNC sampling. Sampling was carried out for 4–25 hours.Results: The UNC samplers underestimated the concentrations compared to PM10 and PM2.5 impactor data. At the location with the highest aerosol concentration, the time-averaged mean of PC showed 24% and CT 35% of the impactor result for PM2.5. For PM10, it was 39% with PC and 58% with CT. Sample blank values differed between PC and CT. For PM2.5, PC blank values were ~7 times higher than those of CT, but only 1.8 times higher for PM10. The blank variations were larger for PC than for CT.Conclusions: Particle mass concentrations appear to be underestimated by the UNC sampler compared to impactors, more so for PM2.5 than for PM10. CT may be preferred as a collection surface because the blank values were lower and less variable than for PC. Future validations in the working environment should include respirable dust sampling.
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| 25. |
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| 26. |
- Shirdel, Mariam, et al.
(författare)
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Choosing the number of images and image position when analysing the UNC Passive Aerosol Sampler for occupational exposure assessment
- 2018
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Ingår i: Journal of Occupational and Environmental Hygiene. - : Taylor & Francis. - 1545-9624 .- 1545-9632. ; 15:11, s. 767-772
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Tidskriftsartikel (refereegranskat)abstract
- The University of North Carolina passive aerosol sampler (UNC sampler) could be an alternative when measuring occupational dust exposure, but the time required for microscopic imaging of the sampler needs to be reduced to make it more attractive. The aims of this study were to 1) characterise the effect on precision when reducing imaging, in order to shorten analysis time and 2) assess if the position of the images makes a difference. Eighty-eight samplers were deployed in different locations of an open pit mine. Sixty images were captured for each UNC sampler, covering 51% of its collection surface, using scanning electron microscopy. Bootstrapped samples were generated with different image combinations, to assess the within-sampler coefficient of variation (CVws) for different numbers of images. In addition, the particle concentration relative to the distance from the centre of the sampler was studied. Reducing the number of images collected from the UNC sampler led to up to 8.3% CVws for ten images when calculating respirable fraction. As the overall CV has previously been assessed to 36%, the additional contribution becomes minimal, increasing the overall CV to 37%. The mean concentrations of the images were modestly related to distance from the centre of the sampler. The CVws changed from 8.26% to 8.13% for ten images when applying rules for the image collection based on distance. Thus, the benefit of these rules on the precision is small and the images can therefore be chosen at random. In conclusion, reducing the number of images analysed from 60 to 10, corresponding to a reduction of the imaged sampling area from 51% to 8.5%, results in a negligible loss in precision for respirable fraction dust measurements in occupational environments.
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| 27. |
- Shirdel, Mariam, et al.
(författare)
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Improving the UNC passive aerosol sampler model based on comparison with commonly used aerosol sampling methods
- 2018
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press. - 2398-7308 .- 2398-7316. ; 62:3, s. 328-338
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: In an occupational environment, passive sampling could be an alternative to active sampling with pumps for sampling of dust. One passive sampler is the University of North Carolina passive aerosol sampler (UNC sampler). It is often analysed by microscopic imaging. Promising results have been shown for particles above 2.5 µm, but indicate large underestimations for PM2.5. The aim of this study was to evaluate, and possibly improve, the UNC sampler for stationary sampling in a working environment.Methods: Sampling was carried out at 8-h intervals during 24 h in four locations in an open pit mine with UNC samplers, respirable cyclones, PM10 and PM2.5 impactors, and an aerodynamic particle sizer (APS). The wind was minimal. For quantification, two modifications of the UNC sampler analysis model, UNC sampler with hybrid model and UNC sampler with area factor, were compared with the original one, UNC sampler with mesh factor derived from wind tunnel experiments. The effect of increased resolution for the microscopic imaging was examined.Results: Use of the area factor and a higher resolution eliminated the underestimation for PM10 and PM2.5. The model with area factor had the overall lowest deviation versus the impactor and the cyclone. The intraclass correlation (ICC) showed that the UNC sampler had a higher precision and better ability to distinguish between different exposure levels compared to the cyclone (ICC: 0.51 versus 0.24), but lower precision compared to the impactor (PM10: 0.79 versus 0.99; PM2.5: 0.30 versus 0.45). The particle size distributions as calculated from the different UNC sampler analysis models were visually compared with the distributions determined by APS. The distributions were obviously different when the UNC sampler with mesh factor was used but came to a reasonable agreement when the area factor was used.Conclusions: High resolution combined with a factor based on area only, results in no underestimation of small particles compared to impactors and cyclones and a better agreement with the APS’s particle size distributions. The UNC sampler had lower precision than the impactors, but higher than the respirable cyclone. The UNC sampler with area factor could be used for PM2.5, PM10 and respirable fraction measurements in this working environment without wind.
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| 28. |
- Shirdel, Mariam, et al.
(författare)
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Passive personal air sampling of dust in a working environment : A pilot study
- 2019
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Ingår i: Journal of Occupational and Environmental Hygiene. - : Taylor & Francis Group. - 1545-9624 .- 1545-9632. ; 16:10, s. 675-684
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to make a preliminary evaluation of the University of North Carolina passive aerosol sampler (UNC sampler) for personal air sampling of particles. Nine personal air samplings of respirable fraction were conducted in an open-pit mine, with pairwise UNC samplers and a respirable cyclone mounted on the chest of workers. UNC samples were analyzed with scanning electron microscopy (SEM) and to some extent energy dispersive X-ray spectroscopy (EDS). Respirable cyclone filter samples were weighed. Correlations and particle elemental compositions were described. Microscopic imaging of the collection surface showed that the particles were heterogeneously deposited across the surface of the UNC sampler. Collected particles were shaped as gravel particles and the resulting particle size distribution in air showed a peak at ca. 3 µm aerodynamic diameter, similarly to what has previously been reported from the same mine. The elemental composition indicated mineral origin. All correlations between the airborne mass concentrations from UNC samplers and respirable cyclones (Pearson = 0.54 and Spearman = 0.43) and between pairs of parallel UNC samplers (Pearson = 0.55 and Spearman = 0.67) were weak. The UNC sampler mass concentrations were approximately 30 times higher than those measured with the respirable cyclone. In conclusion, the UNC sampler, when used for personal sampling in a mine, provides a reasonable particle size distribution and the deposited particles appeared to be of mineral origin and not from textile or skin but the approximately 30-fold overestimation of mass concentrations when comparing with respirable cyclone sampling indicates that further improvements are necessary. Positioning of the sampler may be critical and moving the UNC sampler from the chest to e.g. the top of a helmet might be an improvement. Grounding of the sampler in order to avoid static electricity might also be useful. The UNC sampler should continue to be researched for personal sampling, as passive sampling might become a useful alternative to more laborious sampling techniques.
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