| 4391. |
- Malmqvist, Klas, et al.
(författare)
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Elemental Concentrations in Airborne Particles from Welding and Metal Spraying Operations
- 1981
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Ingår i: Nuclear Instruments And Methods. ; 181:1-3, s. 465-471
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Tidskriftsartikel (refereegranskat)abstract
- An accelerator-based arrangement in which facilities using particle-induced X-rays and gamma-rays and scattered particles are included constitutes a very powerful analytical set-up especially when combined with adequate sampling techniques. In this paper, the designs of two major work environment investigations are described. In one of the investigations (in which 3000 multielemental analyses were performed) a thorough characterization of welding aerosols from different welding operations was carried out. In the other investigation (400 analyses), special concern was devoted to metal spraying operations involving chromium and nickel exposure to workers. To exemplify the fact that the PIXE technique is a fast, multielemental analytical method only requiring very small samples, some results are discussed.
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| 4392. |
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| 4393. |
- Malmqvist, Klas, et al.
(författare)
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Performance of a Personal Low-Weight Aerosol Sampler with Particle Size Fractionation and Time Resolution
- 1983
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Ingår i: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502. ; 14:3, s. 409-413
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Konferensbidrag (refereegranskat)abstract
- A low-weight aerosol sampler has been developed and tested. Internal losses for both sub-micron and large particles ( < 10 tam) are of the order of 5 %. The size fractionation patterns indicate that the sampler may be used to collect a separate respirable fraction in good agreement with the BMRC standard and a coarse fraction deternuned by the inlet design.
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| 4394. |
- Mamsen, Linn Salto, et al.
(författare)
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Concentration of perfluorinated compounds and cotinine in human foetal organs, placenta, and maternal plasma
- 2017
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697. ; 596-597, s. 97-105
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Tidskriftsartikel (refereegranskat)abstract
- Background Perfluoroalkyl substances (PFASs) are bio-accumulative pollutants, and prenatal exposure to PFASs is believed to impact human foetal development and may have long-term adverse health effects later in life. Additionally, maternal cigarette smoking may be associated with PFAS levels. Foetal exposure has previously been estimated from umbilical cord plasma, but the actual concentration in foetal organs has never been measured. Objectives The concentrations of 5 PFASs and cotinine – the primary metabolite of nicotine – were measured in human foetuses, placentas, and maternal plasma to evaluate to what extent these compounds were transferred from mother to foetus and to determine if the PFAS concentrations were associated with maternal cigarette smoking. Methods Thirty-nine Danish women who underwent legal termination of pregnancy before gestational week 12 were included; 24 maternal blood samples were obtained together with 34 placental samples and 108 foetal organs. PFASs and cotinine were assayed by liquid chromatography/triple quadrupole mass spectrometry. Results In foetal organs, the average concentrations of perfluorooctanesulphonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluoroundecanoic acid (PFUnDa), and perfluorodecanoic acid (PFDA) were 0.6 ng/g, 0.2 ng/g, 0.1 ng/g, 0.1 ng/g, and 0.1 ng/g, respectively. A significant positive correlation was found between the exposure duration, defined as foetal age, and foetal to maternal ratio for all five PFASs and cotinine. Smokers presented 99 ng/g cotinine in plasma, 108 ng/g in placenta, and 61 ng/g in foetal organs. No correlation between the maternal cotinine concentrations and PFAS concentrations was found. Conclusions PFASs were transferred from mother to foetus, however, with different efficiencies. The concentrations of PFOS, PFOA, PFNA, PFUnDA, and PFDA in foetal organs were much lower than the maternal concentrations. Furthermore, a significant correlation between the exposure duration and all of the evaluated PFASs was found. The health-compromising concentrations of these substances during foetal development are unknown.
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| 4395. |
- Mamsen, Linn Salto, et al.
(författare)
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Concentrations of perfluoroalkyl substances (PFASs) in human embryonic and fetal organs from first, second, and third trimester pregnancies
- 2019
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 124, s. 482-492
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Tidskriftsartikel (refereegranskat)abstract
- Background: The persistent environmental contaminants perfluoroalkyl substances (PFASs) have gained attention due to their potential adverse health effects, in particular following early life exposure. Information on human fetal exposure to PFASs is currently limited to one report on first trimester samples. There is no data available on PFAS concentrations in fetal organs throughout all three trimesters of pregnancy. Methods: We measured the concentrations of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorohexane sulfonic acid (PFHxS) in human embryos and fetuses with corresponding placentas and maternal serum samples derived from elective pregnancy terminations and cases of intrauterine fetal death. A total of 78 embryos and fetuses aged 7–42 gestational weeks were included and a total of 225 fetal organs covering liver, lung, heart, central nervous system (CNS), and adipose tissue were analyzed, together with 71 placentas and 63 maternal serum samples. PFAS concentrations were assayed by liquid chromatography/triple quadrupole mass spectrometry. Results: All evaluated PFASs were detected and quantified in maternal sera, placentas and embryos/fetuses. In maternal serum samples, PFOS was detected in highest concentrations, followed by PFOA > PFNA > PFDA = PFUnA = PFHxS. Similarly, PFOS was detected in highest concentrations in embryo/fetal tissues, followed by PFOA > PFNA = PFDA = PFUnA. PFHxS was detected in very few fetuses. In general, PFAS concentrations in embryo/fetal tissue (ng/g) were lower than maternal serum (ng/ml) but similar to placenta concentrations. The total PFAS burden (i.e. the sum of all PFASs) was highest in lung tissue in first trimester samples and in liver in second and third trimester samples. The burden was lowest in CNS samples irrespective of fetal age. The placenta:maternal serum ratios of PFOS, PFOA and PFNA increased across gestation suggesting bioaccumulation in the placenta. Further, we observed that the ratios were higher in pregnancies with male fetuses compared to female fetuses. Conclusions: Human fetuses were intrinsically exposed to a mixture of PFASs throughout gestation. The compounds were detected in all analyzed tissues, suggesting that PFASs reach and may affect many types of organs. Collectively, our results demonstrate that PFASs pass the placenta and deposit to embryo and fetal tissues, calling for risk assessment of gestational exposures.
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| 4396. |
- Mandakh, Yumjirmaa, et al.
(författare)
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Association of prenatal ambient air pollution exposure with placental mitochondrial DNA copy number, telomere length and preeclampsia
- 2021
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Ingår i: Frontiers in Toxicology. - : Frontiers Media S.A.. - 2673-3080. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Studies have shown that ambient air pollution is linked to preeclampsia (PE), possibly via generation of oxidative stress in the placenta. Telomere length and mitochondrial DNA copy number (mtDNAcn) are sensitive to oxidative stress damage. Objective: To study the association between prenatal exposure to ambient nitrogen oxides (NOx, a marker for traffic-related air pollution), and PE, as well as potential mediation effects by placental telomere length and mtDNAcn.Methods: This is a cross-sectional study of 42 preeclamptic and 95 arbitrarily selected normotensive pregnant women with gestational ambient NOx exposure assessment in southern Scania, Sweden. Hourly concentrations of NOx were estimated at the residential addresses by a Gaussian-plume dispersion model with 100 × 100 m spatial resolutions and aggregated into trimester-specific mean concentrations. Placental relative mtDNAcn and telomere length were measured using qPCR. Linear and logistic regression models were used to investigate associations, adjusted for perinatal and seasonal characteristics.Results: Exposure was categorized into low and high exposures by median cut-offs during first [11.9 μg/m3; interquartile range (IQR) 7.9, 17.9], second (11.6 μg/m3; IQR: 7.1, 21.1), third trimesters (11.9 μg/m3; IQR: 7.7, 19.5) and entire pregnancy (12.0 μg/m3; IQR: 7.6, 20.1). Increased risk of PE was found for high prenatal NOx exposure during the first trimester (OR 4.0; 95% CI: 1.4, 11.1; p = 0.008), and entire pregnancy (OR 3.7; 95% CI: 1.3, 10.4; p = 0.012). High exposed group during the first trimester had lower placental relative mtDNAcn compared with low exposed group (−0.20; 95% CI: −0.36, −0.04; p = 0.01). Changes in relative mtDNAcn did not mediate the association between prenatal NOx exposure and PE. No statistically significant association was found between placental relative telomere length, prenatal NOx exposure and PE.Conclusion: In this region with relatively low levels of air pollution, ambient NOx exposure during the first trimester was associated with reduced placental relative mtDNAcn and an increased risk of PE. However, we did not find any evidence that mtDNAcn or TL mediated the association between air pollution and PE. Future research should further investigate the role of mtDNAcn for pregnancy complications in relation to exposure to ambient air pollution during pregnancy.
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| 4397. |
- Mandakh, Yumjirmaa, et al.
(författare)
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Maternal Exposure to Ambient Air Pollution and Risk of Preeclampsia : A Population-Based Cohort Study in Scania, Sweden
- 2020
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1660-4601. ; 17:5
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the risk of developing preeclampsia (PE) associated with gestational exposure to ambient air pollutants in southern Sweden, a low-exposure area. We used a cohort of 43,688 singleton pregnancies and monthly mean exposure levels of black carbon (BC), local and total particulate matter (PM2.5 and PM10), and NOX at the maternal residential address estimated by Gaussian dispersion modeling from 2000 to 2009. Analyses were conducted using binary logistic regression. A subtype analysis for small-for-gestational age (SGA) was performed. All analyses were adjusted for obstetrical risk factors and socioeconomic predictors. There were 1286 (2.9%) PE cases in the analysis. An adjusted odds ratio (AOR) of 1.35 with a 95% confidence interval (CI) of 1.11-1.63 was found when comparing the lowest quartile of BC exposure to the highest quartile in the third trimester The AOR for PE associated with each 5 µg/m3 increase in locally emitted PM2.5 was 2.74 (95% CI: 1.68, 4.47) in the entire pregnancy. Similar patterns were observed for each 5 µg/m3 increment in locally emitted PM10. In pregnancies complicated by PE with SGA, the corresponding AOR for linear increases in BC was 3.48 (95% CI: 1.67, 7.27). In this low-level setting, maternal exposure to ambient air pollution during gestation was associated with the risk of developing PE. The associations seemed more pronounced in pregnancies with SGA complications, a finding that should be investigated further.
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| 4398. |
- Mandl, Thomas, et al.
(författare)
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Work disability in newly diagnosed patients with primary sjögren syndrome
- 2017
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Ingår i: Journal of Rheumatology. - : The Journal of Rheumatology. - 0315-162X .- 1499-2752. ; 44:2, s. 209-215
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To study longterm work disability and possible predictors in newly diagnosed patients with primary Sjogren syndrome (pSS). Methods. Because we wanted to include only patients with full work availability potential, eligible patients were aged 18-62 years. Fifty-one patients (mean age 46 yrs, range 18-61 yrs, 50 women) diagnosed with pSS between January 2001 and December 2012 were included in the study. For each patient we randomly selected 4 reference subjects from the general population and matched for age, sex, and area of residence. We linked data to the Swedish Social Insurance Agency and calculated the proportion as well as net days of work disability in 30-day intervals from 12 months before pSS diagnosis until 24 months after . Results. Work disability was increased in patients with pSS in comparison to general population comparators. At diagnosis, 26% of patients were work-disabled, while 37% and 41% were disabled at 12 and 24 months after diagnosis, respectively (p < 0.05 and p < 0.05 vs baseline). Prior work disability status at diagnosis (OR 15.4, 95% CI 2.9-81.9; p = 0.001), concomitant fibromyalgia (OR 10.5, 95% CI 2.0-56.0; p = 0.006), and each additional year of age (OR 1.1, 95% CI 1.0-1.2; p = 0.009) were found to be associated with work disability 24 months after diagnosis. Conclusion. Patients with pSS showed an increased work disability, in comparison with the general population, which increased significantly during the first 2 years after diagnosis. Work disability at diagnosis, concomitant fibromyalgia, and increasing age, but not anti-SSA/anti-SSB antibodies or disease activity, were associated with longterm work disability.
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| 4399. |
- Manjare, S., et al.
(författare)
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Air Dispersion Modelling of Coal Particles Released During Handling of Cargo at Port
- 2021
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Ingår i: Environmental Modelling and Assessment. - : Springer Science and Business Media Deutschland GmbH. - 1420-2026 .- 1573-2967. ; 26:3, s. 371-383
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Tidskriftsartikel (refereegranskat)abstract
- Mormugao Port Trust (MPT) handles 1087 t/h of coal with the help of 6 mooring dolphins situated at around 600-m distance in sea from the port next to the city of Vasco da Gama, Goa, India. During the said operations, the particles are released at lower height (2 to 5 m from sea water level) unlike other emissions. Since the city is situated next to the port, particles released during the handling of coal reach the Vasco city due to dispersion and affect health of the people in the city. The objective of this study was to identify the key variables which affect the dispersion of the particles released during coal loading and unloading operations. Detailed simulation studies are carried out to study the effect of wind speed, atmospheric temperature, atmospheric humidity, moisture content of coal, and the release height of the material from cranes, on dispersion of particles. For this purpose AERMOD software was used. All the necessary data required for the study was collected from Mormugao Port Trust, Vasco, Goa. Wind speed and moisture content of materials are key variables identified as they influence the dispersion significantly. With wind speeds greater than 8 m/s, the concentrations of PM10 and PM2.5 exceed beyond permissible limits up to 1 km radius. Variation in release height from 1 to 3 m does not have significant effect on particle dispersion. Change in atmospheric temperature and atmospheric humidity has no influence on dispersion of particles. The model results are validated with the field data obtained during the actual handling of coal at Mormugao Port Trust.
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| 4400. |
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