Metal and particle analysis of ambient air in Mo i Rana using moss-bags as passive sampler

Mo i Rana har perioder gjennom året med utfordringer tilknyttet luftforurensning, spesielt på vinteren. Denne oppgaven går ut på å undersøke egnethet av mose, som er en passiv prøvetaker til å studere metallbelastning og utføre partikkelanalyse i Mo i Rana. For å forenkle partikkelanalysen ble det utviklet en automatisk metode i varierende trykk modus i sveipelektronmikroskop (VP-SEM) (Hitachi SU6600 med Bruker X-Flash 5010 detektor). Resultatene ble brukt til å undersøke metallbelastning og partikler deponert på mose for å øke kunnskapen om luftforurensning i Mo i Rana. Fra tidligere studier er det kjent at industrien i Mo i Rana er en hovedbidragsyter til luftforurensning i området. I denne studien er det hengt ut mosenett (laget med mosearten Hylocomium splendens) 2 meter over bakken, i område rundt industrien og utover i byen i Mo i Rana. Mikrobølgedekomponerte prøver av mosen ble analysert med ICP-MS (Agilent 8800qqq) for å bestemme anrikningsfaktor for utvalgte metall beregnet i forhold til tre ueksponerte moseprøver. Fire av prøvene med høyest anrikningsfaktor ble analysert med VPSEM. Elever ved Polarsirkelen videregående skole bidro i prøvetakingen ved å preparere og henge ut mosenett i et spredt område av byen. Elevprøvene ble delt inn i tre soner. Resultatene indikerer at mose er en egnet prøvetaker for partikler, og til metallanalyse for å studere metallbelastning tilknyttet grovfraksjonspartikler (1-10 μm) og metall tatt opp av mose. Bulkanalyseresultatene viste god nøyaktighet og presisjon for de fleste bestemte grunnstoff. Prinsipal-komponent-analyse (PCA) ble brukt som statistisk metode for å gruppere metallene. Dette gav fordeling av metall til tre grupper tolket som industrikomponent, jordsmonn og biologisk materiale. I partikkelanalysen ble det detektert metallpartikler i både finfraksjon (0.2-1 μm) og grovfraksjon med en forskjell i partikkelsammensetningen i de ulike prøvepunktene. Et viktig funn fra partikkelanalysen var at mangan hovedsakelig detekteres i finfraksjonen. Instrumentelle faktorer begrenset resultatene fra partikkelanalysen slik at det ikke kunne utføres en detaljert partikkelklassifisering. Den utviklede automatiske metoden med VP-SEM var lite egnet for analyse av partiklene i Mo i Rana fordi metoden ikke gav et klart skille mellom jord og industrielle partikler. Elevprøvene indikerte at sone 1 (boligområde nærmest industri) var påvirket av industrikomponenter, og at sone 2 (7-8 km nord for industri) ikke var påvirket av industrikomponenter. Det anbefales at luftkvaliteten i Mo i Rana undersøkes nærmere over en lengre prøveperiode. Luftprøver bør tas av fin- og grovfraksjonspartikler med en aktiv prøvetaker, både i byen og av uteluften på industriområdet tilknyttet arbeidsmiljø. ABSTRACT: The town of Mo i Rana in Norway experience time periods with high levels of air pollution, especially during winter. This thesis investigates atmospheric deposition of metals and particulate matter on moss-bags. The aim was to find out if moss is a suitable sampler for particle analysis and to study metal load in Mo i Rana. An automated method with variable pressure scanning electronmicroscopy (VP-SEM) (Hitachi SU6600 Bruker X-Flash 5010 detector) were developed for simplification of the particle analysis. The particle analysis and metal load results are used to improve knowledge of air pollution in Mo i Rana. Previous studies showed that the metal industries located in Mo i Rana are the main contributors to air pollution in the area. The present study investigates moss-bags (with Hylocomium splendes) placed 2 meters above ground located around the industrial area and throughout the town of Mo i Rana. Students from Polarsirkelen high school helped preparing and placing mossbags around the town, geographically divided into three zones. All samples were, after microwave digestion, analysed with inductively coupled plasma – mass spectrometry (ICP-MS) (Agilent 8800qqq) which showed good precision and accuracy for most of the metals. The results indicate that moss is a suitable sampler for investigation of metal load with respect to particle analysis and bulk measurement yielding information on coarse particles (1-10 μm) and metals taken up by moss. Principal component analysis (PCA) of the bulk measurements yielded three groups, interpreted as industrial, geogenic and biological component. Enrichment factors for selected elements were calculated relative to the mean of three unexposed mosssamples. Particle analysis, conducted on four samples with the highest enrichment factors, indicated metal particles in both coarse and fine (0.2-1 μm) particles. Metal composition in the particles differed between sample locations. An important finding in the particle analysis is that manganese particles mostly occur in the fine fraction in all samples. Instrumental factors limited the results obtained from the developed automated VP-SEM method, and made it unsuitable for a detailed particle classification. Industrial and geogenic components could not be differentiated with the automated method, which made it unsuitable for analysis of particles deposited on moss in Mo i Rana. The student-samples indicated industrial influence in zone 1 (close to the industry) and no industrial influence in zone 2 (7-8 km north in linear distance). Based on the results, that metals are found in both size fractions, it is advised to investigate the real exposure in the urban area with focus on exposure of the general population as well as inside the industrial area with focus on workplace exposure.M-MIN

Characterisation of ice particle residuals and aerosol particles in laboratory and field experiments by scanning electron microscopy during INUIT (Ice Nuclei research UnIT)

Ice nucleating particles are necessary for formation of ice crystals in mixed-phase clouds, but there are still uncertainties regarding physico-chemical properties, variability and concentration of these particles in the environment. The ice nuclei research unit (INUIT), funded by the German research foundation (DFG), has thoroughly investigated ice nucleation in laboratory, model and field studies. This thesis contains research from a field study (Jungfraujoch, Switzerland) and a laboratory experiment (of coal fly ash) as well as a methodological part to study the performance of single particle techniques applied. Scanning electron microscopy (SEM) with energy dispersive X-ray microanalysis (EDX) was used as main technique in this thesis. The capability of SEM-EDX in ice nucleation research is demonstrated in the following chapters and in the corresponding papers to this thesis. Single particle analysis by SEM-EDX can be performed operator controlled (opSEM) or computer controlled (ccSEM). In this thesis, it is shown that the technique of choice is dependent on the research question and the particle composition. A comparison of the techniques for different types of aerosol samples provided valuable information about the differences and was further used as a guide to the technique of choice in the remaining studies. Ice particle residuals were studied in mixed-phase clouds at Jungfraujoch in February 2017. The results show that different silicate groups were the most important ice nucleating particles, consistent with previous literature. However, in our study, soot and complex secondary particles were not found in the ice particle residual fraction which is inconsistent with previous results. Furthermore, an upgraded sampling procedure gave the opportunity to determine enrichment and depletion of particle groups in the ice particle residual fraction relative to total aerosol, as well as to identify sampling artefacts. The ice nucleation properties of coal fly ash particles were investigated in a laboratory study. In this study, SEM-EDX was applied to characterise the fly ash particles before and after suspension in water. Anhydrite and CaO, in one of the fly ash samples, reacted to gypsum, calcium hydroxide and calcite needles after suspension. This change led to an overestimation of the ice nucleation active surface site density, which was later corrected for because of the morphological information from SEM. Last, a newly developed method for phase determination by single particle mass spectrometry (SP-MS) was tested and compared to SEM-EDX. Both techniques show the same differences in chemical composition of mineral dust from North-Africa. SP-MS could characterise the phase composition of the particles. Still, SP-MS was limited by matrix effects which was seen from a higher abundance of Ca- and Mg-rich silicates obtained by SEM-EDX. A better understanding of these matrix effects is needed to improve the application of the former method to ice particle research

Occupational Exposure among Electronic Repair Workers in Ghana

Electronic repair workers may be exposed to lead, mercury, cadmium and other elements including rare earth elements used in electronic equipment. In this study, repair work took place in small repair shops where, e.g., televisions, radios, video players, compact discs and computers were repaired. Personal full-shift air samples of particulate matter were collected among 64 electronic repair workers in Kumasi (Ghana) and analysed for 29 elements by inductively coupled plasma mass spectrometry. Results showed that air concentrations of all elements were low. The highest air concentration was measured for iron with a geometric mean concentration and geometric standard deviation of 6.3 ± 0.001 µg/m3. The corresponding concentration of Pb and Hg were 157 ± 3 ng/m3 and 0.2 ± 2.7 ng/m3, respectively. The cerium concentration of 5 ± 2 ng/m3 was the highest among the rare earth elements. Source apportionment with ranked principal component analysis indicated that 63% of the variance could be explained by the repair and soldering of electronic components such as batteries, magnets, displays and printed circuit boards. An association between concentrations of lead in the workroom air and lead in whole blood was found (Pearson’s correlation coefficient r = 0.42, p < 0.001). There was, however, no statistically significant difference between whole blood lead concentrations in the workers and references indicating that lead did not exclusively originate from occupational exposure

Metall- og partikkelanalyse av uteluft i Mo i Rana studert ved mosenett som passiv prøvetaker

Mo i Rana har perioder gjennom året med utfordringer tilknyttet luftforurensning, spesielt på vinteren. Denne oppgaven går ut på å undersøke egnethet av mose, som er en passiv prøvetaker til å studere metallbelastning og utføre partikkelanalyse i Mo i Rana. For å forenkle partikkelanalysen ble det utviklet en automatisk metode i varierende trykk modus i sveipelektronmikroskop (VP-SEM) (Hitachi SU6600 med Bruker X-Flash 5010 detektor). Resultatene ble brukt til å undersøke metallbelastning og partikler deponert på mose for å øke kunnskapen om luftforurensning i Mo i Rana. Fra tidligere studier er det kjent at industrien i Mo i Rana er en hovedbidragsyter til luftforurensning i området. I denne studien er det hengt ut mosenett (laget med mosearten Hylocomium splendens) 2 meter over bakken, i område rundt industrien og utover i byen i Mo i Rana. Mikrobølgedekomponerte prøver av mosen ble analysert med ICP-MS (Agilent 8800qqq) for å bestemme anrikningsfaktor for utvalgte metall beregnet i forhold til tre ueksponerte moseprøver. Fire av prøvene med høyest anrikningsfaktor ble analysert med VPSEM. Elever ved Polarsirkelen videregående skole bidro i prøvetakingen ved å preparere og henge ut mosenett i et spredt område av byen. Elevprøvene ble delt inn i tre soner. Resultatene indikerer at mose er en egnet prøvetaker for partikler, og til metallanalyse for å studere metallbelastning tilknyttet grovfraksjonspartikler (1-10 μm) og metall tatt opp av mose. Bulkanalyseresultatene viste god nøyaktighet og presisjon for de fleste bestemte grunnstoff. Prinsipal-komponent-analyse (PCA) ble brukt som statistisk metode for å gruppere metallene. Dette gav fordeling av metall til tre grupper tolket som industrikomponent, jordsmonn og biologisk materiale. I partikkelanalysen ble det detektert metallpartikler i både finfraksjon (0.2-1 μm) og grovfraksjon med en forskjell i partikkelsammensetningen i de ulike prøvepunktene. Et viktig funn fra partikkelanalysen var at mangan hovedsakelig detekteres i finfraksjonen. Instrumentelle faktorer begrenset resultatene fra partikkelanalysen slik at det ikke kunne utføres en detaljert partikkelklassifisering. Den utviklede automatiske metoden med VP-SEM var lite egnet for analyse av partiklene i Mo i Rana fordi metoden ikke gav et klart skille mellom jord og industrielle partikler. Elevprøvene indikerte at sone 1 (boligområde nærmest industri) var påvirket av industrikomponenter, og at sone 2 (7-8 km nord for industri) ikke var påvirket av industrikomponenter. Det anbefales at luftkvaliteten i Mo i Rana undersøkes nærmere over en lengre prøveperiode. Luftprøver bør tas av fin- og grovfraksjonspartikler med en aktiv prøvetaker, både i byen og av uteluften på industriområdet tilknyttet arbeidsmiljø. ABSTRACT: The town of Mo i Rana in Norway experience time periods with high levels of air pollution, especially during winter. This thesis investigates atmospheric deposition of metals and particulate matter on moss-bags. The aim was to find out if moss is a suitable sampler for particle analysis and to study metal load in Mo i Rana. An automated method with variable pressure scanning electronmicroscopy (VP-SEM) (Hitachi SU6600 Bruker X-Flash 5010 detector) were developed for simplification of the particle analysis. The particle analysis and metal load results are used to improve knowledge of air pollution in Mo i Rana. Previous studies showed that the metal industries located in Mo i Rana are the main contributors to air pollution in the area. The present study investigates moss-bags (with Hylocomium splendes) placed 2 meters above ground located around the industrial area and throughout the town of Mo i Rana. Students from Polarsirkelen high school helped preparing and placing mossbags around the town, geographically divided into three zones. All samples were, after microwave digestion, analysed with inductively coupled plasma – mass spectrometry (ICP-MS) (Agilent 8800qqq) which showed good precision and accuracy for most of the metals. The results indicate that moss is a suitable sampler for investigation of metal load with respect to particle analysis and bulk measurement yielding information on coarse particles (1-10 μm) and metals taken up by moss. Principal component analysis (PCA) of the bulk measurements yielded three groups, interpreted as industrial, geogenic and biological component. Enrichment factors for selected elements were calculated relative to the mean of three unexposed mosssamples. Particle analysis, conducted on four samples with the highest enrichment factors, indicated metal particles in both coarse and fine (0.2-1 μm) particles. Metal composition in the particles differed between sample locations. An important finding in the particle analysis is that manganese particles mostly occur in the fine fraction in all samples. Instrumental factors limited the results obtained from the developed automated VP-SEM method, and made it unsuitable for a detailed particle classification. Industrial and geogenic components could not be differentiated with the automated method, which made it unsuitable for analysis of particles deposited on moss in Mo i Rana. The student-samples indicated industrial influence in zone 1 (close to the industry) and no industrial influence in zone 2 (7-8 km north in linear distance). Based on the results, that metals are found in both size fractions, it is advised to investigate the real exposure in the urban area with focus on exposure of the general population as well as inside the industrial area with focus on workplace exposure

Characterisation of Particles Emitted during Laser Cutting of Various Metal Sheets and an Exposure Assessment for the Laser Operators

Laser cutting is used in many industrial settings to achieve precise cuts of metal sheets. Laser operators may be exposed to particles formed during cutting when opening the cabinet or when metal sheets are exchanged. To characterise the potential exposure, particles formed during laser cutting were studied with scanning electron microscopy equipped with an energy dispersive X-ray detector and an energy backscatter diffraction detector. The total concentration of particles (11–615 nm) was determined online with a scanning mobility particle sizer. The chemical composition of the particles formed during the cutting of the different metal sheets was determined by inductively coupled plasma mass spectrometry (ICP-MS). X-ray diffraction was applied to determine the phase composition. The occupational exposure was assessed gravimetrically and by ICP-MS for five laser operators handling different laser cutters, and materials and were found to be low. Agglomerates and aggregates of condensation particles were formed during laser cutting, independent of the sheet type. Iron, present as both magnetite and α-Fe, was the main element found in the particles formed when cutting steel sheets. The size of the particles generated was mainly below 300 nm. Open laser cutters may lead to higher metal exposures, which is especially relevant when cutting metal sheets containing heavy metals

Metal and particle analysis of ambient air in Mo i Rana using moss-bags as passive sampler

Mo i Rana har perioder gjennom året med utfordringer tilknyttet luftforurensning, spesielt på vinteren. Denne oppgaven går ut på å undersøke egnethet av mose, som er en passiv prøvetaker til å studere metallbelastning og utføre partikkelanalyse i Mo i Rana. For å forenkle partikkelanalysen ble det utviklet en automatisk metode i varierende trykk modus i sveipelektronmikroskop (VP-SEM) (Hitachi SU6600 med Bruker X-Flash 5010 detektor). Resultatene ble brukt til å undersøke metallbelastning og partikler deponert på mose for å øke kunnskapen om luftforurensning i Mo i Rana. Fra tidligere studier er det kjent at industrien i Mo i Rana er en hovedbidragsyter til luftforurensning i området. I denne studien er det hengt ut mosenett (laget med mosearten Hylocomium splendens) 2 meter over bakken, i område rundt industrien og utover i byen i Mo i Rana. Mikrobølgedekomponerte prøver av mosen ble analysert med ICP-MS (Agilent 8800qqq) for å bestemme anrikningsfaktor for utvalgte metall beregnet i forhold til tre ueksponerte moseprøver. Fire av prøvene med høyest anrikningsfaktor ble analysert med VPSEM. Elever ved Polarsirkelen videregående skole bidro i prøvetakingen ved å preparere og henge ut mosenett i et spredt område av byen. Elevprøvene ble delt inn i tre soner. Resultatene indikerer at mose er en egnet prøvetaker for partikler, og til metallanalyse for å studere metallbelastning tilknyttet grovfraksjonspartikler (1-10 μm) og metall tatt opp av mose. Bulkanalyseresultatene viste god nøyaktighet og presisjon for de fleste bestemte grunnstoff. Prinsipal-komponent-analyse (PCA) ble brukt som statistisk metode for å gruppere metallene. Dette gav fordeling av metall til tre grupper tolket som industrikomponent, jordsmonn og biologisk materiale. I partikkelanalysen ble det detektert metallpartikler i både finfraksjon (0.2-1 μm) og grovfraksjon med en forskjell i partikkelsammensetningen i de ulike prøvepunktene. Et viktig funn fra partikkelanalysen var at mangan hovedsakelig detekteres i finfraksjonen. Instrumentelle faktorer begrenset resultatene fra partikkelanalysen slik at det ikke kunne utføres en detaljert partikkelklassifisering. Den utviklede automatiske metoden med VP-SEM var lite egnet for analyse av partiklene i Mo i Rana fordi metoden ikke gav et klart skille mellom jord og industrielle partikler. Elevprøvene indikerte at sone 1 (boligområde nærmest industri) var påvirket av industrikomponenter, og at sone 2 (7-8 km nord for industri) ikke var påvirket av industrikomponenter. Det anbefales at luftkvaliteten i Mo i Rana undersøkes nærmere over en lengre prøveperiode. Luftprøver bør tas av fin- og grovfraksjonspartikler med en aktiv prøvetaker, både i byen og av uteluften på industriområdet tilknyttet arbeidsmiljø. ABSTRACT: The town of Mo i Rana in Norway experience time periods with high levels of air pollution, especially during winter. This thesis investigates atmospheric deposition of metals and particulate matter on moss-bags. The aim was to find out if moss is a suitable sampler for particle analysis and to study metal load in Mo i Rana. An automated method with variable pressure scanning electronmicroscopy (VP-SEM) (Hitachi SU6600 Bruker X-Flash 5010 detector) were developed for simplification of the particle analysis. The particle analysis and metal load results are used to improve knowledge of air pollution in Mo i Rana. Previous studies showed that the metal industries located in Mo i Rana are the main contributors to air pollution in the area. The present study investigates moss-bags (with Hylocomium splendes) placed 2 meters above ground located around the industrial area and throughout the town of Mo i Rana. Students from Polarsirkelen high school helped preparing and placing mossbags around the town, geographically divided into three zones. All samples were, after microwave digestion, analysed with inductively coupled plasma – mass spectrometry (ICP-MS) (Agilent 8800qqq) which showed good precision and accuracy for most of the metals. The results indicate that moss is a suitable sampler for investigation of metal load with respect to particle analysis and bulk measurement yielding information on coarse particles (1-10 μm) and metals taken up by moss. Principal component analysis (PCA) of the bulk measurements yielded three groups, interpreted as industrial, geogenic and biological component. Enrichment factors for selected elements were calculated relative to the mean of three unexposed mosssamples. Particle analysis, conducted on four samples with the highest enrichment factors, indicated metal particles in both coarse and fine (0.2-1 μm) particles. Metal composition in the particles differed between sample locations. An important finding in the particle analysis is that manganese particles mostly occur in the fine fraction in all samples. Instrumental factors limited the results obtained from the developed automated VP-SEM method, and made it unsuitable for a detailed particle classification. Industrial and geogenic components could not be differentiated with the automated method, which made it unsuitable for analysis of particles deposited on moss in Mo i Rana. The student-samples indicated industrial influence in zone 1 (close to the industry) and no industrial influence in zone 2 (7-8 km north in linear distance). Based on the results, that metals are found in both size fractions, it is advised to investigate the real exposure in the urban area with focus on exposure of the general population as well as inside the industrial area with focus on workplace exposure.M-MIN

Characterisation of ice particle residuals and aerosol particles in laboratory and field experiments by scanning electron microscopy during INUIT (Ice Nuclei research UnIT)

Ice nucleating particles are necessary for formation of ice crystals in mixed-phase clouds, but there are still uncertainties regarding physico-chemical properties, variability and concentration of these particles in the environment. The ice nuclei research unit (INUIT), funded by the German research foundation (DFG), has thoroughly investigated ice nucleation in laboratory, model and field studies. This thesis contains research from a field study (Jungfraujoch, Switzerland) and a laboratory experiment (of coal fly ash) as well as a methodological part to study the performance of single particle techniques applied. Scanning electron microscopy (SEM) with energy dispersive X-ray microanalysis (EDX) was used as main technique in this thesis. The capability of SEM-EDX in ice nucleation research is demonstrated in the following chapters and in the corresponding papers to this thesis. Single particle analysis by SEM-EDX can be performed operator controlled (opSEM) or computer controlled (ccSEM). In this thesis, it is shown that the technique of choice is dependent on the research question and the particle composition. A comparison of the techniques for different types of aerosol samples provided valuable information about the differences and was further used as a guide to the technique of choice in the remaining studies. Ice particle residuals were studied in mixed-phase clouds at Jungfraujoch in February 2017. The results show that different silicate groups were the most important ice nucleating particles, consistent with previous literature. However, in our study, soot and complex secondary particles were not found in the ice particle residual fraction which is inconsistent with previous results. Furthermore, an upgraded sampling procedure gave the opportunity to determine enrichment and depletion of particle groups in the ice particle residual fraction relative to total aerosol, as well as to identify sampling artefacts. The ice nucleation properties of coal fly ash particles were investigated in a laboratory study. In this study, SEM-EDX was applied to characterise the fly ash particles before and after suspension in water. Anhydrite and CaO, in one of the fly ash samples, reacted to gypsum, calcium hydroxide and calcite needles after suspension. This change led to an overestimation of the ice nucleation active surface site density, which was later corrected for because of the morphological information from SEM. Last, a newly developed method for phase determination by single particle mass spectrometry (SP-MS) was tested and compared to SEM-EDX. Both techniques show the same differences in chemical composition of mineral dust from North-Africa. SP-MS could characterise the phase composition of the particles. Still, SP-MS was limited by matrix effects which was seen from a higher abundance of Ca- and Mg-rich silicates obtained by SEM-EDX. A better understanding of these matrix effects is needed to improve the application of the former method to ice particle research

Composition of ice particle residuals in mixed-phase clouds at Jungfraujoch (Switzerland): enrichment and depletion of particle groups relative to total aerosol

Ice particle residuals (IRs) and the total aerosol particle population were sampled in parallel during mixedphase cloud events at the high-altitude research station Jungfraujoch in January–February 2017. Particles were sampled behind an ice-selective counterflow impactor (Ice-CVI) for IRs and a heated total inlet for the total aerosol particles. A dilution set-up was used to collect total particles with the same sampling duration as for IRs to prevent overloading of the substrates. About 4000 particles from 10 Ice-CVI samples (from 7 days of cloud events at temperatures at the site betwee