What do we know about particles in the air that we breathe?

Transcription

1 What do we know about particles in the air that we breathe? Aneta Wierzbicka Ergonomics and Aerosol Technology, Lund University, Lund Centre for Healthy Indoor Environments, Lund University, Lund

2 Aerosol Group at Ergonomics & Aerosol Technology Lund University Three Multidisciplinary Research Centres CAST - Consortium for Aerosol Science and Technology Metalund Medicine and Technology for Working Life and Society CHIE Centre for Healthy Indoor Environments

3 Aerosol Group at Lund University - Research Topics Pollutant Formation and Emissions from Combustion Atmospheric Research Climate vs Health Effects Indoor and Workplace Exposures Health Effects of Air Pollution Exposure Studies Bioaerosols - Spreading of Disease Nanotechnology & Nanosafety Aerosol Laboratory and Instrumentation

4 Centre for Healthy Indoor Environments (CHIE) Lund University

5 Outline Do exposure to particles affect our health? Airborne particles in our homes recent research findings Changing chemistry of airborne particles a closer look thanks to recent development Do we have enough scientific evidence to include indoor generated particles in the exposure risk assessment?

6 Airborne particles Size range: 2 nm (0.002 µm or 10-9 m) µm (10-4 m) Pollen Sea salt Soil Diesel exhaust Candle Asbestos

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8 PM 10 (<10 mm) PM 2.5 (<2.5 mm) UFP (ultrafine particles, < 0.1 mm) 1 µm = 10-6 m = 10-4 cm = mm

9 Sources of airborne particles?

10 Where do airborne particles come from? Natural outdoor sources Wind-blown soil, sand, rock debris Pollen, bacteria, viruses Sea salt

11 Where do airborne particles come from? Anthropogenic outdoor sources Combustion processes Fugitive emissions from industrial processes (grinding, wind erosion of storage piles) Traffic related (diesel particles, wear of tires, breaks, etc)

12 Indoor sources of airborne particles - examples?

13 Outline Do exposure to particles affect our health? Airborne particles in our homes recent research findings Changing chemistry of airborne particles a closer look thanks to recent development Do we have enough scientific evidence to include indoor generated particles in the exposure risk assessment?

14 Deposition of particles in respiratory tract Predicted total and regional deposition for light exercise (nose breathing) based on ICRP deposition model (from Hinds, 1999).

15 Epidemiological studies ambient particles From epidemiological studies it is known that exposure to ambient airborne particles is associated with: Respiratory diseases Cardiovascular diseases Increased mortality WHO classification: 1996: Tobacco smoke no safe limit of exposure, EPA - human carcinogen (group 1) 2012: Diesel exhaust - human carcinogen (group 1) 2013: Ambient air pollution - human carcinogen (group 1)

16 Epidemiological studies ambient particles Short term effect studies hospitalisation for respiratory and heart disease, aggravation of asthma, respiratory symptoms, impaired lung function Long term effect studies 10 mg/m 3 elevation in PM 2.5 was associated with 4 % increased risk of all-cause mortality, 6 % - cardiopulmonary mortality and 8% - lung cancer mortality (Pope III et al., 2002)

17 Which particle characteristics are the most relevant to assess health effects? Mass concentration Size of particles Number concentration Surface area, surface reactivity Chemical composition Solubility Bioavailable transition metals?

18 Outline Do exposure to particles affect our health? Airborne particles in our homes recent research findings Changing chemistry of airborne particles a closer look thanks to recent development Do we have enough scientific evidence to include indoor generated particles in the exposure risk assessment?

19 Airborne particles in our homes: cocktail effects, chemical composition, physical characteristics and toxicity. Project financed by the Swedish Research Council FORMAS (Dnr ) Partners: Ergonomics and Aerosol Technology, Lund University, Sweden National Research Centre for Working Environment (NRCWE), Denmark IVL Swedish Environmental Institute, Sweden Occupational and Environmental Medicine, Lund University, Sweden

20 Aim To gain knowledge on everyday exposures to airborne particles in our homes Specifically to determine: 1. What are the physico-chemical properties of airborne particles inside and outside occupied residences? 2. What are the differences in toxicity of particles inside and outside occupied residences as assessed by toxicological studies in mice? 3. How properties of particles change in indoor environments due to interaction of particulate and gaseous air pollutants of outdoor and indoor origin (WP3)

21 WP1 Measurements in 16 occupied residences were performed 3 detached houses with natural ventilation 1 apartment with natural ventilation 11 apartments with mechanical ventialtion, 2 of which with new type of ventilation Week long measurements between October 2016 April 2017 Measuremnets were conducted simultanously inside and outside Instructions were given to occupants to ensure that periods with active indoor sources were captured Occupants were asked to keep log books Air exchange rates were assessed and building characteristics gathered

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25 Airborne particles in our homes - measurements NanoTracer particle number concentration, mean size ( nm) DustTrack Proxy mass conc., PM2.5 particles collection for gravimetric and PAHs analysis Mini-aethalometer black carbon mass concentration PM2.5 collection for endotoxins analysis Dekati Gravimetric Impactor, PM2.5 for toxicological studies

26 Collected particles PM2.5 on 37mm filters PM2.5 on 47mm filters Analysis 1.gravimeteric 2. PAHs (half of the filter) 3. metals (quarter of the filter) 4. IC (quarter of the filter) 1. gravimetric 2. endotoxin PM2.5 on 70 mm filters 1. gravimeteric 2. extraction 3. pooling together (seperatly: inside, outdoors, candle white and candle blue) 4. analysis of pooled samples for PAHs, metals, ions, endotoxin, OC/EC and TEM images

27 Number concentrations indoors and outdoors

28 Number size distribution activities indoors

29 Airborne particles in our homes Mixture of outdoor and indoor generated particles + secondary pollutants formed from precursors originating from outdoors and indoors Particles from outdoors always form a background level indoors which depends on: concentrations and characteristics of particles outdoors (regional differences), building type and envelope, ventilation, filtration, airing practices When no activity indoors, concentrations indoors are lower or similar to outdoors Indoor sources/human activities are powerful contributors to particle loads indoors Indoor combustion related sources (cooking, candles) contribute to high ultrafine particle loads

30 Chemical composition? Until recently based on integrated samples (few hours) assessed with off-line analysis Differences between physicochemical properties of particles indoors and outdoors can be large due to influence of indoor sources and change of physicochemical properties upon outdoor-indoor transport Main chemical components of indoor particles: sulfate, nitrate, ammonium, sea salt, minerals, OC, and EC, and several trace consituents (Morawska 2013) Remarkable advancemnets have been made in assessemnt of physioco-chemical characteristics of emissions from specific indoor sources cooking (Amouei Torkmahalleh at al, 2012, 3013, 2017; Buonanno et al., 2009, 2011) e-cigarets, printing (Morawska et al, 2009, Salthammer et al, 2012, Schripp et al 2011, 2013)

31 Chemical composition? Still missing are: Change of physicochemical characteristics upon infiltration - time and size resolved Understanding of gas-particle partitionong of pollutants Understanding of chemical transformations/aging/formation of secondary pollutants in indoor air when outdoor and indoor air pollutants in gas- and particle phase interact

32 Aerosol Mass Spectrometry S ssssssssssssss Particle phase composition with high time- (~ s) and size resolution ( nm), DeCarlo et al. (2006), Onasch et al. (2012) Examples of components: Organic Aerosol (several classes), PAHs, Inorganic salts (nitrates, sulphates.),

33 Aerosol Mass Spectrometry in indoor air studies Transformation of outdoor particle components upon transport indoors nonoccupied residence (Johnson, Waring, DeCarlo, 2016; Talbot et al 2016, 2017) Formation of secondary organic aerosols (SOA) from gas-phase emissions of heated cooking oils (Liu et al, 2017) Emission of VOCs and production of SOA from stir-frying with spices (Liu et al, 2017)

34 Seasonal differences in chemical composition (AMS) - non-occupancy Winter reduced share of NO 3 - indoors Summer very similar proportions of chemical species indoors and outdoors Slide: courtesy of J. Ondracek. Talbot et al. 2017, Aerosol and Air Quality Research, 17:

35 Measurements Malmö, Sweden ( ) Naturally ventilated four-bedroom apartment (117 m 2 )

36 Measurements - Malmö Time-of-Flight Aerosol Mass Spectrometer (HR-TOF-AMS) Aerosol Chemical Speciation Monitor (ACSM) Scanning Mobility Particle Sizer (SMPS) Ultrafine Condensation Particle Counter (UCPC) Aethalometer Ozone monitor Carbon dioxide analyzer

37 Particle mass concentrations of the chemical species inside and outside of the residence - diffrences were presented - results not publish yet

38 Outline Do exposure to particles affect our health? Airborne particles in our homes recent research findings Changing chemistry of airborne particles a closer look thanks to recent development Do we have enough scientific evidence to include indoor generated particles in the exposure risk assessment?

39 Toxicity of indoor particles? Particles collected indoors had higher cytotoxic effects on mouse macrophages than particles collected outside one single family house in Finland (Happo et. al., 2013, 2014) Long et al, 2001 proinflamatory response (bioassays - rat alveolar macrophages) higher for indoor particles than outdoor particles (14 paired samples in Boston area) Oeder et al., 2012 indoor PM10 from school compared with outdoor PM10 induced more inflammatory and allergic reactions, and accelerated blood coagulations

40 Toxicity of indoor particles? Particles collected for toxicological studies were extracted from filters and evaporated. Extracts of filters collected were pooled together, to form: indoor, outdoor and blanks Toxicological testing in mice has been conducted. Mice received a single intratracheal instillation of 18, 54 and 162 μg of each of the pooled particle samples. Lung inflammation and DNA damage in broncheoalveolar lavage cells, lung and liver tissue were evaluated 1, 3 and 28 days after intratracheal instillation. Carbon Black Printex 90 was included as positive control.

41 Toxicity of indoor particles? Results of toxicological studies in mice showed higher toxicity (acute phase response/inflammation) of particles collected indoors compared to outdoors

42 Future? Do we have enough scientific evidence? Needed are: Toxicological studies Epidemiological studies Source: drwriritings.com Sources:

43 Future? Can we provide data on exposures in homes for epidemiological studies? Use of cheaper miniature sensors? Their accuracy/lifetime and reliability? Modelling? The state-of-the-art mass spectrometry analysis of particle and gas phase composition can be used to obtain data needed for modelling Understand transformations and partitioning between gas and particle phase pollutants in indoor air (Ideally combined with PTRMS) Understand oxidation processes and aging in indoor air Source apportionment based on mass spectra and PMF

44 What can we do to decrease our exposure to particles indoors?

45 Four principles for achieving good indoor air quality Minimize indoor emissions Keep it dry Ventilate well Protect against outdoor pollution Nazaroff W. W , Four principles for achieving good indoor air quality Indoor Air 2013; 23:

46 Arbetsmiljöverket (Swedish Work Environment Authority) Airborne Dust Removal using Mobile Air Cleaners With a Focus on Work Environments in the Construction Sector Authors of the report J. Pagels, M. Alsved, V. Malmborg, Y. Omelekhina, A. Wierzbicka, M. Bohgard Ergonomics & Aerosol Technology, Lund University

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