Sisäilmastoseminaari 2019

Katsauksessa käytiin läpi vuosina 2014 – 2018 Aerobiologian laboratoriossa analysoitujen ulkoilmavertailunäytteiden (280 kpl) lajistoa. 80 %:ssa näytteistä löytyi kosteusvaurioindikoivaa lajistoa eli joko aktinomykeettejä tai indikaattorisieniä. Kosteusvauriota indikoivia sieniä esiintyi 76 %:ssa näytteistä, joista yleisimmät olivat Eurotium (23 %), Aspergillus sektio restricti (22 %), Aspergillus fumigatus (19 %) ja Phoma (17 %). Aktinomykeettibakteereita eli sädesieniä esiintyi 35 %:ssa näytteistä. Tulosten perusteella sisäilmasta otettujen näytteiden tulosten tulkinnassa on sulan maan aikana huomioitava kosteusvaurioindikoivan lajiston esiintyminen pieninä määrinä myös ulkoilmassa. Pihapiiristä otetun ulkoilmanäytteen edustavuus vertailunäytteenä on arvioitava huolellisesti tuloksia tulkittaessa.</p

Sisäilmastoseminaari 2019

MALDI-TOF massaspektrometrialla voidaan luokitella ja tunnistaa mikro-organismeja niiden proteiiniprofiilin mukaan. Tämä kustannustehokas ja nopea menetelmä on otettu laajasti käyttöön mikrobiologisessa analytiikassa. Artikkelissa kuvataan aloitettua selvitys­työtä menetelmän hyödynnettävyydestä asumisterveystutkimuksissa. Esikokeissa menetelmää testattiin 10 Aspergillus-kannalla sekä 50 asumisterveysnäytteistä eristetyllä aktinomykeettikannalla. Aspergillus-lajien tunnistus onnistui tyydyttävästi. Aktinomykeetit tunnistettiin käytetyn tietokannan suppeuden vuoksi pääosin vain sukutasolle. Menetelmän käyttöönotto edellyttäisi MALDI-TOF MS kirjastotietokantojen laajentamista DNA-sekvensoinnilla tunnistetuilla ympäristömikrobikannoilla</p

Biomonitoring of Indoor Air Fungal or Chemical Toxins with Caenorhabditis elegans nematodes

Bad indoor air quality due to toxins and other impurities can have a negative impact on human well-being, working capacity and health. Therefore, reliable methods to monitor the health risks associated with exposure to hazardous indoor air agents are needed. Here, we have used transgenic Caenorhabditis elegans nematode strains carrying stress-responsive fluorescent reporters and evaluated their ability to sense fungal or chemical toxins, especially those that are present in moisture-damaged buildings. Liquid-based or airborne exposure of nematodes to mycotoxins, chemical agents or damaged building materials reproducibly resulted in time- and dose-dependent fluorescent responses, which could be quantitated by either microscopy or spectrometry. Thus, the C. elegans nematodes present an easy, ethically acceptable and comprehensive in vivo model system to monitor the response of multicellular organisms to indoor air toxicity.Peer reviewe

Patterns in airborne pollen and other primary biological aerosol particles (PBAP), and their contribution to aerosol mass and number in a boreal forest

We studied variation in concentrations of airborne pollen and other particles of biological origin in a boreal forest in Finland during 2003–2004. The highest concentrations of pollen were observed in late spring and early summer, whereas the peak concentrations of other particles of biological origin (including e.g. fungal spores) occurred in August–September. Although the patterns in concentrations in 2003 and 2004 were similar, the concentration levels were significantly different between the years. The contribution of pollen and other particles of biological origin led to an increase in the measured particulate matter (PM) mass during the pollen season (mass of pollen and other particles of biological origin 5.9 and 0.4 μg m–3, respectively, in respect to PMtotal mass of 9.9 μg m–3) but the effect on total particle number was negligible. The other particles of biological origin constituted the largest fraction of measured primary biological aerosol particle (PBAP) numbers (~99%), whereas pollen showed a higher relative mass fraction (~97%) of PBAP. These results underline the important contribution of PBAP to coarse atmospheric particle mass providing up to 65% of the total mass during the peak pollen season

Impact of rising CO2 and temperature on grass phenology, physiology, and pollen release patterns in northern latitudes

Climate change has complex effects on vegetation, including native grasses and those used as fodder plants. Like many other plant species, grasses respond to climate change by altering their phenology and physiological behavior, leading to changes e.g. in growth, reproduction and metabolic processes. Our study is the first to explore how Phleum pratense and Alopecurus pratensis respond to rising CO2 and temperatures projected for northern latitudes for two growing seasons. We investigated growth, phenology, pollen release, and physiological parameters in plants cultivated under these conditions, simulated within environmentally controlled chambers. Treatment with elevated temperature reduced the number of generative tillers and, consequently, decreased both the number of inflorescences and the season pollen integrals. Pollen release from P. pratense started up to 17 days earlier, and the daily peak concentration of released pollen was observed 1–2 h earlier in chambers with elevated temperatures when compared to the present climate conditions. Similar effects were noted in A. pratensis. Elevated CO2 (EC) increased net photosynthesis of P. pratense, but this effect was reduced under elevated temperature (ET), suggesting an antagonistic interaction. In A. pratensis, both elevated CO2 and temperature had an additive effect on increasing net photosynthesis, with the highest rate observed under the combined ETEC treatment. The elevated temperature or CO2 did not affect the plant biomass. Our findings propose that the rising temperatures in northern latitudes decrease the flowering of studied grasses and shift the seasonal and daily start of the pollen release. Changes in tiller proportions, reduced pollen integrals, and fewer inflorescences suggest that a warmer climate may negatively impact reproductive success, ecological fitness, and allergenic burden of these grasses

Alder pollen in Finland ripens after a short exposure to warm days in early spring, showing biennial variation in the onset of pollen ripening

We developed a temperature sum model to predict the daily pollen release of alder, based on pollen data collected with pollen traps at seven locations in Finland over the years 2000–2014. We estimated the model parameters by minimizing the sum of squared errors (SSE) of the model, with weights that put more weight on binary recognition of daily presence or absence of pollen. The model results suggest that alder pollen ripens after a couple of warm days in February, while the whole pollen release period typically takes up to 4 weeks. We tested the model residuals against air humidity, precipitation and wind speed, but adding these meteorological features did not improve the model prediction capacity. Our model was able to predict the onset of pollen season with similar accuracy as models describing only the start of the pollen release period (average prediction error 8.3, median 5.0 days), while for the end of the pollen release period the accuracy of our predictions was not as good. We split the pollen data into odd and even years, and fitted our model separately to each half. Difference in the parameter values suggests a biennial behavior in the onset of pollen ripening, with almost two weeks of difference in the modeled starting date of the pollen development. Monte Carlo resampling of the observation data confirmed that the difference is not just a random anomaly in the data.peerReviewe

Huokoisten puukuitu- ja kipsilevytuulensuojalevyjen homehtumisherkkyys

publishedVersio

Microbial Growth Inside Insulated External Walls as an Indoor Air Biocontamination Source

The association between moisture-related microbial growth (mesophilic fungi and bacteria) within insulated exterior walls and microbial concentrations in the indoor air was studied. The studied apartment buildings with precast concrete external walls were situated in a subarctic zone. Actinomycetes in the insulation layer were found to have increased concentrations in the indoor air. The moisture content of the indoor air significantly affected all measurable airborne concentrations

Biomonitoring of Indoor Air Fungal or Chemical Toxins with Caenorhabditis elegans nematodes

Bad indoor air quality due to toxins and other impurities can have a negative impact on human well-being, working capacity and health. Therefore, reliable methods to monitor the health risks associated with exposure to hazardous indoor air agents are needed. Here, we have used transgenic Caenorhabditis elegans nematode strains carrying stress-responsive fluorescent reporters and evaluated their ability to sense fungal or chemical toxins, especially those that are present in moisture-damaged buildings. Liquid-based or airborne exposure of nematodes to mycotoxins, chemical agents or damaged building materials reproducibly resulted in time- and dose-dependent fluorescent responses, which could be quantitated by either microscopy or spectrometry. Thus, the C. elegans nematodes present an easy, ethically acceptable and comprehensive in vivo model system to monitor the response of multicellular organisms to indoor air toxicity