Percorrer por autor "Slezakova, Klara"
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- Age-related dose deposition of particulate matter in human respiratory tract: findings from a birth cross-sectional study in PortugalPublication . Madureira, Joana; Slezakova, Klara; Costa, Carla; Silva, Ana Inês; Mendes, Ana; Pereira, Maria do Carmo; Teixeira, João PauloIndoor air pollution remains a great global concern. Particulate matter (PM), namely ultrafine particles (aerodynamic diameter smaller than 0.1 μm; UFP), is considered as one of the most health-relevant air pollutant for various subpopulations, one of which is children. Knowledge on the specific dose deposition of PM may provide a critical link for better understanding of the relationship between individual exposure and the respective health effects. Mathematical models have proven to be important tools for analysing PM dose deposition in the respiratory tract providing relevant data for health risk assessment, source apportionment of human lung burdens and control strategies purposes. This work aimed to estimate the deposition dose of different PM sizes at different age categories. Inhalation dosimetry estimations were carried out using the multiple-path particle dosimetry model (MPPD, v3.04). Age specific 5-lobe model with uniform expansion was adopted in the present study
- Air pollution in urban environments: implications for citizens´healthPublication . Slezakova, Klara; Madureira, Joana; Teixeira, João Paulo; Pereira, Maria do CarmoCurrently, 54% of worldwide population lives in urban areas. While growing urbanization causes environmental pollution and energy demand, it has also adverse implications on health, living conditions and lifestyle habits of the respective citizens. To protect human health, numerous organizations have implemented guidelines to limit environmental pollution, or even proposed recommendation on human activity, but how do these translate to the exposure and risks of the respective population? This work aimed to explore how urban development, using time series data from 2015 to 2018, might influence air quality and potential health risks of citizens living in these zones.
- Assessment of indoor air exposure among newborns and their mothers: Levels and sources of PM10, PM2.5 and ultrafine particles at 65 home environmentsPublication . Madureira, Joana; Slezakova, Klara; Costa, Carla; Pereira, Maria Carmo; Teixeira, João PauloSignificant efforts have been directed towards addressing the adverse health effects of atmospheric particles, emphasizing the relevance of indoor exposure. Homes represent an indoor environment where human spend the majority of their time. Thus, the objective of this work was to concurrently assess different matrix of indoor particles considering both mass (PM10, PM2.5) and number (N20-1000) concentrations in indoor and outdoor air of homes (n = 65). Real-time measurements (PM10, PM2.5, UFP) were conducted simultaneously during 48 h in dwellings situated in Oporto, Portugal. In 75% of homes, indoor PM2.5 (mean = 53 μg m-3) exceeded limit of 25 μg m-3, for PM10 (mean = 57 μg m-3) 41% of homes demonstrated average levels higher than 50 μg m-3, thus indicating potential risks. Indoor PM10 was mostly (82-99%) composed of PM2.5, both PM were highly correlated (|rs|>0.9655), thus suggesting the similar origin. Indoor PM originated from infiltrations of outdoor emissions; ∼70% of homes exhibited indoor to outdoor (I/O) ratio < 1. On the contrary, UFP indoors (mean = 13.3 × 103 # cm-3) were higher than outdoors (mean = 10.0 × 103 # cm-3). Indoor UFP spatially varied as follows: kitchens > living rooms > bedrooms. UFP indoors were poorly correlated (|rs| = 0.456) with outdoor concentrations, I/O ratios showed that indoor UFP predominantly originated from indoor emission sources (combustions). Therefore, in order to reduce exposure to UFP and protect public health, the primary concerns should be focused on controlling emissions from indoor sources.
- Assessment of indoor air exposure at residential homes: Inhalation dose and lung deposition of PM10, PM2.5 and ultrafine particles among newborn children and their mothersPublication . Madureira, Joana; Slezakova, Klara; Silva, Ana Inês; Lage, Bruna; Mendes, Ana; Aguiar, Lívia; Pereira, Maria Carmo; Teixeira, João Paulo; Costa, CarlaAccurate assessment of particulate matter (PM) dose and respiratory deposition is essential to better understand the risks of exposure to PM and, consequently, to develop the respective risk-control strategies. In homes, this is especially relevant in regards to ultrafine particles (UFP; <0.1 μm) which origin in these environments is mostly due to indoor sources. Thus, this study aimed to estimate inhalation doses for different PM mass/number size fractions (i.e., PM10, PM2.5 and UFP) in indoor air of residential homes and to quantify the deposition (total, regional and lobar) in human respiratory tract for both newborn children and mothers. Indoor real-time measurements of PM10, PM2.5 and UFP were conducted in 65 residential homes situated in Oporto metropolitan area (Portugal). Inhalation doses were estimated based on the physical characteristics of individual subjects and their activity patterns. The multi-path particle dosimetry model was used to quantify age-specific depositions in human respiratory tract. The results showed that 3-month old infants exhibited 4-fold higher inhalation doses than their mothers. PM10 were primarily deposited in the head region (87%), while PM2.5 and UFP depositions mainly occurred in the pulmonary area (39% and 43%, respectively). Subject age affected the pulmonary region and the total lung deposition; higher deposition being observed among the newborns. Similarly, lower lobes (left lobe: 37% and right lobe: 30%) received higher PM deposition than upper and middle lobes; right lobes lung are prone to be more susceptible to respiratory problems, since asymmetric deposition was observed. Considering that PM-related diseases occur at specific sites of respiratory system, quantification of site-specific particle deposition should be predicted in order to better evidence the respective health outcomes resulting from inhaled PM.
- Baseline data and associations between urinary biomarkers of polycyclic aromatic hydrocarbons, blood pressure, hemogram, and lifestyle among wildland firefightersPublication . Barros, Bela; Paiva, Ana Margarida; Oliveira, Marta; Alves, Sara; Esteves, Filipa; Fernandes, Adília; Vaz, Josiana; Slezakova, Klara; Costa, Solange; Teixeira, João Paulo; Morais, SimoneIntroduction: Available literature has found an association between firefighting and pathologic pathways leading to cardiorespiratory diseases, which have been linked with exposure to polycyclic aromatic hydrocarbons (PAHs). PAHs are highlighted as priority pollutants by the European Human Biomonitoring Initiative in occupational and non-occupational contexts. Methods: This cross-sectional study is the first to simultaneously characterize six creatinine-adjusted PAHs metabolites (OHPAHs) in urine, blood pressure, cardiac frequency, and hemogram parameters among wildland firefighters without occupational exposure to fire emissions (> 7 days), while exploring several variables retrieved via questionnaires. Results: Overall, baseline levels for total OHPAHs levels were 2 to 23-times superior to the general population, whereas individual metabolites remained below the general population median range (except for 1-hydroxynaphthalene+1-hydroxyacenaphtene). Exposure to gaseous pollutants and/or particulate matter during work-shift was associated with a 3.5-fold increase in total OHPAHs levels. Firefighters who smoke presented 3-times higher total concentration of OHPAHs than non-smokers (p < 0.001); non-smoker females presented 2-fold lower total OHPAHs (p = 0.049) than males. 1-hydroxypyrene was below the recommended occupational biological exposure value (2.5 μg/L), and the metabolite of carcinogenic PAH (benzo(a)pyrene) was not detected. Blood pressure was above 120/80 mmHg in 71% of subjects. Firefighters from the permanent intervention team presented significantly increased systolic pressure than those who performed other functions (p = 0.034). Tobacco consumption was significantly associated with higher basophils (p = 0.01–0.02) and hematocrit (p = 0.03). No association between OHPAHs and blood pressure was found. OHPAHs concentrations were positively correlated with monocyte, basophils, large immune cells, atypical lymphocytes, and mean corpuscular volume, which were stronger among smokers. Nevertheless, inverse associations were observed between fluorene and pyrene metabolites with neutrophils and eosinophils, respectively, in non-smokers. Hemogram was negatively affected by overworking and lower physical activity. Conclusion: This study suggests possible associations between urinary PAHs metabolites and health parameters in firefighters, that should be further assessed in larger groups.
- Biomonitoring of firefighters’ exposure to priority pollutant metal(loid)s during wildland fire combat missions: Impact on urinary levels and health risksPublication . Paiva, Ana Margarida; Barros, Bela; Azevedo, Rui; Oliveira, Marta; Alves, Sara; Esteves, Filipa; Fernandes, Adília; Vaz, Josiana; Alves, Maria José; Slezakova, Klara; Pereira, Maria do Carmo; Teixeira, João Paulo; Costa, Solange; Almeida, Agostinho; Morais, SimoneWildland firefighters are exposed to metal(loid)s released during wildfires through vegetation combustion, which also promotes remobilization of accumulated anthropogenic metal(loid)s. Studies biomonitoring metal(loid)s exposure promoted exclusively by wildfire suppression activities are lacking. This work aimed to characterize, for the first time, the impact of real-life wildland firefighting operations on urinary levels of priority pollutant metal(loid)s [14 included in ATSDR, 11 in USEPA, and 4 in Human Biomonitoring for Europe Initiative priority lists] in firefighters. Spot urines were sampled pre-exposure (105 non-smokers, 76 smokers) and post-exposure to firefighting activities (20 non-smokers, 25 smokers); among those, paired samples were collected from 14 non-smoking and 24 smoking firefighters. Smokers displayed significantly higher baseline levels of zinc (28 %), lithium (29 %), cadmium (55 %), rubidium (13 %), and copper (20 %) than non-smokers. Following wildfire suppression, the concentration of the WHO potentially toxic metal(loid)s rose from 2 % to 3 % in smokers and 2 % to 5 % in non-smokers (up to 4 % for all firefighters and up to 5 % in paired samples). Levels of nickel (33-53 %), antimony (45-56 %), and cesium (40-47 %) increased significantly post-exposure in non-smokers (in all firefighters and in paired samples), whose urinary concentrations were generally more impacted by wildfire emissions than those of smokers. Arsenic (80 %) displayed the only significant increase post-exposure in smokers, being the best discriminant of exposure to wildfire emissions in these subjects. Significant positive correlations were found for age and/or career length with cadmium, lead, barium, strontium, and mercury, and for body mass index with arsenic. The reference/guidance values were exceeded for arsenic, zinc, cesium, nickel, antimony, cadmium, lead, thallium, mercury, copper, and cobalt in 1-90 % of firefighters suggesting augmented health risks due to wildfire combating and emphasizing the need of mitigation strategies. This study also provides biomonitoring data to help setting reference values for the occupationally exposed part of population.
- Children exposure to indoor ultrafine particles in urban and rural school environmentsPublication . Cavaleiro Rufo, João; Madureira, Joana; Paciência, Inês; Slezakova, Klara; Pereira, Maria do Carmo; Aguiar, Lívia; Teixeira, João Paulo; Moreira, André; Oliveira Fernandes, EduardoExtended exposure to ultrafine particles (UFPs) may lead to consequences in children due to their increased susceptibility when compared to older individuals. Since children spend in average 8 h/day in primary schools, assessing the number concentrations of UFPs in these institutions is important in order to evaluate the health risk for children in primary schools caused by indoor air pollution. Thus, the purpose of this study was to assess and determine the sources of indoor UFP number concentrations in urban and rural Portuguese primary schools. Indoor and outdoor ultrafine particle (UFP) number concentrations were measured in six urban schools (US) and two rural schools (RS) located in the north of Portugal, during the heating season. The mean number concentrations of indoor UFPs were significantly higher in urban schools than in rural ones (10.4 × 10(3) and 5.7 × 10(3) pt/cm(3), respectively). Higher UFP levels were associated with higher squared meters per student, floor levels closer to the ground, chalk boards, furniture or floor covering materials made of wood and windows with double-glazing. Indoor number concentrations of ultrafine-particles were inversely correlated with indoor CO2 levels. In the present work, indoor and outdoor concentrations of UFPs in public primary schools located in urban and rural areas were assessed, and the main sources were identified for each environment. The results not only showed that UFP pollution is present in augmented concentrations in US when compared to RS but also revealed some classroom/school characteristics that influence the concentrations of UFPs in primary schools.
- Effect of individual's characteristics on volatile organic compoounds profile analysed by an electronic nosePublication . Slezakova, Klara; Cavaleiro-Rufo, J.; Esteves, F.; Costa, D.; Pereira, M.C.; Teixeira, J.P.; Madureira, J.Breath analysis using an electronic nose (eNose) is a technology for exhaled volatile organic compounds (VOCs) that has shown potential in the diagnosis of respiratory diseases. However, the effect of an individual’s characteristics in the exhaled VOCs profile is far from fully understood. This pilot study aimed to identify the relevant characteristics of participants that may influence the VOCs profiles by the eNose. The study population consisted of 91 volunteers (57.1% males) with an average age of 38 years, randomly recruited among nonexposed individuals to VOCs in Porto, Portugal. Exhaled breath air samples were analysed using the Cyranose® 320. Physiological (e.g. height, weight) and sociodemographic characteristics, behavioural patterns, and occupational/environmental exposures were collected through a self-administered questionnaire. Other data (e.g. type of consumed food, liquids and oral hygiene) was recorded via face-to-face interviews. Results showed that exhaled VOCs profiles are influenced by water intake prior to breath sample air collection. It is suggested that individuals should abstain from drinking water for 2.5 h before VOC analysis. This work will support other ongoing research in occupational exposure scenarios, such as forest firefighters’, to further the understanding of this under-explored scientific area, since we hypothesise that VOCs patterns will differ between persons occupationally exposed to VOCs and those unexposed.
- Exposure of children to ultrafine particles in primary schools in PortugalPublication . Rufo, João Cavaleiro; Madureira, Joana; Paciência, Inês; Slezakova, Klara; Pereira, Maria do Carmo; Pereira, Cristiana; Teixeira, João Paulo; Pinto, Mariana; Moreira, André; Fernandes, Eduardo de OliveiraChildren spend a large part of their time at schools, which might be reflected as chronic exposure. Ultrafine particles (UFP) are generally associated with a more severe toxicity compared to fine and coarse particles, due to their ability to penetrate cell membranes. In addition, children tend to be more susceptible to UFP-mediated toxicity compared to adults, due to various factors including undeveloped immune and respiratory systems and inhalation rates. Thus, the purpose of this study was to determine indoor UFP number concentrations in Portuguese primary schools. Ultrafine particles were sampled between January and March 2014 in 10 public primary schools (35 classrooms) located in Porto, Portugal. Overall, the average indoor UFP number concentrations were not significantly different from outdoor concentrations (8.69 × 10(3) vs. 9.25 × 10(3) pt/cm(3), respectively; considering 6.5 h of indoor occupancy). Classrooms with distinct characteristics showed different trends of indoor UFP concentrations. The levels of carbon dioxide were negatively correlated with indoor UFP concentrations. Occupational density was significantly and positively correlated with UFP concentrations. Although the obtained results need to be interpreted with caution since there are no guidelines for UFP levels, special attention needs to be given to source control strategies in order to reduce major particle emissions and ensure good indoor air quality.
- Exposure to particulate matter in fire stations: preliminary resultsPublication . Slezakova, Klara; Esteves, Filipa; Barros, Bela; Vaz, Josiana; Alves, Maria José; Madureira, Joana; Costa, Solange; Oliveira, Marta; Fernandes, Adília; Teixeira, João Paulo; Morais, Simone; Pereira, Maria do CarmoFirefighters are at increased risk for many types of health diseases (IARC, 2010). While most of the studies on this topic focus on exposures and their impacts due to the fire combats (Oliveira et al., 2017), firefighters spend large portions of their day-by-day shift within the fire stations, where they can be exposed to a variety of air pollutants, including particulate matter (PM), i.e., a known carcinogen. This work aimed to assess the levels of particulate matter (PM) at fire stations and to investigate the possible parameters that may influence the respective levels.
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