Determination of airborne nanoparticles in elderly care centers

Revisiting the atmospheric particles: Connecting lines and changing paradigms

Historically, the atmospheric particles constitute the most primitive and recent class of air pollutants. The science of atmospheric particles erupted more than a century ago covering more than four decades of size, with past few years experiencing major advancements on both theoretic and data-based observational grounds. More recently, the plausible recognition between particulate matter (PM) and the diffusion of the COVID-19 pandemic has led to the accretion of interest in particle science. With motivation from diverse particle research interests, this paper is an 'old engineer's survey' beginning with the evolution of atmospheric particles and identifies along the way many of the global instances signaling the 'size concept' of PM. A theme that runs through the narrative is a 'previously known' generational evolution of particle science to the 'newly procured' portfolio of knowledge, with important gains on the application of unmet concepts and future approaches to PM exposure and epidemiological research.

Sustainable and Active Program—Development and Application of SAVING Methodology

The SAVING project aimed to create a sustainable and active aging program to promote the transition to sustainable aging in residential structures for the elderly (RSEs), developing research activities to apply the best strategies and good practices regarding the promotion of an active, healthy, and sustainable aging regarding social, economic, environmental, and pedagogic aspects. All this innovative methodology was built on a living-lab approach applied in one RSE, that was used as a case study. The results showed that the creation of the SAVING Brigade allowed not only increased reflection and mutual learning, but also created better conditions to face uncertainties and obstacles. Moreover, the use of indicators supported the basic themes and enabled comparison with other studies, between institutions or programs. Finally, the Action Plan acted as a tool for the development of previously defined strategies. It is possible to conclude that the breadth of the concept of quality of life encompasses the physical health of the individual, their psychological state, their social relationships, their perceptions, and the relationship with the characteristics of the context in which they are inserted. Therefore, active, sustainable, and healthy aging should be the goal.

How Is Indoor Air Quality during Sleep? A Review of Field Studies

This review aimed to provide an overview of the characterisation of indoor air quality (IAQ) during the sleeping period, based only on real life conditions’ studies where, at least, one air pollutant was considered. Despite the consensual complexity of indoor air, when focusing on sleeping environments, the available scientific literature is still scarce and falls to provide a multipollutants’ characterisation of the air breathed during sleep. This review, following PRISMA’s approach, identified a total of 22 studies that provided insights of how IAQ is during the sleeping period in real life conditions. Most of studies focused on carbon dioxide (77%), followed by particles (PM2.5, PM10 and ultrafines) and only 18% of the studies focused on pollutants such as carbon monoxide, volatile organic compounds and formaldehyde. Despite the high heterogeneity between studies (regarding the geographical area, type of surrounding environments, season of the year, type of dwelling, bedrooms’ ventilation, number of occupants), several air pollutants showed exceedances of the limit values established by guidelines or legislation, indicating that an effort should be made in order to minimise human exposure to air pollutants. For instance, when considering the air quality guideline of World Health Organisation of 10 µg·m−3 for PM2.5, 86% of studies that focused this pollutant registered levels above this threshold. Considering that people spend one third of their day sleeping, exposure during this period may have a significant impact on the daily integrated human exposure, due to the higher amount of exposure time, even if this environment is characterised by lower pollutants’ levels. Improving the current knowledge of air pollutants levels during sleep in different settings, as well as in different countries, will allow to improve the accuracy of exposure assessments and will also allow to understand their main drivers and how to tackle them.

Particulate Matter Measurement Indoors: A Review of Metrics, Sensors, Needs, and Applications

Many populations spend ∼90% of their time indoors, with household particulate matter being linked to millions of premature deaths worldwide. Particulate matter is currently measured using particle mass, particle number, and particle size distribution metrics, with other metrics, such as particle surface area, likely to be of increasing importance in the future. Particulate mass is measured using gravimetric methods, tapered element oscillating microbalances, and beta attenuation instruments and is best suited to use in compliance monitoring, trend analysis, and high spatial resolution measurements. Particle number concentration is measured by condensation particle counters, optical particle counters, and diffusion chargers. Particle number measurements are best suited to source characterization, trend analysis and ultrafine particle investigations. Particle size distributions are measured by gravimetric impactors, scanning mobility particle sizers, aerodynamic particle sizers, and fast mobility particle sizers. Particle size distribution measurements are most useful in source characterization and particulate matter property investigations, but most measurement options remain expensive and intrusive. However, we are on the cusp of a revolution in indoor air quality monitoring and management. Low-cost sensors have potential to facilitate personalized information about indoor air quality (IAQ), allowing citizens to reduce exposures to PM indoors and to resolve potential dichotomies between promoting healthy IAQ and energy efficient buildings. Indeed, the low cost will put this simple technology in the hands of citizens who wish to monitor their own IAQ in the home or workplace, to inform lifestyle decisions. Low-cost sensor networks also look promising as the solution to measuring spatial distributions of PM indoors, however, there are important sensor/data quality, technological, and ethical barriers to address with this technology. An improved understanding of epidemiology is essential to identify which metrics correlate most with health effects, allowing indoor specific PM standards to be developed and to inform the future of experimental applications.

Comparison of indoor air quality during sleep in smokers and non-smokers' bedrooms: A preliminary study

People spend one third of their life sleeping, but the bedroom, as a specific micro-environment, is often neglected when assessing human exposure to air pollutants. However, exposure during sleep may be significant in the long-term to the integrated individual exposure. This study aimed to assess the exposure during sleep, focusing on a multi-pollutant approach (comfort parameters, carbon dioxide - CO₂, carbon monoxide - CO, formaldehyde (CH₂O), total volatile organic compounds (VOCs), particulate matter - PM_2.5 and PM₁₀ - and ultrafine particles, particle number concentrations - PNC - and lung deposited surface area - LDSA). For that, the air quality during sleep (in real conditions) was monitored using real-time devices in 12 bedrooms of urban (Lisbon and Vila Franca de Xira) and rural (Ponte de Sor) areas of Portugal for one night. Volunteers were smokers and non-smokers. Considering the Portuguese legislation for indoor air quality (IAQ), 67% of the bedrooms registered CO₂ levels above the limit value, while CH₂O, VOC, PM₁₀ and PM_2.5 thresholds were exceeded in 30, 100, 36, and 45% of cases, respectively. Regarding ultrafine parameters, LDSA and PNC ranged from 7.3 to 95.2 μm²/cm³ and from 0.6 to 4.8 × 10³/cm³, respectively. Even with no smoking indoors, smokers' bedrooms were found to have significant higher levels of CO, CH₂O, PM_2.5, PM₁₀ and LDSA than non-smokers' bedrooms, showing the effect of thirdhand smoke, exhalation of pollutants after smoking and infiltration on the degradation of the air quality in the bedroom. A recent new model of real-time monitor was also used for a wide set of IAQ parameters. Its performance to measure PM_2.5 and CO₂ was assessed, showing its applicability in real conditions. Although often neglected, these micro-environments should be considered in the integrated individual exposure to air pollutants and further studied. MAIN FINDINGS OF THE WORK: Several pollutants (CO₂, PM, VOCs and CH₂O) exceeded the guidelines during sleep; smokers are exposed to higher levels of CO, CH₂O, PM, and LDSA than non-smokers while sleeping.

Internal dose of particles in the elderly-modeling based on aerosol measurements

The paper presents an integrated methodology that combines experimental and modeling techniques and links exposure to airborne particulate matter (PM) with internal dose in the respiratory system and burden in adjacent tissues over a period of time. The methodology is used to estimate doses in the respiratory systems of elders that reside in 10 elderly care centers (ECCs) in the metropolitan area of Lisbon. Measurements of PM were performed in the ECCs and combined with a time-budget survey for the occupants. This information served as input to the first model that estimated particle doses in the different regions of the respiratory tract of the elderly, and then a second model was used to calculate particle build-up in the alveolar region, the interstitium and the hilar lymph nodes of the elders over a 5-year exposure period. It was found that in 5 years of continuous exposure to the average particle concentration measured over all ECCs, 258 mg of all particles are deposited on the surface of the alveoli of which 79.6% are cleared, 18.8% are retained in the alveolar region, 1.5% translocate to the hilar lymph nodes, and 0.1% are transferred to the interstitium.

Indoor and outdoor particulate matter in primary school classrooms with fan-assisted natural ventilation in Singapore

We conducted multiday continuous monitoring of indoor and outdoor particulate matter (PM) in classrooms with fan-assisted natural ventilation (NV) at five primary schools in Singapore. We monitored size-resolved number concentration of PM with diameter 0.3-10 μm at all schools and alveolar deposited surface area concentrations of PM with diameter 0.01-1.0 μm (SA0.01-1.0) at two schools. Results show that, during the monitoring period, schools closer to expressways and in the downtown area had 2-3 times higher outdoor PM0.3-1.0 number concentrations than schools located in suburban areas. Average indoor SA0.01-1.0 was 115-118 μm(2) cm(-3) during periods of occupancy and 72-87 μm(2) cm(-3) during unoccupied periods. There were close indoor and outdoor correlations for fine PM during both occupied and unoccupied periods (Pearson's r = 0.84-1.0) while the correlations for coarse PM were weak during the occupied periods (r = 0.13-0.74). Across all the schools, the size-resolved indoor/outdoor PM ratios (I/O ratios) were 0.81 to 1.58 and 0.61 to 0.95 during occupied and unoccupied periods, respectively, and average infiltration factors were 0.64 to 0.94. Average PM net emission rates, calculated during periods of occupancy in the classrooms, were lower than or in the lower range of emission rates reported in the literature. This study also reveals that indoor fine and submicron PM predominantly come from outdoor sources, while indoor sources associated with occupancy may be important for coarse PM even when the classrooms have high air exchange rates.

Source apportionment of indoor PM10 in Elderly Care Centre

Source contribution to atmospheric particulate matter (PM) has been exhaustively modelled. However, people spend most of their time indoors where this approach is less explored. This evidence worsens considering elders living in Elderly Care Centres, since they are more susceptible. The present study aims to investigate the PM composition and sources influencing elderly exposure. Two 2-week sampling campaigns were conducted-one during early fall (warm phase) and another throughout the winter (cold phase). PM10 were collected with two TCR-Tecora(®) samplers that were located in an Elderly Care Centre living room and in the correspondent outdoor. Chemical analysis of the particles was performed by neutron activation analysis for element characterization, by ion chromatography for the determination of water soluble ions and by a thermal optical technique for the measurement of organic and elemental carbon. Statistical analysis showed that there were no statistical differences between seasons and environments. The sum of the indoor PM10 components measured in this work explained 57 and 53 % of the total PM10 mass measured by gravimetry in warm and cold campaigns, respectively. Outdoor PM10 concentrations were significantly higher during the day than night (p value < 0.05), as well as Ca(2+), Fe, Sb and Zn. The contribution of indoor and outdoor sources was assessed by principal component analysis and showed the importance of the highways and the airport located less than 500 m from the Elderly Care Centre for both indoor and outdoor air quality.

Air quality of nursing homes and its effect on the lung health of elderly residents

In industrialized countries the elderly spend most of their time indoors. The elderly may be at a higher risk of suffering from indoor air pollution-related diseases compared to the rest of the population, because of their increased exposure to potential indoor risk factors. This editorial aims to critically analyze the recent literature regarding this important topic. Results of studies performed on the elderly living in nursing homes clearly highlight that they are at risk of respiratory health impairment, even at moderate air pollutant concentrations, particularly if they are over 80 years of age and living in poorly ventilated nursing homes. The future epidemiological research on ageing and respiratory diseases should investigate the underlying biological and physiological mechanisms, in addition to the adverse health effects of potential indoor risk factors, in order to help defining effective strategies for healthy ageing.

Estimating the inhaled dose of pollutants during indoor physical activity

BACKGROUND

It is undeniable that many benefits come from physical activity. People exercise in fitness centers to improve their health and well-being, prevent disease and to increase physical attractiveness. However, these facilities join conditions that cause poor indoor air quality. Moreover, increased inhalation rates during exercise have influence on inhaled doses of air pollution.

OBJECTIVES

This study aims to calculate the inhaled dose of air pollutants during exercise, by estimating minute ventilation of participants and measuring air pollutant concentrations in fitness centers.

METHODS

Firstly, the 20 participants performed an incremental test on a treadmill, where heart rate and minute ventilation were measured simultaneously to develop individual exponential regression equations. Secondly, heart rate was measured during fitness classes and minute ventilation was estimated based on the calculated regression coefficients. Finally, the inhaled dose of air pollutants was calculated using the estimated minute ventilation and the concentrations of the pollutants measured in a monitoring program performed in 63 fitness classes.

RESULTS

Estimated inhaled doses were higher in aerobic classes than in holistic classes. The main difference was registered for PM10 inhaled dose that presented an average ratio between aerobic and holistic classes greater than four. Minute ventilation and PM10 concentrations in aerobic classes were, on average, 2.0 times higher than in holistic classes. Results showed that inhalation of pollutants is increased during heavy exercise, demonstrating the need to maintain high indoor air quality in fitness centers.

CONCLUSIONS

This study illustrates the importance of inclusion minute ventilation data when comparing inhaled doses of air pollution between different population groups. This work has estimated for the first time the minute ventilation for different fitness classes. Also constitutes an important contribution for the assessment of inhaled dose in future studies to be performed in fitness centers.