Perceived Air Quality Research Articles

An effective alerting strategy to facilitate occupants’ perception of indoor air quality: By alarming concentration of indoor air pollution

Previous studies have proven that it is hard for occupants to perceive concentration of indoor air pollution (IAP) and resulting indoor air quality (IAQ) on their own. Therefore, a method is needed to encourage them to turn their attention to actual IAP, in this context, alerting is thus suggested. However, previous studies pose limitations in that they failed to analyze the effects of alerting concentration of IAP on occupants' IAQ perception. To fill the research gap, this study sought to explore a proper strategy to help occupants have a clearer perception of IAQ. A one-month observational experiment was conducted on nine subjects under three scenarios with different alerting strategies. In addition, the visual distance estimation method was used to quantitatively analyze similar tendencies between the subject's perceived IAQ and concentration of IAP for each scenario. The experimental results confirmed that when an alerting notification was not sent, the occupants could not clearly perceive IAQ as the visual distance was the highest at 0.332. On the other hand, when the alerting notification whether the concentration of IAP exceeded the standard or not was sent, the occupants could perceive IAQ relatively clearly as the visual distance was reduced to 0.291 and 0.236. In conclusion, not only installing a monitoring device but also establishing proper alerting strategies on the concentration of IAP is essential to facilitate occupants' IAQ perception and protect occupants' health.

Assessment of people’s perception of air quality in Phnom Penh, the capital city of Cambodia

Air pollution is one of the regional and global ranking environmental issues, and certainly, become worthy of attention in terms of health concerns. The aims of this study are to monitor and measure particulate matter (PM2.5), as well as to study the people’s perception of air quality and their willingness to contribute to controlling air pollution in Phnom Penh. Realtime data of PM2.5 concentration was monitored from October 2018 through January 2019 by using a light-scattering sensor in downtown Chamkar Mon, Tuoll kork, and Chraoy Changva districts which were the places remarked as highly trafficked. The design questionnaire on the perception of people on air pollution and air quality was assessed through an online form called the KoboToolbox application, using simple random sampling. PM2.5 concentrations ranges from 14.879 to 33.481 µg/m3. The concentration found, is obviously above the standard level of the Environmental Protection Agency (EPA) has set. The air quality becomes deteriorated, while participants’ subjective assessment of air quality mostly has a neutral opinion. They don’t seem to take careful attention to how air quality becomes which reveals a significant difference between people’s perceptions and reality. Most participants have a negative impression greatly on vehicles. Seventy-seven and a haft percent of participants recognize vehicles as the main pollution sources followed by industrial facilities, open burning, construction sites, and BBQ restaurants by 52.50 %, 25.83 %, 24.16 %, and 5 %, respectively. Haft of the participants (50.83 %) are unaware of what is sub-degree 2000 related to air quality and noise management still, 65 % of participants give a positive attitude concerning the willingness to report air pollution cases regardless of incentive. Nearly 80 % of participants utilize social media, Facebook to perceive knowledge and related information about air. The result of the survey questionnaire in this study will be an initiative for policymakers to enhance legislative on-air quality management. However, the collective responsibility of society and individual contributors play important role in air quality control measures. Government should educate people about the peak period of air pollution in the city, by educating them on how important prevention is on the Facebook platform.

A Comparison of the Effect of Facemasks on Perceived Breathability and Air Quality during Daily Activities and Indoor Exercises

Transmission of COVID-19 occurs predominantly through respired droplets and aerosols containing the SARS-CoV-2 virus. As a solution, face masks have been used to protect against infection. Wearing face masks during indoor exercises is essential to prevent the spread of virus-containing respiratory droplets and aerosols. However, previous studies have not investigated all elements, including the users' perceived breathability (PB) and perceived air quality (PAQ) when wearing a face mask during indoor exercises. The current study aimed to assess users' perceived comfort (PC) of face masks based on assessment criteria of PB and PAQ during moderate to vigorous exercises, and compare them with those during normal daily activities. Data on PC, PB, and PAQ were collected from an online questionnaire survey from 104 participants doing regular moderate to vigorous exercises. Within-subjects comparison with self-controlled case series design was performed to compare PC, PB, and PAQ between wearing face masks during exercises and daily activities. Results showed that the degree of dissatisfaction with PC, PB, and PAQ while wearing face masks and performing indoor exercises is higher than when performing daily activities (p < 0.05). The significance of the study implies that masks comfortable for daily activities may not remain the same during moderate to vigorous exercises, especially during indoor exercises.

Overlooked Impacts of Urban Environments on the Air Quality in Naturally Ventilated Schools Amid the COVID-19 Pandemic

The density, form, and dimensions of urban morphology are important for healthy living conditions in cities, especially if they are related to the climate and air pollution. Morphology and environmental conditions determine the relationship between open and built space, the width of street spaces, the aerodynamic characteristics of wind currents, albedo, and the retention of pollutants, as well as determining the radiative exchange with the atmosphere. Studies on the COVID-19 pandemic have focused on the assumption of a possible relationship between the spread of the SARS-CoV-2 virus and the presence and concentration of airborne particulate matter (PM10 and PM2.5). This paper focuses on the research of indoor air quality (IAQ) in two schools with naturally ventilated classrooms in Ljubljana, Slovenia. The presence of particulate matter (PM2.5 and PM10) and the concentration of CO2 were studied, along with other microclimatic conditions, e.g., ambient temperature, relative humidity, air pressure, and wind conditions. These were compared and assessed via analysis of variance (ANOVA) and Duncan’s post hoc test. The main concern was to see how effective different ventilation strategies are, as well as how the openings in the classroom impact the concentrations of CO2 relative to the concentrations of PM2.5 and PM10 particles as a side effect of these ventilation strategies. The inconsistent application of recommended COVID-19 ventilation strategies suggests that IAQ in naturally ventilated classrooms is highly determined by individual perceptions of indoor air quality. The results also suggest that the IAQ is significantly affected by the schools’ urban environment; however, this is not considered within the national COVID-19 ventilation recommendations. Future ventilation guidelines for pandemics should also include the urban environment as a risk factor for inadequate IAQ, instead of focusing solely on pathogen characteristics.

Do objective and subjective traffic-related pollution, physical activity and nature exposure affect mental wellbeing? Evidence from Shenzhen, China

Urban environment (e.g. greenspaces, air pollution and traffic noise) and individuals' behaviours (e.g. physical activity) have all been associated with mental wellbeing. The large majority of studies on the influence of nature exposure on mental wellbeing assumed that multiple pathways act independently, ignoring the interactions among potential correlated pathways that engage simultaneously. The parallel mediation approach fails to explore the complex associations of combined exposure to air pollution, traffic noise and nature exposure with physical activity, which in turn affect mental wellbeing. Hence, the interest of understanding the sophisticated interactions among different pathways is warranted. We utilized structural equation modelling to simultaneously evaluate whether actual and perceived traffic-related pollution and physical activity mediate the associations between mental wellbeing and nature exposure, which was assessed by Normalized Difference Vegetation Index (NDVI), green view index (GVI), green space density and park accessibility. In summer 2022, we conducted questionnaires from 1772 adults residing in 117 neighbourhoods in Shenzhen, China. Nature exposure was positively and directly associated with mental wellbeing in the single mediator model that considered physical activity only. The indirect effects of nature exposure on mental wellbeing were observed through all pathways in all models, except through the perceived acoustic quality pathway in the serial mediation model. In addition, the percentage mediated by perceived air quality was higher than that of perceived acoustic quality. The influence of nature exposure on mental wellbeing was only for a small proportion mediated by the physical activity pathway. The associations between nature exposure and mental wellbeing were modified by individual characteristics, such as gender, age, income level and alcohol usage, but not employment status and smoking behaviour. These findings point out the importance of both objective and subjective environmental features and human behaviours on mental wellbeing, as well as the necessity of considering multiple pathways simultaneously.

Inconsistent Association between Perceived Air Quality and Self-Reported Respiratory Symptoms: A Pilot Study and Implications for Environmental Health Studies.

As public awareness of air quality issues becomes heightened, people's perception of air quality is drawing increasing academic interest. However, data about people's perceived environment need scrutiny before being used in environmental health studies. In this research, we examine the associations between people's perceptions of air quality and their self-reported respiratory health symptoms. Spearman rank correlation coefficients were estimated and the associations were tested at the 95% confidence level. Using data collected from participants in two representative communities in Hong Kong, the results indicate a weak but significant association between people's perceived air quality and their self-reported frequency of respiratory symptoms. However, there are disparities in such an association between different genders, age groups, household income levels, education levels, marital statuses, and geographic contexts. The most striking disparities are between genders and geographic contexts. Multiple significant associations were observed for male participants (correlation coefficients: 0.169~0.205, p-values: 0.021~0.049), while none was observed for female participants. Besides, multiple significant associations were observed in the old town (correlation coefficients: 0.164~0.270, p-values: 0.003~0.048), while none was observed in the new town. The results have significant implications for environmental health research using social media data, whose reliability depends on the association between people's perceived or actual environments and their health outcomes. Since inconsistent associations exist between different groups of people, researchers need to scrutinize social media data before using them in health studies.

Odor from Building Air Conditioners: Emission Characteristics, Odor Compounds and Influencing Factors

The odor generated by air conditioners is an important factor influencing the perceived air quality in buildings. In this study, different types of air conditioners and air filters were investigated to study the level of odor emission related to the operation state of the compressor, to identify the odor compounds and to analyze the cooling setpoint temperature on emitted odor intensity. Results show that the odor from constant frequency air conditioner use is periodic and stronger than that from variable frequency air conditioner use due to the different operation strategies of the compressor, which affect the evaporation of condensed water on the surface of the cooling coil. Ethyl acetate, acetic acid, 2-ethyl-1-hexanol, acetaldehyde, hexanal, nonanal, toluene and n-hexane are identified as odor compounds by Odor Active Value (OAV), Gas Chromatography/Olfactory/Mass Spectrometry (GC/O/MS) and Flavornet methods. The higher cooling setpoint temperature would lead to stronger odor, due to greater release of hydrophilic odorous compounds from condensed water. In our opinion, reducing the residual condensed water in air conditioners may be the key to control odor emission before purification.

Influencing factors of air-quality perception in China: What is constructed? What is hidden?

China is known to be widely concerned about the air quality of its major cities. Nevertheless, the factors that influence air-quality perception (AQP) are still a matter of discussion. On the basis of one idea that AQP is constructed by media contact, this study assesses the effects of quantitative approach to compare the effect of constructionism and realism on AQP, that is media contact, individualism, and health condition on AQP. Based on data of the Chinese General Social Survey (CGSS) in 2010, we build an ordered logistic regression model and introduce urban/rural dual structure and urbanization as control variables. The results show that media contact, health condition, and individualization affect AQP. The effect of media contact, however, varies depending on the media type, and the relationships between media contact and AQP change according to region when adding control variables. Health condition is significant only when it affects work and activities as well as when mental health (MH) occurs. Additionally, the function of health effect (HE) and MH on AQP only becomes obvious in some areas after adding control variables. Moreover, in most places, the effect of some individualization variables on AQP disappear after adding control variables, whereas they continue to be obvious in others. Therefore, the effect of control variables, which are urbanization level and urban/rural dual structure, is hidden. Furthermore, there is a need to pursue economic and environmental justice between developed and undeveloped areas. The study replies with the effect of constructionism and realism on AQP. And it also sheds light on both the constructed and hidden functions of media contact.

Percepcija studenata o kvalitetu vazduha - prilika za održivi gradski prevoz u univerzitetskom gradu srednje veličine na Balkanu

The way citizens perceive air quality has a huge impact on the public's willingness to contribute agendas that promote a sustainable future. Consequently, the scientific community wonders do the sudden and short-term shifts in air quality (such as one caused by the COVID-19 pandemic) have the potential to induce long-term changes in community behavior. This study is based on the interpretation and analysis of a facultative survey administered to the student population of a medium-sized university city in the Balkans. The study's goal is to identify the types and strengths of factors that influence students' perceptions of air quality. In this regard, six classification algorithms were compared in order to select the one with the best fit between students' demographics, traveling habits, and air quality perception. Individual variable influence revealed that Weekly lectures attendance and Distances students travel determine the perception of air quality more than Gender and Permanent place of residence. According to the study, potential commuting reorganization should target those living 2-4 km from the faculty building. Students who regularly attend lectures are likely to be willing to rely on better-organized public transport. Those who do not, will generally contribute the initiative once the positive effects are evident.

User’s Perception of Indoor Air Quality (IAQ) in Tall Office Buildings as the Cause of Symptoms of Sick Building Syndrome

The user’s assessment or perception of indoor air quality (IAQ) refers to an individual’s subjective assessment or perception of the quality of the air they breathe inside a particular building or space. This assessment or perception is very individual and can vary from one individual to another. This study aims to determine the IAQ felt by users of the Rectorate Building, State University of Malang, and its effect on Sick Building Syndrome (SBS) symptoms. This research is included in the quantitative research with the study population being all employees at the building, which has 215 people. The data collection technique in this study used the MM040NA questionnaire and the data analysis technique used was binary logistic regression analysis with the help of the IBM SPSS Statistics with crosstabs test. The results of this study indicate that all independent variables have no significant relationship with SBS symptoms experienced by respondents and all independent variables have a very weak correlation. In addition, from 80 respondents, 27 people (33.75%) experienced SBS and 53 people (66.25%) did not experience SBS. This shows that there is a SBS phenomenon in the building. The significance value for all independent variables is greater than the significance level value (&gt;0.05). Furthermore, based on the test criteria, it is concluded that the variable airflow, high temperature, temperature change, low temperature, stale air, dry air, odor, air electrostatics, cigarette smoke, sound level, lighting, and air pollution have approximate significance values greater than 0.05 (null hypothesis was failed to be rejected). It is concluded that those variables have no significant relationship to the dependent variable (the SBS symptoms) experienced by the respondents.

A Data-driven Causality Modeling Framework: An Empirical Study of Modeling the Effect of Indoor Air Quality Perception on Students' Cognitive Performance

In the information age, a paradigm revolution in applied data mining methods has emerged in response to the data explosion in management science research, but this artificial intelligence-based automated data-driven modeling process creates a new "big relationship" problem, where a large number of correlations obfuscate the identification of true causal relationships. In this paper, we use a causality modeling framework that combines correlation modeling and causality pruning processes. First, symbolic regression is used to model white-box correlations of human intelligence, and then spurious correlations that do not conform to causal graph theory are pruned so that ultimately causal relationships and explicit candidate models describing these relationships can be found automatically. In an empirical research problem, the framework is compared with a traditional hypothesis construction-validation process, and the results are consistent between the two. The proposed framework implements a data-driven "correlation + causation" automatic modeling capability, which will greatly improve modeling efficiency and reliability.

Thermal and draught perception in fluctuating stratified thermal environments with intermittent impinging jet ventilation

This study proposes a new integrated air supply strategy of impinging jet ventilation (IJV) and intermittent airflow to improve indoor thermal comfort. Vertical thermal stratification is created by the IJV, and a fluctuating thermal environment is created by the intermittent airflow. Three pulsating periods (3 min, 5 min, and 7 min), two supply air temperatures (18 °C and 16 °C), and four air supply velocities (1.8 m/s steady, 1.5/2.1 m/s, 0.9/2.7 m/s, and 0/3.6 m/s) were designed. In both steady and fluctuating indoor environments, fifteen college students were asked to report their perceptions of thermal sensation, thermal comfort, thermal preference, ankle air movement acceptability and preference, and perceived air quality. The results showed that pulsating airflow could lower the mean air temperature above 0.6 m and raise it below 0.6 m. Furthermore, pulsating airflow could reduce overall and local thermal sensation by up to 0.21 and 0.28 scale unit, respectively, and the thermal sensation difference between the head and the foot by up to 0.23 scale unit. While in neutral thermal conditions, the pulsating period of 3 min had the best cooling effect of the 10 cases, but the corresponding percentage of mean dissatisfied ankle draught was 4.3% higher than in the steady operation case. Draught sensation is so closely related to ankle thermal sensation that extending the pulsating periods to 5 or 7 min could reduce ankle draught risk by up to 12.3%. The perceived air quality did not differ significantly between the steady and intermittent cases. The intermittent operation of IJV was shown to have superior cooling performance in order to improve indoor thermal comfort.

Are air quality perception and PM2.5 exposure differently associated with cardiovascular and respiratory disease mortality in Brussels? Findings from a census-based study

BackgroundThere is ample evidence that air pollution increases mortality risk, but most studies are based on modelled estimates of air pollution, while the subjective perception of air quality is scarcely assessed. We aimed to compare the effects of objective and subjective exposure to air pollution on cardiorespiratory mortality in Brussels, Belgium. MethodsData consisted of the 2001 Belgian census linked to registry-based mortality data for the follow-up period 2001–2014. We included individuals aged >30 years of age residing in Brussels at baseline (2001). Air pollution exposure was assessed with objective (modelled annual mean concentrations of PM2.5 in micrograms per cubic metre, μg/m3) and subjective indicators (poor self-reported air quality perception in the census). We used Cox Proportional Hazard models with age as the underlying time scale to evaluate associations with cardiovascular disease (CVD) and respiratory disease mortality, and separately, ischaemic heart disease (IHD), cerebrovascular disease, and COPD excluding asthma mortality. We specified single- and two-exposure models and evaluated effect modification by neighbourhood unemployment rate. Results437,340 individuals were included at baseline. During follow-up (2001–2014), 22,821 (5%) individuals had died from CVDs and 8572 (2%) from respiratory diseases. In single-exposure models, PM2.5 was significantly associated with an increased risk in CVD and IHD mortality (e.g. for IHD, per 5 μg/m3 increase: Hazard Ratio, HR:1.22, 95%CI:1.08–1.37), and poor air quality perception with COPD excluding asthma mortality (HR:1.23, 95%CI:1.15–1.33). Associations remained significant in the two-exposure models, and additionally, perception was associated with respiratory disease mortality. Associations became gradually stronger with increasing neighbourhood unemployment rate [e.g. in the highest, Q3: PM2.5 and cerebrovascular disease mortality (HR:1.53, 95%CI:1.04–2.24)]. ConclusionOur findings suggest that objective and subjective exposure to air pollution increased the risk of dying from cardiovascular and respiratory diseases respectively in Brussels. These results encourage policies reducing pollution load in Brussels whilst considering socio-economic inequalities.

Critical analysis of monitoring indoor air quality in education centres

Indoor Air Quality perception in education centres has being a special concern based on their high occupancy and lack of ventilation. This study aims to present an overview of 20 relevant previous studies carried out in the last 5 years regarding monitoring and evaluating Indoor Air Quality in education centres. This analysis focuses on four specific aspects: general description of each study, ventilation typology, indicators measured and the number of locations measured. The results show that 60 % of the studies were located in an urban context, 75 % included primary schools and 75 % included naturally ventilated buildings. Indoor and outdoor was measured in 60 % of the studies. The most measured indicators were CO2 (60 %), PM2.5 (55 %), Temperature (50 %) and Relative Humidity (40 %) all indoor. In 60 % of studies were carried in more than five centres, mostly two rooms were measured and 35 % of studies placed one sensor per room. This can be a major limitation, as the monitored data may differ significantly from the actual situation. In conclusion, the greater correlations found relating to what indicators have been measured, were the ventilation typology and the location of the building, which influences what parameters and concentration can be expected.

EFFECTS OF APPLYING ALCOHOL TO DIFFERENT WOODEN SURFACES ON VOC EMISSIONS AND PERCEIVED AIR QUALITY EVALUATION

When alcohol is applied to wooden surfaces, the amount and composition of released substances and secondary products influence the perceived air environment. This study aimed to determine the effects of applying alcohol to indoor wood surfaces on volatile organic compounds emissions and perceived air quality. The perceived air quality in the room deteriorated and the odor rating decreased when cleaning work was performed indoors with 130 mL/m2 of alcohol applied to unpainted wood interior and furniture surfaces. Furthermore, the airborne concentration of acetaldehyde was detected more than the indoor guideline values.

Age differences in thermal comfort and physiological responses in thermal environments with temperature ramp

The well-being of the elderly is critical in today's aging society. However, the age difference in thermal comfort in buildings with unstable thermal environments is poorly understood. In this study, 32 gender-balanced elderly and young participants were recruited to investigate differences in thermal perceptions and physiological responses to thermal environments with temperature ramps between 34 °C and 18 °C (up and down) in a climate chamber. We found that the elderly have a time lag and smaller variation in thermal responses than the young group when air temperature changes, especially in non-neutral conditions. The elderly reported less thermal discomfort (P < 0.05) and fewer complaints of sick building syndrome (SBS) and perceived air quality (PAQ). Local thermal sensation vote (TSV) and local skin temperature (LST) results also revealed age differences in the coldest local body parts and TSV-LST relationships. The LST of the arms and head of the elderly was lower in some conditions, indicating that health risks should be considered more carefully. The elderly had significantly higher blood pressure and were more sensitive to temperature ramps than the young. Thermal perceptions and physiological responses were affected by both air temperature values and ramp direction. Linear regressions were performed to predict TSV as a function of PMV and temperature ramp rate ΔT for the elderly and young groups, respectively. Therefore, age should be considered when evaluating the thermal comfort of older adults in unstable environments.

Community perception about air pollution, willingness to pay and awareness about health risks in Chandigarh, India

Air pollution is one of the major risk factors for mortality, as per the Global Burden of Diseases. Various natural and anthropogenic sources contribute to air pollution, which makes air quality worse. Community perceptions of air pollution are crucial in deciding how people will react and whether they will accept relevant policies. Therefore, people's awareness, behavior and perception must be known to engage communities in air pollution reduction. This study aimed to determine the levels and correlations between people's perceptions of pollution and health risk before COVID-19 and during the COVID-19 period in Chandigarh. The study was conducted following the interview schedule methodology using a standard questionnaire. Univariate and air pollution hotspot analysis was conducted to assess the correlation of variables and to evaluate the spatial variation in the perceived levels. The results revealed that 79.9% of respondents were worried about the city's air quality. It was observed that 39.2% of study participants perceived that automobile emissions were the primary source of air pollution. Association of sociodemographic factors with the awareness of air pollution, health effects, and people's attitudes was also assessed. The study observed a strong correlation between people's education status and their knowledge of air pollution during the COVID-19 period (p-value = 0.064) and the pre-COVID period (p-value = 0.035). On assessing the air quality perception and respondent's happiness as a place to live, participants' happiness was found to be strongly correlated with their neighborhood as a place to live with their opinion of the air quality (p-value = 0.000). However, this correlation was insignificant during the COVID-19 period (p-value = 0.192). Respondents perceived that exposure to air pollution is related to respiratory and chest problems. A linear relationship was observed between people's willingness to improve air quality and awareness, which shows a statistically significant association (0.076 and 0.001) during the COVID-19 and pre-COVID period. People's attitudes and actions towards air pollution suggested that people are willing to pay to mitigate air pollution to enhance environmental sustainability and quality of life.

Effects of occupant behaviors on perceived dormitory air quality and sick building syndrome symptoms among female college students.

We performed a cross-sectional survey of 2143 female students in a university in Tianjin, China regarding perceived air quality (PAQ) and sick building syndrome (SBS) symptoms in the student dormitory. The prevalence of general, mucosal, and skin symptoms was 22.1%, 21.9%, and 26.3%, respectively. The three most prevalent PAQ complaints were "dry air" (48.9% often), "stuffy odor" (18.2%), and "other unpleasant odors" (5.1%), and they were significant risk factors for 11-12 out of 12 SBS symptoms (adjusted odds ratios [AOR]: 1.6-5.8). Survey data of 1471 undergraduates, whose dorms were of uniform layout and furnishing, were used to further investigate the influences of occupancy level and occupant behaviors on PAQ and SBS symptoms. Frequent use of air freshener/perfume was a significant risk factor for "dry air," less frequent room cleaning and higher occupancy density were significant risk factors for "stuffy odor," and less natural ventilation was a significant risk factor for both "stuffy odor" and "pungent odor." These factors were also significantly associated with some SBS symptoms. In particular, the use of air freshener/perfume exhibited a significant dose-response pattern with "fatigue" (sometimes: AOR 1.3; often: AOR 2.0) and with "irritated, stuffy, or runny nose" (sometimes: AOR 1.6; often: AOR 2.2).

Parental knowledge and usage of air quality in childhood asthma management.

The current United States asthma management guidelines recommend usage of the Air Quality Index (AQI) for outdoor activity modification when air pollution is high. Little is known about parental knowledge and usage of air quality including the AQI in managing childhood asthma. Forty parents (or legal guardians) of children with persistent asthma completed a questionnaire designed to assess 4 areas related to outdoor air pollution: awareness, perception, behavioral modification, and prior healthcare provider discussion. Descriptive statistics were obtained and Fisher's exact test was used for analysis of behavioral change by selected variables. Almost all parents reported awareness of air quality alerts or AQI, however, only 20% checked the AQI on the AirNow app or website. Most parents reported air pollution as a trigger (65%), yet few parents reported behavioral modification of their child's outdoor activity based on the perception of poor air quality (43%) or based on AQI or alerts (40%). Over half of parents reported a healthcare provider had ever discussed air pollution as a trigger, with few parents (23%) reporting recommendations for behavior change. Perception of air pollution as a trigger, healthcare provider discussion and recommendations, and usage of AirNow were associated with increased reported activity change. Healthcare providers should discuss outdoor air pollution during asthma management in children and should discuss AirNow as a source for AQI information and behavioral recommendations.

Exploring the impact of perceived control on thermal comfort and indoor air quality perception in schools

Perceived control, as an integral part of the psychological impact, can be considered an important factor in the adaptive thermal comfort model. With the aim of exploring the relationship between perceived control and thermal comfort and indoor air quality (IAQ) in school buildings, a three-month field study was conducted during the heating season involving 26 school classrooms in the Italian Province of Pisa. The experimental campaign was conducted by carrying out measurements of thermal and IAQ parameters. In addition to instrumental measurements, subjective analysis was carried out by collecting 859 questionnaires filled in by students concurrently with objective measurements. The study demonstrate that the thermal neutral temperatures of the occupants with and without perceived control are, respectively, 21.7 °C and 22.2 °C and that the enhancing influence of the perceived control on the thermal sensation decreases with the increase of indoor operative temperature. The study shows that the perception of IAQ by the occupants is inversely proportional to the operative temperature and CO2 concentration. Furthermore, it emerges that students with the perception of control express better subjective judgments regarding the IAQ. It is suggested to ensure environmental control in order to improve indoor comfort and decrease the energy demand for heating.