P.T.B.S. Branco

The microenvironmental modelling approach to assess children's exposure to air pollution – A review

Exposures to a wide spectrum of air pollutants were associated to several effects on childrens health. Exposure assessment can be used to establish where and how air pollutants exposures occur. However, a realistic estimation of childrens exposures to air pollution is usually a great ethics challenge, especially for young children, because they cannot intentionally be exposed to contaminants and according to Helsinki declaration, they are not old enough to make a decision on their participation. Additionally, using adult surrogates introduces bias, since time-space-activity patterns are different from those of children. From all the different available approaches for exposure assessment, the microenvironmental (ME) modelling (indirect approach, where personal exposures are estimated or predicted from microenvironment measurements combined with time-activity data) seemed to be the best to assess childrens exposure to air pollution as it takes into account the varying levels of pollution to which an individual is exposed during the course of the day, it is faster and less expensive. Thus, this review aimed to explore the use of the ME modelling approach methodology to assess childrens exposure to air pollution. To meet this goal, a total of 152 articles, published since 2002, were identified and titles and abstracts were scanned for relevance. After exclusions, 26 articles were fully reviewed and main characteristics were detailed, namely: (i) study design and outcomes, including location, study population, calendar time, pollutants analysed and purpose; and (ii) data collection, including time-activity patterns (methods of collection, record time and key elements) and pollution measurements (microenvironments, methods of collection and duration and time resolution). The reviewed studies were from different parts of the world, confirming the worldwide application, and mostly cross-sectional. Longitudinal studies were also found enhancing the applicability of this approach. The application of this methodology on children is different from that on adults because of data collection, namely the methods used for collecting time-activity patterns must be different and the time-activity patterns are itself different, which leads to select different microenvironments to the data collection of pollutants concentrations. The most used methods to gather information on time-activity patterns were questionnaires and diaries, and the main microenvironments considered were home and school (indoors and outdoors). Although the ME modelling approach in studies to assess childrens exposure to air pollution is highly encouraged, a validation process is needed, due to the uncertainties associated with the application of this approach.

Particulate matter in rural and urban nursery schools in Portugal

Studies have been showing strong associations between exposures to indoor particulate matter (PM) and health effects on children. Urban and rural nursery schools have different known environmental and social differences which make their study relevant. Thus, this study aimed to evaluate indoor PM concentrations on different microenvironments of three rural nursery schools and one urban nursery school, being the only study comparing urban and rural nursery schools considering the PM1, PM2.5 and PM10 fractions (measured continuously and in terms of mass). Outdoor PM2.5 and PM10 were also obtained and I/O ratios have been determined. Indoor PM mean concentrations were higher in the urban nursery than in rural ones, which might have been related to traffic emissions. However, I/O ratios allowed concluding that the recorded concentrations depended more significantly of indoor sources. WHO guidelines and Portuguese legislation exceedances for PM2.5 and PM10 were observed mainly in the urban nursery school.

Children's exposure to indoor air in urban nurseries-part I: CO2 and comfort assessment

Indoor air quality (IAQ) in nurseries is an emerging case-study. Thus, this study, as the Part I of the larger study Childrens exposure to indoor air in urban nurseries, aimed to: i) evaluate nurseries indoor concentrations of carbon dioxide (CO2), a global IAQ indicator, in class and lunch rooms; ii) assess indoor comfort parameters-temperature (T) and relative humidity (RH); and iii) analyse them according to guidelines and references for IAQ, comfort and childrens health. Indoor continuous measurements were performed. Non-compliances with guidelines were found in comfort parameters, which could cause discomfort situations and also microbial proliferation. Exceedances in CO2 concentrations were also found and they were caused by poor ventilation and high classroom occupation. More efficient ventilation and control of comfort parameters, as well as to reduce occupation by reviewing Portuguese legislation on that matter, would certainly improve IAQ and comfort in nurseries and consequently safeguard childrens health.

Children’s Exposure to Radon in Nursery and Primary Schools

The literature proves an evident association between indoor radon exposure and lung cancer, even at low doses. This study brings a new approach to the study of children’s exposure to radon by aiming to evaluate exposure to indoor radon concentrations in nursery and primary schools from two districts in Portugal (Porto and Bragança), considering different influencing factors (occupation patterns, classroom floor level, year of the buildings’ construction and soil composition of the building site), as well as the comparison with IAQ standard values for health protection. Fifteen nursery and primary schools in the Porto and Bragança districts were considered: five nursery schools for infants and twelve for pre-schoolers (seven different buildings), as well as eight primary schools. Radon measurements were performed continuously. The measured concentrations depended on the building occupation, classroom floor level and year of the buildings’ construction. Although they were in general within the Portuguese legislation for IAQ, exceedances to international standards were found. These results point out the need of assessing indoor radon concentrations not only in primary schools, but also in nursery schools, never performed in Portugal before this study. It is important to extend the study to other microenvironments like homes, and in time to estimate the annual effective dose and to assess lifetime health risks.

Children's exposure to indoor air in urban nurseries – Part II: Gaseous pollutants' assessment

This study, Part II of the larger study Childrens exposure to indoor air in urban nurseries, aimed to: (i) evaluate nursery schools indoor concentrations of several air pollutants in class and lunch rooms; and (ii) analyse them according to guidelines and references. Indoor continuous measurements were performed, and outdoor concentrations were obtained to determine indoor/outdoor ratios. The influence of outdoor air seemed to be determinant on carbon monoxide (CO), nitrogen dioxide (NO2) and ozone (O3) indoor concentrations. The peak concentrations of formaldehyde and volatile organic compounds (VOC) registered (highest concentrations of 204 and 2320 µg m(-3) respectively), indicated the presence of specific indoor sources of these pollutants, namely materials emitting formaldehyde and products emitting VOC associated to cleaning and childrens specific activities (like paints and glues). For formaldehyde, baseline constant concentrations along the day were also found in some of the studied rooms, which enhances the importance of detailing the study of childrens short and long-term exposure to this indoor air pollutant. While CO, NO2 and O3 never exceeded the national and international reference values for IAQ and health protection, exceedances were found for formaldehyde and VOC. For this reason, a health risk assessment approach could be interesting for future research to assess childrens health risks of exposure to formaldehyde and to VOC concentrations in nursery schools. Changing cleaning schedules and materials emitting formaldehyde, and more efficient ventilation while using products emitting VOC, with the correct amount and distribution of fresh air, would decrease childrens exposure.

Asthma prevalence in Portuguese preschool children: The latest scientific evidence

http://dx.doi.org/10.1016/j.rppnen.2016.03.013 2173-5115/© 2016 Sociedade Portuguesa de Pneumologia. Published by BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) ubMed, and Google Scholar. Only studies in press or fully ublished (in English and/or Portuguese) were analyzed. lthough 8 studies were found published in the last 10 ears on the assessment of childhood asthma prevalence n Portuguese young children, only two of them focused on reschool aged children. Thus, this letter reviews those only two published papers, ne recently published3 and the other one published 5 years go,4 concerning study design, methodologies used, prevaence rates and risk factors.

Asthma prevalence and risk factors in early childhood at Northern Portugal.

Asthma is the commonest and most important chronic non-infectious disease in childhood and it has become more prevalent in recent years. There is a shortage of studies in relation to early childhood and so, as part of the INAIRCHILD project, this cross-sectional study aimed to assess the prevalence of asthma and its associated risk factors, namely demographic, environmental, psychosocial and clinical factors for infants and preschoolers living in Northern Portugal. Data concerning asthma prevalence were collected through questionnaires based on those from the International Study of Asthma and Allergies in Childhood (ISAAC-derived), the questionnaires were distributed to 1042 children attending the 17 nurseries involved in the INAIRCHILD project (10 in urban and suburban context, and 7 in rural context). The response rate was 48%. Prevalence of asthma based on symptomatology and odds ratio was calculated. Around 52% of the studied children presented at least one of the respiratory symptoms investigated (wheeze, dyspnea and cough) in the absence of upper respiratory infections. The prevalence of asthma was 10.7%, comparable to the figures for Portuguese schoolchildren (6-7 years old) reported by the national Directorate-General of Health, thus showing that an early diagnosis might be possible and helpful for the mitigation of childhood asthma. Environmental context (urban, suburban or rural), gender and family asthma history showed clear associations with asthma prevalence, namely non-rural location, male gender, and having an asthmatic parent were found to be risk factors.

Radon Levels in Nurseries and Primary Schools in Bragança District—Preliminary Assessment

Lung cancer has been associated with radon concentration even at low levels such as those found in dwellings. This study aimed to (i) determine radon diurnal variations in three nurseries and one primary school in the Bragança district (north of Portugal) and (ii) compare radon concentrations with legislated standards and assess the legislated procedures. Radon was measured in three nurseries and a primary school in a rural area with nongranite soil. Measurements were performed continuously to examine differences between occupation and nonoccupation periods. Indoor temperature and relative humidity were also measured continuously. A great variability was found in radon concentrations between the microenvironments examined. Radon concentrations surpassed by severalfold the recommended guidelines and thresholds, and excessive levels of health concern were sporadically found (361.5–753.5 Bq m−3). Thus, it is of importance to perform a national campaign on radon measurements and to reduce exposure.

Evaluation of Low-Cost Mitigation Measures Implemented to Improve Air Quality in Nursery and Primary Schools

Indoor air pollution mitigation measures are highly important due to the associated health impacts, especially on children, a risk group that spends significant time indoors. Thus, the main goal of the work here reported was the evaluation of mitigation measures implemented in nursery and primary schools to improve air quality. Continuous measurements of CO2, CO, NO2, O3, CH2O, total volatile organic compounds (VOC), PM1, PM2.5, PM10, Total Suspended Particles (TSP) and radon, as well as temperature and relative humidity were performed in two campaigns, before and after the implementation of low-cost mitigation measures. Evaluation of those mitigation measures was performed through the comparison of the concentrations measured in both campaigns. Exceedances to the values set by the national legislation and World Health Organization (WHO) were found for PM2.5, PM10, CO2 and CH2O during both indoor air quality campaigns. Temperature and relative humidity values were also above the ranges recommended by American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). In general, pollutant concentrations measured after the implementation of low-cost mitigation measures were significantly lower, mainly for CO2. However, mitigation measures were not always sufficient to decrease the pollutants’ concentrations till values considered safe to protect human health.

Gaseous pollutants on rural and urban nursery schools in Northern Portugal

Indoor air quality in nursery schools is different from other schools and this has been largely ignored, particularly in rural areas. Urban and rural nursery schools have different environmental characteristics whose knowledge needs improvement. Thus, this study aimed to evaluate continuously the concentrations of CO2, CO, NO2, O3, CH2O and total VOC in three rural nursery schools and one urban, being the only one comparing urban and rural nurseries with continuous measurements, thus considering occupation and non-occupation periods. Regarding CO2, urban nursery recorded higher concentrations (739-2328xa0mgxa0m(-3)) than rural nurseries (653-1078xa0mgxa0m(-3)). The influence of outdoor air was the main source of CO, NO2 and O3 indoor concentrations. CO and NO2 concentrations were higher in the urban nursery and O3 concentrations were higher in rural ones. CH2O and TVOC concentrations seemed to be related to internal sources, such as furniture and flooring finishing and cleaning products.