Investigation and Health Risk Assessment of Indoor and Outdoor Nitrogen Dioxide at Preschools in Haze Areas of Lampang Province and Industrial Areas of Rayong Province, Thailand

Indoor, Outdoor, and Personal Exposure to Nitrogen Dioxide Comparing Industrial Complex Area With Country Area

Relationship between indoor and outdoor NO2: A review

Indoor nitrogen dioxide (NO₂) concentration is an important factor for personal exposure despite the wide distribution of its sources. Exposure to NO₂ may produce adverse health effects. The aims of this study were to characterize the indoor air quality of wayside shops using multiple NO₂ measurements, and to estimate the contribution of outdoor NO₂ sources such as vehicle emission to indoor air quality. Daily indoor and outdoor NO₂ concentrations were measured for 21 consecutive days in wayside shops (5 convenience stores, 5 coffee shops, and 5 restaurants). Contributions of outdoor NO₂ sources to indoor air quality were calculated with penetration factors and source strength factors by indoor mass balance model in winter and summer, respectively. Most wayside shops had significant differences in indoor and outdoor NO₂ concentrations both in winter and in summer. Indoor NO₂ concentrations in restaurants were twice more than those in convenience stores and coffee shops in winter. While outdoor NO₂ contributions in indoor convenience stores and coffee shops were dominant, indoor NO₂ contributions were dominant in restaurants. These could be explained that indoor NO₂ sources such as gas range and smoking mainly affect indoor concentrations comparing to outdoor sources such as vehicle emission. The indoor mass balance model by multiple measurements suggests that quantitative contribution of outdoor air on indoor air quality might be estimated without measurements of ventilation, indoor generation and decay rate.

Roles of pollution in the prevalence and exacerbations of allergic diseases in Asia

Continuous measurement of the dynamics of residential indoor and outdoor NO2 and the contributions to human exposure

Background and Aims: Home outdoor NO2 has been used as a marker of personal exposure to traffic-related air pollution. However, recent studies suggest that exposure to indoor NO2 may be a risk factor in itself for respiratory health and neurodevelopment. We aimed at assessing the relationship between indoor and outdoor NO2 levels and their determinants in a subset of the INMA birth cohort of Sabadell, Spain. Methods: Indoor and outdoor NO2 levels were measured with passive samplers during two measurement campaigns of one week (1st campaign in fall/winter, 2nd campaign in summer) at home addresses of 96 children. Characteristics of the home surroundings (street configuration, building density, and traffic-related variables) were obtained by the field workers and by Geographic Information Systems (GIS). Information on sources of NO2 indoor levels (gas appliances, tobacco smoke) and additional variables (e.g.use of extractor fan, air conditioning) were obtained through questionnaires in each campaign. Results: Mean levels of outdoor NO2 were 36.7 µg/m3 in fall/winter and 34 µg/m3 in summer, while mean levels of indoor NO2 were 22.8 µg/m3 in fall/winter and 26 µg/m3 in summer. The correlation between indoor and outdoor levels was lower in fall/winter (r=0.35) than in summer (r=0.51). The main determinants of outdoor NO2 were the street configuration (continuous buildings on both sides vs. other configurations) and traffic-related GIS variables. Indoor NO2 levels were influenced by tobacco smoke, time using gas cooking, time opening windows to ventilate, house age, and an interaction between outdoor NO2 levels and use of air conditioning. Conclusions: The influence of traffic-related NO2 pollution on indoor levels is higher in summer than in fall/winter, probably due to differences in ventilation patterns. Gas cooking and tobacco smoke are the main indoor sources of NO2, whereas ventilation, use of air conditioning, and house age are additional determinants.

Nitrogen dioxide is one of the most important indoor air pollutants which can be generated from sources inside the private home and is one of the criteria pollutants for which ambient air quality standards have been promulgated. Investigation of the relationship between indoor and outdoor levels of these pollutants is important for epidemiological studies on the adverse health effects of air pollutants.Simultaneous measurements were made of the concentrations of nitrogen dioxide (NO2) and nitrogen monoxide (NO) for a year at a home in Tokyo. It was seen that indoor NO levels roughly corresponded to those of outdoors over the long-term. In regard to diurnal variations, two peaks were observed, i. e., in the mornings and in the evenings, for indoor and outdoor levels of NO. The long-term and the diurnal variations of indoor NO2 levels were different from those of outdoor NO2 levels. It was shown that the relationships between indoor and outdoor NO2 concentrations varied seasonally. There was not a close correlation between the daily average of indoor NO2 concentrations and the daily maximum of hourly indoor NO2 concentrations. Thus it appears to be difficult to estimate the peak levels of indoor NO2 from daily average concentrations.

Nitrogen dioxide (NO2) is produced from the exhausts of vehicles and gas appliances and is known to pose certain health risks. In this study, we characterize the exposure to this substance during the first year of life, which is an important period of development. To this end, we used passive samplers to measure indoor and outdoor NO2 levels for 2 weeks in the homes of 352 children. To compensate for the fact that NO2 levels were measured only once in each home, a correction factor was calculated to assign each child an outdoor NO2 exposure value for the first year of life. The outdoor NO2 concentrations were 26.1 microg/m(3) while those measured indoors averaged 18.0 microg/m(3). A multivariate linear regression analysis showed that the main determinants of outdoor NO2 levels were the degree of urbanization and the frequency of vehicle traffic at the location of the residence while for indoor NO2 levels the principal determinants were the type of cooking range and water heater present in the home, the season of the year, and both the country of origin and educational level of the mother. Exposure to NO2 has been related to respiratory and other health problems among children. Precise identification of the main sources of both indoor and outdoor NO2 should shed light on appropriate intervention periods and methods. Our results indicate that while population density and traffic-related variables are the main determinants of outdoor NO2 levels, the use of gas appliances have the greatest impact on indoor levels. Strategies should thus be developed to reduce such exposure, especially with regard to reducing emissions from vehicle traffic.

Activity pattern and personal exposure to nitrogen dioxide in indoor and outdoor microenvironments

Modeling Personal and Indoor Exposure to Nitrogen Dioxide Among Adults in Eight Swiss Cities in 1993 and 2003

The study of exposure to nitrogen dioxide (NO2) is important because of its significant health effects. As it is associated with combustion processes, road traffic is one of the main outdoor sources and gas cookers and gas heaters are the main indoor sources. Indoor NO2 is a significant health problem due to people spending most of their time indoors. Activity patterns and lifestyles vary and, consequently, people may be exposed NO2 from several different sources during a typical day. In order to understand and quantify total personal exposure, it is, therefore, important to determine both the indoor and outdoor concentration levels. This thesis reports on two pilot studies, spring and summer 2000 and three full campaigns, autumn, winter 2000 and summer 2001 to investigate the relationship between NO2 personal exposure of office workers in relation to indoor and outdoor sources and activity patterns. The study has been carried out in the area of Hertfordshire, UK. This region is adjacent to London and has a population of just over one million people. It consists of several major commuter routes connecting medium sized towns to London. Volunteers using gas cookers and electric cookers in their kitchens were asked to fill in activity patterns records and questionnaires. At the same time, weekly average personal exposure to N02 and indoor (bedroom, living room, kitchen and office) and front door N02 concentrations were measured by using passive diffusion tubes. Correlation between weekly personal exposures and mean indoor and outdoor concentrations during the same periods were examined. The results show significant differences in indoor and outdoor concentrations of NO2 in autumn and winter. The data indicated that NO2 concentrations in all rooms in houses with gas cookers were significantly higher than those with electric cookers especially in kitchens where levels of NO2 were 3 to 4 times greater. Interpretation of time activity daily diaries showed that the subjects spent on average 80% of their time indoors. Despite the very high concentrations in kitchens with gas cookers, personal exposure did not increase similarly as volunteers only spent a small amount of time cooking over the 7 day period. Good correlation was observed between the average indoor NO2 concentrations, especially in bedrooms and living rooms, and personal exposure. This indicated that indoor levels in areas like the bedroom and living rooms could be used as a proxy for NO2 personal exposure for this group of volunteers. An empirical time weighted average concentration model was developed based on the NO2 concentrations measured in the microenvironments and the data on time spent in each microenvironment. This was tested by comparison between time weighted average calculations and the personal exposure measurements of NO2 concentrations. The comparison yielded good relationships for most of the campaign periods despite the fact that NO2 concentrations were not similar in the different micro environments and …

BackgroundAlthough nitrogen dioxide (NO2) is one of the most common air pollutants encountered indoors, and extensive literature has examined the link between NO2 exposure and duration causing adverse respiratory effects in susceptible populations, information about global and local exposure to NO2 in different indoor environments is limited. To synthesize the existing knowledge, this review analyzes the magnitude of and the trends in global and local exposure to NO2 in schools and offices, and the factors that control exposure. MethodsFor the literature review, Web of Science, SCOPUS, Google Scholar, and PubMed were searched using 42 search terms and their combinations to identify manuscripts, reports, and directives published between 1971 and 2019. The search was then extended to the reference lists of relevant articles. ResultsThe calculated median, as well as the mean, concentration of NO2 in school (median 21.1 μg/m3; mean 29.4 μg/m3) and office settings (median 22.7 μg/m3; mean 25.1 μg/m3) was well below the World Health Organization (WHO) guideline of 40 μg/m3 for the annual mean NO2 concentration. However, a large range of average concentrations of NO2 were reported, from 6.00 to 68.5 μg/m3 and from 3.40 to 56.5 μg/m3 for school and office environments, respectively, indicating situations where the WHO guidelines are exceeded. Outdoor levels of NO2 are a reliable predictor of indoor NO2 levels across seasons, with mean and median Indoor/Outdoor (I/O) ratios of 0.9 and 0.7 in school and 0.9 and 0.8 in office environments, respectively. The absence of major indoor NO2 emission sources and NO2 sinks, including chemical reactions and deposition, are the reasons for lower indoor NO2 concentrations. During the winter, outdoor NO2 concentrations are generally higher than during the summer. In addition, various building and indoor environment characteristics, such as type of ventilation, air exchange rates, airtightness of the envelope, furnishing and surface characteristics of the building, location of the building (urban versus suburban and proximity to traffic routes), as well as occupants' behavior (such as opening windows), have been statistically significantly associated with indoor NO2 levels in school and office environments. ConclusionsIndoor exposure to NO2 from the infiltration of ambient air can be significant in urban areas, and in the case of high traffic volume. Although reducing transportation emissions is challenging, there are several easier means to reduce indoor NO2 concentrations, including a ventilation strategy with suitable filters; location planning of new schools, classrooms, and ventilating windows or intakes; traffic planning (location and density); and reducing the use of NO2-releasing indoor sources.

Epidemiology| January 01 2001 Nitrogen Dioxide (NO2) and Respiratory Symptoms AAP Grand Rounds (2001) 5 (1): 6–7. https://doi.org/10.1542/gr.5-1-6-a Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Nitrogen Dioxide (NO2) and Respiratory Symptoms. AAP Grand Rounds January 2001; 5 (1): 6–7. https://doi.org/10.1542/gr.5-1-6-a Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: nitrogen dioxide, signs and symptoms, respiratory Source: Shima M, Adachi M. Effect of outdoor and indoor nitrogen dioxide on respiratory symptoms in schoolchildren. Int J Epidemiology. 2000;29:862–870. This is an ecologic study of the relation between nitrogen dioxide (NO2) levels and respiratory symptoms among 842 9-to-11-year-old children in 7 Japanese communities during 1992–1994. The children’s parents completed a standard respiratory questionnaire annually for 3 years. The questionnaire asked parents if their child had ever been diagnosed with asthma by a physician (2 or more episodes of wheezing accompanied by dyspnea). The authors analyzed the relationship between respiratory symptoms and both indoor levels of NO2 (measured in the children’s homes for one 24-hour period in both winter and summer) and a 3-year average of the outdoor NO2 concentration for each community. The authors found that the prevalence of bronchitis, wheezing and asthma increased with each 10 ppb (parts per billion) increase in indoor NO2 concentrations among girls (OR=1.63; 95% CI, 1.06–2.54), but not among boys. They also report that the incidence of asthma increased (OR=2.10; 95% CI, 1.10–4.75) among children living in urban areas with a high concentration of outdoor NO2. NO2 is an oxidant gas that can penetrate deep into the lungs and damage delicate lung tissues.1 Short-term exposure to concentrations as low as 100 ppb can irritate lungs and long-term exposure can destroy lung tissue, leading to emphysema. The average outdoor levels of NO2 found in the Japanese communities in this study ranged from 31.3 ppb in one urban community to 7.0 ppb in one rural community (both are well below the health-based US National Ambient Air Quality Standard for NO2 of 53 ppb). In the US between 1988 and 1997, ambient NO2 concentrations decreased 14%.2 The principal source of NO2 in outdoor air is motor vehicle emissions, but electric power plants and industrial boilers also contribute. In most US cities, annual average NO2 concentrations range from 15 ppb to 35 ppb, depending on traffic density.1 Although the authors suggest that NO2 pollution may be particularly important with respect to the development of wheezing and asthma among children, there are other possible explanations for the association they have described. Living in urban areas with high traffic density exposes children to higher outdoor NO2 levels, but they are also simultaneously exposed to crowding and higher levels of a variety of other air pollutants not measured in this study, including airborne particulates. Thus, it is safe to conclude that some factor or factors associated with urban life may be associated with increased asthma, but it may be premature to conclude from this study that NO2 plays a major role. With regard to the interesting finding that girls were more susceptible to the effects of indoor NO2 (primarily from gas stoves), there are several possible explanations. In Japan, girls may be spending more time than boys in the kitchen, resulting in higher exposures... You do not currently have access to this content.

Levels of indoor nitrogen dioxide (NO2) in a home equipped with butane gas stove and heaters are reported between the months of February and July 2003. Diffusion passive sampling was used for the simultaneous measurements of indoor and outdoor NO2 concentrations. The overall average indoor NO2 concentrations were 15.6 and 22.3 μg m-3 for the living room and kitchen, respectively, while that for outdoors was 17.9 μg m-3. In order to assess the input of indoor combustion to exchanged outdoor levels of NO2, the ratios of the living room and kitchen NO2 values to their corresponding outdoor levels were found to be higher in winter than in spring and summer. An I/O ratio as high as 2.1 detected in winter was attributed to the excess use of butane gas heaters in both the kitchen and the living room. Other sources and fates of indoor NO2 are also evaluated. This study will have significant effects on estimating health risks related to the used of butane gas heaters in residential homes.

This study examined indoor nitrogen dioxide (NO2) concentrations in Ashford, Kent (UK), Menorca Island and Barcelona city (Spain) and the contribution of their most important indoor determinants (e.g. gas combustion appliances and cigarette smoking). The homes examined (n = 1421) were those from infants recruited for the Asthma Multicentre Infants Cohort Study, which aimed to assess, using a standard protocol, the effects of pre- and post-natal environmental exposures in the inception of atopy and asthma. Indoor NO2 was measured using passive filter badges placed on a living room wall of the homes for between 7 and 15 days. Homes in the three centers had significantly different concentrations of indoor NO2, with those in Barcelona showing the highest levels (median NO2 levels: 5.79, 6.06 and 23.87 p.p.b. in Ashford, Menorca and Barcelona, respectively). Multiple regression analysis showed that the principal indoor determinants of NO2 concentrations in the three cohorts were the heating/cooking fuel used in the house (gas fire increased average NO2 concentrations by 1.27-fold and gas cooker by 2.13 times), parental cigarette smoking and season of measurement. Those variables significantly related to indoor NO(2) accounted for 23, 14 and 39% of the variation in indoor NO2 concentration in Ashford, Barcelona and Menorca, respectively. In all the cohorts combined, 52% of the variation could be explained in this way. Although outdoor NO2 was not measured concurrently, its additional contribution was estimated. In conclusion, despite differences in indoor NO2 mean concentrations probably reflecting different outdoor NO2 level, home factors affecting indoor NO2 values and their specific contributions were constant across the three cohorts. This study found that principal determinants associated to indoor NO2 in three different sites of Europe: Ashford (UK), Barcelona and Menorca (Spain) were the energy source present in the home and cigarette smoking, despite these areas presented different climates, levels of outdoor contamination, housing characteristics and ventilation behavior. It is suggested that interventions in homes of these three centers will need to address principally cigarette smoking and gas combustion appliances. These latter factors require institutional intervention, while cigarette smoking mainly require personal changes.