Nitrogen Dioxide (NO2) and Respiratory Symptoms

Abstract

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.