The respiratory health effects of nitrogen dioxide in children with asthma

Abstract

There is growing evidence that asthma symptoms can be aggravated or events triggered by exposure to indoor nitrogen dioxide (NO 2 ) emitted from unflued gas heating.The impact of NO 2 on the respiratory health of children with asthma was explored as a secondary analysis of a randomised community trial, involving 409 households during the winter period in 2006 (June to September).Geometric mean indoor NO 2 levels were 11.4 mg?m -3, while outdoor NO 2 levels were 7.4 mg?m -3 . Higher indoor NO 2 levels (per logged unit increase) were associated with greater daily reports of lower (mean ratio 14, 95% CI 1.12-1.16) and upper respiratory tract symptoms (mean ratio 1.03, 95% CI 1.00-1.05), more frequent cough and wheeze, and more frequent reliever use during the day, but had no effect on preventer use. Higher indoor NO 2 levels (per logged unit increase) were associated with a decrease in morning (-17.25 mL, 95% CI -27.63--6.68) and evening (-13.21, 95% CI -26.03--0.38) forced expiratory volume in 1 s readings. Outdoor NO 2 was not associated with respiratory tract symptoms, asthma symptoms, medication use or lung function measurements.These findings indicate that reducing NO 2 exposure indoors is important in improving the respiratory health of children with asthma.

Effect of indoor nitrogen dioxide on lung function in urban environment

“…4) to identify, separately for spring and winter, NO 2 levels representing a possible risk for respiratory symptoms. Our results support an association between indoor NO 2 concentration and respiratory health in adolescents: conversely, as previously reported (Gillespie-Bennett et al, 2011), no significant association with outdoor NO 2 concentration was found. In bivariate models, we found that 82% of children reporting chronic phlegm and 78% of those with wheeze in the past 12 months were exposed to higher indoor NO 2 levels.…”

“…Finally, in children presenting both a personal history of wheeze ever and an exposure to higher indoor NO 2 concentration we found a significantly lower FEF 25-75% with respect to those exposed to lower indoor NO 2 levels. This result is in agreement with a previous paper by Gillespie-Bennett et al (2011) showing the effect of indoor NO 2 exposure on asthmatic children in New Zealand. In this paper, NO 2 exposure was associated with increased frequency of respiratory tract symptoms and decreased FEV 1 .…”

“…Children spend most of their time each day in indoor environments (Klepeis et al, 2001), and it appears that exposure to higher home indoor -and not outdoor -NO 2 levels is associated with an increased frequency of respiratory symptoms and poorer respiratory function in asthmatic children (Gillespie-Bennett et al, 2011). Nevertheless, in the Mediterranean area of southern Europe, data on the effects of indoor NO 2 -measured in general population samples of indoor residential settlements in urban environments -on respiratory symptoms and pulmonary function are scanty.…”

“…Since the indoor concentration of NO 2 may be even more elevated than outdoor levels (Lee et al, 2002), there has been increased interest in recent decades in indoor NO 2 pollution, and various research programs on the health effects of indoor air quality have been developed worldwide, regarding both school (Simoni et al, 2010(Simoni et al, , 2011 and domestic (Gillespie-Bennett et al, 2011;Belanger et al, 2013) indoor environments. Children spend most of their time each day in indoor environments (Klepeis et al, 2001), and it appears that exposure to higher home indoor -and not outdoor -NO 2 levels is associated with an increased frequency of respiratory symptoms and poorer respiratory function in asthmatic children (Gillespie-Bennett et al, 2011).…”

Tumor Necrosis Factor-Alpha as Biomarkers of Exposure to Indoor Pollutants Among Primary School Children in Klang Valley

“…Epidemiological studies have reported relationships between increased ambient of indoor air pollutants including particulate matter (Turner et al, 2011;Faustini et al, 2011;Mehta et al, 2013) and NO 2 (Gillespie-Bennett et al, 2011;Meng et al, 2012) with the increase risks of respiratory tract symptoms. Other studies also correspond with the current study reported that school children in urban density communities had a significant higher prevalence of respiratory symptoms compared to those living in the rural community of low traffic exposures (Skrzypek et al, 2013;Middleton et al, 2010;Siddique et al, 2011;McCormack et al, 2009).…”