Residential exposure to motor vehicle emissions and the risk of wheezing among 7-8 year-old schoolchildren: a city-wide cross-sectional study in Nicosia, Cyprus

<p>Abstract</p> <p>Background</p> <p>Several studies have reported associations between respiratory outcomes in children and a range of self-reported, administrative or geographical indicators of traffic pollution. First-time investigation into the frequency of asthmatic symptoms among 7-8 year-old Cypriot children in 1999-2000 showed increased prevalence in the capital Nicosia compared to other areas. Geographical differences on an island the size of Cyprus may reflect environmental and/or lifestyle factors. This study investigates the relationship between self-reported symptoms and residential exposure to motor vehicle emissions among Nicosia schoolchildren.</p> <p>Methods</p> <p>The addresses of children in the metropolitan area of Nicosia who participated in the original survey (N = 1,735) were geo-coded and the level of exposure of each child was assessed using distance- and emission-based indicators (i.e. estimated levels of particulate matter and nitrogen oxides emissions due to motor vehicles on main roads around the residence). Odds ratios of wheezing and asthma diagnosis in relation to levels of exposure were estimated in logistic regression models adjusting for person-based factors, co-morbidity and intra-school clustering.</p> <p>Results</p> <p>We found an increased risk of wheezing at distances less than 50 m from a main road and/or only among those experiencing the highest levels of exposure. The strongest effect estimates were observed when exposure was defined in terms of the cumulative burden at all roads around the residence. Adjusted odds ratios for current wheezing were 2.33 (95% CI 1.27, 4.30) amongst the quartile of participants exposed to the highest levels of PM at all roads 50 m of their residence and 2.14 (95% CI 1.05, 4.35) for NOx, with no effect at intermediate levels of exposure. While the direction of effect was apparent at longer distances, differences were generally not statistically significant.</p> <p>Conclusions</p> <p>Children experiencing the highest burden of emissions in Nicosia seem to be at a higher risk of reporting asthmatic symptoms. Due to the small number of children residing at close proximity to main roads and lack of evidence of risk at intermediate levels of exposure or longer distances, the observed pattern alone does not explain the generally higher prevalence observed in urban Nicosia compared to other areas.</p

The risk of respiratory symptoms near power stations among 15-17 year-old students in Cyprus, 2006-07

Paper presented at DISTRES Conference (Distributed Renewable Energy Sources in the Mediterranean region) Nicosia, Cyprus, 2009Exposure to air pollutants has been repeatedly shown to be associated with a range of adverse respiratory effects. Differences in asthma prevalence on an island the size of Cyprus may reflect such environmental factors. This study assessed the geographical distribution of self-reported asthmatic symptoms in 15-17-year old participants recorded in an ISAAC survey across Cypriot schools (N=6393). Using GIS software, circular zones were constructed around each of the three power stations on the island in increments of 5km. vidence of an increased risk among participants with regards to their community’s proximity to the source of emissions was investigated in logistic regression models before and after adjusting for person-based risk factors, co-morbidity and intradistrict correlation. Adjusted odds ratio for active asthma was 1.79 (95%CI: 1.27, 2.53) among residents in the 5km radius compared to those more than 30km away with no evidence, however, of a dose-response relationship at intermediate distances

Residential exposure to motor vehicle emissions and the risk of wheezing among 7-8 year-old schoolchildren in Nicosia, Cyprus

Presented at the International Epidemiological Association (IEA) and European Epidemiology Federation (EEF)Congress of Epidemiology, Warsaw, 2009.Background: First-time investigation into the frequency of asthmatic symptoms among Cypriot children showed increased prevalence in the capital compared to all other areas. Exposure to traffic pollutants have been repeatedly shown to be associated with a range of cardiorespiratory effects. Differences in asthma prevalence on an island the size of Cyprus may reflect such environmental factors. Objective: To investigate the association between residential exposure to traffic pollution and the risk of asthmatic symptoms within the city of Nicosia. Methods: The addresses of participating children in Nicosia were geo-coded (N = 1,735) and levels of exposure were assessed using both (a) distance-based and (b) emissions-based indicators e.g. estimated levels of traffic pollutants at all roads within a pre-defined distance around the residence. Odds ratios of self-reported symptoms in relation to exposure were estimated in logistic regression models adjusting for person-based risk factors and co-morbidity as well as intra-school clustering. Results: Up to 2-fold differences in symptoms were observed; however, increased risk seemed to concentrate at distances less than 50 m from a main road and/or only among those experiencing the highest levels of cumulative exposure. Associations persisted after adjusting for other risk factors. While the direction of effect was apparent at longer distances, differences were not statistically significant. Adjusted odds ratios for current wheezing were 2.33 (95% CI 1.27, 4.30) amongst the quartile of participants exposed to the highest levels of particulate matter (PM) at all roads 50 m of their residence and 2.14 (95% CI 1.05, 4.35) for levels of nitrogen oxides (NOx). Conclusions: Children with the highest vehicular emissions burden around their residence seem to be at higher risk of reporting symptoms. However, due to the small number of children residing at close proximity to main roads and with no evidence of effect at longer distances, this alone would not explain the generally higher prevalence observed in the urban areas in Nicosia