Lung function growth in children with long-term exposure to air pollutants in Mexico City

Instituto Nacional de Salud Publica, 655 Avenida Universidad, Col. Santa Maria Ahuacatitlán, Cuernavaca, Morelos 62508, México.
American Journal of Respiratory and Critical Care Medicine (Impact Factor: 11.99). 09/2007; 176(4):377-84. DOI: 10.1164/rccm.200510-1678OC
Source: PubMed

ABSTRACT Although short-term exposure to air pollution has been associated with acute, reversible lung function decrements, the impact of long-term exposure has not been well established.
To evaluate the association between long-term exposure to ozone (O(3)), particulate matter less than 10 mum in diameter (PM(10)), and nitrogen dioxide (NO(2)) and lung function growth in Mexico City schoolchildren.
A dynamic cohort of 3,170 children aged 8 years at baseline was followed from April 23, 1996, through May 19, 1999. The children attended 39 randomly selected elementary schools located near 10 air quality monitoring stations and were visited every 6 months. Statistical analyses were performed using general linear mixed models.
After adjusting for acute exposure and other potential confounding factors, deficits in FVC and FEV(1) growth over the 3-year follow-up period were significantly associated with exposure to O(3), PM(10), and NO(2). In multipollutant models, an interquartile range (IQR) increase in mean O(3) concentration (IQR, 11.3 ppb) was associated with an annual deficit in FEV(1) of 12 ml in girls and 4 ml in boys, an IQR range (IQR, 36.4 microg/m(3)) increase in PM(10) with an annual deficit in FEV(1) of 11 ml in girls and 15 ml in boys, and an IQR range (IQR, 12.0 ppb) increase in NO(2) with an annual deficit in FEV(1) of 30 ml in girls and 25 ml in boys.
We conclude that long-term exposure to O(3), PM(10), and NO(2) is associated with a deficit in FVC and FEV(1) growth among schoolchildren living in Mexico City.

  • [Show abstract] [Hide abstract]
    ABSTRACT: A limited number of studies have reported an association between long-term exposure to ambient air pollutants and lung function growth among children, with inconclusive results. To assess the relationship between air pollutant exposure and lung function growth, and to examine potential sex differences in the susceptibility of lung function growth to air pollution. We conducted a two-year prospective cohort study of Taiwanese children aged 12 at baseline who were followed from October 1, 2007 to November 31, 2009. The study population comprised 2941 non-smoking children who completed pulmonary function tests at both baseline and follow-up surveys. We applied spatial modeling for individual-level exposure assessment to capture relevant exposures and also attempted to eliminate potential community-level confounding. The exposure parameters were annual averages and values calculated from 24-hourly PM2.5 and 8-hourly ozone (O3) concentrations, corresponding to the residential addresses over the study period. The effect estimates were presented as lung function growth deficits per interquartile range (IQR) for PM2.5 and O3. In a multiple linear mixed effect model, adjusted for confounding, growth deficits in the forced vital capacity (FVC), forced expiration volume in 1s (FEV1), and forced expiratory flow between the 25th and 75th percentiles of the FVC were associated with increased exposure to PM2.5 and O3. For example, greater exposure to PM2.5 (IQR, 17.92μg/m(3)) was associated with an annual deficit in FVC growth of 75mL in boys and 61mL in girls (p for interaction <0.05). Similar associations were found for O3. The study provides evidence that long-term exposure to PM2.5 and O3 may have a detrimental effect on the development of lung function in children. The estimated deficits were generally larger in boys, compared to girls. Copyright © 2015 Elsevier Inc. All rights reserved.
    Environmental Research 01/2015; 137C:382-390. DOI:10.1016/j.envres.2015.01.009 · 3.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Data of total suspended particulate, O3, SO2, NO, NO2, CO, methane, and non-methane hydrocarbons gathered from three monitoring stations in Baghdad City for the period from 2009 to 2012 have been analyzed. So an attempt is made to calculate the monthly quality indexes based on US EPA and UK system. Concentrations of most air pollutants in Baghdad City have shown a downward trend in recent years, but they are generally in many instances worse than natural ambient air; thus, all pollutants (except CO) fluctuated between high and below limits certified by Iraqi and international standards. The results show that the average of TSP during 2009–2012were very high, and they pose concern for Baghdad population. The SO2/CO concentration ratios were less than 1 suggesting that mobile emissions are the primary sources within the study area. It has been observed that the concentrations of the most pollutants are high in summer in comparison to the other seasons. The peak concentrations of pollutants are linked to traffic density, private generators, and chemical processes in the atmosphere. Aside from single air pollutant standards, AQI and API indices enable an additional assessment of the air quality conditions. The application of the UK system suppose low pollution with all pollutants expect TSP. Analysis of AQI values for an average of concentrations CO, NO2, SO2, and O3 are categorized as good to moderate during the study period, while the same index indicated that the TSP located within the three categories (unhealthy, very unhealthy, and hazardous).
    Environmental Monitoring and Assessment 12/2014; 187(1). DOI:10.1007/s10661-014-4203-x · 1.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Information on the long-term effects of different air pollutant levels on lung function is relatively lacking in Asia and still inconclusive in the world. Age differential effects of air pollution are not known. To assess the acute and subchronic effects of ambient air pollution on lung function and compared among children of different ages. From April to May 2011, a nationwide study was conducted on schoolchildren aged 6-15 years in 44 schools of 24 districts in Taiwan. Spirograms were obtained from 1494 non-asthmatic children. Air pollution data were retrieved from air monitoring stations within one kilometre of the schools. Using three-level hierarchical linear models, individual lung function was fitted to air pollution, with adjustments for demographics, indoor exposures, outdoor activity, and districts. Lung function changes per inter-quartile increase of the past two-months average levels of particulate matter <2.5μm (PM2.5) and ozone (12μg/m(3), 32-44 and 6.7ppb, 32-38, respectively) were -103 and -142ml on FVC, -86 and -131 on FEV1, and -102 and -188ml/s on MMEF, respectively. Lag-1-day ozone exposure was associated with decreased MMEF. In children aged 6-10, PM2.5 was associated with decreased FEV1/FVC and MMEF/FVC ratios. In children aged 6-15 years, sub-chronic exposure to ambient PM2.5 and ozone leads to reduced lung capacity, whereas acute exposure to ozone decreases mid-expiratory flow. In children aged 6-10 years, additional airway obstructive patterns in lung function may be associated with PM2.5 exposure. Copyright © 2014 Elsevier Inc. All rights reserved.
    Environmental Research 12/2014; 137C:40-48. DOI:10.1016/j.envres.2014.11.021 · 3.95 Impact Factor

Full-text (2 Sources)

Available from
May 22, 2014