Publish in this journal
Journal Information
Scientific Letter
DOI: 10.1016/j.anpede.2019.04.003
Open Access
Available online 8 May 2019
Influence of meteorological factors and air pollutants on severe bronchiolitis cases in the metropolitan area of Barcelona: A pilot study
Influencia de los factores meteorológicos y contaminantes del aire en casos de bronquiolitis grave en el área metropolitana de Barcelona: estudio piloto
Visits
102
M. Esther Estebana,b, María Bote-Gonzáleza, Carme Alejandrec, Mònica Balaguerc, Iolanda Jordanc,
Corresponding author
a Sección de Zoología y Antropología Biológica, Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Facultad de Biología, Universitat de Barcelona, Grup de Recerca en Antropologia Biològica (GREAB), Barcelona, Spain
b Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
c Unidad de Cuidados Intensivos Pediátricos (UCIP), Hospital Sant Joan de Déu, Institut de Recerca Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain
This item has received
102
Visits

Under a Creative Commons license
Article information
Full Text
Bibliography
Download PDF
Statistics
Figures (1)
Tables (2)
Table 1. Total number of patients admitted to the PICU of the Hospital Sant Joan de Déu with bronchiolitis from 2011 to 2016. The clinical and demographic data correspond to patients residing in the metropolitan area of Barcelona (MAB).
Table 2. Air quality values on days with bronchiolitis cases from 2011 to 2016.
Show moreShow less
Full Text
Dear Editor:

In the metropolitan area of Barcelona, as well as in other Spanish cities, air quality is getting worse by the year. At the same time, projections of temperature and rainfall alert us to future increases in both parameters.1 In this context, studies assessing the influence of climate and air pollution in children, particularly in relation to respiratory diseases, are necessary. A recent systematic review confirmed the association between exposure to air pollutants (particulate matter with diameters >2.5μm [PM2.5] and >10μm [PM10], nitrogen dioxide [NO2] and sulfur dioxide [SO2]) and the risk of hospital admission due to bronchiolitis.2 A study conducted in primary health care centres in Madrid concluded that NO2 levels (particularly those exceeding 40μg/m3) were associated with increases in paediatric respiratory disease.3 To our knowledge, no similar studies have been done in Barcelona.

As a pilot study, we analysed data for 391 patients from the metropolitan area of Barcelona admitted with bronchiolitis to the paediatric intensive care unit of the Hospital Sant Joan de Déu (Esplugues de Llobregat) between 2011 and 2016. We used the postal code of each patient to add the monthly average temperature and humidity values to the database. We also added the value of the air quality index (“Index Català de Qualitat de l’Aire”, ICQA) 10 days before the date of admission (Barcelona City Council website: https://www.barcelona.cat/ca/; ICQA website: http://dtes.gencat.cat/icqa/?elementsComparacio=ICQA_Municipi.e=Setmana).

Using the information collected in the database, we found no differences between the years under study in the demographic and clinical characteristics of the patients (Table 1). We conducted time series analyses to identify trends in the number of bronchiolitis cases, temperature and humidity. After adjusting for the effect of seasonality, we found a significant increasing trend in the incidence of bronchiolitis and a significant decreasing trend in the temperature between 2011 and 2016 (Fig. 1). However, the values of adjusted R2 in the regression analyses were less than 10% in both cases. We found no differences in humidity between the years under study.

Table 1.

Total number of patients admitted to the PICU of the Hospital Sant Joan de Déu with bronchiolitis from 2011 to 2016. The clinical and demographic data correspond to patients residing in the metropolitan area of Barcelona (MAB).

Parcheos  Change the decimal points to commas in the Spanish version 
Total PICU admissions  Total ingresos UCIP 
P  p-valor 
Bronchiolitis cases (%)  Casos de bronquiolitis (%) 
Bronchiolitis cases MAB (%)  Casos de bronquiolitis AMB (%) 
Age in days, N  Edad en días, N 
Median  Mediana 
IQ25  P25 
IQ75  P75 
Male sex  Sexo, varón (%) 
Infection (%)  Infección 
RSV  VRS 
Otherc  Otrac 
Overinfectiond (%)  Sobreinfecciónd (%) 
Pneumonia (%)  Neumonía 
Previous bronchiolitis (%)  Bronquiolitis previa 
Relevant history (%)  Antecedentes 
None  Ninguno 
Preterm birth  Prematuridad 
Otherc  Otroc 
Hospital stay, days  Estancia hospitalaria, días 
Median  Mediana 
IQ25  P25 
IQ75  P75 
PICU stay, days  Estancia UCIP, días 
Median  Mediana 
IQ25  P25 
IQ 75  P75 
PRISMD score  Escala PRISMf 
Median  Mediana 
IQ25  P25 
IQ75  P75 
BROSJODg score  Escala BROSJODg 
Median  Mediana 
IQ25  P25 
IQ75  P75 

BROSJOD, bronchiolitis severity scale of the Hospital Sant Joan de Déu; PRISM III, Paediatric Risk Score of Mortality III; RSV, respiratory syncytial virus.

a Mann–Whitney U test; bChi square test; cOther: rhinovirus, metapneumovirus, flu, adenovirus, coronavirus, enterovirus, human bocavirus or Bordetella; dHaemophilus and Moraxella; eOther: heart disease, neurologic disease, lung disease or other diseases.

Figure 1.

Box plots of cases of bronchiolitis and temperature for each year under study. Each graph shows the adjusted R2 values of the additive models fitted in the regression analysis.

(0.1MB).

As for the relationship between bronchiolitis and air quality, we observed that the median value of the ICQA on the days with bronchiolitis cases was always within the acceptable range (medians ranging from 50 to 65) with no significant differences between years (Table 2). The median values of the global ICQA in the metropolitan area of Barcelona were similar (medians from 55 to 60) to those observed on the days with cases of bronchiolitis. The pollutant most strongly associated with bronchiolitis cases in the metropolitan area of Barcelona was NO2.

Table 2.

Air quality values on days with bronchiolitis cases from 2011 to 2016.

Parcheos  Change the decimal point from p-value to comma in the Spanish version 
P  p-valor 
ICQAa  ICQA 
Min/Max  Min/Max 
Median  Mediana 
IQ25  P25 
IQ75  P75 
a

Catalan Air Quality Index); Mann–Whitney U test.

The main limitations of this study are the substantial dispersion of cases within the metropolitan area, which posed challenges to the retrieval of environmental data. The heterogeneity found in the databases available for temperature and ICQA, with an insufficient number of weather monitoring stations in some areas and the closure of some stations from 2011 to 2016, have also limited the analyses.

Neither temperature nor pollutants seem to have had an impact on the incidence of bronchiolitis in the metropolitan area of Barcelona from 2011 to 2016. During these years, the city showed sustained pollution levels corresponding to 1.3–1.5 times the recommended limits of the WHO for NO2 and particulates.4 The fact that these pollution levels were sustained over time may explain why our study did not find an association with pollutants, as opposed to the results reported in the United States, where bronchiolitis cases were associated with high values of PM10 due to the presence of steel mills and geographical areas with episodic pollution.5,6 Although we have not detected differences in the distribution of the main pollutants between days with bronchiolitis cases and the rest of the month, it is important to underline that NO2 is the main pollutant present throughout the year in the metropolitan area of Barcelona. This pollutant has already been associated with increased paediatric respiratory disease in Madrid.3 Further studies with larger databases including recent data are needed to understand the relationship between bronchiolitis and the environment.

References
[1]
Ministerio de Medio Ambiente.
A preliminary general assessment of the impacts in Spain due to the effects of climate change.
(2005),
[2]
C. King, J. Kirkham, D. Hawcutt, I. Sinha.
The effect of outdoor air pollution on the risk of hospitalisation for bronchiolitis in infants: a systematic review.
PeerJ, 6 (2018), pp. e5352
[3]
R. Martín Martín, M. Sánchez Bayle.
Impact of air pollution in paediatric consultations in Primary Health Care: ecological study.
An Pediatr (Barc), 89 (2018), pp. 80-85
[4]
Consorci Sanitari de Barcelona.
Informe d’avaluació de la qualitat de l’aire a la Ciutat de Barcelona.
Agència de Salut Pública, (2016),
[5]
C.J. Karr, P.A. Demers, M.W. Koehoorn, C.C. Lencar, L. Tamburic, M. Brauer.
Influence of ambient air pollutant sources on clinical encounters for infant bronchiolitis.
Am J Respir Crit Care Med, 180 (2009), pp. 995-1001
[6]
P. Sheffield, A. Roy, K. Wong, L. Trasande.
Fine particulate matter pollution linked to respiratory illness in infants and increased hospital costs.
Health Aff (Millwood), 30 (2011), pp. 871-878

Please cite this article as: Esteban ME, Bote-González M, Alejandre C, Balaguer M, Jordan I. Influencia de los factores meteorológicos y contaminantes del aire en casos de bronquiolitis grave en el área metropolitana de Barcelona: estudio piloto. An Pediatr (Barc). 2019. https://doi.org/10.1016/j.anpedi.2019.01.026

Copyright © 2019. Asociación Española de Pediatría
Idiomas
Anales de Pediatría (English Edition)

Subscribe to our newsletter

Article options
Tools
es en

¿Es usted profesional sanitario apto para prescribir o dispensar medicamentos?

Are you a health professional able to prescribe or dispense drugs?

es en
Política de cookies Cookies policy
Utilizamos cookies propias y de terceros para mejorar nuestros servicios y mostrarle publicidad relacionada con sus preferencias mediante el análisis de sus hábitos de navegación. Si continua navegando, consideramos que acepta su uso. Puede cambiar la configuración u obtener más información aquí. To improve our services and products, we use "cookies" (own or third parties authorized) to show advertising related to client preferences through the analyses of navigation customer behavior. Continuing navigation will be considered as acceptance of this use. You can change the settings or obtain more information by clicking here.