Aerobiologia 16: 35–37, 2000.© 2000Kluwer Academic Publishers. Printed in the Netherlands.

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The effects of air pollution on children

Guido Marcer1∗, Carla Gemignani1, Loredana Berardino1, Francesca Giuffreda1, Liviana DaDalt2 & Giuseppe Mastrangelo1

1Department of Occupational Health, Padua University, Italy;2Department of Children Hospital, Padua Univer-sity, Italy(∗author for correspondence, e-mail: guimar47@ux1.unipd.it; fax: +39 49 8212542; address: Istituto di Medicinadel Lavoro, via Giustininiani, 2-35128 Padova, Italy)

(Received 3 February 1999; accepted in final form 5 January 2000)

Key words:air pollution, asthma, bronchitis, bronchiolitis, children, laryngitis, ozone

Abstract

Air pollutants have been associated with a wide variety of adverse health effects in children. A description of theimpact of air pollutants on children’s health is complicated by the presence of many types of air pollution andby the variety of indicators of adverse health effects. Over the period April-September 1994, the frequency ofemergency room visits for asthma, bronchitis, laryngitis and bronchiolitis in the Paediatrics Department in Padua(Italy) has been documented and compared to outdoor concentrations of airborne particulate, sulphur dioxide(SO2), nitrogen oxides (NOx) and ozone in a case-control study. Two control groups of children affected byair pollution not related diseases (acute gastro-enteritis or cranial trauma) have been considered. Atmosphericairborne particulate, SO2, NOx and ozone concentrations were obtained from the Air Quality MonitoringNetwork of Padua. Statistical analysis was performed by multiple logistic step-wise regression. A total of 468emergency room visits were noted; 139 children suffering from respiratory symptoms and 339 controls. Thehighest pollution levels were observed for ozone, with average 24 hr – concentrations, ranging from 30 to 160mcg per cubic meter, still lower than permitted limits. No significant relationships could be found between any ofthe pollution indices and the incidence of emergency room visits for respiratory symptoms. No difference relatedto air pollutants was found between daily frequency of visits between cases and controls. Only bronchiolitis inthe age< 2 years was related to the concentrations of NO2 (p < 0.05). In conclusion, short-term exposure tomoderately high levels of photochemical air pollution did not result in clear acute respiratory adverse effects inchildren.

1. Introduction

Main health effects related to air pollution are adecrease of lung function, an increase of airway react-ivity, lung inflammation, an increase of respiratorysymptoms, and a decrease of exercise capacity. Sev-eral authors demonstrated that respiratory symptomsand hospital admission of children for acute respir-atory illness were closely associated with levels ofdifferent airborne pollutants (Wardlaw, 1993; Whiteet al., 1994; Cuijpers et al., 1995; Bates, 1995).Ozone is a major component of photochemical smog

(Hackney et al., 1975). Decrements in lung func-tion, non-productive cough and chest discomfort, andlung injury and inflammation have been demonstratedin exercising subjects at controlled ozone exposurelower than 160 mcg for several hours (Folinsbeeet al., 1988). Hospital admissions for asthma werefound to be significantly correlated with ozone levels(Girsch et al., 1967; Cody et al., 1992), in somecase lower than those given as guidelines (Bates etal., 1983). In order to investigate the impact of airpollution on children’s health, we examined the asso-ciation between hospital emergency room visits for

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Figure 1. Air pollution levels of Ozone, SO2, NOx on April–May 1994.

respiratory symptoms and sulphur dioxide, nitrogenoxides, ozone, and respirable particulate matter con-centrations in Padua over the period April–September1994.

2. Methods

2.1 Air pollution level

Information about levels of air pollutants was obtainedfrom the Air Pollution Monitoring Network of theProvince of Padua. Continuous samplers were placedin the city centre. Levels of main pollutants duringthe considered period are shown in Figure 1. Dataare expressed as average 24 hours concentrations.The highest pollution levels were observed for ozone,which concentrations ranged from 30 to 160 mcg percubic meter, still lower than permitted limits suggestedby the National Ambient Quality Standards in Italy.In the same period 1-hour concentration peaks over200 mcg were measured.

2.2 Emergency room visits

Visits for acute respiratory illness and other diseases,non-related to airborne pollution, were abstracted dur-

ing the period April–September 1994 in the paediatricemergency room of the Padua Hospital. One hun-dred thirty nine children were admitted for respiratorysymptoms (bronchial asthma, bronchitis, laryngitisand bronchiolitis and 349 for acute gastro-enteritis(n. 113) or cranial trauma (n. 226).

2.3 Statistical analysis

The multiple logistic regression “step-wise” wasemployed. The dependent variable was a dichotomicvariable having value 1 for cases and 0 for controls,while independent variables were age, gender, andthe pollutants concentrations. For each pollutant, theeffect of the level on the visiting day and on theprevious two days was analyzed separately.

3. Results

The distribution of respiratory syndromes in theexamined samples is summarized in Table 1. Bron-chial asthma and laryngitis were the most frequentsyndromes observed. The statistical analysis (logisticregression “step-wise”) was unable to demonstrate anassociation between ozone and other pollutants con-

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Table 1. Distribution of respiratory symptoms in the pae-diatric emergency room during the period April–September1994

Diagnosis n. %

Bronchial asthma 63 45.3

Acute Bronchitis 25 18.0

Bronchiolitis 7 5.0

Laryngitis 44 31.7

centrations and respiratory illness. In particular, emer-gency room visits for asthma attacks were independentof ozone levels. No relation was found between sul-phur oxide and respiratory symptoms. A significant (p< 0.05) relationship was found between such symp-toms and nitrogen oxide levels in children aged lessthan 2 years (Relative Risk 1.12, confidence limits1.03–1.22).

4. Discussion and conclusions

In our study short-term exposure to moderately highlevels of photochemical air pollution did not resultin acute respiratory adverse effects in children. Con-trolled acute single-exposure studies of patients withasthma and of patients with chronic obstructive lungdisease have failed to reveal significantly greater lungfunction changes in these groups as compared withhealthy people (Cuijpers et al., 1995; Luttmann etal., 1995). The effect of nitrogen oxide on bronchi-olitis, suggested by the significant relationship res-ulting from the statistical analysis, may be a casualassociation. In effect nitrogen oxide levels are oftenhigher indoors than outdoors.

The lack of association between respiratory symp-toms and pollutant levels may be due to the fact thatin Padua the pollution samplers are placed in critical(that is more polluted) areas. Far from the sampler theconcentration of airborne pollutants may be lower.

References

Bates D.V. and Sizto R.: 1983, Relationship between air pollut-ant levels and hospital admissions in southern Ontario.Can. J.Public Health74, 117–122.

Bates D.V.: 1995, The effects of air pollution on children.Environ.Health Perspect103, 49–53.

Cody R.P., Weisel C.P., Birnbaum G. and Lioy P.J.: 1992, Theeffect of ozone associated with summertime photochemical smogand the frequency of asthma visits to hospital emergency depart-ments.Environ. Res.58, 184–194.

Cuijpers C.E.J., Swaen G.M.H., Wesseling G., Hoek G., SturmansF. and Wouters E.F.M.: 1995, Acute respiratory effects of lowlevel summer smog in primary school children.Eur. Respir. J.8,967–975.

Folinsbee L.J., McDonnell W. and Horstman D.J.: 1988, Pulmonaryfunction and symptom responses after 6.6 hour ozone exposureto 0.12 ppm ozone with moderate exercise.JAPCA38, 28–35.

Girsch L.S., Shubin E., Dick C. and Schulaner F.A.: 1967, A studyon the epidemiology of asthma in children in Philadelphia.JAllergy 39: 347–357.

Hackney J.D., Linn W.S., Mohler J.G., Pederson E.E., Breisacher P.and Russo A.: 1975, Experimental studies on human effects ofair pollutants.Arch. Environ. Health30, 379–384.

Luttmann H., Gromping U., Kreienbrock L., Treiber-Klotzer C.and Wichmann H.E.: 1995, Cohort study of respiratory diseasesand lung function in school children in Southwest Germany.4. Inner city environment influences on respiratory diseases inMannheim.Zentralbl. Hyg. Umweltmed198, 172–189.

Wardlaw A.J.: 1993, The role of air pollution in asthma.Clin.Experim. Allergy23, 81–96.

White M.C., Etzel R.A., Wilcox W.D. and Lloyd C.: 1994, Exacer-bations of childhood asthma and ozone pollution in Atlanta.Environ. Res.65, 56–68.