Objectives-To investigate the relation between traYc indicators in the area of residence and the occurrence of chronic respiratory disorders in children. Methods-A population based survey was conducted in 10 areas of northern and central Italy (autumn 1994 to winter 1995) in two age groups (6-7 and 13-14 years). Information on several respiratory disorders and on traYc near residences was collected with a questionnaire given to children and to their parents. The sample analysed included 39 275 subjects (response rate 94.4%). Outcomes were: (a) early (first 2 years of life) respiratory diseases, and (b) current respiratory disorders (asthma, wheeze, cough, or phlegm in the past year). Odds ratios (ORs) and 95% confidence intervals (95% CIs), adjusted for several potential confounders, were estimated from logistic regression models. Main results were stratified by level of urbanisation (metropolitan areas, other centres). Results-In the metropolitan areas, high frequency of lorry traYc in the street of residence was associated with significantly increased risks for many adverse respiratory outcomes. Among early respiratory diseases, the strongest associations were found for recurrent bronchitis (OR 1.69, 95% CI 1.24 to 2.30), bronchiolitis (1.74, 1.09 to 2.77) and pneumonia (1.84, 1.27 to 2.65), although no association was detected for episodes of wheezing bronchitis. All the current respiratory disorders were positively and consistently associated with frequency of lorry traYc, particularly the most severe bronchitic and wheezing symptoms: persistent phlegm for >2 months (1.68; 1.14 to 2.48), and severe wheeze limiting speech (1.86; 1.26 to 2.73). No or weaker associations with heavy vehicular traYc were detected in urban and rural areas and no increased risks were found in the whole sample with the reported traYc density in the zone of residence. After extensive evaluations, the potential of reporting bias seems unlikely. Conclusion-Exposure to exhausts from heavy vehicular traYc may have several adverse eVects on respiratory health of children living in metropolitan areas, increasing the occurrence of lower respiratory tract infections early in life and of wheezing and bronchitic symptoms at school age. (Occup Environ Med 1998;55:771-778)

Wheezing in childhood is not a single disorder and different wheezing-associated respiratory illnesses have been recently described. We investigated the association between wheezing conditions and familial, pre-, peri-, and postnatal risk factors. We studied 16,333 children, 6 to 7 yr old, enrolled in a population-based study. Standardized questionnaires were filled in by parents. A total of 1,221 children had transient early wheezing, 671 had persistent wheezing, 918 had late-onset wheezing, and 13,523 never had wheezing or asthma (control group). Maternal asthma or chronic obstructive airway disease were significantly (p < 0.0001) more associated with persistent wheezing than with transient early and late-onset wheezing. The same pattern was observed for exposure to maternal smoke during pregnancy. Having a mother > 35 yr old was protective against transient early wheezing (odds ratio [OR]: 0.68, 95% confidence intervals [95% CI]: 0.53 to 0.86). Breast feeding >/= 6 mo was slightly protective against transient early wheezing (OR: 0.82, 95% CI: 0.68 to 0.97), whereas it was a moderate risk factor for late-onset wheezing (OR: 1.22, 95% CI: 0.99 to 1.50). On the contrary, having siblings and attending a day care center were both risk factors for transient early wheezing (OR: 1.41 [95% CI: 1.21 to 1.64] and 1.70 [95% CI: 1.48 to 1.96], respectively) and protective factors against wheezing of late onset (OR: 0.83 [95% CI: 0.70 to 0.97] and 0.72 [95% CI: 0.59 to 0.88]). There was a stronger (p < 0.0001) positive association between personal history of eczema or allergic rhinitis and persistent and late-onset wheezing than transient early wheezing. Our findings suggest a different contribution of risk factors to wheezing conditions in childhood.

The results indicate that the epidemiologic features of asthma and allergies in Italy are changing rapidly, although the causes are still uncertain.

Rationale: There is increasing interest in the potential influence of fetal and early life conditions on childhood wheezing. Objectives: To investigate the associations between maternal complications and procedures in pregnancy and at birth and the risk of various wheezing phenotypes in young children. Methods: We studied 15,609 children, aged 6-7 yr, enrolled in a population-based study. Standardized questionnaires were completed by the children's mothers. AT A GLANCE COMMENTARY Scientific Knowledge on the SubjectMaternal smoking in pregnancy influences lung development and is associated with wheezing in childhood; other prenatal and perinatal factors (maternal infections, obstetric conditions) have been inconclusively associated with wheezing among offspring. What This Study Adds to the FieldAn association was found between maternal hypertension, diabetes, and urinary tract infections during pregnancy and exposure to antibiotics at delivery with wheezing disorders, in particular wheezing of early onset.(1). The most studied in utero environmental influence on lung development is maternal smoking in pregnancy, which has been shown to be associated not only with wheezing in childhood (2-5) but also with a dose-related reduction in lung function in the newborn period. Fetal development seems therefore to represent a critical time of pulmonary vulnerability with respect to smoking exposure. More recently, some studies have also investigated the relationships between exposure to maternal infections in pregnancy (6-8), maternal obstetric conditions (hyperemesis, hypertension, and preeclampsia) (9-11), uterine factors (antepartum hemorrhage, preterm contractions, placental insufficiency, and uterine growth restriction) (9-11), malposition or malpresentation of the fetus (11), mode of delivery (11)(12)(13)(14)(15)(16)(17)(18), and the development of asthma among offspring. However, the findings of these studies have been inconsistent.In a report published in 1999 (19), we found associations between a number of pre-, peri-, and early postnatal factors and different wheezing phenotypes in a large multicenter crosssectional population-based study, the SIDRIA (Italian Studies of Respiratory Disorders in Childhood and the Environment) phase 1 study, an extension of the International Study on Asthma and Allergies in Childhood (ISAAC) phase 1 study (20). The enrolled children were categorized, on the basis of criteria derived from Martinez and coworkers (21), as transient early wheezers (children with wheezing in the first 2 yr of life but not at school age), persistent wheezers (children who continued to wheeze at school age), late-onset wheezers (children who did not wheeze in the first years of life but who wheezed when 6-7 yr

We confirmed an important role of prenatal exposure to maternal smoking on the induction of wheezing and asthma in offspring, particularly in the first years of life. More studies with a consistent number of subjects only exposed to smoke postnatally are needed to better investigate the harmful effects on the induction of wheezing or asthma, particularly in schoolchildren.

No abstract

Background-A beneficial eVect of fresh fruit consumption on lung function has been observed in several studies. The epidemiological evidence of the eVect on respiratory symptoms and asthma is limited. The consumption of fruit rich in vitamin C was examined in relation to wheezing and other respiratory symptoms in cross sectional and follow up studies of Italian children. Methods-Standardised respiratory questionnaires were filled in by parents of 18 737 children aged 6-7 years living in eight areas of Northern and Central Italy. The winter intake of citrus fruit and kiwi fruit by the children was categorised as less than once per week, 1-2 per week, 3-4 per week, and 5-7 per week. A subset of 4104 children from two areas was reinvestigated after one year using a second parental questionnaire to record the occurrence of wheezing symptoms over the intervening period. Results-In the cross sectional analysis, after controlling for several confounders (sex, study area, paternal education, household density, maternal smoking, paternal smoking, dampness or mould in the child's bedroom, parental asthma), intake of citrus fruit or kiwi fruit was a highly significant protective factor for wheeze in the last 12 months (odds ratio ( In the follow up study fruit intake recorded at baseline was a strong and independent predictor of all symptoms investigated except noncoryzal rhinitis. In most cases the protective eVect was evident even among children whose intake of fruit was only 1-2 times per week and no clear dose-response relationship was found. The eVect was stronger (although not significantly so (p = 0.13)) in subjects with a history of asthma; those eating fresh fruit at least once a week experienced a lower one year occurrence of wheeze (29.3%) than those eating fruit less than once per week (47.1%) (OR = 0.46, 95% CI 0.27 to 0.81). Conclusions-Although the eVect of other dietary components cannot be excluded, it is concluded that the consumption of fruit rich in vitamin C, even at a low level of intake, may reduce wheezing symptoms in childhood, especially among already susceptible individuals.

The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One showed large worldwide variations in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema, up to 10 to 20 fold between countries. Ecological analyses were undertaken with ISAAC Phase One data to explore factors that may have contributed to these variations, and are summarised and reviewed here.In ISAAC Phase One the prevalence of symptoms in the past 12 months of asthma, rhinoconjunctivitis and eczema were estimated from studies in 463,801 children aged 13 - 14 years in 155 centres in 56 countries, and in 257,800 children aged 6-7 years in 91 centres in 38 countries. Ecological analyses were undertaken between symptom prevalence and the following: Gross National Product per capita (GNP), food intake, immunisation rates, tuberculosis notifications, climatic factors, tobacco consumption, pollen, antibiotic sales, paracetamol sales, and outdoor air pollution.Symptom prevalence of all three conditions was positively associated with GNP, trans fatty acids, paracetamol, and women smoking, and inversely associated with food of plant origin, pollen, immunisations, tuberculosis notifications, air pollution, and men smoking. The magnitude of these associations was small, but consistent in direction between conditions. There were mixed associations of climate and antibiotic sales with symptom prevalence.The potential causality of these associations warrant further investigation. Factors which prevent the development of these conditions, or where there is an absence of a positive correlation at a population level may be as important from the policy viewpoint as a focus on the positive risk factors. Interventions based on small associations may have the potential for a large public health benefit.