OBJECTIVES: To investigate the relation between traffic 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 traffic 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 traffic 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 traffic, particularly the most severe bronchitic and wheezing symptoms: persistent phelgm 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 traffic were detected in urban and rural areas and no increased risks were found in the whole sample with the reported traffic density in the zone of residence. After extensive evaluations, the potential of reporting bias seems unlikely. CONCLUSION: Exposure to exhausts from heavy vehicular traffic may have several adverse effects 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.

BACKGROUND A beneficial effect of fresh fruit consumption on lung function has been observed in several studies. The epidemiological evidence of the effect 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 (OR) = 0.66, 95% confidence intervals (CI) 0.55 to 0.78, for those eating fruit 5–7 times per week compared with less than once per week), shortness of breath with wheeze (OR = 0.68, 95% CI 0.56 to 0.84), severe wheeze (OR = 0.59, 95% CI 0.40 to 0.85), nocturnal cough (OR = 0.73, 95% CI 0.65 to 0.83), chronic cough (OR = 0.75, 95% CI 0.65 to 0.88), and non-coryzal rhinitis (OR = 0.72, 95% CI 0.63 to 0.83). In the follow up study fruit intake recorded at baseline was a strong and independent predictor of all symptoms investigated except non-coryzal rhinitis. In most cases the protective effect 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 effect 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 effect 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.

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. Rusconi F, Galassi C, Corbo GM, Forastiere F, Biggeri A, Ciccone G, Renzoni E, and the SIDRIA Collaborative Group. Risk factors for early, persistent, and late-onset wheezing in young children.

BACKGROUND. Several studies conducted during the 1990s indicated an increase in the prevalence of symptoms of asthma; more recent investigations suggest that the trend is stabilizing or may even be reversing. OBJECTIVE. We compared 2 cross-sectional surveys conducted in 1994 and 2002 in 8 areas in northern and central Italy, to evaluate prevalence changes for asthma, allergic rhinitis, and eczema. METHODS. The International Study of Asthma and Allergies in Childhood methods and questionnaires were used to investigate 6- to 7-year-old children (16115 and 11287 questionnaires completed by parents in 1994–1995 and 2002, respectively) and 13- to 14-year-old adolescents (19723 and 10267 questionnaires completed by adolescents in 1994–1995 and 2002, respectively). In each phase, the overall response rate was >90%. Prevalence changes were calculated as the absolute difference between the prevalence recorded on the 2 occasions. RESULTS. The prevalence of wheeze (past 12 months) increased slightly among children (change: 0.8%; 95% confidence interval [CI]: 0.0% to 1.6%) and was rather stable among adolescents. Symptoms of allergic rhinitis (children: change: 5.2%; 95% CI: 4.0% to 6.4%; adolescents: change: 4.1%; 95% CI: 1.9% to 6.3%) and symptoms of atopic eczema (children: change: 4.4%; 95% CI: 3.6% to 5.2%; adolescents: change: 2.1%; 95% CI: 1.2% to 3.0%) increased clearly in both age groups. There was some heterogeneity across the centers among adolescents, especially for allergic rhinitis, with larger increases seen in the 3 metropolitan areas. The changes observed paralleled profound family changes, ie, better parental education, higher rates of maternal employment, and lower rates of exposure to parental smoke. These factors, however, do not explain all of the observed changes in prevalence. CONCLUSIONS. 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. Results: Of the children, 9.5% (1,478) had transient early wheezing, 5.4% (884) had persistent wheezing, and 6.1% (948) had late-onset wheezing. Maternal hypertension or preeclampsia was associated with an increased risk of all three wheezing phenotypes (for transient early wheezing: odds ratio [OR], 1.40; 95% confidence interval [95% CI], 1.08–1.82; for persistent wheezing: OR, 1.59; 95% CI, 1.15–2.19; and for late-onset wheezing: OR, 1.47; 95% CI, 1.06–2.01). Use of antibiotics for urinary tract infections was associated with transient early wheezing (OR, 1.52; 95% CI, 1.16–2.00), whereas antibiotic administration at delivery was associated with both transient early wheezing (OR, 1.21; 95% CI, 1.01–1.46) and persistent wheezing (OR, 1.39; 95% CI, 1.10–1.75). Children who had a mother with diabetes were also more likely to have persistent wheezing (OR, 1.72; 95% CI, 0.99–3.00). Neither amniocentesis/chorionic villus sampling, nor weight gain in pregnancy, nor cesarean section was associated with the subsequent development of wheezing. Maternal asthma or atopy was not an effect modifier of the associations found. Conclusions: Some maternal complications during pregnancy and at delivery may increase the risk of developing different phenotypes of wheezing in childhood.