Cyberbullying and problematic social media use: an insight into the positive role of social support in adolescents-data from the Health Behaviour in School-aged Children study in Italy.

OBJECTIVES: The global spread of electronic devices has made cyberbullying and problematic social media use (PSMU) emerging public health concerns. This study aimed to investigate the prevalence of cyberbullying and PMSU among adolescents in northwestern Italy. We also explored the association between cyberbullying and PSMU and whether this association was moderated by social support. STUDY DESIGN: Data were collected as part of the Italian 2018 Health Behaviour in School-aged Children (HBSC) study in the Piedmont region; 186 school classes participated, comprising 3022 children aged 11, 13 and 15 years. The prevalence of cyberbullying and PSMU were estimated in subgroups of age and gender. Multivariate logistic regression was used to investigate the association between cyberbullying and PSMU, before and after taking into account social support. RESULTS: Girls reported higher cyber-victimisation and PSMU than boys (9.1% vs 6.0% and 10.2% vs 6.1%, respectively), and the risk of cyber-victimisation was higher in the presence of PSMU. This risk was attenuated in the presence of social support. CONCLUSIONS: PSMU is an important driver of cyberbullying, although social support can mediate these behaviours. Public health interventions are needed to guide adolescents how to use social media appropriately and to prevent cyberbullying and the mental health problems they can provoke.

Self-reported recurrent pain and medicine use among 15-year-olds: results from the HBSC Italian study.

BACKGROUND: The prevalence of adolescent pain varies considerably across epidemiological studies, and little information is available on pain-related behaviours among adolescents, including medicine use. The aims of this study were: [1] to examine the prevalence of recurrent pain among 15-year-old adolescents in Italy; [2] to investigate the association between recurrent pain and medicine use among boys and girls; and [3] to evaluate the consistency of these associations across Regions. METHODS: The World Health Organization (WHO) collaborative International Health Behaviour in School-aged Children 2013/2014 study collected self-reported data on pain and medicine use from 13611 15-year-old adolescents in 21 Italian Regions. We used multi-level multivariate logistic regression, stratified by gender, to analyse the association between recurrent pain and medicine use for headache, stomachache, nervousness and difficulties in getting to sleep. RESULTS: On average, across all Regions, almost 45% of adolescents reported recurrent headache, more than 30% reported recurrent backache and approximately 30% reported recurrent stomachache. Although the prevalence of both pain and medicine use was much higher among girls, the association between pain and medicine use was similarly strong in adolescents of both genders. Adolescents with recurrent pain proved more likely to use medicines also for non-corresponding pain, nervousness and difficulties in getting to sleep. The association between recurrent pain and medicine use was consistent across Regions despite large inter-regional differences in the prevalence of both phenomena. CONCLUSIONS: Recurrent pain in adolescence is common nationwide. Adolescents with recurrent pain are more likely to use medicines in general. Recurrent pain and medicine use should be addressed by adolescent health policies.

Zona pellucida gene mRNA expression in human oocytes is related to oocyte maturity, zona inner layer retardance and fertilization competence.

STUDY QUESTION: Do the mRNA expression levels of zona pellucida (ZP) genes, ZP1, 2, 3 and 4 in oocyte and cumulus cells (CC) reveal relevant information on the oocyte? SUMMARY ANSWER: The ZP mRNA expression in human oocytes is related to oocyte maturity, zona inner layer (IL) retardance and fertilization capacity. WHAT IS KNOWN ALREADY: ZP structure and birefringence provide useful information on oocyte cytoplasmic maturation, developmental competence for embryonic growth, blastocyst formation and pregnancy. In order to understand the molecular basis of morphological changes in the ZP, in the current study, the polarized light microscopy (PLM) approach was combined with analysis of the expression of the genes encoding ZP1, 2, 3 and 4, both in the oocytes and in the surrounding CC. STUDY DESIGN, SIZE, DURATION: This is a retrospective study comprising 98 supernumerary human cumulus oocyte complexes (COC) [80 Metaphase II (MII), 10 Metaphase I (MI) and 8 germinal vesicle (GV)] obtained from 39 patients (median age 33.4 years, range 22-42) after controlled ovarian stimulation. PARTICIPANTS/MATERIALS, SETTING, METHODS: Single oocytes and their corresponding CC were analysed. Oocytes were examined using PLM, and quantitative RT-PCR was performed for ZP1, 2, 3 and 4 in these individual oocytes and their CC. Ephrin-B2 (EFNB2) mRNA was measured in CC as a control. Presence of ZP3 protein in CC and oocytes was investigated using immunocytochemistry. Data were analysed using one-parametric and multivariate analysis and were corrected for the potential impact of patient and cycle characteristics. MAIN RESULTS AND THE ROLE OF CHANCE: Oocytes contained ZP1/2/3 and 4 mRNA while in CC only ZP3 was quantifiable. Also ZP3 protein was detected in human CC. When comparing mature (MII) and immature oocytes (MI/GV) or their corresponding CC, ZP1/2 and 4 expression was lower in mature oocytes compared to the expression in immature oocytes (all P < 0.05) and ZP3 expression was lower in the CC of mature oocytes compared to the expression in CC of immature oocytes (P < 0.05). This coincided with a significantly smaller IL-ZP area and thickness in mature oocytes than in immature oocytes (all P < 0.05). In mature oocytes, IL-ZP retardance was significantly correlated with the expression of all four ZP mRNAs (all P < 0.05). The oocyte ZP3 expression was the main predictor of the fertilization capacity, next to IL-retardance and IL-thickness. Using stepwise regression analysis, IL-thickness combined with EFNB2 expression in CC and the patient's ovarian response resulted in a noninvasive oocyte fertilization prediction model. LARGE SCALE DATA: Not applicable. LIMITATIONS, REASONS FOR CAUTION: This is a retrospective study and the relation of oocyte mRNA levels to fertilization capacity is indirect as oocyte gene expression analysis required lysis of the oocyte. WIDER IMPLICATIONS OF THE FINDINGS: Overall relations between PLM observations, mRNA expression changes and intrinsic oocyte competence were successfully documented. As such PLM and CC gene expression are confirmed as valuable noninvasive techniques to evaluate oocyte competence. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by University of Torino, Italy, WFWG UZ-Brussel and Agentschap voor Innovatie door Wetenschap en Technologie IWT 110680, Belgium. All authors declare that their participation in the study did not involve actual or potential conflicts of interests.

Oxidative stress generation of silver nanoparticles in three bacterial genera and its relationship with the antimicrobial activity.

Oxidative stress is a condition caused by the high intracellular concentrations of reactive oxygen species (ROS) that includes superoxide anion radicals, hydroxyl radicals and hydrogen peroxide. Nanoparticles could cause rapid generation of free radicals by redox reactions. ROS can react directly with membrane lipids, proteins and DNA and are normally scavenged by antioxidants that are capable of neutralizing; however, elevated concentrations of ROS in bacterial cells can result in oxidative stress. The aim of this work was contribute to the knowledge of action mechanism of silver nanoparticles (Ag-NPs) and their relation to the generation of oxidative stress in bacteria. We demonstrated that Ag-NPs generated oxidative stress in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa mediated by the increment of ROS and this increase correlated with a better antimicrobial activity. On the other hand, we showed that the oxidative stress caused by the Ag-NPs biosynthesized was associated to a variation in the level of reactive nitrogen intermediates (RNI). Oxidative stress in bacteria can result from disruption of the electronic transport chain due to the high affinity of Ag-NPs for the cell membrane. This imbalance in the oxidative stress was evidentiated by a macromolecular oxidation at level of DNA, lipids and proteins in E. coli exposed to Ag-NPs. The formation of ROS and RNI by Ag-NPs may also be considered to explain the bacterial death.

Large randomized trial comparing transabdominal ultrasound-guided embryo transfer with a technique based on uterine length measurement before embryo transfer.

OBJECTIVE: To compare in a randomized, non-inferiority trial the embryo transfer (ET) technique based on uterine length measurement before transfer (ULMbET) with transabdominal ultrasound-guided embryo transfer (TA-UGET) in a large population of patients undergoing in-vitro fertilization (IVF). METHODS: Patients undergoing IVF with ET with cleaving fresh embryos were randomized to receive ULMbET or TA-UGET. The transfer of one to three embryos on day 2-3 of culture was performed using a soft catheter either under transabdominal ultrasound guidance (TA-UGET group) or after measurement of the uterine cavity by transvaginal ultrasound and calculation of the discharge site (ULMbET group). The primary outcome measures were clinical pregnancy rate, ongoing pregnancy rate and implantation rate, and secondary outcomes included patient discomfort during ET. RESULTS: A total of 1648 patients undergoing IVF were randomized to receive ULMbET (n = 828) or TA-UGET (n = 820) and were included in the analysis. Comparable clinical pregnancy rate (38.2% vs 38.9%), implantation rate (24.8% vs 25.2%) and ongoing pregnancy rate (33.1% vs 34.8%) were observed in ULMbET and TA-UGET groups. The discomfort intensity score and the proportion of patients with moderate-to-severe discomfort during ET were significantly higher in the TA-UGET group (2.6 vs 1.5 visual analog scale points and 19.8% vs 1.2%; P = 0.045 and P = 0.003, respectively). CONCLUSION: The ULMbET technique leads to IVF results comparable to those obtained with UGET, but is better tolerated than is TA-UGET and is technically easier to perform for a single operator. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Written versus verbal information for patients' education on healthcare-associated infections: a cross-sectional study.

In 2008, Piedmont region, Italy, recommended delivering written information on healthcare-associated infection (HCAI) to every patient admitted to hospitals. We interviewed 363 patients admitted to five hospitals to evaluate whether patients who received written information were more informed about HCAI than the other patients. We found no statistically significant difference between the two groups. We did observe that knowledge of HCAI was significantly lower among women and significantly higher among patients with higher education and those admitted to a surgical ward.

Comparative study of the electrochemical behavior and analytical applications of (bio)sensing platforms based on the use of multi-walled carbon nanotubes dispersed in different polymers.

This review present a critical comparison of the electrochemical behavior and analytical performance of glassy carbon electrodes (GCE) modified with carbon nanotubes (CNTs) dispersed in different polymers: polyethylenimine (PEI), PEI functionalized with dopamine (PEI-Do), polyhistidine (Polyhis), polylysine (Polylys), glucose oxidase (GOx) and double stranded calf-thymus DNA (dsDNA). The comparison is focused on the analysis of the influence of the sonication time, solvent, polymer/CNT ratio, and nature of the polymer on the efficiency of the dispersions and on the electrochemical behavior of the resulting modified electrodes. The results allow to conclude that an adequate selection of the polymers makes possible not only an efficient dispersion of CNTs but also, and even more important, the building of successful analytical platforms for the detection of different bioanalytes like NADH, glucose, DNA and dopamine.

The methodology of the Italian HBSC 2010 study (Health Behaviour in School-aged Children).

Italy has participated in the Health Behaviour in School-aged Children (HBSC) study since 2000. These surveys collect data every four years on the well-being and health behaviour of boys and girls aged 11, 13 and 15. Until 2007, the coordination group of the University of Turin, Siena and Padua directly sent the questionnaires to each sampled school to collect the data. The sample of about 4500 students was nationally representative. In 2008 the HBSC became part of the project "Surveys on behavioral risks in children aged 6-17 years", coordinated by the National Institute of Health (ISS) and promoted by the Ministry of Health, in collaboration with the Ministry of Education, University and Research. For the first time, in 2010, the survey was conducted by health workers in collaboration with teachers in all regions with a representative sample, not just at the national level, but also at regional level. In the 2,504 sampled schools, 77,113 students (25,079 eleven-year-old, 26,048 thirteen-year-old and 25,986 fifteen-year-old) completed an anonymous questionnaire. Knowledge of the health-related behaviour of school-aged adolescents may help monitoring and enable policies for young people to be formulated and implemented.

Spatial analysis of the distribution of endometriosis in northwestern Italy.

OBJECTIVE: The aim of this study is to estimate the incidence of endometriosis in a northwestern region of Italy. The potential sources of geographical variations in the incidence of endometriosis within the region are discussed. METHODS: The patients selected were women between 18 and 45 years of age, born and residing in Piedmont who had undergone medical or surgical treatment for endometriosis between 2000 and 2005. The data were obtained from official hospital discharge records. RESULTS: The number of women contributed to the study was 3,929. The age-standardized incidence rate of endometriosis was 81.8/100,000 patient-years (95% CI 79.1-84.2). The distribution of relative risks showed some areas with an increased rate of around 30% (southern and central Piedmont), while for other areas the disease risk was lower (southwestern Piedmont). These areas have greater exposure to environmental risk due to the presence of chemical pollutants. CONCLUSION: In order to achieve reliable data and good management of the disease, there is great need for national registers, as well as networks of excellence for the treatment of endometriosis. Our findings suggest that environmental factors may be associated with the development of the disease, but the observed results need to be cautiously interpreted in the context of ineligible biases.

Reduction of crying episodes owing to infantile colic: A randomized controlled study on the efficacy of a new infant formula.

OBJECTIVES: The aim of this study was to evaluate the efficacy on crying episodes owing to infantile colic of a new infant formula containing partially hydrolysed whey proteins, prebiotic oligosaccharides (OS), with a high beta-palmitic acid content. DESIGN: Prospective randomized controlled study. SETTING: Italy. SUBJECTS: Two hundred and sixty-seven formula-fed infants, aged less than 4 months, with infantile colic, were randomized to receive either the new infant formula (study treatment (ST)) or a standard formula and simethicone (6 mg/kg twice a day) (control treatment (CT)). A questionnaire was given to parents to evaluate for 14 days the daily number of colic episodes and crying time. RESULTS: Out of the 199 infants who completed the study, 96 were treated with the new formula and 103 were not treated. Infants receiving the new formula had a significant decrease in colic episodes after 1 week (2.47+/-1.94 at day 7 vs 5.99+/-1.84 at the study entry) compared to infants receiving the CT (3.72+/-1.98 at day 7 vs 5.41+/-1.88 at the study entry) (P < 0.0001). Also at day 14, the crying episodes were significantly different between the two groups of infants (1.76+/-1.60 in ST vs 3.32+/-2.06 in CT) (P < 0.0001). CONCLUSIONS: The use of a partially hydrolysed formula supplemented with fructo- and galacto-OS induces a reduction of crying episodes in infants with colic after 7 and 14 days when compared with a standard formula and simethicone.

Pre-pubertal onset of type 1 diabetes and appearance of retinopathy.

OBJECTIVES: It was suggested that the years of diabetes preceding puberty may not contribute to the development of retinopathy but evidence for this is conflicting. To verify the influence of pre-pubertal diabetes, we compared the correlations between prevalence of retinopathy and diabetes duration in patients who developed type 1 diabetes before and after puberty. METHODS: Six hundred and twenty-eight patients with diabetes onset at age< or =29, on insulin treatment and aged< or =60 at the time of screening for retinopathy were considered retrospectively. Pre-pubertal age was defined as 0-12 in males and 0-11 in females. Two hundred patients had developed diabetes before puberty and 428 after puberty. Screening was by ophthalmoscopy + 35 mm photography or digital photography. RESULTS: Prevalence of retinopathy was lower among patients with pre-pubertal onset and diabetes durations 10-14 and 15-19 years (p=0.006 and p=0.003, respectively) but prevalence rates became similar after 20 yrs duration. CONCLUSION: That retinopathy is infrequent and mild during childhood, is probably due to the short duration of diabetes rather than a specific protective effect of pre-puberty. After 20 years' duration, however, the prevalence of retinopathy is no longer influenced by age at onset, suggesting that, in the longer term, pre-pubertal years do contribute to the onset of retinopathy.

"Minor" feeding problems during the first months of life: effect of a partially hydrolysed milk formula containing fructo- and galacto-oligosaccharides.

BACKGROUND: Colic, regurgitation and constipation are common feeding problems in formula-fed infants that might benefit from dietary treatment. A formula containing fructo- and galacto-oligosaccharides, partially hydrolysed proteins, low levels of lactose and palmitic acid in the beta position and higher density has been tested to reduce the occurrence of these symptoms. The aim of this prospective study was to describe the effects of such a formula in infants with minor gastrointestinal disorders. METHODS: An observational prospective trial involving practising Italian paediatricians was performed. Formula fed-infants up to 90 d of age with minor gastrointestinal problems such as infantile colics and/or regurgitation and/or constipation were enrolled in the study from January 2001 to May 2001. The study was completed within 14 d of treatment. On days 1, 7 and 14 the infants were visited by the paediatricians. Parents were given a structured diary to record daily episodes of colic, regurgitation and type and number of stools. RESULTS: Of the 932 infants enrolled, 604 completed the study. Of the 214 infants with colic, 169 (79%) demonstrated a reduction in frequency of colic from 4.1 +/- 2.0 per day at the beginning of the study to 2.0 +/- 1.8 at the end of the study (I.C. 95%: 1.72-2.39; p < 0.005). A reduction in the number of episodes of colic of 1.8 per day at the beginning of the study (I.C. 95%: 1.49-2.11; p < 0.05) was recorded between day 1 and day 7, and of 0.26 (I.C. 95%: 0.15-0.37; p < 0.05) between day 7 and day 14. Of the 201 infants with regurgitation problems, 141 (70%) demonstrated a reduction of frequency of the symptoms from 4.2 +/- 2.0 per day at the beginningof the study to 2.1 +/- 2.2 at the end of the study (I.C. 95%: 1.75-2.35; p < 0.005). A reduction of 1.87 in the number of regurgitation episodes was reported between day 1 and day 7 (I.C. 95%: 1.57-2.16; p < 0.05) and of 0.18 (I.C. 95%: 0.06-0.31; p < 0.05) between day 7 and day 14. Of the 232 infants with constipation, 147 (63%) demonstrated an increase in the daily number of stools of 0.42 (I.C. 95%: 0.5-0.3; p < 0.005). An increase in stool frequency of 0.41 (I.C. 95%: 0.51-0.23; p < 0.05) was reported between day 1 and day 7, and of 0.04 (I.C. 95%: 0.22-0.14; p = ns) between day 7 and day 14. Parents' evaluation of the formula was 7.9 +/- 1.8 (score 0-10); 550 parents (91%) gave a positive judgement (score > 6). The evaluation by the paediatricians of the improvement in symptoms after the treatment was 8.2 +/- 1.5; 574 (95%) a positive effect (score > 6). CONCLUSION: This study shows that the majority of infants followed by paediatricians for minor gastrointestinal symptoms improve within 2 wk of feeding with this new formula. Further double-blind, controlled studies are needed to confirm whether the amelioration of symptoms observed in this trial is in fact due to the new formula.

Increased risk of malignant mesothelioma of the pleura after residential or domestic exposure to asbestos: a case-control study in Casale Monferrato, Italy.

The association of malignant mesothelioma (MM) and nonoccupational asbestos exposure is currently debated. Our study investigates environmental and domestic asbestos exposure in the city where the largest Italian asbestos cement (AC) factory was located. This population-based case-control study included pleural MM (histologically diagnosed) incidents in the area in 1987-1993, matched by age and sex to two controls (four if younger than 60). Diagnoses were confirmed by a panel of five pathologists. We interviewed 102 cases and 273 controls in 1993-1995, out of 116 and 330 eligible subjects. Information was checked and completed on the basis of factory and Town Office files. We adjusted analyses for occupational exposure in the AC industry. In the town there were no other relevant industrial sources of asbestos exposure. Twenty-three cases and 20 controls lived with an AC worker [odds ratio (OR) = 4.5; 95% confidence interval (CI), 1.8-11.1)]. The risk was higher for the offspring of AC workers (OR = 7.4; 95% CI, 1.9-28.1). Subjects attending grammar school in Casale also showed an increased risk (OR = 3.3; 95% CI, 1.4-7.7). Living in Casale was associated with a very high risk (after selecting out AC workers: OR = 20.6; 95% CI, 6.2-68.6), with spatial trend with increasing distance from the AC factory. The present work confirms the association of environmental asbestos exposure and pleural MM, controlling for other sources of asbestos exposure, and suggests that environmental exposure caused a greater risk than domestic exposure.

Multicentric study on malignant pleural mesothelioma and non-occupational exposure to asbestos.

Insufficient evidence exists on the risk of pleural mesothelioma from non-occupational exposure to asbestos. A population-based case-control study was carried out in six areas from Italy, Spain and Switzerland. Information was collected for 215 new histologically confirmed cases and 448 controls. A panel of industrial hygienists assessed asbestos exposure separately for occupational, domestic and environmental sources. Classification of domestic and environmental exposure was based on a complete residential history, presence and use of asbestos at home, asbestos industrial activities in the surrounding area, and their distance from the dwelling. In 53 cases and 232 controls without evidence of occupational exposure to asbestos, moderate or high probability of domestic exposure was associated with an increased risk adjusted by age and sex: odds ratio (OR) 4.81, 95% confidence interval (CI) 1.8-13.1. This corresponds to three situations: cleaning asbestos-contaminated clothes, handling asbestos material and presence of asbestos material susceptible to damage. The estimated OR for high probability of environmental exposure (living within 2000 m of asbestos mines, asbestos cement plants, asbestos textiles, shipyards, or brakes factories) was 11.5 (95% CI 3.5-38.2). Living between 2000 and 5000 m from asbestos industries or within 500 m of industries using asbestos could also be associated with an increased risk. A dose-response pattern appeared with intensity of both sources of exposure. It is suggested that low-dose exposure to asbestos at home or in the general environment carries a measurable risk of malignant pleural mesothelioma.

[Malignant Mesothelioma Registry from Piedmont. Incidence in 1990-1995]. / Il Registro dei Mesoteliomi Maligni del Piemonte. Incidenza nel periodo 1990-1995.

This paper describes methods and results of the Piedmont Malignant Mesothelioma Registry. The Registry is active since 1990 and collects all histologically confirmed incident cases of malignant mesothelioma (m.m.) occurring in the residents of Piedmont. In the period 1990-95, 346 cases of pleural m.m. (211 males and 135 females) and 41 (28 males and 13 females) of peritoneal m.m. have been observed. Amongst the inhabitants of the Local Health Authority of Casale Monferrato, where manufacturing of cement asbestos has determined serious asbestos exposures both in the work place and general environment, there have been 105 pleural m.m. and 17 peritoneal m.m. (incidence rate were 15.6 for men and 13.0 for women and 3.6 for men and 0.6 for women respectively). Leaving out the Local Health Authority (LHA) of Casale Monferrato, the annual incidence rate in Piedmont (for 10(5) person-years, age standardised on the 1981 Italian population), has been 1.0 in men and 0.6 in women for the pleural m.m. (respectively 154 and 87 cases) and 0.09 and 0.06 for peritoneal m.m. (14 and 10 cases). Possible cases of m.m. (cytological and/or x-ray diagnosis) have been searched in the file of hospital admission and discharges (SDO) in 1994-95: 46 additional cases were found, with a 25% increase in incidence rates. The analysis of incidence according to geographical aggregations (defined according to the LHA borders) has identified, besides some already known important sources of exposures, as Casale Monferrato and the LHA of Lanzo (Balangero mine), other areas with excess of incidence as the LHA's of Galliate and Caluso which show an increased incidence of pleural m.m. in men or Vercelli and Chieri with increased incidence of pleural m.m. in women. These observation deserves further analysis.

[Pediatric Tumor Registry of Piedmont. Descriptive epidemiology of malignant tumors in children in Piedmont, 1976-1994]. / Il Registro dei Tumori Infantili del Piemonte. Epidemiologia descrittiva dei tumori maligni in età pediatrica in Piemonte, 1967-1994.

Since 1967, the Childhood Cancer Registry of Piedmont measures cancer incidence and lethality among children aged 0-14 residents in the Region. Two thousand seven hundred twenty cases were recorded in the period 1967-94. Males were 55.4%. The highest frequency was observed in the age class 0-4 including 41.3% of cases. The most frequent malignancies were: Acute Lymphocytic Leukemias, CNS Tumours and Lymphomas. Incidence rates showed limited variation, both for total neoplasm and for the largest diagnostic categories. On the contrary, lethality decreased markedly: rate (per million children years) was 77.2 in 1967-69 and 59.4 in 1988-94. This trend as more evident for acute leukemias and CNS tumours. Better diagnostic techniques, anticancer and support therapies are the likely explanation for the improved prognosis. Prevalence increased, as a consequence of improved survival and curability: in the Province of Torino it increased from 62 cases per 100,000 children (age 0-14) in 1980 to 98 cases in 1994.

Road traffic and adverse respiratory effects in children. SIDRIA Collaborative Group.

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.