[Show abstract][Hide abstract] ABSTRACT: Background
Aetiology of childhood leukaemia and childhood neoplasm is poorly understood. Information on the prevalence of risk factors in the childhood population is limited. SETIL is a population based case¿control study on childhood leukaemia, conducted with two companion studies on non-Hodgkin Lymphoma (NHL) and neuroblastoma. The study relies on questionnaire interviews and 50 Hz magnetic field (ELF-MF) indoor measurements. This paper discusses the SETIL study design and includes descriptive information.Methods
The study was carried out in 14 Italian regions (78.3% of Italian population aged 0¿10). It included leukaemia, NHL and neuroblastoma cases incident in 0¿10 year olds in 1998¿2001, registered by the Italian Association of Paediatric Haematology and Oncology (AIEOP) (accrual over 95% of estimated incidence). Two controls for each leukaemia case were randomly sampled from the Local Health Authorities rolls, matched by gender, birthdate and residence. The same controls were used in NHL and neuroblastoma studies. Parents were interviewed at home on: physical agents (ELF-MF and ionizing radiation), chemicals (smoking, solvents, traffic, insecticides), occupation, medical and personal history of children and parents, infectious diseases, immunizations and associated factors. Occupational exposure was collected using job specific modules. ELF-MF was measured in the main rooms (spot measurement) and close to child¿s bed (48 hours measurement).ResultsThe study included: 683 leukaemia cases (87% ALL, 13% AnLL), 97 NHL, 155 neuroblastomas, and 1044 controls.ELF-MF long term measurements were obtained for 61.1% of controls and 81.6% of leukaemia cases; 8.8% of controls were exposed at over 0.1 microTesla (¿T), 3.5% and 2.1% at respectively over 0.2 and 0.3 ¿T. 25% of controls¿ fathers had smoked over 10 cigarettes/day during the year of conception, varying according to education and region. Maternal smoking was less common (71.4% did not smoke in pregnancy). Maternal passive smoking during pregnancy was reported by 31.2% of controls; the child¿s passive smoking for 28.6%.Occupational exposure to solvents was estimated in 18.3% of controls¿ fathers and 7.7% of mothers. Contact with public was more frequent among mothers (36.1%) than fathers (23.4%).ConclusionsSETIL represents a data source on exposure of Italian children to a broad array of potential carcinogenic factors.
Rivista italiana di pediatria = The Italian journal of pediatrics 12/2014; 40(1):1. DOI:10.1186/s13052-014-0103-5 · 1.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Parental smoking and exposure of the mother or the child to environmental tobacco smoke (ETS) as risk factors for Acute non-Lymphocytic Leukemia (AnLL) were investigated.
PLoS ONE 11/2014; 9(11):e111028. DOI:10.1371/journal.pone.0111028 · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Neuroblastoma (NB) is the most common extra-cranial paediatric solid tumour. Incidence peaks in infancy, suggesting a role of in-utero and neonatal exposures but its aetiology is largely unknown. The aim of the present study is to evaluate the association between maternal characteristics and perinatal factors with the risk of NB, using data from the SETIL database.
Cancer Epidemiology 09/2014; 38(6). DOI:10.1016/j.canep.2014.09.007 · 2.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Tobacco smoke could cause childhood acute lymphoblastic leukemia (ALL) through at least three pathways: (1) prenatal parental smoking; (2) fetal exposure through maternal smoking during pregnancy; and (3) childhood exposure to secondhand smoke (SHS). We tested these hypotheses in a large population-based case-control study (SETIL) primarily designed to evaluate the role of electromagnetic fields in childhood hematopoietic malignancies.
From 1998 to 2003, we enrolled 602 incident cases of ALL from 14 Italian Regions, and 918 controls were individually matched by birthdate, sex, and area of residence. Cases (n = 557) and controls (n = 855) with complete information were analyzed; odds ratios (OR) and 95 % confidence intervals (95 % CI) were estimated with logistic regression models conditioned on matching variables and adjusted by birth order, birthweight, duration of breastfeeding, parental age at delivery, education, and occupational exposure to benzene.
No evidence associating paternal smoking in the conception period or maternal smoking during the pregnancy with ALL was found. An association of ALL with maternal exposure to SHS during pregnancy (adjusted OR for mothers exposed more than 4 h/day = 2.18, 95 % CI 1.39-3.42) was observed, but recall bias cannot be excluded. Exposure of the children to SHS was associated with ALL only in unadjusted analysis (unadjusted OR for highly exposed children = 1.64; 95 % CI 1.10-2.45).
This study does not support the hypothesis that parental active smoking is associated with ALL. We found very weak evidence of increased risk of ALL for children exposed to SHS. Maternal exposure to SHS was associated with ALL, but recall bias is likely to inflate our estimates.
Cancer Causes and Control 04/2014; 25(6). DOI:10.1007/s10552-014-0371-9 · 2.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives Leukaemia is the most common cancer in children, but its aetiology is still poorly understood. We tested the hypothesis that traffic-related air pollution is associated with paediatric leukaemia because of chronic exposure to several potential carcinogens.
Methods The Italian SETIL study (Study on the aetiology of lymphohematopoietic malignancies in children) was conducted in 14 Italian regions. All incident cases of leukaemia in children aged ≤10 years from these regions (period 1998–2001) were eligible for enrolment. Two controls per case, matched on birth date, gender and region of residence were randomly selected from the local population registries. Exposure assessment at birth residence included traffic indicators (distance to main roads and length of main roads within 100 m) and estimates of pollutants concentrations (particulate matter -PM2.5 and PM10- and gases -NO2 and O3-) from national dispersion model and land use regression models. The association between the exposure variables and leukaemia was assessed by logistic regression analyses.
Results Participation rates were 91.4% among cases and 69.2% in controls; 620 cases (544 acute lymphocytic and 76 acute non-lymphocytic leukaemia) and 957 controls were included. Overall, when considering the residence at birth, 35.6% of cases and 42.4% of controls lived along busy roads, and the mean annual PM10 levels were 33.3 (SD=6.3) and 33.4 µg/m3 (SD=6.5), respectively. No association was found, and all ORs, independent of the method of assessment and the exposure windows, were close to the null value.
Conclusions Using various exposure assessment strategies, air pollution appears not to affect the incidence of childhood leukaemia.
Occupational and Environmental Medicine 12/2013; 70(12):876-883. DOI:10.1136/oemed-2013-101604 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aim In the context of the Italian Multicentric Epidemiological Study on Risk Factors for Childhood Leukaemia and Non-Hodgkin's Lymphoma (SETIL), the risk of childhood cancer was investigated in relation to parental occupational exposures.
Methods All cases of childhood leukaemia and non-Hodgkin's lymphoma (NHL) in children aged 0–10 years were identified. Controls were chosen at random from the local population in each region. Parents were interviewed using a structured questionnaire. The collected data were blindly reviewed by expert industrial hygienists in order to estimate exposure to a list of agents. Statistical analyses were performed for each agent using unconditional multivariable logistic regression models, taking into account timing of exposure.
Results 683 cases of acute childhood leukaemia, 97 cases of NHL and 1044 controls were identified. Increased risk of childhood leukaemia was found for maternal exposure to aliphatic (OR 4.3) or aromatic hydrocarbons (OR 3.8) in the preconception period, and for paternal exposure to diesel exhaust (OR 1.4), lead exposure (OR 1.4) and mineral oils (OR 1.7). Risk of NHL appeared to be related to paternal exposure to oxygenated solvents (OR 2.5) and petrol exhaust (OR 2.2).
Conclusions We found increased risk for childhood leukaemia associated with maternal occupational exposure to aromatic and aliphatic hydrocarbons, particularly in the preconception period; increased risks were also observed for paternal exposure to diesel exhaust fumes, mineral oils and lead. The risk of NHL appeared to be related to paternal exposure to oxygenated solvent and petrol exhausts.
Occupational and environmental medicine 06/2013; 70(9). DOI:10.1136/oemed-2012-100951 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: the aims of Tuscany Regional project were: to study the sun protection attitude of outdoor workers; to measure solar ultraviolet (UV) exposure in work environment; to describe the frequency of photoaging, precancerous lesions, and skin cancers in outdoor workers; to collect information on solar ultraviolet radiation exposure from incident cases of Non-Melanoma Skin Cancer (NMSC) recruited from Tuscany Cancer Registry.
outdoor workers completed a questionnaire devoted to collect information on sun protection attitudes during a typical summer working week. Environmental and personal measurements were carried out. Expert dermatologists examined outdoor workers to assess the frequency of photoaging, precancerous lesions, and skin cancer. A structured questionnaire was mailed to incident cases of NMSC. Information were collected on personal habits and working history, focusing on solar ultraviolet radiation exposure.
agriculture, construction, quarrying and fishing activities were considered: 292 employees responded to questions about the type of clothing used in the morning and in the afternoon,while working outdoors; 637 outdoor workers underwent skin examination. We contacted 743 cases of NMSC occurred in 2004; 498 subjects accepted to participate in this study.
the clothing worn by surveyed subjects was often inadequate compared to the high level of exposure to UV. The skin examination of 637 outdoor workers highlighted 2 melanomas, 7 epitheliomas and 35 actinic keratoses.Among the 498 cases of NMSC, 135 (27%) were diagnosed in outdoor workers. Most represented economic activity sectors were: agriculture, construction, transport, sports.
the characterization of outside workers revealed unsatisfactory sun protection behaviours. Moreover, previously undetected skin cancers were diagnosed. The study on MNSC confirms the complexity of studying the exposure to UV radiation.The Tuscany Regional project provided useful information on the risk of solar ultraviolet radiation in outdoor workers. Prevention programs are needed.
Epidemiologia e prevenzione 05/2013; 37(1):51-9. · 1.46 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this research was to assess dermal and respiratory exposure of workers to imidacloprid during manual operations with ornamental plants previously treated in greenhouses or tunnels. A total of 10 female workers, 5 in greenhouses and 5 in tunnels, were monitored for 3 or 5 consecutive days. Actual skin contamination, excluding hands, was evaluated using nine filter paper pads placed directly on the skin. To evaluate the efficacy of protective clothing in reducing occupational exposure we also placed four pads on top of the outer clothing. Hand contamination was evaluated by washing with 95% ethanol. Respiratory exposure was evaluated by personal air sampling. Respiratory dose was calculated on the basis of a lung ventilation of 15 l/min. Absorbed doses were calculated assuming a skin penetration of 10% and a respiratory retention of 100%. Dislodgeable foliar residues (DFRs) were determined during the days of re-entry in order to determine the dermal transfer factor. From the dependence of dermal exposure of hands from DFRs, a mean transfer factor was estimated to be 36.4 cm(2)/h. Imidacloprid was determined by liquid chromatography with selective mass detection and electrospray interface in all matrices analysed. Respiratory dose was 4.1+/-4.0 (0.1-14.3)% and 3.0+/-2.0 (0.6-6.9)% (mean+/-SD (range)) of the total real dose during work in tunnels and greenhouses, respectively. The estimated absorbed doses, 0.29+/-0.45 microg/kg (0.06-2.25 microg/kg) body weight and 0.32+/-0.18 microg/kg (0.07-0.66 microg/kg) body weight (mean+/-SD (range)) in tunnels and in greenhouses, respectively, were less than the acceptable operator exposure level of 0.15 mg/kg body weight and than the acceptable daily intake of 0.05 mg/kg body weight. The hands and exposed skin of all workers were found to be contaminated, indicating that greater precautions, such as daily changing of gloves and clothing, are necessary to reduce skin exposure.
Journal of Exposure Science and Environmental Epidemiology 01/2009; 19(6):555-69. DOI:10.1038/jes.2008.50 · 3.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: While there is a general consensus about the ability of benzene to induce acute myeloid leukemia (AML), its effects on chronic lymphoid leukemia and multiple myeloma (MM) are still under debate. We conducted a population-based case-control study to evaluate the association between exposure to organic solvents and risk of myeloid and lymphoid leukemia and MM.
Five hundred eighty-six cases of leukemia (and 1,278 population controls), 263 cases of MM (and 1,100 population controls) were collected. Experts assessed exposure at individual level to a range of chemicals.
We found no association between exposure to any solvent and AML. There were elevated point estimates for the associations between medium/high benzene exposure and chronic lymphatic leukemia (OR = 1.8, 95% CI = 0.9-3.9) and MM (OR = 1.9, 95% CI = 0.9-3.9). Risks of chronic lymphatic leukemia were somewhat elevated, albeit with wide confidence intervals, from medium/high exposure to xylene and toluene as well.
We did not confirm the known association between benzene and AML, though this is likely explained by the strict regulation of benzene in Italy nearly three decades prior to study initiation. Our results support the association between benzene, xylene, and toluene and chronic lymphatic leukemia and between benzene and MM with longer latencies than have been observed for AML in other studies.
American Journal of Industrial Medicine 11/2008; 51(11):803-11. DOI:10.1002/ajim.20592 · 1.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A number of studies have shown possible associations between occupational exposures, particularly solvents, and lymphomas. The present investigation aimed to evaluate the association between exposure to solvents and lymphomas (Hodgkin and non-Hodgkin) in a large population-based, multicenter, case-control study in Italy.
All newly diagnosed cases of malignant lymphoma in men and women age 20 to 74 years in 1991-1993 were identified in 8 areas in Italy. The control group was formed by a random sample of the general population in the areas under study stratified by sex and 5-year age groups. We interviewed 1428 non-Hodgkin lymphoma cases, 304 Hodgkin disease cases, and 1530 controls. Experts examined the questionnaire data and assessed a level of probability and intensity of exposure to a range of chemicals.
Those in the medium/high level of exposure had an increased risk of non-Hodgkin lymphoma with exposure to toluene (odds ratio = 1.8; 95% confidence interval = 1.1-2.8), xylene 1.7 (1.0-2.6), and benzene 1.6 (1.0-2.4). Subjects exposed to all 3 aromatic hydrocarbons (benzene, toluene, and xylene; medium/high intensity compared with none) had an odds ratio of 2.1 (1.1-4.3). We observed an increased risk for Hodgkin disease for those exposed to technical solvents (2.7; 1.2-6.5) and aliphatic solvents (2.7; 1.2-5.7).
This study suggests that aromatic and chlorinated hydrocarbons are a risk factor for non-Hodgkin lymphomas, and provides preliminary evidence for an association between solvents and Hodgkin disease.
[Show abstract][Hide abstract] ABSTRACT: Exposure to pesticides is recognized as an important environmental risk factor associated with development of cancer. Epidemiological studies, although sometimes contradictory, have linked phenoxy acid herbicides with non-Hodgkin's lymphoma (NHL) and Soft Tissue Sarcoma (STS); organochlorine insecticides with STS, NHL, and leukemia; organophosphorous compounds with NHL and leukemia; and triazine herbicides with ovarian cancer. Exposure assessment is a crucial point in studying the association between cancer and pesticides. In order to investigate the association between hematolymphopoietic malignancies and occupational exposures, including pesticides, a population-based case-control study was carried out in Italy in 11 areas, 9 of which are agricultural or mixed areas. All newly diagnosed cases of hematolymphopoietic malignancies were collected in a 3-year period (1991-1993). The control group consisted of a random sample of the population residing in each area. The approach to infer exposures in agriculture was based on: the use of an agricultural questionnaire with 24 crop-specific questionnaires; expert agronomists who reviewed the collected information for each subject and translated it into pesticides histories. In total, 1925 cases and 1232 controls were interviewed in the nine agricultural areas. Increased risk was observed for some specific classes of pesticides. Furthermore, a nonstatistically significant increased risk of NHL was observed for subjects who were exposed to phenoxy herbicides not using protective equipment and a significant increased risk for exposure to 2, 4-dichlorophenoxy acetic acid (2,4-D).
Annals of the New York Academy of Sciences 10/2006; 1076:366-77. DOI:10.1196/annals.1371.036 · 4.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Exposure to pesticides is recognized as an important environmental risk factor associated with development of cancer. Epidemiological studies, although sometimes contradictory, have linked phenoxy acid herbicides with non-Hodgkin's lymphoma (NHL) and Soft Tissue Sarcoma (STS); organochlorine insecticides with STS, NHL, and leukemia; organophosphorous compounds with NHL and leukemia; and triazine herbicides with ovarian cancer. Exposure assessment is a crucial point in studying the association between cancer and pesticides.In order to investigate the association between hematolymphopoietic malignancies and occupational exposures, including pesticides, a population-based case–control study was carried out in Italy in 11 areas, 9 of which are agricultural or mixed areas. All newly diagnosed cases of hematolymphopoietic malignancies were collected in a 3-year period (1991–1993). The control group consisted of a random sample of the population residing in each area. The approach to infer exposures in agriculture was based on: the use of an agricultural questionnaire with 24 crop-specific questionnaires; expert agronomists who reviewed the collected information for each subject and translated it into pesticides histories. In total, 1925 cases and 1232 controls were interviewed in the nine agricultural areas. Increased risk was observed for some specific classes of pesticides. Furthermore, a nonstatistically significant increased risk of NHL was observed for subjects who were exposed to phenoxy herbicides not using protective equipment and a significant increased risk for exposure to 2, 4-dichlorophenoxy acetic acid (2,4-D).
Annals of the New York Academy of Sciences 08/2006; 1076(1):366 - 377. · 4.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In the context of a population-based case-control study in Italy, the authors investigated the possible association between the personal use of hair dyes and non-Hodgkin's lymphoma (NHL), leukemia, multiple myeloma, and Hodgkin's disease. They collected all incident cases of hematolymphopoietic malignancies; the control group was formed with a random sample of the general population. Overall, the authors interviewed 2,737 research subjects and 1,779 control subjects. Among women, the authors found no association between ever using hair dyes and the risk of hematolymphopoietic malignancies. However, for permanent hair dyes, the authors observed a slightly increased risk of lymphocytic leukemia (odds ratio [OR] = 1.3; 95% confidence interval [CI] = 0.8-2.2) and of follicular subtypes of NHL (OR= 1.3; 95% CI = 0.8-2.0). Women who used black hair dye colors were at an increased risk of developing leukemia (OR = 1.9; 95% CI = 1.0-3.4), in particular chronic lymphocytic leukemia (OR = 3.0; 95% CI = 1.1-7.5). In spite of the lack of information on the timing and frequency of hair dye use and the imprecision of the ORs, associations were suggested between leukemia and permanent black hair dye use and follicular NHL and the use of permanent hair dyes.
Archives of Environmental and Occupational Health 09/2005; 60(5):249-56. DOI:10.3200/AEOH.60.5.249-256 · 0.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The etiology of non-Hodgkin's lymphoma (NHL) and leukemia is still largely unknown, but exposure to chemicals, in particular pesticides, has been suggested to be a risk factor.
A large population-based case-control study was conducted in Italy with the aim of investigating the associations between pesticide exposure and NHL, and solvents and leukemia. Data presented in this article refer to 1,575 interviewed cases and 1,232 controls in the nine agricultural study areas.
Exposure to nitro-derivatives and phenylimides among fungicides, hydrocarbon derivatives and insecticide oils among insecticides, and the herbicide amides are the chemical classes observed to be associated with the pathologies under investigation.
The results of the case-control study suggest an increased risk for NHL and leukemia, and some chemical classes of pesticides, although few are statistically significant and some are based on few exposed cases. The results also show that men and women experience both similar and different risks for the same environmental agricultural exposures. Am. J. Ind. Med. 44:627-636, 2003.
American Journal of Industrial Medicine 12/2003; 44(6):627-36. DOI:10.1002/ajim.10289 · 1.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We conducted a population-based, case-control study on hematolymphopoietic malignancies in 12 areas in Italy to investigate associations between different hematolymphopoietic malignancies and exposure to solvents and pesticides. We collected all incident cases 20-74 years of age from 12 areas, with a combined population of approximately 7 million residents. The control group was formed by a random sample of the study population. Data presented in this paper refer to 2,737 interviewed cases of 3,357 eligible cases and to 1,779 of 2,391 eligible controls. We analyzed risks associated with occupation using job-title information to evaluate disease pattern according to job category. An earlier publication presented results for women; here, we report the findings for men and discuss the overall patterns in both genders. The most consistent overall finding was an approximate doubling in relative risk for all four types of malignancies among male managers and related occupations. Several additional occupations were associated with elevated risk of one or more malignancies among men. These included cooks, waiters, and bartenders, and building caretakers and cleaners, for non-Hodgkin's lymphoma; textile workers and machinery fitters for Hodgkin's lymphoma; metal processors, material handlers, rubber workers, and painters for leukemia; and hairdressers, metal processors, tailors, electrical workers, and plumbers for multiple myeloma. The finding of increased risk of non-Hodgkin's lymphoma among both male and female cooks, waiters, and bartenders has not been previously reported; nor has the elevated risk of leukemia among material handlers. Among people engaged in agriculture, those employed as tractor drivers and as orchard, vineyard, and related tree and shrub workers appeared to be at increased risk for hematolymphopoietic malignancies.
[Show abstract][Hide abstract] ABSTRACT: INTRODUZIONE L'inquinamento atmosferico continua a destare l'attenzione e la preoccupazione dei cittadini e dei media, come un nemico subdolo che dall'esterno arriva nelle nostre case ad aggredire la nostra salute, spesso dimenticando che l'aria che respiriamo nelle nostre case o uffici può essere influenzata anche dall'ambiente interno. Gli ambienti "confinati" o "indoor", luoghi di vita e di lavoro non di carattere industriale, sono infatti avvertiti come luoghi esenti da potenziali rischi che tuttavia espongono la popolazione ed in particolare i gruppi più vulnerabili, quali i bambini, ad un prolungato contatto con agenti fisici (es.: temperatura, illuminazione, rumore), agenti chimici (compresi quelli naturali e quelli derivanti da attività umane) ed agenti biologici (es.: batteri, virus, parassiti, insetti) che possono essere potenziali fonti di inquinamento. L'aria presente negli ambienti confinati è una delle matrici che più influisce sull'insalubrità dell'ambiente in quanto subisce alterazioni e modificazioni dovute ad una serie di fattori, tra i quali emergono la presenza di persone, dei materiali e dei rivestimenti con cui sono costruiti gli edifici, gli arredi, i sistemi di trattamento dell'aria, le operazioni di pulizia dei locali. Altro elemento importante nella valutazione delle possibili fonti di inquinamento è l'interazione indoor-outdoor, ovvero quanto influisce il ruolo dell'inquinamento presente all'esterno, come ad esempio quello derivante da traffico urbano, nell'ambiente confinato. La qualità degli ambienti confinati è quindi di interesse rilevante per la Sanità Pubblica ed il raggiungimento di un ambiente indoor salubre rappresenta una sfida per chi è impegnato a effettuare scelte per i cittadini. E' cresciuta pertanto da parte dell'Igiene e Sanità Pubblica delle AUSL toscane l'attenzione alla tematica dell'inquinamento indoor, anche a fronte di alcuni casi emersi, che hanno stimolato l'approfondimento ed insieme la necessità di capire l'influenza di tale inquinamento sulla popolazione. Il primo progetto è stato ideato pensando ad una comunità che trascorre molte ore al giorno in ambienti confinati e più vulnerabile, individuando così la popolazione scolastica. L'Assessorato al Diritto alla Salute e Politiche di Solidarietà della Regione Toscana attraverso il Progetto Indoor ha promosso nel 2003 un'indagine per monitorare lo stato dell'inquinamento indoor negli edifici scolastici attraverso un campione casuale di 61 scuole, elementari e medie dislocate sul territorio regionale, 5 scuole per ciascuna delle 12 AUSL, ed una in più per l'AUSL fiorentina, conclusosi nel 2006. Il progetto è stato realizzato grazie al lavoro svolto dalle Unità Funzionali di Igiene e Sanità Pubblica e dai Laboratori di Sanità Pubblica dei Dipartimenti di Prevenzione delle Aziende USL toscane e dal Centro per lo Studio e la Prevenzione Oncologica, con il coordinamento del settore Igiene Pubblica della Regione Toscana e la preziosa disponibilità delle autorità scolastiche.