RESUMO
Background: Classrooms are an important environment for young children as this is where they spend a large part of their time. Aims: This study was designed to quantify the levels of heavy metals in classroom dusts in Shiraz, a city southwestern Iran. The potential association between heavy metal levels and childhood asthma was also investigated.Methods: We selected 32 schools for collecting classroom dust samples during September–November 2016. The con-centration of 10 heavy metals was measured in these dust samples by optical emission spectrometry. The diagnosis of childhood asthma was made using both the medical chart of each student and examination by an allergist. The data were analysed using SPSS, version 21.0.Results: The concentration of heavy metals in classroom dust samples ranged from 7559 to 53 723.0 mg/kg (mean: 16 945.5 mg/kg) for Fe, 169.0 to 952.0 mg/kg (mean 288.9 mg/kg) for Mn, and 9.0 to 971.0 mg/kg (mean 258.8 mg/kg) for Pb. We found no correlation between heavy metals in classroom dust and childhood asthma.Conclusion: In comparison with studies reported elsewhere, the maximum levels of lead in our study were greater. A potential explanation for the lack of correlation with childhood asthma is the large mass of the particles, preventing them from reaching the lower airways. Nevertheless, special attention should be paid to reducing high levels of heavy metals in classroom dust in this area.
Contexte : Les salles de classe constituent un environnement important pour les jeunes enfants, étant donné qu’ils passent une grande partie de leur temps dans ce lieu. Objectifs : La présente étude a été réalisée pour quantifier les niveaux de métaux lourds présents dans les poussières de salle de classe à Shiraz, ville du sud-ouest de la République islamique d’Iran. Le lien potentiel entre les concentrations de métaux lourds et l’asthme infantile a également été examiné. Méthodes : Nous avons sélectionné 32 écoles pour y prélever des échantillons de poussière dans les classes entre septembre et novembre 2016. La concentration en dix métaux lourds dans ces échantillons a été mesurée par spectrométrie d’émission optique. Le diagnostic d’asthme infantile a été posé à la fois sur la base du dossier médical de chaque élève et d’un examen réalisé par un allergologue. Les données ont été analysées à l’aide du logiciel SPSS, version 21.0. Résultats : La concentration en métaux lourds dans les échantillons de poussière des salles de classe variait de 7 559 à 53 723,0 mg/kg (moyenne : 16 945,5 mg/kg) pour Fe, de 169,0 à 952,0 mg/kg (moyenne : 288,9 mg/kg) pour Mn et de 9,0 à 971,0 mg/kg (moyenne : 258,8 mg/kg) pour Pb. Nous n’avons établi aucune corrélation entre les métaux lourds présents dans la poussière des salles de classe et l’asthme infantile. Conclusion : Comparativement aux études menées ailleurs, les niveaux maximaux de plomb étaient supérieurs dans notre étude. L’absence de corrélation avec l’asthme infantile pourrait s’expliquer par la masse élevée des particules, qui pourrait les empêcher d’atteindre les voies respiratoires basses. Néanmoins, une attention particulière doit être portée à la réduction des hauts niveaux de métaux lourds présents dans les salles de classe de cette région.
Assuntos
Doenças não Transmissíveis , Metais Pesados , Poeira , Asma , Criança , Instituições Acadêmicas , Meio Ambiente , Irã (Geográfico) , Região do MediterrâneoRESUMO
Various allergens are implicated in the pathogenesis of allergic diseases in different regions. This study attempted to identify the most common allergens among patients with allergies based on the results of skin prick tests in different parts of Iran. Relevant studies conducted from 2000 to 2016 were identified from the MEDLINE database. Six common groups of allergen types, including animal, cockroach, food, fungus, house dust mite, and pollen were considered. Subgroup analysis was performed to determine the prevalence of each type of allergen. The Egger test was used to assess publication bias. We included 44 studies in this meta-analysis. The overall prevalence of positive skin test results for at least one allergen was estimated to be 59% in patients with allergies in various parts of Iran. The number of patients was 11,646 (56% male and 44% female), with a mean age of 17.46±11.12 years. The most common allergen sources were pollen (47.0%), mites (35.2%), and food (15.3%). The prevalence of sensitization to food and cockroach allergens among children was greater than among adults. Pollen is the most common allergen sensitization in cities of Iran with a warm and dry climate; however, sensitization to house dust mites is predominant in northern and southern coastal areas of Iran.
Assuntos
Adulto , Animais , Criança , Humanos , Masculino , Alérgenos , Clima , Baratas , Fungos , Hipersensibilidade , Irã (Geográfico) , Ácaros , Pólen , Prevalência , Viés de Publicação , Pyroglyphidae , Pele , Testes CutâneosRESUMO
Various allergens are implicated in the pathogenesis of allergic diseases in different regions. This study attempted to identify the most common allergens among patients with allergies based on the results of skin prick tests in different parts of Iran. Relevant studies conducted from 2000 to 2016 were identified from the MEDLINE database. Six common groups of allergen types, including animal, cockroach, food, fungus, house dust mite, and pollen were considered. Subgroup analysis was performed to determine the prevalence of each type of allergen. The Egger test was used to assess publication bias. We included 44 studies in this meta-analysis. The overall prevalence of positive skin test results for at least one allergen was estimated to be 59% in patients with allergies in various parts of Iran. The number of patients was 11,646 (56% male and 44% female), with a mean age of 17.46±11.12 years. The most common allergen sources were pollen (47.0%), mites (35.2%), and food (15.3%). The prevalence of sensitization to food and cockroach allergens among children was greater than among adults. Pollen is the most common allergen sensitization in cities of Iran with a warm and dry climate; however, sensitization to house dust mites is predominant in northern and southern coastal areas of Iran.
