RESUMO
BACKGROUND: The Soufriere Hills, a stratovolcano on Montserrat, started erupting in July 1995, producing volcanic ash, both from dome collapse pyroclastic flows and phreatic explosions. The eruptions/ash resuspension result in high concentrations of suspended particulate matter in the atmosphere, which includes cristobalite, a mineral implicated in respiratory disorders. AIMS: To conduct toxicological studies on characterised samples of ash, together with major components of the dust mixture (anorthite, cristobalite), and a bioreactive mineral control (DQ12 quartz). METHODS: Rats were challenged with a single mass (1 mg) dose of particles via intratracheal instillation and groups sacrificed at one, three, and nine weeks. Acute bioreactivity of the particles was assessed by increases in lung permeability and inflammation, changes in epithelial cell markers, and increase in the size of bronchothoracic lymph nodes. RESULTS: Data indicated that respirable ash derived from pyroclastic flows (20.1% cristobalite) or phreatic explosion (8.6% cristobalite) had minimal bioreactivity in the lung. Anorthite showed low bioreactivity, in contrast to pure cristobalite, which showed progressive increases in lung damage. CONCLUSION: Results suggests that either the percentage mass of cristobalite particles present in Montserrat ash was not sufficient as a catalyst in the lung environment, or its surface reactivity was masked by the non-reactive volcanic glass components during the process of ash formation.
Assuntos
Silicatos de Alumínio/toxicidade , Poeira/efeitos adversos , Pulmão , Dióxido de Silício/toxicidade , Erupções Vulcânicas/efeitos adversos , Animais , Líquido da Lavagem Broncoalveolar/citologia , Células Epiteliais/efeitos dos fármacos , Pulmão/patologia , Masculino , Minerais/análise , Tamanho do Órgão/efeitos dos fármacos , Surfactantes Pulmonares/metabolismo , Ratos , Ratos Sprague-Dawley , Índias OcidentaisRESUMO
Determinou-se o nível de chumbo (Pb) presente no ar em ambientes externos e na poeira doméstica de residências localizadas próximo a uma reformadora de baterias (RB). Uma das principais fontes de exposiçäo ao Pb säo empresas do setor de RB, que ainda utilizam processos e tecnologia obsoletos em instalaçöes precárias. Na área externa à RB foram realizadas coletas em seis pontos localizados a aproximadamente 25m e a 500m da RB. Os resultados obtidos mostram que o limite para Pb no ar atmosférico (Pb-Ar) de 1,5µg Pb.m-3 foi excedido em 50 por cento das amostras coletadas, variando de 0,03 a 183,3µg Pb.m-3. As coletas nas dependências internas e externas das residências foram realizadas em seis pontos de quatorze residências localizadas a aproximadamente 25m, 50m e a 500m da RB. O limite de Pb na poeira doméstica (Pb-Pd) de 1.500µg Pb.m-2 foi excedido em 44 por cento das amostras coletadas, apresentando valores variáveis de 2,2 a 54.338,9µg Pb.m-2.
Assuntos
Poeira/efeitos adversos , Chumbo , Poluição do Ar em Ambientes Fechados/análiseRESUMO
The purpose of this study was to correlate soybean dust (SD) exposure, skin reactivity to soybean hull (SH) allergens, and symptoms of asthma and/or allergic rhinitis. A group of 365 subjects with asthma and/or allergic rhinitis and a control group of 50 individuals without respiratory symptoms were studied. The level of exposure to SD is defined as follows: 1) direct (DE); 2) indirect (ID), and 3) urban (UE). All subjects completed standard questionnaires. Skin tests with a SH extract and with common allergens were performed by the prick technique (SPT). Fifty-six (15.3%) patients and no subjects from control group had positive SPT (histamine index > or = 0.5) with a SH allergen extract. The percentages of positive SPT to SH extract were 38.7%, 20.3% and 8.4% in subjects with DE, IE and UE, respectively (p < 0.001). Monosensitization to SH was absent in all subjects. The percent of subjects with positive SPTs to mites (p < 0.01), pollen (p < 0.01) and molds (p < 0.05) were higher in subjects with a positive SPT to SH versus those with a negative SPT to SH. Sixty-six percent of subjects with DE and 13.6% of subjects with IE or UE reported respiratory symptoms after SD inhalation (Odds Ratio: 12.67 [2.4-74.9], p < 0.001). Compared to subjects exclusively sensitized to mites, patients sensitized to SH presented significantly different clinical characteristics. Soybean production has been increasing in Argentina during the last 20 years, determining an increase in the population exposed to chronic SD inhalation. This fact determines a high risk of sensitization and triggering of respiratory symptoms in atopic subjects. This study demonstrates that there is: 1) a high prevalence of skin reactivity to SH in subjects with asthma and/or allergic rhinitis from Argentina and that this prevalence is associated with the level of exposure to SD, and 2) an association between sensitivity to SH and severity of asthma. Measures to avoid release and inhalation of SD in rural areas from Argentina are needed.
Assuntos
Poeira/efeitos adversos , Exposição Ambiental/efeitos adversos , Glycine max , Hipersensibilidade Respiratória/epidemiologia , Adolescente , Adulto , Idoso , Alérgenos/efeitos adversos , Asma/induzido quimicamente , Asma/epidemiologia , Criança , Pré-Escolar , Relação Dose-Resposta Imunológica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Hipersensibilidade Respiratória/induzido quimicamente , Rinite Alérgica Perene/induzido quimicamente , Rinite Alérgica Perene/epidemiologia , Testes CutâneosAssuntos
Alveolite Alérgica Extrínseca/imunologia , Poeira/efeitos adversos , Adulto , Humanos , Masculino , América do Sul , MadeiraRESUMO
AIMS: The characteristics and real dimension of the environmental problems are frequently unknown. These results in a poor knowledge about health impact and deficient planning of the measures required for their protection. Asthma is a prior health problem at Comarca Lagunera. OBJECTIVE: The analysis of environment characteristics that could affect its presentation is the objective of this paper. MATERIAL AND METHOD: We took information form several official bureaus and regional records. It identified that the coexistence of some factors, like regional weather characteristics, with extreme temperature and frequent dust storm, growing deforest, dominant flora and acute and chronic contamination by particulates material, mainly at urban areas, could explain the epidemiological profile of the disease in this urban area so an interdisciplinary participation is required for solving this problem. RESULTS: In the Comarca Lagunera, several factors coexist which precipitate symptoms in asthmatic subjects: climatological features which favor the inflammatory process and increase susceptibility to respiratory tract infections which can set off asthmatic crises. CONCLUSION: The epidemiological behavior os asthma in this regions may be associated with its climatological characteristics.
Assuntos
Asma/epidemiologia , Exposição Ambiental , Poluição Ambiental/efeitos adversos , Poluentes Atmosféricos/efeitos adversos , Asma/etiologia , Poeira/efeitos adversos , Humanos , Indústrias , México/epidemiologia , Pólen/efeitos adversos , Estações do Ano , Saúde da População Urbana , Tempo (Meteorologia)RESUMO
A preliminary study explored the relative contribution of residential sources of lead exposure on mentally challenged children who attend "special education" institutions (GI) compared to a group of age and sex matched school children (G2). We captured descriptive information and analyzed demographic variables, personal and household information, medical effects, environmental exposure factors, and children habits. Home paint, dust, soil, and water sampling was conducted and blood lead (BPb) levels determined. Eighteen G1 and 20 G2 children were studied. The mean G1 BPb was 16.9 +/- 7.9 microg/dl and was significantly higher than that in G2. Fifty percent of G1 children had PbB >20 microg/dl and 72.2% were >10 microg/dl. Low muscular strength, decreased osteotendinose reflexes, fine and gross motricity, deficient equilibrium, and hipotonic muscular tone coincided with >18 microg/dl BPb levels. In 61.1% of G1 homes paint lead levels were higher than permissible levels and 33.3% had dust lead exceeding that level. The high BPb levels in G1 probably resulted from ingestion of household paint, dust, and soil via "hand-to-mouth" activity. Environmental exposure to lead can be an important source of lead intake by infants and children and could affect neurological development. This study provides new insights currently unavailable for these children in Venezuela.
Assuntos
Exposição Ambiental/efeitos adversos , Intoxicação do Sistema Nervoso por Chumbo na Infância/etiologia , Chumbo/sangue , Doenças do Sistema Nervoso/etiologia , Antropometria , Criança , Pré-Escolar , Poeira/efeitos adversos , Feminino , Humanos , Intoxicação do Sistema Nervoso por Chumbo na Infância/sangue , Estilo de Vida , Masculino , Pintura/efeitos adversos , Pica/complicações , Projetos Piloto , Pobreza , Classe Social , Poluentes do Solo/efeitos adversos , Espectrofotometria Atômica , Estatísticas não Paramétricas , Inquéritos e Questionários , Venezuela , Poluentes Químicos da Água/efeitos adversosRESUMO
BACKGROUND: There are no antecedents in Cuba of studies developed to prove the efficacy of an allergy test to Blomia tropicalis despite of being one of the main mites which cause this ailment which affects more than 2,200,000 people. OBJECTIVES: Evaluate the allergenic extract Blomia tropicalis elaborated at the Centro Nacional de Biopreparados (BioCen), in the prick skin test, as a diagnose of allergy to this allergen which exists in all the tropical and subtropical countries. MATERIAL AND METHODS: We selected 50 patients with a positive clinic history of allergy to house dust and 50 healthy persons. Al the persons selected were skin prick tested with dilution's of the extracts (20,000 UB/mL) and positive and negative control. We measured the average diameter of the wheal and the perpendicular diameter, then we calculated the average. We also calculated size of the wheal in the duplicated, which constituted the size of the reaction. We estimated the validity of the test calculating the sensitivity and specificity. We used the EPITABLE program to do this. RESULTS: The skin prick tested positive in 78% of the patients and 6% in the healthy persons, for a sensitivity of 78% the interval of confidence (IC) 63.7-88.0 and a specificity of 94%, IC 82.5-98.4 the predictive negative value 81%, IC 68.2-89.7. CONCLUSIONS: The allergenic extract of Blomia tropicalis elaborated in BioCen is very sharp to test the allergy to this mite.
Assuntos
Ácaros e Carrapatos/imunologia , Alérgenos , Hipersensibilidade/diagnóstico , Adolescente , Adulto , Animais , Poeira/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A pneumoconiose é uma doença pulmonar de origem ocupacional, considerada de elevada prevalência entre os trabalhadores expostos à poeiras minerais, como a sílica e o asbesto, nos diversos ramos da produçao industrial. A inalaçao destas poeiras minerais pode desenvolver uma fibrose intersticial pulmonar intensa, caracterizada por reaçao inflamatória, liberaçao de fatores quimiotáxicos, produçao de colágeno e conseqüente formaçao de granuloma no pulmao. Os indicadores biológicos podem ser úteis na compreensao deste processo inflamatório do adoecimento pulmonar, na identificaçao da fase pré-fibrogênica, no acompanhamento e no tratamento destas doenças. Realiza um estudo do nível de concentraçao de três citoquinas: Fator de Necrose Tumoral Alfa (TNFÓ, do inglês), interleucina-1ß (IL-1ß) e interleucina-6 (IL-6), no adoecimento pulmonar causado pela exposiçao à sílica e ao asbesto, na pneumoconiose. O objetivo específico foi determinar sua concentraçao no soro sanguíneo de pacientes expostos à sílica e ao asbesto e verificar a associaçao das citoquinas com as exposiçoes e com a pneumoconiose. Foram estudadas 161 pessoas, das quais 107 pacientes trabalhadores expostos à poeiras minerais, sendo 85 expostos à sílica e 22 expostos ao asbesto, e 54 trabalhadores nao expostos no grupo de comparaçao. Para a determinaçao quantitativa da TNFÓ, da IL-1ß e da IL-6, foi coletado sangue de todos os trabalhadores incluídos no projeto e utilizado o método de Elisa para a análise. Encontraram-se, também, diferenças significativas, entre os pacientes com pneumoconiose e o grupo nao exposto para as três citoquinas, em níveis diferenciados. A análise dos resultados nao discriminou o papel das citoquinas na fase pré-fibrótica do adoecimento. Os resultados, no subgrupo exposto à sílica com silicose, nao apresentaram níveis elevados de IL-6 e TNF, mas, apresentaram níveis elevados de IL-1ß das citoquinas dosadas no sangue. No subgrupo exposto ao asbesto com asbestose houve um aumento apenas dos níveis de IL-6. No campo da saúde pública, ainda näo se dispöe de instrumentos capazes de predizerem processos patológicos em trabalhadores expostos à poeiras minerais, principalmente à sílica e ao asbesto. O campo de estudo das citoquinas e outros marcadores mostra-se promissor, mas até o momento, a única arma para reduzir ou eliminar os danos causados por poeiras minerais nos ambientes de trabalho é a retirada do agente nocivo do ambiente.