Browsing by Author "Linhares, Diana P."
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- Biodisponibilidade ambiental de iodo : o caso dos AçoresPublication . Linhares, Diana P.; Garcia, Patrícia; Rodrigues, Armindo[…]. Nos Açores, já na década de 80 do século passado, foi efetuado um rastreio de bócio, na ilha de São Miguel, pela equipa do Dr. Lopes de Oliveira, tendo-se concluído que esta patologia era endémica entre as crianças em idade escolar, uma vez que apresentava taxas de prevalência entre 11% e 41%. Mais recentemente, outros trabalhos liderados pelo Professor Limbert, verificaram uma grande heterogeneidade na concentração de iodo na urina (iodúria) de crianças e de mulheres grávidas, observando-se em alguns casos níveis preocupantes de deficiência em iodo. Cerca de 78% das crianças apresentavam níveis de iodúrias inadequados (<100 mg/L) e 26% níveis de iodúrias severas (<50 mg/L); as iodúrias mais satisfatórias foram obtidas nas ilhas de Santa Maria e Graciosa. Tendo em conta, por um lado, os resultados avançados por estes trabalhos e, por outro, a localização geográfica dos Açores no meio do oceano (o maior reservatório natural de iodo) coloca-se a seguinte questão: como explicar a heterogeneidade de iodúrias entre os habitantes das varias ilhas? […].
- Deficiency of essential elements in volcanic soils : potential harmful health effects on grazing cattlePublication . Linhares, Diana P.; Pimentel, Adriano; Garcia, Patrícia; Rodrigues, ArmindoSeveral essential nutrients such as Fe, Co, Cu, I, Se, and Zn are vital to grazing cattle as they play a significant role in intracellular enzyme systems, with antioxidant and repair functions of DNA lesions. Feeds may supply most essential nutrients in adequate amounts. However, essential nutrient deficiencies are common and are mainly related to the geochemical characteristics of the soils, inherited from parent rocks. This study aims to assess the concentrations of the selected essential nutrients in topsoils and pasture grass from São Miguel Island (Azores) and discuss the possible effects of its deficiency in grazing cattle health. Sixty-eight samples of agricultural (pastures) topsoil and thirty samples of pasture grass were collected throughout São Miguel Island in areas with basaltic and trachytic parent rocks. Soil physicochemical properties and geochemical baselines of selected elements were determined on composite samples of soil and pasture grass in each site. Results indicate that the highest concentrations of the selected essential nutrients were observed in areas with basaltic soils, while the lowest values were found in areas with trachytic soils. These differences are considered of geogenic origin since they result from the weathering of volcanic parent rocks with different geochemical compositions. Data indicate a lack of some essential nutrients in topsoils (Co and Se) and/or pasture grass (Co, Cu, Se, and Zn) that can contribute to harmful health effects on grazing cattle. The uneven distribution of essential nutrients in topsoil and pasture grass and their deficiency can lead to several health problems in the cattle since these elements regulate physiological functions in biological systems. The identification of these deficit sites is important as it can help farmers to implement soil and/or animal supplementation programs to diminish possible health problems.
- Drinking Bottled and Tap Water for Healthier Living in Volcanic Areas : Are All Waters the Same?Publication . Linhares, Diana P.; Gaspar, Diogo; Garcia, Patrícia; Rodrigues, ArmindoIn most volcanic areas, the population considers the use of bottled waters as a healthier and safer option. This study aimed to (i) assess the fluoride concentrations in tap and bottled water consumed on São Miguel Island, (ii) confirm the accuracy of the labeling of fluoride levels on bottled water, and (iii) assess the fluoride daily intake and risk exposure and discuss the possible health effects in adults and children. Fluoride concentrations were measured in tap water (49 samples) and bottled water (23 samples) with a fluoride ion-selective electrode. The fluoride concentration was above the recommended limit in tap water from Sete Cidades (1.71 mg/L), in bottled waters nº 5 and 7 from category C (2.05 ± 0.04 mg/L and 2.36 ± 0.14 mg/L, respectively), and in bottled water nº 5 from category D (1.92 ± 0.03 mg/L). Fluoride daily intake in children reached a maximum value in gasified water nº 7 (0.059 mg F/day/kg). The risk assessment evidenced that all the brands with over 1.2 mgF/L might be a concern for potential non-cancer health effects, especially in adults. The most recognized brands of gasified and gasified flavored waters represent a higher risk of exceeding fluoride daily intake when compared to tap and mineral bottled waters.
- Evaluation of Respiratory, Genotoxic and Cytotoxic Effects from Occupational Exposure to Typography ActivitiesPublication . Linhares, Diana P.; Rocha, Joana Gonçalves; Rodrigues, Armindo; Camarinho, Ricardo; Garcia, PatríciaThis cross-sectional study was structured to allow the evaluation of the respiratory, genotoxic, and cytotoxic effects of occupational exposure to products resulting from the activity of printers in typographies and, to determine the risk of genotoxicity associated with such exposure. This study comprised 69 subjects, 25 individuals occupationally exposed to the products of typographies (study group), and 44 individuals non-exposed to the environment studied (reference group). The frequency of micronucleated cells and other nuclear anomalies (binucleated, karyolitic, pyknotic, and karyorrhectic cells) in the oral epithelia of each subject were analyzed. The frequency of micronucleated cells was significantly higher in the study group when compared to the reference one (12.96 MN/2000 cells vs. 4 MN/2000 cells, respectively). Occupational exposure to products of typography is a risk factor for the occurrence of micronucleated cells in the study group (RR = 3.2; 95% CI, 2.7–3.9; p < 0.001). The results of the spirometry test did not reveal significant respiratory effects between the reference and study groups.
- Exposure of thermoelectric power-plant workers to volatile organic compounds from fuel oil: Genotoxic and cytotoxic effects in buccal epithelial cellsPublication . Garcia, Patrícia; Linhares, Diana P.; Amaral, A. F. S.; Rodrigues, ArmindoThermoelectric power-plant workers are constantly exposed to high levels of potentially genotoxic gaseous substances, such as volatile organic compounds (VOCs) from the combustion of fuel oil or the processing of naphtha. The aim of the present study was to estimate the association between such occupational exposure and the frequency of micronucleated cells and cells with other nuclear anomalies. Buccal epithelial cells were collected from a total of 44 power-plant workers (exposed group) and 47 administrative workers (non-exposed group), and examined for the frequency of micronucleated cells (MNC) and of cells with other nuclear anomalies (ONA: pyknosis, karyolysis, and karyorrhexis) by means of the micronucleus assay. The frequencies of MNC and ONA per 1000 cells in the exposed group (1.8‰ and 82.4‰, respectively) were significantly higher than in the non-exposed group (0.2‰ and 58.3‰, respectively). The exposed group had a twelve-fold increase in risk for formation of MNC compared with non-exposed individuals (RR = 12.1; 95% CI, 5.0–29.2; P < 0.001). The confounding factors analyzed (age, smoking status, alcohol consumption, and mouthwash use) did not show any significant association with the frequency of MNC or ONA. The findings of this study show that workers from power plants exposed to VOCs have a significantly elevated risk for DNA damage. Therefore, bio-monitoring of DNA damage is recommended for this group of workers.
- Fluor : um bom ou mau amigo? Desfazer os mitosPublication . Linhares, Diana P.[…]. Nos Açores, e na ilha de São Miguel em particular, a fluorose dentária era endémica em freguesias como a Ribeira Quente, as Sete Cidades e o Porto Formoso. Porque e que isto acontecia? Porque as aguas subterrâneas destas regiões com atividade vulcânica são naturalmente enriquecidas em flúor, devido à lenta dissolução dos sais minerais das rochas e dos gases vulcânicos. Uma vez que, só na década de 90 do século passado, foi estabelecido um conjunto de normas de qualidade relativas a agua para consumo humano (Decreto-Lei 236/98), muitas populações consumiam água com concentrações de flúor muito acima dos limites máximos recomendados (ex: a nascente da Lobeira que abastecia parte da freguesia da Ribeira Quente apresentava concentrações médias de flúor de 5.09 mg/L antes do seu encerramento). Aliado a exposição natural ao flúor por conta da atividade vulcânica da ilha, a exposição total diária ao flúor pode ser consideravelmente superior ao desejado devido ao tipo de práticas, como, por exemplo, o consumo excessivo de chá, que é uma planta biocaumuladora de flúor. […].
- Fluoride in volcanic areas : a case study in medical geologyPublication . Linhares, Diana P.; Garcia, Patrícia; Rodrigues, ArmindoVolcanic regions have always attracted many people worldwide because of the high fertility of their soils. However, human proximity to volcanoes can lead to several health problems as consequence of the chronic exposure to the materials released from the volcanic activity. An element often found in elevated concentrations in volcanic regions is fluorine. Although fluoride is recognized to have a beneficial effect on the rate of occurrence of dental caries when ingested in small amounts, its excessive intake results in a widespread but preventable pathological disease called fluorosis. While skeletal fluorosis, the most severe form of fluorosis, requires a chronic exposure to high concentrations of fluoride in water (4-8 mg/L), dental fluorosis occurs after shorter periods of exposure to fluoride in lower concentrations (1.5-2.0 mg/L). In some volcanic regions, where exposure to elevated amounts of fluoride is persistent, biomonitoring programs are fundamental to assess the main sources of exposure and to evaluate the effects of the exposure in resident populations. This chapter aims to cover the main effects of fluoride exposure in humans and discuss the use of a multidisciplinary approach that brings together the geoscience, biomedical, and public health communities to address environmental health problems.
- H2S – Sulfeto de Hidrogénio : «aquele» cheiro a ovos podresPublication . Rodrigues, Armindo; Linhares, Diana P.; Garcia, Patrícia[…]. Num estudo recente, sujeitos humanos voluntários foram expostos durante exercício físico moderado, e por um período de 30 minutos, a níveis de H₂S abaixo do disposto na legislação dos EUA (14 mg/m³). Foram observadas alterações no sangue e nos músculos, mas nenhum voluntário apresentou sintomas adversos, nem foram registadas alterações nos parâmetros da função pulmonar. A legislação portuguesa (Decreto-Lei n.º 1/2021, de 6 de janeiro) prevê os seguintes valores-limite para o H₂S: 8 horas de exposição (7 mg/m³) e curta duração de exposição (15 minutos) (14 mg/m³). Recentemente, alguns estudos têm encontrado efeitos positivos para a saúde em sujeitos expostos a baixas concentrações deste gás. […].
- Iodine Intake and Related Cognitive Function Impairments in Elementary SchoolchildrenPublication . Bailote, Helga G. B.; Linhares, Diana P.; Carvalho, Célia; Prazeres, Susana; Rodrigues, Armindo; Garcia, PatríciaIodine deficiency, the most common cause of preventable mental impairment worldwide, has been linked to poorer intellectual function in several studies. However, to our knowledge, no studies have been performed in moderate iodine-deficient schoolchildren using the complete form of Wechsler Intelligence Scale for Children (WISC-III; Portuguese version). The main purpose of this study was to ascertain whether moderate iodine deficiency would affect the cognitive function of schoolchildren (7–11 years old; 3rd and 4th grades). Raven’s Colored Progressive Matrices (CPM; Portuguese version) were used for measuring the intelligence quotient (IQ) of the total population (n = 256; median UIC = 66.2 μg/L), and the WISC-III was used to study two selected subgroups: one moderately iodine-deficient (n = 30) and the other with adequate iodine intake (n = 30). WISC-III was shown to be the prime instrument for cognitive function assessment among moderate iodine-deficient schoolchildren; this subgroup had a Full-Scale IQ 15.13 points lower than the adequate iodine intake subgroup, with a magnitude effect of d = 0.7 (p = 0.013). Significant differences were also registered in 6 of the 13 Verbal-Performance IQ subtests. Moderate iodine deficiency has a substantial impact on mental development and cognitive functioning of schoolchildren, with significant impairment in both Performance IQ and Verbal IQ spectrum, adversely impacting their educational performance.
- Iodo e Selénio na linha da frente como minerais essenciais : será que ingerimos o suficiente?Publication . Linhares, Diana P.[…]. Relativamente aos Açores já foi evidenciado, em vários estudos, que a população adulta e infantil apresenta, na sua generalidade, um aporte deficitário de Iodo correspondendo a cerca de 50% das gravidas e 80% das crianças em idade escolar; esta carência no aporte de Iodo, resulta da heterogeneidade na distribuição deste elemento no solo. Fatores ambientais e geológicos como a orografia e o índice de pluviosidade das ilhas poderão explicar a irregularidade deste elemento no solo, uma vez que, poderão contribuir para um aumento da lixiviação dos solos. Contrariamente ao Iodo, para a disponibilidade e aporte do Selénio na população humana não existem estudos desenvolvidos na região. […].