Loading...
Publication
Poluição dos solos por metais pesados na zona urbana de Ponta Delgada : implicações na saúde pública
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 5.24 MB | Adobe PDF |
Authors
Abstract(s)
A descarga de metais pesados no ambiente contribui para a contaminação dos solos urbanos, quer a partir de fontes naturais (material parental, alteração das rochas, vulcanismo, etc.), quer de fontes antropogénicas (uso de pesticidas e fertilizantes na agricultura, efluentes domésticos e industriais, tráfego rodoviário, deposição atmosférica, etc.). Este estudo visou a avaliação da poluição por metais pesados dos solos na zona urbana de Ponta Delgada, localizada no extremo sudoeste da ilha de São Miguel, nos Açores. Nesta área em estudo, enquadrada no Sistema Vulcânico dos Picos, predominam os Andossolos Saturados Normais ou Pouco Espessos e um clima mesotérmico húmido, com estações secas no Verão. Foram recolhidas 40 amostras de solos em diferentes locais desta zona urbana, e determinado o pH, o conteúdo em matéria orgânica, a distribuição granulométrica, e as concentrações dos metais pesados (Co, Cr, Cu, Ni, Pb e Zn) por ICP/MS. O pH revelou-se em média neutro (7,03), o que sugere uma boa retenção de metais pesados no solo como o Cu, Pb e Zn, o teor em matéria orgânica foi em média baixo (1,62%), o que impossibilitará uma maior retenção de metais como o Co, Pb e Ni, e a análise granulométrica revelou predominância de elementos grosseiros, como areias (53,45%) e fenoclastos ou ruditos (41,77%). Sugere-se que Co, Cr e Ni deverão ter sido lixiviados durante a pedogénese, uma vez que apresentaram medianas inferiores às registadas na rocha-mãe, ao contrário do Pb e Zn, que terão origem antrópica. A distribuição espacial destes metais pesados evidenciou concentrações superiores de Pb e Zn na zona mais urbana de Ponta Delgada, nomeadamente junto à rede viária, o que é sustentado pela correlação (r=0.802) entre as concentrações de Pb e Zn nos locais amostrados. Relativamente aos níveis de referência estabelecidos em solos urbanos e de protecção da saúde humana, verificou-se que apenas os níveis de Co não oferecem perigo para a Saúde Pública. Para o Cr, Cu, Ni, Pb e Zn alguns locais apresentaram concentrações acima dos valores referência, podendo em caso de exposição crónica, por ingestão, inalação ou absorção cutânea, causar efeitos deletérios na saúde humana. Para estes metais, sugere-se a descontaminação dos solos, ou então a implementação de medidas preventivas que reduzam as fontes emissoras destes metais pesados.
ABSTRACT: The release of heavy metals into the environment contribute to the contamination of urban soils, from both natural sources (parent material, weathering, volcanism, etc), and anthropogenic sources (use of pesticides and fertilizers in agriculture, domestic and industrial emissions, traffic road, atmospheric deposition, etc). This study aimed to evaluate the heavy metal pollution of soils in the urban area of Ponta Delgada, located in the extreme southwest of the island of São Miguel in the Azores Arquipelago. In the study area, framed by the Volcanic System of Picos, Andosoils Saturated Normal or Thick dominate, and climate is humid mesothermal, with dry seasons in summer. Fourty soil samples were collected at different locations of this urban area, and therefore analyzed for pH, particle size, organic matter content, and concentrations of heavy metals (Co, Cr, Cu, Ni, Pb and Zn) by ICP/MS. Our findings reveal that pH was average neutral (7.03), which enables retention of heavy metals such as Cu, Pb and Zn, the organic matter content was on average low (1.62%), precluding a greater retention of metals such as Co, Pb and Ni, and particle size analysis revealed, predominantly, coarse elements such as sand (53.45%) and fenoclastos or ruditos (41.77%). Data also suggest that Co, Ni and Cr should have been leached during pedogenesis contrarily to Pb and Zn that should reflect mainly an anthropogenic origin. The spatial distribution of these heavy metals distinguished higher concentrations of Pb and Zn in the main urban area of Ponta Delgada, particularly near the highway, and urban streets, as shown by the correlation (r = 0802) between Pb and Zn at the sampled locations. For established baseline levels in urban soils and human health protection, it was found that only Co levels no offer danger to public health. At several locations, values of Cr, Cu, Ni, Pb and Zn were above the reference levels, which may have in case of chronic exposure by ingestion, inhalation or skin absorption deleterious effects on human health. For these heavy metals it is suggested decontamination of soils, or the implementation of prevention measures to reduce their sources.
ABSTRACT: The release of heavy metals into the environment contribute to the contamination of urban soils, from both natural sources (parent material, weathering, volcanism, etc), and anthropogenic sources (use of pesticides and fertilizers in agriculture, domestic and industrial emissions, traffic road, atmospheric deposition, etc). This study aimed to evaluate the heavy metal pollution of soils in the urban area of Ponta Delgada, located in the extreme southwest of the island of São Miguel in the Azores Arquipelago. In the study area, framed by the Volcanic System of Picos, Andosoils Saturated Normal or Thick dominate, and climate is humid mesothermal, with dry seasons in summer. Fourty soil samples were collected at different locations of this urban area, and therefore analyzed for pH, particle size, organic matter content, and concentrations of heavy metals (Co, Cr, Cu, Ni, Pb and Zn) by ICP/MS. Our findings reveal that pH was average neutral (7.03), which enables retention of heavy metals such as Cu, Pb and Zn, the organic matter content was on average low (1.62%), precluding a greater retention of metals such as Co, Pb and Ni, and particle size analysis revealed, predominantly, coarse elements such as sand (53.45%) and fenoclastos or ruditos (41.77%). Data also suggest that Co, Ni and Cr should have been leached during pedogenesis contrarily to Pb and Zn that should reflect mainly an anthropogenic origin. The spatial distribution of these heavy metals distinguished higher concentrations of Pb and Zn in the main urban area of Ponta Delgada, particularly near the highway, and urban streets, as shown by the correlation (r = 0802) between Pb and Zn at the sampled locations. For established baseline levels in urban soils and human health protection, it was found that only Co levels no offer danger to public health. At several locations, values of Cr, Cu, Ni, Pb and Zn were above the reference levels, which may have in case of chronic exposure by ingestion, inhalation or skin absorption deleterious effects on human health. For these heavy metals it is suggested decontamination of soils, or the implementation of prevention measures to reduce their sources.
Description
Dissertação de Mestrado em Ciências Biomédicas.
Keywords
Metais Pesados Poluição dos Solos Saúde Pública Açores Heavy Metals Public Health Soil Pollution Azores
Citation
Amaral, Marco Albino Bento – "Poluição dos solos por metais pesados na zona urbana de Ponta Delgada : implicações na saúde pública". Ponta Delgada : Universidade dos Açores. 2013. XI, 98 p.. Dissertação de Mestrado.