Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cells
Autor(a) principal: | |
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Data de Publicação: | 2022 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10773/34462 |
Resumo: | Air pollution consitutes the largest risk to health in Europe. Particulate matter (PM) is considered the most harmful pollutant for humans. Road traffic represent a major source of PM. Emissions from traffic can be subdivided in exhaust emissions (tailpipe) and non-exhaust emissions, which comprise particles from tyre and brake wear, as well as road dust ressuspension. Contrary to exhaust PM, non-exhaust PM has been much less studied. Despite their low contribution to the PM mass, polycyclic aromatic hydrocarbons (PAH) constitute a group of persistent organic pollutants with a high carcinogenic and mutagenic potential. In this work the A549 pulmonary epithelial cell line was used to study the toxic effects of PAH extracted from PM emitted by traffic, including exhaust samples obtained under different driving cycles, samples collected in a road tunnel and simultaneously in a nearby urban background atmosphere, and samples from the wear of distinct types of brakes. Tests to assess cell viability, cell cycle and reactive oxygen species (ROS) intracellular levels were performed. The PM-bound PAH extracts from the wear of low steel brake pads induced greater decreases in cell viability. It was observed that cytotoxicity was more dependent on the individual composition of PAH than on the global concentration. The results obtained for the exhaust PM samples from from heavy-duty vehicles reveladed that Euro V trucks produce more toxic particles. The Euro VI norm adopted a limit of PM emission that is ten times lower than the levels allowed in the previous norm, contributing to a significant decrease of particulate matter in the exhaust and of the corresponding toxicity. Among Euro V vehicles, the one powered with GTL was the most toxic to A549 cell line. The composite weekly sample of the urban background atmosphere of the School Valsassina showed to be extremely toxic,decreasing the cell viability to 2.66%, while the maximum reduction observed for the daily road tunnel samples was 83.6%. Retene and naphthalene, which were not detected or were present at trace levels in samples from the tunnel, were found in the particulate extracts of the school sample. Irrespective of the sample, although some changes were observed in the A549 cell cycle after 24 h exposure in all the phases, the differences in the mean values were not great enough to exclude the possibility of random variability. When the results from the three phases (G0/G1, S and G2/M) from the cells exposed to all PM extracts were compared to control, no statistically significant difference was detected. Regardless of the type of sample, significant increases in cellular ROS levels were observed in cells exposed to the PM extracts of some heavy-duty vehicles. |
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Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cellsPMPAHExhaustNon-exhaustA549CytotoxicityAir pollution consitutes the largest risk to health in Europe. Particulate matter (PM) is considered the most harmful pollutant for humans. Road traffic represent a major source of PM. Emissions from traffic can be subdivided in exhaust emissions (tailpipe) and non-exhaust emissions, which comprise particles from tyre and brake wear, as well as road dust ressuspension. Contrary to exhaust PM, non-exhaust PM has been much less studied. Despite their low contribution to the PM mass, polycyclic aromatic hydrocarbons (PAH) constitute a group of persistent organic pollutants with a high carcinogenic and mutagenic potential. In this work the A549 pulmonary epithelial cell line was used to study the toxic effects of PAH extracted from PM emitted by traffic, including exhaust samples obtained under different driving cycles, samples collected in a road tunnel and simultaneously in a nearby urban background atmosphere, and samples from the wear of distinct types of brakes. Tests to assess cell viability, cell cycle and reactive oxygen species (ROS) intracellular levels were performed. The PM-bound PAH extracts from the wear of low steel brake pads induced greater decreases in cell viability. It was observed that cytotoxicity was more dependent on the individual composition of PAH than on the global concentration. The results obtained for the exhaust PM samples from from heavy-duty vehicles reveladed that Euro V trucks produce more toxic particles. The Euro VI norm adopted a limit of PM emission that is ten times lower than the levels allowed in the previous norm, contributing to a significant decrease of particulate matter in the exhaust and of the corresponding toxicity. Among Euro V vehicles, the one powered with GTL was the most toxic to A549 cell line. The composite weekly sample of the urban background atmosphere of the School Valsassina showed to be extremely toxic,decreasing the cell viability to 2.66%, while the maximum reduction observed for the daily road tunnel samples was 83.6%. Retene and naphthalene, which were not detected or were present at trace levels in samples from the tunnel, were found in the particulate extracts of the school sample. Irrespective of the sample, although some changes were observed in the A549 cell cycle after 24 h exposure in all the phases, the differences in the mean values were not great enough to exclude the possibility of random variability. When the results from the three phases (G0/G1, S and G2/M) from the cells exposed to all PM extracts were compared to control, no statistically significant difference was detected. Regardless of the type of sample, significant increases in cellular ROS levels were observed in cells exposed to the PM extracts of some heavy-duty vehicles.A poluição atmosférica constitui o maior risco ambiental para a saúde na Europa. A matéria particulada (PM) é considerada o poluente mais nocivo para o ser humano. O tráfego rodoviário representa uma das principais fontes emissoras de PM. As emissões desta fonte podem ser subdivididas em emissões de exaustão (cano de escape) e emissões de não-exaustão, as quais abrangem as partículas que resultam do desgaste de pneus e travões e ainda a ressuspensão de poeiras rodoviárias. Contrariamente às partículas de exaustão, as de não-exaustão têm sido muito pouco estudadas. Apesar de contribuírem pouco para a massa das partículas, os hidrocarbonetos aromáticos policíclicos (PAH) constituem um grupo de poluentes orgânicos persistentes com elevado potencial carcinogénico e mutagénico. Neste trabalho foi utilizada a linha celular A549 de epitélio alveolar humano para estudar os efeitos tóxicos dos PAH extraídos de PM emitido pelo tráfego, incluindo amostras de exaustão obtidas em distintos ciclos de condução, amostras coletadas num túnel rodoviário e paralelamente numa atmosfera de fundo urbano próxima, e ainda amostras resultantes do desgaste de vários tipos de travões. Foram realizados ensaios de viabilidade, ciclo celular e níveis intracelulares de espécies reativas de oxigénio (ROS). Os extratos com PAH resultantes das partículas do desgaste de travões com baixo teor de aço induziram maiores decréscimos na viabilidade celular. Observou-se que a citotoxicidade é mais dependente da composição individual dos PAH do que da concentração global. Os resultados obtidos para as amostras de exaustão de veículos pesados, revelaram que os veículos Euro V produzem partículas mais tóxicas. A norma Euro VI impôs um limite de emissão de PM dez vezes menor que os níveis permitidos na norma anterior, contribuindo significativamente para o decréscimo do material particulado na exaustão e correspondente toxicidade. Dentro dos veículos Euro V, o combustível GTL foi o mais tóxico para as A549. A amostra compósita semanal da atmosfera de fundo urbano da Escola Valsassina revelou ser extremamente tóxica, reduzindo a viabilidade celular para 2.66%, enquanto a redução máxima observada para as amostras diárias do túnel foi de 83.6%. No extrato orgânico da amostra da escola foi encontrado reteno e naftaleno, o reteno não foi detetado e o naftaleno está presente em níveis vestigiais nas amostras do túnel rodoviário. Embora, para algumas amostras, tenham sido observadas alterações em todas as fases do ciclo celular A549 após 24 h de exposição, as diferenças nos valores médios não foram suficientes para excluir a possibilidade de variabilidade aleatória. Quando os resultados das três fases (G0/G1, S e G2/M) das células expostas a todos os extratos de PM foram comparados com o controlo, não foram detetadas diferenças estatisticamente significativas. Independentemente do tipo de amostra, foram observados alguns incrementos significativos nos níveis celulares de ROS nas células expostas às amostras da exaustão de camiões.2023-07-27T00:00:00Z2022-07-26T00:00:00Z2022-07-26info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10773/34462engSoares, Marlene de Jesus Salvadoinfo:eu-repo/semantics/embargoedAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-02-22T12:06:40Zoai:ria.ua.pt:10773/34462Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:05:49.347028Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cells |
title |
Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cells |
spellingShingle |
Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cells Soares, Marlene de Jesus Salvado PM PAH Exhaust Non-exhaust A549 Cytotoxicity |
title_short |
Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cells |
title_full |
Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cells |
title_fullStr |
Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cells |
title_full_unstemmed |
Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cells |
title_sort |
Effects of particulate polycyclic aromatic hydrocarbons from traffic emissions on human lung epithelial cells |
author |
Soares, Marlene de Jesus Salvado |
author_facet |
Soares, Marlene de Jesus Salvado |
author_role |
author |
dc.contributor.author.fl_str_mv |
Soares, Marlene de Jesus Salvado |
dc.subject.por.fl_str_mv |
PM PAH Exhaust Non-exhaust A549 Cytotoxicity |
topic |
PM PAH Exhaust Non-exhaust A549 Cytotoxicity |
description |
Air pollution consitutes the largest risk to health in Europe. Particulate matter (PM) is considered the most harmful pollutant for humans. Road traffic represent a major source of PM. Emissions from traffic can be subdivided in exhaust emissions (tailpipe) and non-exhaust emissions, which comprise particles from tyre and brake wear, as well as road dust ressuspension. Contrary to exhaust PM, non-exhaust PM has been much less studied. Despite their low contribution to the PM mass, polycyclic aromatic hydrocarbons (PAH) constitute a group of persistent organic pollutants with a high carcinogenic and mutagenic potential. In this work the A549 pulmonary epithelial cell line was used to study the toxic effects of PAH extracted from PM emitted by traffic, including exhaust samples obtained under different driving cycles, samples collected in a road tunnel and simultaneously in a nearby urban background atmosphere, and samples from the wear of distinct types of brakes. Tests to assess cell viability, cell cycle and reactive oxygen species (ROS) intracellular levels were performed. The PM-bound PAH extracts from the wear of low steel brake pads induced greater decreases in cell viability. It was observed that cytotoxicity was more dependent on the individual composition of PAH than on the global concentration. The results obtained for the exhaust PM samples from from heavy-duty vehicles reveladed that Euro V trucks produce more toxic particles. The Euro VI norm adopted a limit of PM emission that is ten times lower than the levels allowed in the previous norm, contributing to a significant decrease of particulate matter in the exhaust and of the corresponding toxicity. Among Euro V vehicles, the one powered with GTL was the most toxic to A549 cell line. The composite weekly sample of the urban background atmosphere of the School Valsassina showed to be extremely toxic,decreasing the cell viability to 2.66%, while the maximum reduction observed for the daily road tunnel samples was 83.6%. Retene and naphthalene, which were not detected or were present at trace levels in samples from the tunnel, were found in the particulate extracts of the school sample. Irrespective of the sample, although some changes were observed in the A549 cell cycle after 24 h exposure in all the phases, the differences in the mean values were not great enough to exclude the possibility of random variability. When the results from the three phases (G0/G1, S and G2/M) from the cells exposed to all PM extracts were compared to control, no statistically significant difference was detected. Regardless of the type of sample, significant increases in cellular ROS levels were observed in cells exposed to the PM extracts of some heavy-duty vehicles. |
publishDate |
2022 |
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2022-07-26T00:00:00Z 2022-07-26 2023-07-27T00:00:00Z |
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info:eu-repo/semantics/publishedVersion |
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info:eu-repo/semantics/masterThesis |
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masterThesis |
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http://hdl.handle.net/10773/34462 |
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