Suspended particles in outdoor and indoor air : characterization to support epidemiological studies
Year: 2009
Type: dissertation
Abstract: The assessment of the health impacts associated with exposure to particulate matter (PM) required more comprehensive information, mainly related to detailed physical-chemical characterisation of the respective particles.Thus this work studied the physical and chemical characterisation of suspended particles present in urban atmospheres (outdoor air) and in confined polluted environments (indoor air).The specific objectives were to study the influence of traffic emissions and of tobacco smoke on the physical and chemical characteristics in different fractions of inhalable particles with special attention to PM 10 and PM 2.5 , considering: PM concentrations and size distributions, elemental compositions, carbonaceous content, and the composition of polycyclic aromatic hydrocarbons (PAHs).PM 10 and PM 2.5 were collected using low-volume samplers at various sites influenced by traffic emissions and tobacco smoke as well at background (reference) sites used for the comparison, not being directly influenced by the respective emissions.The elemental analyses were performed by proton induced X-ray emission (PIXE) and scanning electron microscopy combined with X-ray microanalysis; carbonaceous components were determined by thermal combustion whereas PAHs were analysed by microwave assisted extraction (MAE) combined with liquid chromatography (LC).The results showed that traffic emissions significantly increased the concentrations of PM 10 , PM 2.5 and their metal contents.The elements originated mostly from anthropogenic activities were predominantly present in PM 2.5 , whereas the elements mostly originated from crust predominantly occurred in PM 2.5-10 .Regarding the carbonaceous content traffic emissions increased mainly the levels of elemental carbon being 500-900% and 490-740% higher for PM 10 and PM 2.5 , respectively.When influenced by traffic emissions the total concentration of nine carcinogenic PAHs increased by 2400% and 3000% in PM 10 and PM 2.5 , respectively, being mainly present in PM 2.5 ; these nine carcinogenic compounds represented 68% and 74% of total PAHs for PM 10 and PM 2.5 , respectively.Tobacco smoke significantly increased PM 10 and PM 2.5 concentrations being higher for PM 2.5 .The total concentrations of five carcinogenic elements (Cr, Ni, As, Cd and Pb) were 1100-3500% higher for PM 10 and 840-2200% higher for PM 2.5 , being predominantly present in PM 2.5 ; tobacco smoke increased mainly the levels of organic carbon being 290-500% and 300-590% higher for PM 10 and PM 2.5 , respectively.Considering the carcinogenic PAHs the increase was 780% and 770% in PM 10 and PM 2.5 , respectively; nine carcinogens compounds represented, respectively, 56% and 55% of total PAHs in PM 10 and PM 2.5 .All PAHs (including the carcinogenic ones) were mainly present in PM 2.5 , which corresponds to a strong risk for cardiopulmonary disease and lung cancer.Considering that carcinogenic components were predominantly present in particles of smaller sizes, the obtained conclusions confirm the strong risks associated with exposure to traffic emissions and tobacco smoke.The results obtained in this work are relevant for development of strategies to protect public health and to support future epidemiological studies evaluating passive smokers and populations affected by traffic emission sources. RésuméL'évaluation des impacts sur la santé associés à l'exposition aux particules en suspension (PM) nécessite plus d'informations détaillées et complètes sur leur composition physico-chimique.Ce travail est dédié à la caractérisation physique-chimique des particules dans les atmosphères urbaines (air extérieur) et dans des milieux pollués (air intérieur).Les objectifs spécifiques sont d'étudier l'influence des émissions du trafic et des émissions de la fumée de tabac sur les caractéristiques physiques et chimiques des différentes fractions de particules inhalables avec une attention particulière à la PM 10 et PM 2.5 , en tenant compte: la concentration et la distribution de taille, la composition élémentaire, la teneur en carbone élémentaire et le carbone organique et la composition de les hydrocarbures aromatiques polycycliques (HAPs).PM 10 et PM 2.5 ont été recueillies au moyen d'échantillonneurs à faible volume sur divers sites influencée par les émissions du trafic et de la fumée de tabac, ainsi que des sites de référence qui ne sont pas directement influencés par leurs émissions.L'analyse élémentaire des PM été faite par les techniques d'émission de photons X induite par protons (PIXE) et la microscopie électronique à balayage (MEB) en combinaison avec X-ray micro-analyse; la teneur en carbone élémentaire et le carbone organique a été déterminée par la combustion thermique et les HAPs ont été analysés par extraction assistée par micro-ondes (MAE), combinée avec la chromatographie en phase liquide (CPL).For Mum, For Sis, With my love.
Author: Klára Slezáková
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W307639895