Physico-chemical properties and biological effects of diesel and biomass particles (original) (raw)
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Importance of Components and Sources for Health Effects of Particulate Air Pollution
2010
Inflammation involves a variety of cells, including migrating immune cells that may enter inflamed organs. In the lung the first line of defence includes the phagocytising macrophages and the epithelial cells (Figure 1). These cells may release a variety of signalling molecules, such as chemokines, cytokines, leukotrienes and prostaglandins, in addition to adhesion molecules. Local inflammation Systemic inflammation ASTHMA COPD FIBROSIS CANCER Importance of sources and components of particulate air pollution for cardio-pulmonary inlammatory responses 49 sized particles, like the more arbitrarily-shaped mineral particles from road wear, the small diameters of the primary carbon particles provide a relatively large surface area per mass unit. A large surface area implicates a greater potential for adsorption of various components to the particle surface, including metals, organic compounds, allergens and bacterial components like endotoxins. The contribution from residential wood combustion to ambient PM concentrations is highly dependent on the season, but in the cold season wood smoke may contribute substantially to increased levels of PM locally. Similar to combustion particles from traffic, emissions from wood stoves generally consist of aggregates of small carbon particles. However, under very poor combustion conditions spherical organic carbon particles dominate wood smoke emissions, whereas inorganic ash particles are emitted from complete high-temperature combustion (Kocbach et al., 2009). The size and composition of both traffic-and wood smoke-derived particles varies substantially in time and space, depending on the source, fuel type and post-formation processes.
Particulate matter components, sources, and health: Systematic approaches to testing effects
Journal of the Air & Waste Management Association, 2015
Exposure to particulate matter (PM) is associated with adverse health outcomes. There has long been a question as to whether some components of the PM mixture are of greater public health concern than others so that the sources that emit the more toxic components could be controlled. In this paper, we describe the National Particle Component Toxicity (NPACT) initiative, a comprehensive research program that combined epidemiologic and toxicologic approaches to evaluate this critical question, partly relying on information from a national network of air quality monitors that provided data on speciated PM 2.5 (PM with an aerodynamic diameter <2.5 μm) starting in 2000. We also consider the results of the NPACT program in the context of selected research on PM components and health in order to assess the current state of the field. Overall, the ambitious NPACT research program found associations of secondary sulfate and, to a somewhat lesser extent, traffic sources with health effects. Although this and other research has linked a variety of health effects to multiple groups of PM components and sources of PM, the collective evidence has not yet isolated factors or sources that would be closely and unequivocally more strongly related to specific health outcomes. If greater success is to be achieved in isolating the effects of pollutants from mobile and other major sources, either as individual components or as a mixture, more advanced approaches and additional measurements will be needed so that exposure at the individual or population level can be assessed more accurately. Enhanced understanding of exposure and health effects is needed before it can be concluded that regulations targeting specific sources or components of PM 2.5 will protect public health more effectively than continuing to follow the current practices of targeting PM 2.5 mass as a whole. Implications: This paper describes a comprehensive epidemiologic and toxicologic research program to evaluate whether some components and sources of PM may be more toxic than others. This question is important for regulatory agencies in setting air quality standards to protect people's health. The results show that PM from coal and oil combustion and from traffic sources was associated with adverse health outcomes, but other components and sources could not definitively be ruled out. Thus, given current knowledge, the current practice of setting air quality standards for PM mass as a whole likely remains an effective approach to protecting public health.
2019
Particulate Matter (PM) is one of the most relevant environment-related health issues all over the world. In 2013, the International Agency for Research on Cancer (IARC) has classified air pollution and PM as a carcinogen for humans [1]. However, the mechanisms involved in the toxicity of these particles remains poorly understood, mainly because PM are uniquely complex owing to their physicochemical characteristics. In this study, fine particles were collected in the city center of Dunkirk, northern France using a 5 stages high volume cascade impactor (Staplex® 235, 68m3/h) and a Digitel DA80 high volume sampler (30m3/h).Samples were extensively characterized for their physico-chemical properties, including trace metals, water-soluble ions and organic species. Normal human bronchial epithelial cells (BEAS-2B) were used as cell model for toxicological analysis. Cytotoxicity, PAHs-metabolizing enzymes gene expression and genotoxic alterations were evaluated after 24, 48 or 72 h of exp...
Environmental Science Technology, 2012
One of the most widely used in vitro particulate matter (PM) exposures methods is the collection of PM on filters, followed by resuspension in a liquid medium, with subsequent addition onto a cell culture. To avoid disruption of equilibria between gases and PM, we have developed a direct in vitro sampling and exposure method (DSEM) capable of PM-only exposures. We hypothesize that the separation of phases and post-treatment of filtercollected PM significantly modifies the toxicity of the PM compared to direct deposition, resulting in a distorted view of the potential PM health effects. Controlled test environments were created in a chamber that combined diesel exhaust with an urban-like mixture. The complex mixture was analyzed using both the DSEM and concurrently collected filter samples. The DSEM showed that PM from test atmospheres produced significant inflammatory response, while the resuspension exposures at the same exposure concentration did not. Increasing the concentration of resuspended PM sixteen times was required to yield measurable IL-8 expression. Chemical analysis of the resuspended PM indicated a total absence of carbonyl compounds compared to the test atmosphere during the direct-exposures. Therefore, collection and resuspension of PM into liquid modifies its toxicity and likely leads to underestimating toxicity.
Environmental research, 2017
Exposure to particulate matter (PM) is increasing worldwide as a result of increased human activity, the rapid industrialization of developing countries, and effects of climate change. Adverse effects of PM on human health are well documented, and because PM exposure occurs mostly through the airways, PM has especially deleterious impact on the lungs. We investigated whether surrogate PM particles like carbon black (CB), diesel exhaust particle (DEP), coal fly ash (CFA) can recapitulate the allergic airway inflammatory response induced by urban particulate matter. We compared the pro-inflammatory potential of urban PM collected from New York (NYC) and Baltimore (Balt) with CB, DEP and CFA surrogate PM particles. Eight to ten weeks old BALB/cJ mice were exposed through the airways to particulate material, and markers of airway inflammation were determined. Specifically, we assessed cellular influx, mucus production, lung function, cytokine levels as well as immune cell profiling of t...