Environmental dusts

Sources and composition of the inorganic component of atmospheric particulate matter in remote areas

The atmospheric aerosol takes part in many physical and chemical processes in the atmosphere; it interacts with the solar radiation and it is capable to influence both the balance of the energy fluxes in the atmosphere and the chemico-physical characteristics of clouds. Great uncertainties still exist about these processes and their influence on the global climate. For this reason the  Arctic regions, which play a fundamental role, on the global climate system, are extensively investigated. In particular, trace elements in the atmospheric aerosol in Ny Ålesund site(Svalbard Islands) are being studied due to their important role in influencing the behaviour of the atmospheric aerosol and, finally, the climate forcing at regional and global level.

 

Characteristics of the inorganic components of atmospheric particulate matter in anthropized areas

Atmospheric particulate matter is a major source of pollution in urban areas. In recent years the interest in fine particulate matter (PM10) has been increasing due to the growing evidence of its negative effects on health. For this reason it is important to constantly monitor the levels of particulate matter and determine its chemical composition. The knowledge of the contents of major, minor and trace elements in PM10, determined by high resolution mass spectrometry with ICP source (HR-ICP-MS), enables one to get information on: natural and anthropogenic sources of particulate matter: effect of weather conditions on aerosol; changes in its composition over the years. These studies can be carried out with the aid of chemometric techniques of data processing.

 

Surface reactivity and cell responses of sugarcane ash

Sugarcane ash results form the combustion of commercial sugarcane crops before the harvest to remove superfluous leaf material and increase cutting efficiency. Bagasse ash is a residue resulting from the burning of bagasse in the sugarcane/alcohol industry. About 5.8 million hectares of sugarcane plantations are located in Brazil and approximately 20,000 kg of waste matter is burnt for every hectare. Agricultural burning events are rapid, with high temperatures recorded during the flaming phase. Biogenic silica found in sugarcane may undergo phase transformation during burning to form airborne respirable crystalline particles. A link between respiratory illnesses and sugarcane burning was recently reported in child and elderly respiratory hospital admissions, during the sugarcane-burning season in Sao Paulo, Brazil.

Physico-chemical properties of sugarcane and bagasse ash (size, composition, potential to generate radical species, bioavailable iron) were combined with in vitro toxicity assays (cytotoxicity, NO generation on alveolar macrophages ) and compared with those of a commercial quartz of well know fibrogenicity. This study was performed in tight collaboration with the Institute of Hazard, Risk and Resilience, Durham University.

 

Our bibliography on the subject:

 

Le Blond et al., 2012 (DOI: 10.1002/tox.21776)

 

Volcanic ash

Volcanic ash- formed during volcanic explosions- is composed of fine particles of fragmented volcanic rock. Ash composition and morphology may vary depending upon the type of volcano and the form of the eruption.

Many epidemiological and toxicological studies were carried out, especially during the 1980s, to try to assess the pathogenicity of the ash. The studies gave a range of conclusions from toxic to inert.

The main health effects of ash include eye symptoms, skin irritation, asthma and bronchitis.

Detailed examination of the characteristics of the ash itself – e.g grain size distribution, presence of fibrous particles, ash composition, oxidative potential - can help assess the potential health hazard.

The Scansetti Centre focus on the ability of volcanic ash to generate free radical in test cell free and on the presence of bioavailable iron on the particle surface, as a part of a protocol specifically developed by the International Volcanic Health Hazard Network for the assessment of the health hazard of volcanic ash. The study was developed in tight collaboration with the Institute of Hazard, Risk and Resilience, Durham University.
 

Our bibliography on the subject

Horwell et al., 2003  DOI:10.1016/S0013-9351(03)00044-6
Horwell et al., 2007 DOI: 10.1016/j.epsl.2007.07.032
Horwell et al., 2010 DOI: 10.1016/j.jvolgeores.2010.01.014
Le Blond et al., 2010 DOI: 10.1007/s00445-010-0382-7
Hillman et al., 2012 DOI: 10.1007/s00445-012-0575-3
Damby et al., 2012 DOI: 10.1016/j.jvolgeores.2012.09.001