[1] Calculations from a microphysics model are shown which indicate the factors that control droplet nucleation scavenging of hydrophilic mineral dust particles over a large range of conditions including the size, chemical composition, and number density of particles in both cumulus and stratus clouds. We focus specifically on the activation threshold radius (ATR) for droplet nucleation which d...

The recently developed Zurich Ice Nucleation Chamber (ZINC) was used to explore ice nucleation of size-selected mineral dust particles at temperatures between −20C and −55C. Four different mineral dust species have been tested: montmorillonite, kaolinite, illite and Arizona test dust (ATD). The selected particle diameters are 100 nm, 200 nm, 400 nm and 800 nm. Relative humidities with respect t...

Recent investigations of the fundamental mechanisms of the mineral dust diseases have substantially increased our understanding of the pathogenesis of the pneumoconioses. In all the mineral dust pneumoconioses, the initial early lung lesion is a fibrosing macrophagic alveolitis. The additional contribution of other lung cell populations is currently under investigation and may identify specific...

Uptake experiments of N2O5 on several mineral dust powder samples were carried out under continuous molecular flow conditions at 298±2 K. At [N2O5]0=(4.0±1.0)×10 cm−3 we have found γ ss values ranging from (3.5±1.1)×10−2 for CaCO3 to (0.20±0.05) for Saharan Dust with γss decreasing as [N2O5]0 increased. The uptake coefficients reported in this work are to be regarded as upper limiting values ow...

The purpose of this study was to estimate the risk of adult asthma in relation to certain occupational exposures. The study was designed as a case-control study in Göteborg, including 321 subjects with asthma, born between 1926 and 1970. Controls (n=1,459) were randomly selected from the same area from registers of the 1986 population. Questionnaire information was collected in 1996, and includ...

OBJECTIVES To clarify whether high tooth wear of employees in a mining industry that extracts the mineral olivine could be associated with airborne dust exposure in their working environment. METHOD The cumulative exposure to airborne mineral dust for the workers in the company was calculated on the basis of their period of employment multiplied by the airborne olivine-dust concentrations, wh...

Bergman, I., and Casswell, C. (1972). Brit. J. industr. Med., 29, 160-168. Lung dust and lung iron contents of coal workers in different coalfields in Great Britain. Lung dust analyses from seven coalfields are studied and it is found that the average dust composition varies significantly with the rank of coal. The higher the rank, the higher the coal percentage and the lower the quartz percent...

mineral dust is produced from both natural and anthropogenic sources. dust aerosols can be transported over long distances in the atmosphere. they reduce the incident shortwave radiation to the surface by absorbing and scattering the solar radiation; thereby leading to a cooling effect at the surface and lower tropospheric temperature. on the other hand, by absorption and re-emission of longwav...

Mineral dust aerosol is created by wind erosion of soil particles. In addition to its direct radiative effect, dust aerosol mediates ocean carbon uptake and the chemical cycles of other aerosols like sulfates. Dust observations during the past decade span measurements of local concentration and deposition to global satellite retrievals of aerosol optical thickness [Prospero et al., 2002]. Measu...

The ice nucleation characteristics of montmorillonite mineral dust aerosols with and without exposure to ammonia gas were measured at different atmospheric temperatures and relative humidities with a continuous flow diffusion chamber. The montmorillonite particles were exposed to pure (100%) and diluted ammonia gas (25 ppm) at room temperature in a stainless steel chamber. There was no signific...