Quartz dust

Granularity characteristic curves of an identical quartz dust obtained by... 

Mehlhorn, J. et al., Analysis for the association between progressive systemic scleroderma, exposure to quartz dust, and silicosis in East German uranium mining, Zbl. Arbeitsmed., 49, 134, 1999. 

Conrad, K. et al., Systemic lupus erythematosus after heavy exposure to quartz dust in uranium mines clinical and serological characteristics, Lupus, 5, 62, 1996. 

Prinsloo, H. Effect of exposure to quartz dust in vivo on pentose cycle activity in guinea pig lung. Environ. Res. 6 68-76, 1973. 

Adverse effects on the lungs of workers exposed to the fumes of ferrosilicon furnaces have been recognized since 1937. Subsequent clinical studies of workers exposed to amorphous silica fume in silicon and ferrosilicon plants reported pulmonary symptoms and X-ray findings difficult to differentiate from classic silicosis due to crystalline silica, especially because there is often concurrent exposure to quartz dust during furnace operations. 

By subcutaneous or intravenous injection of an aqueous solution of (PVNO) (20) or by inhalation of an aerosol of a PVNO-sohition (21) the cytotoxieal action of quartz dust can be prevented prophylactically and acute or chronic silicosis can be... 

Qzm has been treated to decrease the surface hydrophilicity. Three different hydrophobization procedures have been followed (i) the condensation of silanols into siloxane bridges by outgassing the powder at 1073 K, largely irreversible by re-exposure to water (ii) the functionalisation of silanols with tryethylsilyl groups and (iii) treatment with diluted HF. This last treatment dissolves the external disordered layers of particles containing impurities. In Figure 4, the amount of BSA adsorbed on the three treated quartz dusts is compared with untreated samples of pure quartz. All treatments decreased the... 

Figure 4. BSA adsorption on modified quartz dusts, amount of protein adsorbed vs initial concentration of Qzm ( ) Qzm outgassed at 800° C (V), silanized ( ) and treated with diluted HF (T) and pure quartz (O).

The effect of hydrophylicity and the presence of impurities has been evaluated on a series of different quartz dusts which are similar in dimension... 

Silicosis. The disease resulting from the inhalation of flint or quartz dust, and apparently due to the irritating action of those particles on the lung tissue. It is an incapacitating disease and predisposes the victim to pulmonary tuberculosis. 

The determination of quartz dust in the air samples in industrial workplace is an established procedure. Although capable of collecting the particulates, organic polymer membranes can not be employed as an XRD substrate since the diffuse diffraction lines at or near the 10 angle of quaru makes polymeric membtanes not suitable for this application [Minneci and Paulson, 1988]. It is possible to quantify as low as 0.005 mg quartz under well controlled conditions (Bumsted, 1973]. Similarly, silver membranes can also be used as a collecting medium and XRD substrate for measuring crystalline and amorphous silica, lead sulfide, boron carbide and chrysotile asbestos [Leroux and Powers. 1970]. 

Silica may be transferred to the site of silcrete development by wind and/or water. Quartz dust, for example, may be transported considerable distances from desert areas by the wind (Goudie and Middleton, 2001). Similarly, plant phytoliths, sponge spicules and diatoms can be subject to aeolian transport (Clarke, 2003). All other transfers rely upon silica transport in solution as undissociated monosilicic acid, either as the monomer H4Si04 or the dimer H6Si207 (Dove and Rimstidt, 1994). Organic or inorganic complexes may also be formed. 

It is interesting to note that in West Germany the increased occurrence of bronchial carcinomas in patients with silicosis cannot be based on statistical records (65). In other words, even if silicosis develops as a result of quartz dust, the silicosis cannot be associated with a cancerous disease. According to Mayer (69), the findings from animal experiments that showed that quartz dust also caused an increase in carcinomas cannot be applied to human beings. 

EXPOSURE GUIDELINES ACGIH TLV TWA 0.100mg(of contained respirable quartz dust)/m OSHA PEL TWA 250mppcf(respirable dust)/(%Si02 + 5) or lOmg (respirable dust/mV(% S1O2 + 2) NIOSH REL TWA 0.050 mg(respirable dust)/m IDLH 50 mgW. 

Chronic exposure to crystalline silica particulates may cause silicosis, which is a chronic lung disease with symptoms of scattered rounded nodules of scar tissue in the lungs. Very heavy exposures to quartz dusts of very small particle size can cause acute silicosis. This disease is rapidly progressive aud can develop within a few months of initial exposure. It is often associated with mbercu-losis. Death can occur within 1 or 2 years. 

Tatrai, E., Adamis, Z., Timar, M., and Ungvary, G., Comparative histopathological and biochemical analysis of early stages of exposure to non-sihcogenic aluminium silicate- and strongly silicogenic quartz-dust in rats, Exp. Pathol, 23,163-171,1983. 

Respirable dusts, including friable insulation or heat-resistant materials, and sand or quartz dust, especially from grinding or blasting. 

Insufficient rnedical data On the chronic harmful effects to humans. Carborundum aKvsys contains quartz. Exposure to quartz dust can cause king disorders Ksiicon ddxadl. It is unknown whether carborundum itseir has these effects. ... 

Saturated sodium nitrite solution Copper sulfate solution treated with cone, ammonia and piperidine (1) Quartz dust... 

Fig. X.10. Entrainment of quartz dust with particle size below 30 jum (numbers on curves) as a function of average air-flow velocity.

Removal of Adherent Dust. The regeneration of filters, i.e., freeing the filters from adherent dust, may be performed by various methods. The adherent layer may be removed by back purging this method, however, is quite ineffective. For example, v/ith an air-flow velocity of 2 m/sec through a bed made up of 1 m of filter fabric surface, out of 500 g of quartz dust with particles sizes below 10 jum, no more than 0.2% of the particles are blown free. In this operation, only the weakly adherent particles are removed. Most of the adherent particles require higher air-flow velocities for detachment, up to 50 m/sec (see Section 43). 

Granite Hairdresser s chemicals Halogens (fluorine, chlorine, bromine, iodine) Abrasive quartz dust increased prevalence of gingivitis and dental caries in Danish granite-industry workers (Petersen and Henmar 1988) Laryngitis (Sala et al. 1996) Irritate in high concentrations ... 

Choudat D (1994) Occupational lung diseases among dental technicians. Tuber Lung Dis 75 99-104 Christy WC, Rodnan GP (1984) Conjuged progressive systemic sclerosis (scleroderma) report of the disease in husband and wife. Arthritis Rheum 27 1180-1182 Conrad K, Mehlhorn J, Liithke K, Dorner T, Frank KH (1996) Systemic lupus erythematosus after heavy exposure to quartz dust in uranium mines clinical and serological characteristics. Lupus 5 62-69... 

Rihs HP, Conrad K, Mehlhorn J, May-Taube K, Welticke B, Frank KH, Baur X (1994) Association between HLA-D alleles and scleroderma-specific autoantibodies in quartz dust exposed persons (in German). Z Arztl Fortbild (Jena) 88 513-518 Rihs HP, Conrad K, Mehlhorn J, May-Taube K, Welticke B, Frank KH, Baur X (1996) Molecular analysis of HLA-DPBi alleles in idiopathic systemic sclerosis patients and uranium miners with systemic sclerosis. Int Arch Allergy Immunol 109 216-222... 

---