Monitoring airborne dust in an Italian basalt quarry: comparison between sampling methods

Abstract

A field study in a dark grey basalt quarry nearby Rome is presented. PM 10 airborne concentration due to typical quarry operations was recorded during a period of two months. The aim of the work is testing the suitability of the laser light scattering method in measuring airborne dust concentration in such typical environmental conditions like those from quarrying operations. To the scope, two sampling campaigns were developed according with two different methods: from one side a traditional gravimetric method (NIOSH 0600) based on an air sampling pump connected with PVC filters through a 37 mm aluminum cyclone was used to assess PM 10 concentration. On the other hand, a light scatter technology developed with a real time dust monitor was applied. This method, which is based on a photo detector that measures laser light scattered by particles in the sampled stream, allows us to assess airborne dust concentration through a specific calibration generally carried out by comparing the time weighed average photometer readings with field measures of a known dust test (A1 Arizona Road Dust in this case). The step of assessing airborne dust concentration from a sampled particle number is a critical passage, as concentration itself is strictly connected to the physical and chemical characteristics of the sampled aerosol, such as particle size distribution, density and refractive index that obviously vary from pollutant to pollutant. So after a preliminary comparison of the sampled sets of values, some further analysis was developed in order to test the accuracy of the sampled values and the correlation factor was assessed. The R 2 value (0.706) showed a fairly good correlation between the two methods suggesting we consider the optical method suitable to survey PM 10 in the specific case. So basalt airborne dust was taken into account and a field calibration was developed. The results showed a fulfilling improvement of correlation factor Air Pollution XXI 75

Dust formed during drilling in natural stone quarries

“…Drilling in open pit quarry, where also other quarrying processes (crushing) appeared, had significantly higher dust concentrations: approximately 5000 µg PM /m (Degan et al 2013 ), on average 14,000 µg TSP/m (Junttila et al 1996 ) and approximately 16,000 µg PM /m (Olusegun et al 2009 ). The highest reported concentrations were measured in natural stone quarry in Iran, where TSP and PM concentrations varied 78,000-110,000 and 6000-11,000 µg/m , respectively (Golbabaei et al 2004 ).…”

“…The knowledge of dust emissions from quarries is limited and consistency of results is low. A number of studies (Organiscak and Page 1995 ;Junttila et al 1996 ;Aatos 2003 ;Golbabaei et al 2004 ;Organiscak and Page 2005 ;Olusegun et al 2009 ;Bada et al 2013 ;Degan et al 2013 ;Sairanen 2014 ) have emphasis on dust formation during the drilling. Dust concentrations from drilling varied between approximately 100 -110,000 µg TSP/m (Sairanen et al 2016(Sairanen et al 2017.…”

Field evaluation of pm10detectors in a quarry environment

“…This step was aimed to better fit the characteristics of the photometer with those of the basalt dust from the quarry. In fact, as demonstrated by Alfaro Degan et al [23], specific calibration of the optical device [24] in relation to the dust being measured may reduce the bias between the two sets of values. The central part of this step was, therefore, that of comparing the dimensional characteristics of A1 Arizona Road dust (used in the factory calibration of the photometer) with the data from the dust collected in the case study.…”

Detecting seismic waves induced by blast operations at a limestone quarry by means of different transducer mounting

“…In order to test the differences between the two sets of values and hence the two methodologies, the same technique often utilized to assess differences between different sampling devices [28,29] is adopted. So a correlation analysis is presented, a Pearson product-moment correlation coefficient (PPMCC) is evaluated and a linear regression is modelled according to the expression shown in the following figure where results are presented.…”