Creation of a database of occupational and environmental concentrations of crystalline silica dust for the purpose of assessing past and current exposures

Abstract

«Creation of a database of occupational and environmental concentrations of crystalline silica dust for the purpose of assessing past and current exposures».

Background:: Professional exposure to respirable dust containing crystalline silica is of great interest for the serious lung diseases resulting from exposure.

Methods:: During the period 1986-2019, 3611 exposure data to crystalline silica were collected from companies in central Italy. The data were divided and statistically analyzed based on the sampling system (Cyclone Dorr Oliver, CIP 10-R, Cyclone GS3, SKC plastic selector, Cyclone Higgins-Dewell and Cyclone Lippmann) and the ATECO code (code of economic activity, Italian acronym, used to classify companies when they interface with public institutions) of the companies in which they were collected. For each ATECO code, the division was made according to the type of sampling (personal or static) and the descriptive statistics of the data were calculated.

Results:: Overall, for personal samples, 8.8% of the data exceeds 0.1 mg/m³, 19.6% exceeds 0.05 mg/m³ and 33.8% exceeds 0.025 mg/m³, the limit values set by the EU Directive 2019/130, suggested by the SCOEL and published by ACGIH respectively. The ATECO codes with the highest worker exposure (geometric means 0.067 and 0.069 mg/m³) were 23.31.00 (manufacture of ceramic tiles for floors and walls) and 23.42.00 (manufacture of ceramic sanitary ware), while the lowest exposure is found in 81.29.91 (cleaning and washing of public areas, removal of snow and ice including shedding of sand) with a geometric mean of 0.002 mg/m³.

Discussion:: Despite the general reduction over time, there are still many sectors in which data are higher than the current occupational exposure limits; especially in these sectors it is necessary to implement the measures to fully assess worker exposure.

Figura 1

Percentuale di dati ottenuti per sistema di campionamento Figure 1 - Percentage of data obtained by sampling system

Figura 2

Percentuale di dati quantificati in base al flusso di campionamento dei selettori Figure 2 - Percentage of data quantified based on the sampling flow of the selectors

Figura 3

Confronto tra le medie geometriche (µg/m³) dei dati relativi ai campionamenti personali dei codici ATECO con numero di dati maggiore di 6 attraverso l’applicazione del test parametrico “t” di Student: solo i confronti segnati con "S" sono statisticamente significativi Figure 3 - Comparison between the geometric means (µg/m³) of the data relating to personal sampling of the ATECO codes with a data number greater than 6 through the application of the Student’s "t" parametric test: only the comparisons marked with "S" are statistically significant

Figura 4

Medie geometriche (µg/m³) e percentuali dei dati totali da campionamento personale maggiori di 0,1 mg/m³, 0,05 mg/m³ e 0,025 mg/m³ raggruppati in base a periodi temporali di 5 anni: tutti i confronti tra i diversi periodi sono statisticamente significativi al test “t” di Student eseguito sui logaritmi dei dati. Figure 4 - Geometric means (µg/m³) and percentages of total personal sampling data greater than 0.1 mg/m³, 0.05 mg/m³ and 0.025 mg/m³ grouped according to time periods of 5 years: all the comparisons between different periods are statistically significant at Student’s "t" test performed on the logarithms of the data.