Variation of ozone and aerosol particle numerical concentrations on the working premises under different microclimatic parameters

Abstract

Investigations of air quality on the working and residential premises as well as its effect on human health and materials have been started many years ago and are still intensively carried out now. This is a result of application of new materials in the field of construction, implementation of new technological processes as well as intensive use of various devices at home and workplaces. It is known that a high concentration of ozone and aerosols could have negative effects on human health as well as on materials. Quite frequently not quite new copying machines which might be a strong source of pollutant emission are used for copying. An experiment was carried out on the working premises with three operating copying machines and a laser printer. The changes and distribution of ozone concentration and numerical concentration of aerosol particles (d > 0.4 %m) from the source of emission, i. e. a copying machine, were investigated. Measurements were carried out under different conditions of copying work intensity and ventilation. The microclimate parameters (temperature gradients, noise level, relative humidity, light) and spectrum of aerosol particles (0.4–2.0 μm) were measured as well. A copying machine was found to be the main source of ozone and aerosol particles. Intensity of copying work largely determined dynamics of these pollutants on the office premises. The maximum ozone concentration and minimum concentration of aerosol particles were estimated during automatic copying. It was found that ozone concentrations outside could not be the main and significant source of this pollutant in the room. Positive relationship between ozone concentration and temperature gradient was found; the correlation coefficient was 0.85, and the negative one (–0.81) was between aerosol particles and temperature gradient. During experiment it was found that the pollutants under examination were mostly influenced by relative humidity and temperature gradient.

Nustatyta, kad ozono koncentracijos lauke negalėjo būti pagrindinis arba svarbus šio teršalo patalpoje šaltinis. Automatinio kopijavimo metu nustatyta maksimali vidutinė ozono koncentracija 166 μg/m³. Nustatytas teigiamas ryšys tarp ozono koncentracijos ir temperatūros gradiento, koreliacijos koeficientas – 0,85, tačiau tarp aerozolio dalelių ir temperatūros gradiento gautas neigiamas koreliacijos koeficientas (–0,81). Darbo patalpoje labiausiai kito 0,4–0,5 μm aerozolio dalelės, o didesniu kaip 1,5 μm dalelių kiekis buvo mažiausias. Tiriant aplinkos rodiklių poveikį ozono ir aerozolio dalelių sklaidai patalpoje gauta, kad tiriamiems teršalams didžiausios įtakos turėjo santykinė drėgmė ir temperatūros gradientas.