A portable air quality monitor based on low-cost sensors

National systems of automatic air quality monitoring are based on automatic measuring instruments that are installed in stationary air quality monitoring stations. Substantial financial resources are required for the procurement, installation, calibration, and maintenance of such measuring devices. For this reason, existing national and local air quality monitoring networks are not able to provide a high temporal and spatial resolution of measurement results. In the last decade, as a possible alternative to the conventional approach to air quality monitoring, real-time monitoring systems using low-cost sensors and sensor plat-forms have begun to be applied. This paper describes the basic characteristics of a portable air quality monitor PAQMAN 2020 based on low-cost sensors. Part of the results of comparative measurements of this device with the reference instruments is presented in the paper

Air quality and thermal comfort measurements in the offices using the low-cost sensors and monitors

The subjective experience of the environment where people live defines the comfort of that environment. The elements of environmental comfort are the air quality, thermal comfort, visual comfort, and sound comfort. The air quality in the room where people stay can significantly affect their concentration, i.e., the ability to work and study. The concentration of CO 2 in the room is used as an indicator of ventilation, that is, as an indicator of the air quality in the observed room. The thermal comfort defines a state of satisfaction with the thermal environment. The thermal comfort is achieved when the environment properties are such that they ensure the release of BAKAR 48 (2023) 1 COPPER body heat within the comfortable limits. This paper presents a part of the air quality and thermal comfort measurement results in the selected office in the Mining and Metallurgy Institute Bor from 2020 to 2022. Based on the analysis of measurement results, it was determined that the air quality in the selected office was satisfactory on an average of more than 90% of the working time, and the thermal comfort on an average of about 60% of the working time

Suspended particles concentrations in the secondary schools in Bor (Serbia) in heating season

This paper presents the results of measurements the suspended particles of the PM 10 and PM 2.5 fractions in two high schools in Bor (School of Mechanical and Electrical Engineering-MS and Grammar School-GM). The measurements were conducted in two heating seasons for a duration of seven days (five weekdays, and two weekend days). Periods during the weekdays when there were classes and weekend days when there were no classes at school were analyzed separately. The measurement results show that the average concentrations of suspended particles PM 10 during the class period were 1.7 (GM) and 2.4 (MS) times higher than in the period without classes. The average concentrations of suspended particles PM 2.5 in both schools during the class period were 1.5 times higher than in the period without classes. In MS the average PM 10 and PM 2.5 concentrations during classes were above daily limit values for 3 of 5 working days. In contrast, there was no exceeding of the average daily limit values for concentrations of suspended particles during classes in GM. The results of measurements indicate that more attention should be paid to the way classrooms are cleaned to reduce the possibility of particles resuspension due to the movement of pupils during the teaching period

Air quality in the city of Bor in 2023

The air quality in the city of Bor in 2023 is analysed in this paper. In the period from May 1, 2022 until April 1, 2023 the copper smelter in Bor was not working due to reconstruction and capacity increase. The analyses show that in 2023, no exceeding of the daily limit value for SO2 , PM10, and soot concentrations was detected at any measuring point. During the reconstruction of the copper smelter, correlation coefficients (Pearson) at measurement point "Jugopetrol" between PM10 and the chemical elements Cd and As were moderate (0.6>r>0.4), while in the period before and after the reconstruction of the smelter, they were strong (0.8>r>0.6), and very strong (r>0.8). The results presented in the paper indicate that despite the reconstruction of the copper smelter, the problem of emission of high concentrations of carcinogenic elements in PM10 from the copper smelter is still present. It is necessary to urgently implement additional measures to reduce these emissions to the values provided by law

Measurement of the air quality in the agglomeration of Bor in 2022 during the copper smelter reconstruction in Bor

This paper presents the results of the air quality measurements in the agglomeration of Bor in the period June-December 2022, in which the Copper Smelter in Bor was not working due to the works on reconstruction and increasing the capacity for copper concentrate processing. Based on an analysis of the existing measuring points and concentrations of pollutants, measured in the local and national air quality monitoring network in the territory of the Bor agglomeration, as well as the possible impact of the new mining and metallurgical facilities in the company Serbia ZiJin Copper Bor, the additional locations, where the measurements were performed, were selected. The air quality measurement results show that there was no exceedance of the hourly and daily limit values for gaseous pollutants, nor were there an exceedance of the limit value for the mean daily concentration of lead in the suspended particles of the PM10 fraction, as well as the target values for the concentrations of cadmium and nickel in PM10. The arsenic concentration in PM10 at the measuring point of PU Bor was above the target annual value for 3 days. The maximum measured mean daily value of arsenic concentration in PM10 at this measuring point was 11.3 ng/m3 . Based on a complete insight into the results of air quality measurements in the Bor agglomeration in 2022, it can be concluded that the dominant share of concentration of SO2 , CO, as well as the concentration of arsenic, cadmium, and lead in PM10, originates from the gaseous pollutant emissions from the Copper Smelter Bor in the period when it operates. It was established that at the measuring point MMI Bor, the nitrogen oxide emissions from traffic mostly affect the level of nitrogen oxides in the air. Also, the measurement results indicate that the operation of the Smelter in 2022 did not significantly contribute to the concentration increase of suspended PM10 particles in the agglomeration of Bor, and that during the period of operation of the Copper Smelter in 2022, no copper concentrates with increased nickel content were processed

Analysis of seasonal variations in the nitrogen dioxide levels in the city of Bor in the periods 2010-2013 and 2019-2023

In addition to traffic, the main source of nitrogen dioxide is also industrial plants where combustion takes place at high temperatures, such as heating plants and smelters. Nitrogen oxides from traffic are the dominant component of air pollution in large cities and represent an important source of exposure and health risk for people, especially those who move along busy roads. In Bor, real-time nitrogen dioxide concentrations have been measured since 2010 at the measuring point "Institute IRM Bor" near Mining and Metallurgy Institute Bor. This paper presents an analysis of the results of measuring nitrogen dioxide concentrations in Bor in the periods 2010-2013 and 2019-2023. Based on the analysis of nitrogen dioxide measurement results, it was established that in both periods there are seasonal changes (heating/non-heating season) in nitrogen dioxide concentrations. Nitrogen dioxide concentrations were on average 17% higher in the heating season than in the non-heating season. Also, in the period 2019-2023 the average concentration of nitrogen dioxide was 28.6 µg/m3 , which is about 18% more compared to the period 2010-2013 in which the average concentration of nitrogen dioxide was 24.3 µg/m3 . In the observed periods, there was no exceedance of the limit value for the average annual concentration of nitrogen dioxide of 40 µg/m3 . However, several days were recorded with an average daily concentration of nitrogen dioxide above the daily limit value of 85 µg/m3