Scope of Air Quality Monitoring Within the Network of Public Health Institutes in Republic of Serbia

Coal burning power plants, household solid fuel combustion, industrial contamination, traffic, and topography of urban settings are key reasons for labelling air pollution as a serious public health threat for urban population in Republic of Serbia, where air quality (AQ) is monitored by both National and Local network of measuring stations. The research tool in this cross-sectional study is a database formed by the Institute of Public Health of Serbia (IPHS) as a part of continuous AQ monitoring process for the Ministry of Health, through regular reporting of local IPHs, from the Network of Public Health Institutes (Network). Depending on the Local AQ monitoring Program, sources of continuous air pollution and pollutants ́ chemical nature, local IPHs monitor among the following: SO2, black carbon (BC), NO2, total atmospheric deposited matter, BeToXy, PM10 and PM2.5. SO2 and BC are measured daily. In 2018, 18 out of 25 Network IPHs monitored AQ for any of the given parameters: SO2 at 76 measuring points in 33 urban settlements; both BC and NO2 at 70 measuring points in 31 settlements. The pollutants most needed to be monitored are PM10 and PM2.5 particles, but are still monitored with the least frequency within the Network. Only 8 out of 25 IPHs monitors PM10 in 15 settlements at 28 measuring points. Local programs of AQ monitoring in Serbia, conducted with the participation of the IPHs Network, give an incomplete coverage of potential public health threats for quantifying the burden of disease originating from urban air pollution.


INTRODUCTION
Air pollution, from both outdoor and indoor sources, represents the single largest environmental risk to health globally. WHO estimated that air pollution was responsible for more than 550 000 premature deaths in the WHO European Region in 2016, almost 6.600 of which were attributed to air pollution in Serbia. This disease burden is preventable, if air quality improves [1]. Coal burning power plants, household solid fuel combustion, industrial contamination, traffic, and topographic position of urban settings are key reason for labeling air pollution as a serious public health threat for urban population in Republic of Serbia [2]. AQ is monitored by both National and Local network of measuring stations. National network of automatic measuring stations (AMSs) consists of 40 stations, being distributed and maintained by the Serbian Environment Protection Agency (SEPA) [3]. Besides the broad terrestrial distribution of SE-PA's AMSs (Figure 1), their number is still accounted as insufficient. In order to increase the density of AQ monitoring, local self-government administration is contracting with other stakeholders able to carry out this task, which, in most of the cases is a local IPH, belonging jointly to the Network of IPHs, a constitutive part of the health sector of the Republic of Serbia [4,5,6]. Official administrator for the Local Network is local self-government [7]. In total, 25 institutions comprise the Network of Public Health Institutes (PHIs) in Serbia (Figure 2), lead by the National PHI (1+24), of which AQ laboratories are operational in 20 of them [6].

Figure 2 -IPHs Network
Our aim was to present the scope of urban AQ quality monitoring undertaken by the above-mentioned laboratories, as part of a mix of stations belonging to both the State Network of AMS and the network of local measuring stations. Also, we aimed to present a decreasing trend in monitoring, in general, when these legal entities are the case.

METHODS AND DATA COLLECTION
The research tool used in this cross-sectional study is a data base formed by the Institute of Public Health of Serbia (IPHS), as a segment of a continuous AQ monitoring process implemented for the Ministry of Health, through regular reporting of local IPHs from the Network. Sampling, measuring and analyzing level of defined indicators are done by environmental health departments of local/regional IPHs. Data collation, processing and analysis are undertaken by the IPHS, whose assignment is to forward its remarks on possible public health risks to decision-makers. Due to the clear market conditions established in the field of operation of accredited laboratories, the data collected at the IPHS may vary from year to year [4].
Indicators that are monitored are grouped according to the nature of pollution sources, population coverage, traffic density and potential public health risks: SO2, black carbon (BC), NO2 and other specific pollutants, such as NH3, PM10, heavy metals, and traffic-originated organic chemicals. Together with the key stakeholders at the local level (local self-government, local IPH), each municipality/town produces a Local Action Plan for AQ monitoring, defining the time schedule of monitoring activities and spatial distribution of sampling points, sources of air pollution and choice of pollutants in need of monitoring. Sulfur dioxide and BC are measured daily due to the strong correlation among their ambient air concentrations and fossil fuel combustion, as Serbia's key energy source is lignite coal [8]. NO2 is the most frequently measured specific pollutant, on daily basis.
Presence of particulate pollution in ambient air is monitored through sampling of coarse particles of total atmospheric deposition (mg/m 2 /day), PM10 and PM2.5, with different measurement frequency, according to local AQ monitoring plans and specific indication, depending on pollution sources and financial resources of the local administration and the polluter, per se [9].

RESULTS
SO2 and BC are measured on daily basis. In 2018, 18 out of 25 IPHs from the Network has monitored AQ for any of the given parameters, with the following distribution: SO2 measurements covered 76 measuring points in 33 urban settlements; BC 70 measuring points in 31 urban settlements; as traffic-induced pollutant NO2, measured also in 31 urban environments at 70 measuring points. Table 1 presents the overall picture of monitoring dynamics for the period 2009 -2018, performed for SO2, BS and specific pollutants (SPs) by the local IPHs. (Table 1). If we analyze the data trend line, we clearly note that a decrease in the dynamics occurred steadily, throughout the last decade, for both general pollutants (SO2, BC), and the heterogeneous group of "specific pollutants", strictly speaking of the IPHs Network activities (Figure 3 -4). Among all of the SPs, the pollutants most needed to be monitored are PM10 and PM2.5 particles, but are still monitored with the least frequency within the Network of IPHs. Only 8 out of 25 IPHs monitors PM10, in 15 urban settlements at 20 measuring points ( Table 2). The other public health mischief is that among them, only in 5 settlements (Veliki Crljeni, Obrenovac, Kraljevo, Sremska Mitrovica, Užice), the parameter is measured continuously, while in other 10 it is performed only once in a week, which is insufficient for any serious EHIA analysis. Regular air sampling for the PM10 contents is of essential importance, as those two municipalities are hosting two lignit-burning power plants, of which, the one in Obrenovac is the largest in the Western Balkans Region, marking it as a source of substantial public health concern [12]. The same disproportion is met in the capital city of Belgrade (agglomeration), having only 2 sampling sites with continuous PM10 monitoring, while the other 7 are engaged only once in a week.

DISCUSSION
Besides pure technical AQ measuring practice, local IPHs pursue their expertise with the local administrative bodies established for the cause of environmental pollution prevention, which is, also, a legally-defined activity [6,10]. One of the most substantial improvements in local ambient AQ was implemented in the TEHNIKA -KVALITET IMS, STANDARDIZACIJA I METROLOGIJA 20 (2020) 2 town of Užice (West Serbia), known for its historical high levels of BC, generating from household fossil fuel combustion, in combination with its specific terrain topography. These long-lasting mix of environmental conditions was recognized by the expert community as a cause of different, mostly respiratory, health problems [11]. Due to locally adopted by-laws and financial subsidies for switching to other energy sources and pollution sustainable heating modes, Užice is experiencing a steep drop in the BC pollution trend line ( Figure 5).

Figure 5 -Užicedecrease of BC annual mean values
The measures applied in Užice local self-government are in line with suggestions given by the European Environment Agency on the issue of local authorities as legal entities responsible for giving examples on air pollution mitigation measures [12]. As given in this EEA publication, local measures include expanding district heating, using cleaner fuels for heating, introducing lowemission transport zones, switching to cleaner buses or trams, promoting cycling, lowering speed limits and issuing congestion charges. Because of the variety of these measures and the different types of city, there is not one specific solution that fits all cities. What is remarkable about these measures is that they both reduce local air pollution and improve the quality of life in those cities. Furthermore, they cut greenhouse gas emissions and, in many cases, save money.
Last but not least, local IPHs are filling-in the data to the IPHS database for admissions to primary health care units on cases of exacerbation of asthma bronchiale and COPD (chronic obstructive pulmonary disease), which is, then, used to distribute them spatially using GIS in comparison to high mean annual concentration of PM10 and BC [13].

CONCLUSIONS
Local programs of AQ monitoring in Serbia, conducted by the Network of IPHs give an incomplete coverage of potential public health threats for quantifying the burden of disease originating from urban air pollution. One of the main reasons for such a situation is the constant non-compliance with the provisions of the legislation of those stakeholders (any accredited laboratory, be it private or public) who are obliged to forward all data on pollution monitoring in any environmental medium to the public health authority in charge of a specific territory, as well as to the IPHS, responsible for the country level [14].