Aspects regarding the impact of cloth waste burning in the historical residential areas of the Petroșani municipality

. The restructuring of the mining sector in the Jiu Valley basin in the context of decarbonization has as its main goal the reduction of atmospheric pollution. Despite the fact that previous studies suggest an overall improvement in air quality as a result of this process, most ignore the lack of an immediate alternative to the use of coal as a primary energy resource both locally and regionally. This lack of alternatives has been found to have a negative influence on air quality through the noxious gases and Particulate Matter released into the atmosphere following the burning of some fuels, cloth and footwear waste, especially in the historical residential areas of the cities. In this paper, some of the results obtained from the instrumental determinations carried out in different areas of the Petroșani Municipality are presented, with special regard to the air quality in the Historical Center of this city.


Introduction
Air pollution is a complex phenomenon involving a multitude of pollutants that can cause alterations of population health and environmental quality, depending on concentration or duration, causing serious effects acting either by high concentrations in a short time, or by reduced concentrations over a long time [1].The current paper addresses a highly topical issue regarding the complex mechanisms that act post-restructuring in the Mining Basin of Jiu Valley, with special regard to the air quality in the Municipality of Petroșani, in the context of decarbonization, knowing that this area has faced serious pollution problems over time (caused by exploitation and preparation of useful minerals) [1].Most of the studies carried out previously suggest the reduction of the impact and a general improvement of air quality as a result of the cessation of extractive activities without taking into account the immediate lack of alternatives to the use of coal as a primary energy resource at the local and regional level.Without having solid scientific arguments, other collectives of authors rather than basing their statements on the interpretation of general theoretical aspects placed in an inadequate local context, intentionally omit or completely misunderstand the issue and the deep interactions between the specific industrial area, geology, morphology, climate and other elements that define this special geographical area, due to the lack of alternative energy resources in the short and medium term.All this, combined with an alarming increase in the number of oncological patients in the area, forces a different approach to highlight through comparative studies the influence of different sources of air pollution and, as far as possible, their quantification.At different levels of depth, the documentation of the subject was started about four years ago by collectives that did not lack students, masters or doctoral students and the collective of authors, with different responsibilities and contributions [2,3,4,5].Thus, two important sources were identified that negatively influence the air quality in the analyzed area, namely the noxious gases and Particulate Matters resulting from the increase of the number of vehicles and implicitly the values of road traffic [6], but also as a result of the systematic burning of some fuels and/or/especially cloth and footwear waste in the historic districts of the cities.One of the most polluting industries is textiles and clothing; its detrimental ecological footprint is caused by high energy, water and chemical use, the generation of textile waste and microfiber shedding into the environment during laundering, apparel and footwear industries generate 8 -10% of global carbon emissions, superseding emissions from the aviation and shipping industries combined.[7,8,9].Throughout the entire life cycle of textile products, from obtaining fibers to storing waste, they generate multiple sources of pollution [10].Numerous studies show that reuse and recycling of textiles have more environmental benefits than landfill and incineration.For example, according to Dutch aWEARness's calculations, textiles recycling can offer energy, water and carbon dioxide savings of 64%, 95% and 73% respectively, in comparison to standard non-recycled textiles.This also reduces the consumption of raw materials by 61% because waste is eliminated [10,11].

Description of the studied area
The Jiu Valley is a place with a long history, as a result of the existence in its depths of a primary resource, coal.Coal and the industrial revolution allowed, in a short period of time, the transformation of land with strong pastoral-agrarian values into an important industrial center, strongly integrated and dedicated to mining.The organizational and technological development led to a demographic increase that determined, over time, along with the existing physical space, built space expansion, which acquires the attributes of modernity [2].The municipality of Petroșani, the administrative center of the Jiu Valley, is located in the homonymous depression, on the Eastern Jiu River, in the central, south-western part of Romania, Hunedoara County.The relief in the administrative territory is very uneven, specific to the mountainous area, with gorges on the routes of the two Jiu rivers (Eastern Jiu and West Jiu), the elevation of the land in the central area of the city being 600 m [2].Currently, the city has a population of about 32000 inhabitants and covers an area of about 43.5 km² (Fig. 1).Historically, the region has been inhabited since the Neolithic period, and in the 13 th century it was first mentioned in documents as an important mining region [12].The Former Workers' Colony of Petroșani (Figure 1) is an important historical area of the municipality, currently classified as the Historical Center.This area was built in the 1920s, as part of the project to develop the city as an industrial center.In this residential area, housing was built for the workers who were employed in the coal mines in the area.These houses were designed in a specific architectural style, with a single level and adjacent garden plots.It is a neighborhood where many families with modest material possibilities currently live [3,13].Unfortunately, despite the beauty and cultural value of the Historical Center of Petroșani, this area has become one of the most polluted in the city due to the low standard of living and the lack of alternative heating sources.People in this area use, in addition to wood, a significant amount of textiles and other waste for heating, causing polluting emissions.These emissions affect not only the health of the people in this area, but also the environment.The phenomenon of burning clothing and footwear waste from the second-hand industry in the historical neighborhoods of Jiu Valley is a complex and alarming one that has an adverse impact on human health and the environment.The burning of textile and footwear waste has become a common practice in the historical districts of Jiu Valley, in the context in which the inhabitants face the lack of alternative heating sources following the closure of the mines and the decarbonization process [4].The elongated shape but also the fact that it is surrounded by high mountains determine certain climatic peculiarities of the depression, and the city of Petroșani is no exception to them (Figure 1).Mountain ranges generally stop the movement of air masses, so the shelter they provide prevents the "ventilation" of the depression.Thus, the circulation of air masses is from north to south, through the "windows" that separate the mountains: Bănita-Merisor and Surduc-Lainici.Another interesting thermal phenomenon takes place in Petroșani, that of "thermal inversion" [1].In winter, the cloud layers invade the low depression forms allowing the establishment of a normal gradient at 800 m altitude from the cloud ceiling which favors the formation of an inverse temperature layer [5,14,15].This phenomenon also complicates the dispersion of atmospheric pollutants, as they persist longer in the areas affected by pollution.In this natural environment, in the neighborhoods of the historical area of the city, the population is accustomed to using textile and footwear waste to heat their homes.The reasons why they do this are constituted by the fact that the procurement of other fuels is more inconvenient to obtain, but also poverty, in some cases.The incineration of such waste is not new, but the problem is the way in which it is carried out.Pyrolysis and combustion have always been considered attractive alternatives for waste disposal, since these techniques provide a reduction in the volume of waste and also involve profitable energetic and/or chemical products.Thermal decomposition of waste can take place both in controlled conditions (incinerators, cement kilns) and noncontrolled conditions, for example, during fires or open-air burning.The substances emitted during non-controlled plastic thermal degradation may create a serious hazard to human health and to the environment [16].The elemental analysis and net calorific value for textile wastes are presented in Table 1 [17].From the data presented, the energy characteristics of this waste are good, compared to local coal (3500 -4000 kcal/kg), which is difficult to procure, or wood (2800 kcal/kg -4800 kcal/kg depending on humidity) which it has become very expensive in the last five years.Given the very low price of textile waste from the second-hand trade, the population's option to use it for heating becomes understandable.In extremely good combustion conditions, all organics should be oxidized.When the combustion conditions are not so good, some of these organics are obtained, representing the possible pollutants formed in the process.Table 2 shows the yields obtained for the main gases, volatiles and semivolatiles, and also the total of light hydrocarbons and semi-volatiles for the different studied wastes.For all wastes, the sum of the 16 priority PAHs constituted roughly 40% of the total yield of semi-volatiles.Naphthalene had the highest yield of the PAHs when combusting polyester, sewage sludge and used lube oil [16].Taking into account everything presented, for the evaluation of the impact due to the burning of textile waste, it was decided that in a first phase of the research, only the immissions of suspended particles and the content of Volatile Organic Compounds will be determined.The measurement of the emissions due to the burning of these materials was not possible due to the reluctance of the inhabitants, aware of the illegality of this activity.

The methodology and the devices used
In first stage, measurements were carried out in 42 different points, but the first 11 of them were excluded from the current study due to the greater distance between them and Petroșani municipality and these will represent the subject for a different paper.Also, another 8 sets of values, corresponding to MP 18 , MP 20 , MP 22 , MP 29 , MP 31 , MP 33 , MP 35 and MP 36 were not taken into account because the measured values were quite similar to those of neighboring points and thus were considered inconclusive.The experimental determinations were made with the help of the following devices: -DANI THM 411 Total Hydrocarbons Monitor.DANI THM 411 determines the total organic contents (HC) in ambient air or inert gases by means of the Flame Ionization Detection principle (FID).A pump aspirates the air to be analyzed and a small part of it is converted to the analyzer at constant flowrate, whereas the rest is vented through a precision backpressure regulator.The gas portion to be analyzed is sent directly to FID.The operative parameters are managed by a microprocessor, which controls all the operative phases of the instrument; -Verewa's F-701 beta gauge particulate monitor determines particulate concentration by measuring the amount of radiation a sample absorbs when exposed to a radioactive source.In general, the more energy absorbed, the greater the particulate concentration.Depending on their energy, the emitted electrons will be absorbed by any material (solid, liquid, gas) within their reach.The absorption constant is therefore based on both the energy (in MeV) of the emitted electrons and the chemical composition of the absorbing material.Simplified, the correlation is: the lower the energy of the electrons, the lesser the absorption's dependence on the chemical composition of the absorbing material.The F-701 utilizes a flat-top C-14 source with a half-life of 5730 years.This particular isotope offers several advantages over other emitting isotopes in that its emitted electrons are very low energy (0,156 MeV) and decay into a non-radioactive chemical.

Measurements results and interpretation
For the most accurate assessment of the impact on air quality due to the burning of textile and footwear waste in the homes of the Historical Center, measurements of Particulate Matters and Volatile Organic Compounds immissions were carried out at several points, both during the day (when waste is not burned) and during the evening when everyone lights the fires for warmth.The immission measurement points in the Historical Center (HC), Downtown (D) and Surroundings (S/Brădet Hill) are indicated in Figure 2.For comparison, immission measurements were also carried out downtown (MP 38 , MP 39 and MP 40 ) and also in the surroundings (MP 41 and MP 42 ), where there are no homes in which to burn textile and footwear waste (Figure 2).The obtained results are reproduced separately, for day and evening, in Tables 3 and 4 for the Historical Center (including the Beltway Overpass) respectively in Tables 5 and 6 for downtown and surroundings (Brădet Hill).
Particular attention should be paid to the values measured at point 13.This point is located on the Beltway Overpass, above measurement point number 12 and captures the subtle variations due to pollution resulting from heavy road traffic on the city's ring road (Figure 3).The synergy of road traffic with the new environmental objectives for sustainable development requires new correlations between the inputs of instruments measuring pressures of road traffic on ecosystems and environmental targets [6].As it was shown before, for comparison, Table 5 and 6 reveal the result of the measurements made in the downtown and Brădet Hill area, during the day and evening.Although the air quality is slightly better in the central area of the city, it can be observed that in the measurement points that lead to the historical area, the measured values worsen.However, this influence is not felt in the Brădet Hill area, as these measurement points are located at a greater distance from the sources of pollution in the historical area.Figure 4 shows the appearance of the Historical Center during the day, respectively in the evening, when the residents start lighting the fires for heating, in different seasons.From the two diagrams it can be seen that in the Historical Center area the average concentrations of the monitored pollutants are 2.8 -3.5 during day and 0.7 -1.3 times higher during evening in the case of dusts and 1.8 -2.2 during day and 5.4 -6.1 times higher during evening in the case of VOCs in the Historical Center area in the evening than in the downtown.

Conclusions
The municipality of Petroșani presents the geomorphological peculiarity of being located in a basin-shaped depression that greatly limits the circulation of atmospheric currents, to the detriment of the dispersion of pollutant emissions.In the Historical Center, due to poverty or the inaccessibility of other fuels, the population got used to heating themselves by burning textile and footwear waste which sometimes has a higher net calorific value than the usual fuels in the area.The burning or incineration of textile waste, under appropriate conditions, should not raise environmental problems.However, when this combustion does not take place in optimal conditions, pollutant emissions can reach worrying values especially in the Historical Center but also downtown.To determine whether the burning of these wastes has an effect on air quality, emissions of Particulate Matters and VOCs were monitored at 18 points in the Historical Center and at 5 points in the central area of the city and surroundings.From the interpretation of the results, as was predictable, in the interval of the day in which the burning of textile and footwear waste takes place in the homes of the Historical Center, the VOC and formaldehyde values are 5.4 and 6.1 higher respectively in Historical Center than in the central area.Due to the fact that the obtained results are worrisome, it is necessary to continue and deepen the research in this case, by expanding the determinations so as to know the chemical composition of the pollutants existing in the ambient air.

Fig. 1 .
Fig. 1.The map of Petroșani Municipality with location of the historical residential area (The Workers' Colony/Historical Center) and the geomorphological representation of the area of interest (after https://www.google.com/mapsand https://earth.google.com/web,Accessed in 20.08.2023)

Figure 4 .Figure 5 .
Figure 4. Details of the historical residential area; Historical Center in different seasons.For comparison, Figures5 and 6show the average values of the determinations made in the two areas, Historical Center and downtown.

Figure 6 .
Figure 6.Average values of formaldehyde and Volatile Organic Compounds in the Historical Center on day and evening in comparison with downtown.

Table 1 .
Elemental analysis and net calorific value for textile wastes.

Table 2 .
Comparison of the emissions from combustion at 850°C of different wastes (mg compound/kg sample).

Table 3 .
Immisions in the Historical Center during the day.

Table 4 .
Immisions in the Historical Center during the evening, when textile and footwear waste is burned.
Figure 3. General view of road traffic on the beltway of Petroșani municipality, captured from the beltway overpass in summer and winter.https://doi.org/10.1051/matecconf/202438900083SESAM 2023

Table 5 .
Results of the measurements carried out downtown and in the Brădet Hill, during the day.

Table 6 .
Results of the measurements carried out in the downtown and in the Brădet Hill, during the evening.