Macro and microplastic pollution in Romania: addressing knowledge gaps and potential solutions under the circular economy framework

Landfills

The closure of non-compliant landfills is followed by the post-monitoring process to detect the risks of environmental pollution (Sluser et al., 2017). The most problematic issues in terms of plastic waste management in Romania were pointed out in its Circular Economy Strategy. Low recycling levels (31%), reduced content of recycled materials in new products, and low consumer awareness (Ministry of Environment, 2022) were especially indicated in this official document. As also emphasized in the literature, the norm in the last decades in Romania is given by the non-compliant landfills, with plastic waste that is known to tend to infiltrate into the soil and further into aquifers or reach nearby lands via wind (Pop et al., 2021). Microplastics tend to be released during these fire events at landfill sites (Wojnowska-Baryła, Bernat & Zaborowska, 2022) or by regular gas emissions, and carried out by the wind. Leachate is another important route for macro and microplastic contamination of soil, aquifers, or surface water bodies in the proximity as demonstrated in Serbia (Narevski et al., 2021). Besides mixed municipal waste flows, sewage sludge, or construction and demolition waste contaminated with plastics are still disposed of in landfills. Plastic waste accumulated could degrade in the landfill body as a source of microplastics (Petrović et al., 2023) but there are no such studies performed in Romania.

Therefore, future plastic pollution research should target the following topics regarding landfill sites: (i) leachate as the source of microplastics from closed or active landfills; (ii) former landfill sites–a source of plastic pollution for soil and groundwater; (iii) active landfill source of plastic pollution for surrounding areas.

Illegal dumping and open burning practices

Illegal dumping of solid waste such as municipal waste, packaging waste, textile waste, e-waste, construction and demolition waste, and end-of-life vehicles including plastic items contaminate the terrestrial environments. Therefore, both natural and built environments are exposed to plastic pollution such as public lands, roadsides, forest areas, pastures, degraded lands, or floodplains (see Fig. 4). The presence of illegal dumping sites in certain geographical areas indicates that waste collection is not efficient, there is poor law enforcement, and low environmental awareness in the community.

The MPW flows are fed by domestic waste management deficiencies (e.g., lack of proper waste collection schemes), nearby waste imports through illegal channels that contain non-valuable plastic items for the recycling sector such as e-waste and end-of-life vehicles. These end up in dumps, buried, or burnt while metal recovery via rudimentary practices such as copper and ferrous items are sold (Modoi & Mihai, 2022). A general survey of local authorities revealed that 536 communes had no access to waste collection services, favoring open dumping practices before 2010 (Centru de Excelenta pentru Dezvoltare Durabila (CEDD), 2010). The closure of rural dumpsites in 2009–2010 revealed that most of the localities from extra-Carpathian regions had the largest open dumps (surface and volumes). This is explained by the lack of poor waste management facilities, particularly in rural areas combined with higher population density (Mihai, 2015) while in the Carpathian regions, the dumps tended to be smaller and frequently located near freshwater bodies. In April-May 2019, a law enforcement campaign regarding illegal waste disposal practices in the proximity of water bodies was performed by the National Environmental Guard revealing 1908 dumps (C&DW, household waste, and other waste fractions) on riverbanks while the total inventory of illegal dumping sites detected in open environments in Romania reached 3,837 sites covering 1,384,980 m² (National Environmental Guard (GNM), 2020). On this background, it can be assumed that the MPW near freshwater bodies tend to be mobilized by river flows and flood events in downstream areas (Mihai, 2018; Liro et al., 2023).

In the spring and autumn seasons, there is a traditional cleaning campaign of backyards and this practice could either eradicate some wild dumps with support from local authorities and NGOs or contribute to illegal plastic waste disposal or open burning practices as shown in Fig. 4.

Therefore, several actions are required to reduce MPW levels in terrestrial environments such as (i) GIS databases about the illegal dumping sites for both urban and rural regions; (ii) citizen-science projects in mitigating illegal dumping and open burning practices of plastic waste; (iii) better law enforcement with community support; (iv) cleaning up events; (v) source separation of waste improvement involving various stakeholders of the community.

Macroplastic pollution of aquatic environments

Figure 5 reveals the current knowledge gaps and future research topics related to plastic pollution sources and loads of aquatic environments in Romania from direct inputs or transferred from terrestrial environments linked to solid waste and wastewater management deficiencies, and agricultural or industrial practices. Aquatic environments are represented by two major categories such as the Black Sea as a marine environment and the Danube River basin as the main freshwater environment. As observed from the bibliometric analysis, the Black Sea with its coastal areas and the Danube Delta were considered in the context of plastic pollution. It represents an advancement in the literature dedicated to this topic; however, these appear to be under-investigated from the distinction between macroplastic and microplastic point of view. Moreover, in the case of the Danube River basin, water body categories exposed to plastic pollution must be further investigated such as lakes (natural and anthropic), groundwater, rivers, and tributaries in diverse geographical conditions, and the Danube Delta. Special considerations should be given to the transboundary tributaries (e.g., Tiza, Siret, Prut) that require international scientific cooperation to determine the magnitude of transboundary plastic loads from upper to lower sections of river systems toward the Danube River. This is also the case of this river course where upper sections are exposed to plastic pollution before reaching Romania (Hohenblum & Maier, 2019). On the other hand, the role of extreme events (floods, drought) in revealing the active plastic loads and historical pollution besides the plastic fragmentation and retention levels in river basins is essential to be quantified in Romania.

Furthermore, sectoral contributions to macro and microplastic pollution of aquatic environments related to municipalities (urban and rural), tourist destinations, agriculture and fishing activities, plastic industries, and transportation are largely unknown in Romania.

Coastal areas and the Black Sea

The local population density and the differences in human activities, such as intense naval traffic, fishing activities like abandoned fishing gear (seines, trawl, purse, etc.) or even illegal fishing, nearby tourism activities and the Danube River, through the three discharge mouths are among the major factors that determine a high level of marine litter in the Romanian Black Sea area. These are frequently remembered across the existent studies (Anton et al., 2013; Galatchi & Anton, 2020; Golumbeanu et al., 2017). As a consequence, the waste abundance appears to be attributed especially to the direct anthropogenic influence (Stoica et al., 2021). Golumbeanu et al. (2017) clearly emphasized that plastic and related materials represent the most severe threat to the marine and coastal environment, being hardly degradable. Despite the local waste management efforts, plastic waste disposal near the marine environment (formed especially by bags, bottles, buckets, cans, linoleum, etc.) is seen as a macroplastic pollution source. It constitutes an aesthetic problem and also a threat to the biodiversity of the basin (Galatchi & Anton, 2020). In addition, tourism contributes to the plastic pollution problem through single-use plastic products (Giurea et al., 2018). In the same way, a kind of tendency among tourists to generate more waste compared to local citizens was observed in other research (Liu et al., 2022). Still, detailed analyses in this regard in Romanian tourism destinations are lacking. In detail, according to Table 1, the ratio of artificial polymer is prevalent in all beach locations (>70%) and it ranges from 74.3% in Eforie to 91.9% in Vama Veche. Therefore, the contribution of tourist littering and fishing gear to plastic pollution of the marine environment is obvious, but the data broken down per sources (tourist vs fishing activities) is not available for beach litter.

Field measurements revealed that marine litter has a higher average density (81.5 item/km²) compared to the Mediterranean Sea and plastic materials are abundant (González-Fernández et al., 2022). Still, the proximity of the Danube Delta could decrease this density to 30.9 ± 7.4 items/km² in the Romanian part of the Black Sea (Suaria et al., 2015). Therefore, regional differences are expected and the plastic contribution of the river network beyond the Danube River basin needs to be examined to determine the source of plastic pollution in the Black Sea region.

Danube Delta

The Danube Delta is a unique biosphere of Europe, a crucial wetland system and protected area, but it is exposed to plastic pollution. In terms of macroplastic, the domestic sources are related to Sulina towns and rural communities’ mismanagement practices besides the additional plastic pollution leakage associated with tourism flows. However, there are no studies to reveal the magnitude of domestic plastic pollution leakage or tourist contribution to the plastic waste management problem in this area. The last environmental report of Biosphere Danube Delta does not include any mention in terms of plastic pollution of the aquatic environment. However, it specifies that there is an increase in plastic packaging materials (PET bottles and lightweight) in both urban and rural localities due to consumer goods (Başcău, Ivanov & Niţu, 2022). The municipal waste management is landfilled-based and some manual sorting for PET bottles is performed at Sulina (city-port), Chilia Veche, and Sfantu Gheorghe, while the separate collection of household waste increased a bit from 18.9% in 2021 to 21.5% in 2022 (Başcău, Ivanov & Niţu, 2022). Edighiol is more an isolated location and a higher percentage of artificial polymer could be attributed to fishing gear on the Black Sea. Vadu and Vadu Sud are wild beaches with tourists’ contributions to beach litter through plastic packaging materials, but also paper/cardboard, aluminium cans, or glass bottles as shown in Table 2.

Rivers

Plastic pollution modeling of the Bistrita river basin was performed by Mihai (2018) for the upstream sector of Izvoru Muntelui Lake and surrounding localities. This study tested the local river plastic pollution generated by villages with data obtained from sanitation campaigns (e.g., Schitu creek, Ceahlau commune).

The first mapping of MPW along all Carpathian rivers is performed by Liro et al. (2023) while taking into account the entire Eco-Carpathian region where median values of MPW in Romania were the highest (118.4 tons.yr.km²) along the fifth-order watercourses. This study relies on MPW data at the national level derived from Lebreton & Andrady (2019) providing a general framework of macroplastic potential magnitude. However, regional plastic pollution modeling is required using the local waste generation rates (urban and rural) and municipal waste composition data (e.g., plastic waste fraction % of total MSW stream) to adjust the MPW levels to local geographies and waste management performances.

Plastic pollution in the Danube basin is significant for both macro and microplastic flows and international cooperation is crucial to reduce this environmental threat (Miklos, 2022). Transboundary plastic pollution is documented in the Tiza river for microplastic (Kiss et al., 2021) but further macroplastic studies are required in each country of the river basin (Molnar & Hanko, 2022). For example, in Romania, plastic pollution mobilization from the Mures and Somes rivers towards the Tisza river (Hungary) is largely unknown. Also, there is a lack of plastic pollution research in the case of other important transboundary rivers of the Danube basin such as Siret (Ukraine, Romania) and Prut rivers (Ukraine, Romania, Republic of Moldova), and how these river systems feed the plastic pollution of the lower Danube sector and delta region in Romania. Both Ukraine and the Republic of Moldova are facing waste mismanagement practices that contribute to plastic pollution of aquatic and terrestrial environments (Procházková, Ivanova & Muntean, 2019; Safranov, Prykhodko & Mykhailenko, 2023). Therefore, macroplastic pollution studies based on field measurements for different seasons and sections of rivers from the Siret and Prut basins are required for Ukraine, Moldova, and Romania. The river basin management plans must include data and analysis concerning plastic pollution levels.

Lakes

Mihai (2018) tested the plastic pollution modeling generated by rural localities of the Bistrita River basin upstream of the Izvoru Muntelui with the data resulting from sanitation campaigns. The results showed that rural communities contribute to 85% of plastic pollution, the rest could be attributed to business, fishing, and tourism activities. The floods of 2005, 2008, and 2010 mobilized the mismanaged plastic waste upstream and accumulated on the lake water surface and shorelines in the mix with wood debris and other household waste fractions. In the period between 2000 and 2010, most rural localities lacked or had rather a poor waste collection infrastructure where source-separated collection of waste was marginal (Mihai, 2018). In these circumstances, the uncollected waste ended up in rural dumpsites or was burnt (Mihai, 2015).

The cleaning-up campaigns revealed that Izvorul Muntelei Lake is affected by macroplastic pollution, particularly by pet bottles despite being one of the most recyclable items. Accordingly, the Bicaz clean-up events organized in 2022 and 2023 revealed the historical plastic pollution of Izvoru Muntelui Lake. The drought led to the retreated water line of the lake and macroplastics could be collected from inaccessible places including the forest areas near shorelines, bays, and plastic trapped by riparian vegetation and sediment (Liro et al., 2023).

Terrestrial environments (soil/land)

Even though most of the plastic-related studies on agricultural land are performed in Asia and Europe (Sa’adu & Farsang, 2023), in Romania, there are significant knowledge gaps regarding the concentrations of microplastics in soil compartments or various agricultural or other land-use ecosystems. Besides the degradation of macroplastics related to mismanagement practices in municipal and agricultural waste systems, sludge application is demonstrated as a key source of MPs contamination of soils in rural areas (Van Den Berg et al., 2020). Although plastic materials are omnipresent nowadays, research studies on different geographical areas are still incomplete including terrestrial environments. In Turkey, 41.5% of extracted plastics from 10 soil samples were microplastics and 16.3% were macroplastics related to single-use greenhouse cover and irrigation pipes (Gündoğdu et al., 2022). Similar studies are required to be performed in Romanian soils near large urban areas, industrial sites, towns, and rural municipalities.

Tudor et al. (2019) discussed the problem of microplastic contamination in the soil as a general review, but no experimental studies conducted so far in Romania have been performed. The problem of sewage sludge application as a source of microplastics is recognized (Tudor et al., 2019) and some alternatives are proposed to divert such waste streams from landfills or agriculture (Purdea, Rusănescu & Tucureanu, 2019). The use of pesticides on agricultural lands leads to plastic packaging generation that could leak into terrestrial environments. In Romania, there are no available waste statistics related to agri-plastics, and research on this topic is limited (Tudor et al., 2022). However, there are some experimental studies to provide biodegradable alternatives to the use of conventional studies (Râpă et al., 2011), but updated investigations are required.

Coastal areas and the Black Sea

Macroplastic fragmentation and unmanaged plastic waste from terrestrial and riverine environments are the Black Sea region’s main diffuse sources of MPs (Strokal et al., 2022).

In the case of the Eastern coast of the Black Sea in Turkey, more attention is paid to research on plastic pollution (Bat & Öztekin, 2022; Terzi et al., 2022), if compared with the western coast of the sea, which is related to the delta and the discharge of the Danube River into the sea. To fill this knowledge gap in Romania, Pojar et al. (2021a) collected 12 samples from surface waters with a neuston net. The results showed an average concentration of seven plastic particles/m³ of which fibers (~76%) had the highest concentration, followed by foils (~13%) and finally fragments (~11%). Their statistical analyses related to the concentration of plastic show that it was significantly higher near the mouth of the Danube River than in those four regions along the Romanian and Bulgarian coasts. This shows that the Danube River has a significant contribution to the concentration of plastic, i.e., macro, micro, and nanoplastic in the western part of the Black Sea. The plastic accumulation in the Danube Delta and Black Sea coasts poses risks to both freshwater and marine life (Buruiana, Ghisman & Obreja, 2022). MPs having a long persistence in the environment are transported by the flow and deposited in the sedimentary systems. The abundance and morphology of the particles change due to the flow rate and speed of the currents (Pojar et al., 2021b). Stoica et al. (2021) found that cigarette butts and pieces of plastic/styrofoam (2.5–50 cm) accounted for more than 50% along three Black Sea beaches. Significant differences between Mamaia resort and the protected wild areas of Vadu were found, revealing, in this way, the role of tourism flows in the plastic pollution problem. According to Strokal et al. (2022), an increasing collection of plastic materials and reduced consumption will diminish MPs from the sea by 40% till 2050. Therefore, improvement of waste management performances along the Black Sea coast is imperative in Romania to reduce the magnitude of plastic leakage into marine environments. However, the plastic waste transport from the Danube River basin to the Black Sea will remain a key environmental threat to be managed in the following decades.

Freshwater environments (including groundwater)

Plastic pollution in the Danube River basin requires a complex analysis involving transboundary pollution (Balla et al., 2022) in various rich ecosystems with international cooperation on this matter (Kittner et al., 2022). In Romania, there are serious knowledge gaps in research regarding MPs’ presence in all types of freshwater environments. Previous studies examined the organic and inorganic pollutants including micropollutants of transboundary rivers like Siret (Zait et al., 2022) and Prut (Moldovan et al., 2018), but no investigations concerning MPs were performed. Multisectoral cooperation (businesses-academic-institutions-authorities-NGOs) in relevant plastic research projects is undertaken in Romania. Microplastics were found in all water samples collected from 10 rivers, four lakes, and the Danube River course in Romania, suggesting that microplastics represent widespread pollution in freshwater environments. Thus, further investigations are required to compare the results (Act for Tomorrow, 2021). The first comprehensive report on the magnitude of plastic pollution on the Danube River in the Romanian sector reveals the fact that the Danube-Black Sea river transport has an average of 48.5 tons of MPs and 48 tons of macroplastic. The highest transport yield was recorded in the station sampling of Moldova Veche with values between 93 and 100 tons of plastic material transported per year with a volume of MPs between 46 and 51 tons (Mai Mult Verde Association, 2023). In this collaborative research, water samples of surface water (0–0.6 m) and depth were performed. Their results reveal that MPs have higher concentrations related to the retention process of river rocks/minerals, fauna, and flora (Mai Mult Verde Association, 2023).

Kiefer, Knoll & Fath (2023) revealed a high concentration of MPs in the Danube River Delta with a maximum value of 2,677 p∙L⁻¹ (>20 µm in size) and requested standardized sampling methods with different mesh sizes to avoid underestimation of MPs concentration. The problem of the harmonized approach of MPs in the Danube is also claimed by other studies (Kittner et al., 2022). Besides MPs transportation dynamics and retention levels by vegetation and sediment (Pojar et al., 2021c), the effects on freshwater biota are concerning and some species could be used as bioaccumulators of MPs pollution for freshwater ecosystems (Stankovic et al., 2021). Freshwater biota is exposed to microplastic pollution as shown in the case of Chondrostoma nasus with samples taken near the urban settlement of Mures river basin (Curtean-Bănăduc et al., 2023). Samples collected upstream, downstream, and from nearby wastewater treatment plants on the Jiu River detected the presence of microplastics with higher organic load in the downstream sector (Batrinescu et al., 2021). In the case of the Dambovita River, the highest microplastic concentrations were detected downstream to the wastewater treatment plant with a significant difference between sediment (90 mg/kg) and water column (9 mg/L) (Maria et al., 2023). Laboratory tests were performed to detect microplastics of surface water in vitro conditions through the phthalates’ desorption (Scutariu et al., 2019). According to Nesterovschi et al. (2023), the presence of Mps in karst spring water was not reported until their study in Romania. Following the analyses, the presence of Mps was confirmed in the spring water samples collected from two karst springs in the Apuseni Mountains (Țarina and Josani), located in North-West Romania. They obtained a quantitative estimate expressed as the number of fragments or fibers per liter (0.034 at Josani and 0.06 at the Țarina karst spring in the spring of 2021 and, in the fall of the same year, 0.05 microplastics per liter). Most of the MPs found here were dominated by polyethylene terephthalate (PET), followed by polypropylene.

Gundogdu et al. (2023) highlighted the knowledge gaps related to MPs contamination in groundwater at the global level and their potential implications for both public health and the environment. Such studies need to be developed in Romania because it is an important source of drinking water. On the other hand, old landfills still represent an environmental threat to surrounding groundwater sources. Therefore, landfill sites could act as microplastic sources for groundwater (Marinov & Marinov, 2014) as well as for the application of sewage sludge in agriculture.

Air microplastic pollution

Landfills and wild dumps fires that contain plastic items could release MPs into the air besides open burning practices of agricultural and household waste in rural regions. In addition, the burning of plastic waste from waste collection sites or recycling centers releases toxins into the atmosphere, smoking representing one of the main reasons in the latter case (Dragan, 2021). On the other hand, burning plastic waste in households releases toxic polycyclic aromatic hydrocarbons beside PM10 (Hoffer et al., 2020) while PVC burning poses concerns related to particles with cadmium content (Kováts et al., 2022), exposing rural populations to health risks. The burning of plastic waste is proven to be a source of microplastic pollution in Hungary (Kováts et al., 2022), while preliminary studies were performed for both Romania and Hungary countries (Hoffer et al., 2023). Thus, microplastic pollution research and investigations about the mismanagement practices such as open burning/illegal dumping of plastic waste, accidental fires at waste recycling sites, self-ignition (landfills), or intentional burning (waste collection points) as the source of MPs released in the air beside the role of wind transport in the case of lightweight plastic fragments from landfills, wild dumps, or sorting stations toward surrounding areas should be further considered.

The MPs research is gaining scope and public interest, according to Pop et al. (2023), but it remains a research field that requires better geographical coverage, both at the European and worldwide levels.

Waste management

Improvement of waste collection efficiency is compulsory to reduce as much as possible the illegal dumping of household waste in the surroundings. The source separation of the dual system (dry and humid fractions) is inefficient and contaminates the plastic waste. The poor quality of plastic waste collected from domestic sources increases the refuse rate at sorting stations. The refused household waste (including plastic fraction) is usually disposed of in landfills. For each ton of refused waste, there is an additional fee of 80 lei (around 17 euros) as a contribution to the circular economy as in the case of landfilled waste. However, this fee is low and, consequently, favors the importation of plastic waste that ends up in Romania’s landfills or natural environment (Mihai & Ulman, 2024). Gherheş, Fărcaşiu & Para (2022) indicated that, in the case of public institutions, the legislation regarding waste collection is coherent and comprehensible, but, when referring to households and blocks of flats, there are no clear methodological norms from the central authorities for a more efficient separate waste collection to be put into practice. The shift from a dual system to four or five fractions (paper/cardboard, plastic, metal, glass organics, residual) combined with strong environmental awareness campaigns could catalyze the recycling sector and plastic waste diversion from landfills and natural environments. In this regard, the Salacea commune from Bihor County is a good example. Bihor County signed a partnership with Zero Waste Romania, in 2018, through which the concept of zero waste was implemented in the Salacea community, with benefits like saving money, faster progress, more support to sustainability targets, and waste diversion from landfills (Zero Waste Europe, 2019). In this way, the amount of waste was reduced in just 3 months and this result made Salacea to become the only community in Romania to fulfill the target of reducing the amount of waste in landfills (Bodog et al., 2018).

Policies for reducing microplastic pollution

For a reduction of MPs pollution in Romania, as in other developing countries, a comprehensive approach with several ramifications is needed, involving primarily government policies, regulations in this direction of reducing pollution with MPs, public awareness campaigns (NGOs, questionnaires addressed to the population, mass media, etc.) as well as a close collaboration with all interested parties related to this type of risk. The major directions of action are composed of (i) upstream potential responses, namely the ones for microplastic pollution prevention or reduction of microplastic use, and emissions, and (ii) downstream ones, i.e., those for microplastic pollution mitigation or capture of microplastics, followed by their controlled disposal (Munhoz et al., 2022). However, the European Commission (2023) clearly emphasized the fact that the current legislation lacks a comprehensive approach. On this background, the reduction of MPs pollution in Romania requires a multi-sectoral approach, involving government policies, regulations, public awareness campaigns, local authorities’ participation, and collaboration with plastic and recycling industries. Some potential policies that could reduce both macro and microplastic pollution in Romania are revealed in Table S1 (see Supplemental Information). It is essential to be careful and to recognize that the approach to MPs pollution requires a coordinated common effort of the Romanian government, the industry, the communities, and individuals. Periodic monitoring and policy adjustments based on new research results as well as technological advances can be essential for an effective long-term strategy that would lead to control and a significant decrease in the pollution of environmental factors in Romania.

Circular plastic economy

An Action Plan for Implementing Circular Economy in Romania was elaborated by the authorities (Romanian Ministry of Environment, Water and Forests, 2023) with a major aim of increasing the capture rate levels of domestic plastic waste while following the circular economy approach. This plan aims to expand the rates of separate collection and waste recycling concentrated around pay as you throw system and the development of an adequate infrastructure for waste collection (Mic & Mic-Soare, 2021), but also with the necessity of increasing the pro-environmental education among Romanians, nearby innovation and collaboration between stakeholders with community support (Modoi et al., 2022). Plastic shopping bag bans were a type of policy option to mitigate single-plastic use at the consumer level (Androniceanu & Drăgulănescu, 2016). On the business level, effective recycling systems such as “bottle to bottle” promoted by Green Tech Buzau require high-quality source-separated “pet bottles”. Because of high contamination rates derived from domestic source separation schemes, this company imports plastic waste from abroad to keep the recycling facilities in operation at optimum levels. The implementation of a deposit-return scheme (DRS) in Romania could play a key role in providing a better quality of plastic waste products for recycling industries and decreasing their importation levels and downcycling practices but such system requires community involvement (Cliza & Spătaru-Negură, 2021). The new DRS system that started on 30 November 2023 is the key to fulfilling the material recycling rates related to plastic waste packaging materials. The recycling market is developed for PET and HDPE polymers, but other plastic waste materials are more difficult to recycle. The use of non-recyclable plastic products in cement factors as a substitute for fossil fuels raises environmental concerns and it should be avoided taking into account the waste hierarchy approach. Some laboratory-scale studies look for alternative reuse of plastic materials in the construction sector. For example, PET bottles could be used as concrete additives (Baciu et al., 2022) while polypropylene could be used in asphalt mixtures (Buruiana et al., 2023). The recycling of HDPE for industrial-scale applications is required to improve the diversion rate of this plastic waste flow from landfills in Romania (Teuşdea et al., 2020). The use of PVC plastic waste in producing ecological mortars is another alternative route for this plastic waste flow that is not well regarded in recycling markets such as pet bottles or HDPE packaging materials (Aciu et al., 2018).