# Bacterial Contamination of Parcel Vending Machines in Lublin, Poland
## 1 Introduction  
The parcel vending market has developed significantly in recent years. It is one of the most widely used forms of parcel delivery and collection. The concept of parcel vending machines (PVMs) dispensing different types of parcels dates back to 1883 and the invention of [PERSON]'s machine for selling postcards, envelopes, letterheads, and other items. By the 1880s, they were already popular in railway stations and post offices. The first Packstation, which dispensed parcels ordered by customers, was installed by a German courier company in 2001 [1]. In Poland, the market pioneer was InPost, which created its own Paczkomaty(r), the first of which was launched in Krakow in 2009. Today, the company has the largest number of machines and its share of the market for PVMs in Poland amounts to 57% [2]. According to the report, there are an average of 19 PVMs per 100 km\({}^{2}\) in southern Poland. The analysis also shows that 92% of respondents use a machine near their home; of all the possible ways of collecting parcels, respondents prefer to collect their parcels from PVMs, with almost 40% of them stating that they only use this form of parcel collection if it is offered by the seller [2]. Logistics operators of parcel delivery chains are increasingly focusing on environmental solutions, such as using photovoltaic panels, built-in batteries, or renewable energy,installing air quality sensors, and reducing their carbon footprint by increasing the proportion of electric vehicles in their fleet. There is also increasing attention to ensuring that machines do not disrupt the urban landscape (no advertising, covering walls with plants) [2]. The brief research carried out for this study shows that none of the existing courier companies in the Polish market provide data on their procedures for disinfecting or cleaning the touchscreens of the machines, nor have they paid attention to their microbial contamination. Touchscreens are now a key element of most devices used in different areas of both private (mobile phones) and social life (ATMs, gaming machines), including PVMs in public spaces. They are accessed by a large number of people in a very short period of time. Although in some cases PVMs allow for fast contactless operation in a remote form using a special app, this is not always possible. Only one of the logistic companies has completely abandoned the use of machines with secondary touchscreens, which largely allows contactless use of their services. Similarly, we have found no information on the presence of modifications to the touchscreen surfaces themselves that could reduce the adhesion and survival of microorganisms on PVMs. There is no shortage of proposals for such scientific solutions in the literature. One example is the 'command' surfaces with thermo-switchable antibacterial activity proposed by [PERSON] et al. [3]. These are so-called'smart' antibacterial (at 37 \({}^{\circ}\)C) surfaces based on silver nanoparticles (AgNPs) embedded in temperature-responsive poly(di(ethylene glycol)methyl ether methacrylate)--(POEGMA188) as well as poly(4-vinylpyridine)--(P4 VP) coatings attached to a glass surface. Another solution is an inorganic-organic silica/PDMS nanocomposite release coating with ultra-hardness (3.07 GPa) and thermal stability (up to 400 \({}^{\circ}\)C) presented by [PERSON] et al. [4]. The authors claim that it has significant potential for large-area applications, especially under harsh operating conditions. Literature data are scarce and fragmentary on the level of biological contamination of the facilities described. Several studies have investigated the microbiological contamination of shared public spaces, including automated teller machines (ATMs) [5; 6], fitness equipment [7], playgrounds [8], swimming pools [9], airport surfaces [10], and public transport vehicles [11]. A stochastic simulation designed to assess this risk presented by [PERSON] [12] described an updated model for microbial transmission using an asymmetric gradient transfer.