The potential emission of personal care products derived plastic microbeads: a case study of Ho Chi Minh City, Vietnam

Plastic microbeads are commonly used in many personal care products and can cause adverse impacts to the environment and ecosystem. The toxicological problem with these pollutants are due to their non-biodegradable materials, which washed down the drain; end up accumulating in the aquatic system causing increased frequency and quantity of items ingested by biota. Several polymers (e.g. Polyethylene) especially those found in plastic microbeads have been reported to be in tandem with other toxic contaminants serving as a vector for their transports in the environment. Thus, the legislative ban for plastic microbeads is used in some developed countries, but many countries including Vietnam do not take any legal action. This present study aimed at potential microbead’s existence in the cosmetic market of Ho Chi Minh City (HCMC). The list and ingredients of microbeads containing personal care products (toothpaste, facial cleanser/scrubs and body wash/scrubs) have been checked. The microbeads containing PCPs are common for all explored categories, especially in toothpaste. Data from the online questionnaire survey have shown that 98% of respondents have frequently used at least one microbead containing product. Four polymers (Polyethylene, Acrylates Copolymer Styrene/Acrylates Copolymer and Acrylates/C10-30 Alkyl Acrylate Crosspolymer) have been observed in the product package of several facial cleansers and body scrubs. Thus, the potential negative impacts of this contaminant should not be ignored.


Introduction
The pollution caused by microplastics is of growing environmental concern [1]. Microplastics are defined as plastic items sized between 100 nm and 5 mm. Plastic microbeads, which are ingredients of personal care products (PCPs), have been considered as a significant primary source of microplastics in This paper provides the updated information with regards to the currents situation of PCPs deriving microbeads and the potential risks to residents in Ho Chi Minh city (HCMC). In addition to conclusive remarks, future directions on how to enhance community awareness as a priority measure to reduce microplastic contamination are also suggested.

Study area
HCMC is an attractive city and located in the south-eastern region of Vietnam. According to the 2019 census, the City has a population of over 8.9 million within the city's border and over 21 million within its metropolitan area. HCMC is the economic center of Vietnam and accounts for a large proportion of the economy of Vietnam. The tropical climate together with the rising living standards, have caused cosmetics to be incorporated into communities. Together with the capital city of Hanoi, 90-95% of the market for international personal care products is centered in these cities [27]. The average expense for skincare products in HCMC is higher than any region in Vietnam and estimated to be about 14 U$ per month. Up to 73% use skincare products once per week or more often [28]. Regularly-used skincare products are facial cleansers. The personal care sector of HCMC has strong growth of 7 percent a year on average. Especially, the rate of municipal wastewater treatment was only 21% of 1.5 million m 3 /day that 79% of domestic wastewater discharged directly into the surface water receiving in HCMC [29]. Therefore, HCMC has been selected for the present study.

Market survey
HCMC is an attractive and expanding market for PCPs, which have been increasingly consumed by the last few decades. To meet the growing demand, a lot of PCPs are imported in addition to local shops. Many multinational companies in HCMC, (namely Proctor & Gamble, Unilever, Johnson & Johnson, etc.) are up against strong competition from local firms, such as Dalan, Myhao, etc (Appendix C). With the miracle effectiveness through extensive advertising by producers together with widespread distribution in the market, microbeads containing PCPs became ordinary in HCMC. A brief overview of the potential microbead's existence in the cosmetic market of HCMC has been explored. Three  (Lotte Mart, Coopmart, and Bachhoaxanh) in District 7 were twice visited, which are present in almost all HCMC. Due to the Covid 19 pandemic, the survey has been further conducted through the websites of these supermarkets and two other cosmetic shops in HCMC (Guardian and Hasaki). Firstly, beads containing products from four different categories (toothpaste, facial cleanser/scrubs, and body wash/scrubs) were explored. Then, the ingredients will be checked to determine if this product contains plastics or not. However, it is not easy to find out the ingredients of the PCPs since it was not available on the shop's website except the websites from Bachhoaxanh supermarket, where all the ingredients of PCPs are shown.

Community awareness of microbeads in PCPs
Besides the legislative action, community awareness is important because it can increase their knowledge base to influence purchasing decision. Therefore, a quantitative analysis was carried out in the form of an online questionnaire. The survey period extended over five weeks from 12 th May to 19 th June 2021. The survey was performed with an online survey (Google Forms). The survey asked participants for their opinion about (1) beads/microbeads containing PCPs usage and (2) consumer product decisions. The consumer product decisions are based on the following hypothesis: -H1. The customer chooses microbeads containing PCPs because of their effectiveness in comparison with other products; -H2. The microbeads containing PCPs is the new trend of the cosmetic industry; -H3. The natural ingredients in PCPs are important to make a decision of buying PCPs; -H4. The usage of microbeads from PCPs could cause environmental pollution. Five-level Likert scale, ranging from (0) Strongly disagree; (1) Disagree; (2) Fairy Agree; (3) Agree to (4) Strongly agree, has been used (Appendix B). A total of 200 respondents, between 18 to 40 years old, mainly students and officers, have participated in this survey (Table 1). The data from five respondents, who do not use any beads containing PCPs, are not further processed. Statistical analysis has been performed with SPSS Version 11.0 statistical software package. The statistical reliability was first tested to assess the overall consistency of the psychometric questions. The Cronbach's alpha coefficient was used to estimate the internal consistency of the Likert scale.

The present situation of the beads containing PCPs in HCMC and the potential risks
It has been observed that it is not difficult to find microbeads containing PCPs in the supermarkets and/or shops of HCMC. The microbeads containing PCPs are common for all explored PCPs categories, especially in toothpaste (Table 2, Appendix C). The present study showed that 17 brands from 29 brands of toothpaste, 29 from 123 brands of facial cleansers/scrubs, and 30 from 426 brands body wash/ shower gels, respectively, contain microbeads. The percentages of microbeads containing PCPs in each category could be arranged as follow: Toothpaste (58%) >Facial cleanser/scrubs (18%) >Body wash/Scrubs (6%). However, for HCMC, not all PCPs list plastic in their ingredient list. In the case of toothpaste, none of the polymers are listed. In the case of facial cleansers and scrubs, 23% of microbeads containing products have listed polymers as Polyethylene, Acrylate Copolymer, and Acrylates/C10-30 Alkyl Acrylate Crosspolymer. For body wash and scrubs, the polymers including Polyethylene, Acrylate Copolymer, Styrene/Acrylates Copolymer, and Acrylates/C10-30 Alkyl Acrylate Crosspolymer have listed in 53% of microbeads containing products (Table 2).  (4) This is not consistent with previous studies, which stated that plastic ingredients are present in all PCPs at different percentages, ranging from a fraction of a percent to more than 90% in some cases. According to physical characteristics, the plastic microbeads could be classified as thermoplastics e.g. Polyethylene, Polypropylene, Polystyrene, Polyamide, Polytetrafluoroethylene (Teflon), and thermoset plastics, e.g. Polyurethanes and certain Polyesters. All thermoset plastics are solid-phase materials. Thermoplastics are also solid materials but they can be melted into liquids when they are heated to temperatures exceeding their melting point (or glass transition temperature). Since the melting points far exceed the temperatures in the marine environment, these plastics are considered solid too. Based on the polymer chain, the microbeads have defined homopolymers and copolymers. Homo-polymers are polymer chains of a single monomer type whereas copolymers are made by polymerizing different monomers in the same chain, either in random order, alternating monomers, or as 'block' copolymers (i.e. monomers clustered into blocks in the polymer chain of the copolymer molecule) [6].
More precisely, polyethylene has been found in 10.3% (3 products made in India and Thailand from 29 microbeads containing products) of facial cleanser/scrub, and 6.7% (2 products made in Malaysia from 30 microbeads containing products) of body wash/scrub (Appendix B). In comparison with previous studies, it can be seen that although microbeads containing PCPs are common in the HCMC market but Polyethylene was not always present in their ingredients. This is different from previous studies. For example, Godoy et al. [30] explored eleven supermarkets in the province of Granada (Spain) and found a higher percentage of products containing Polyethylene particles in ingredients as 50% (2 products; bath gel), 63% (12 products; body treatment), 27.5% (11 products: facial treatment) and 80% (4 products; foot treatment), respectively. Furthermore, Napper et al. [12] Fendall and Sewell [10], all four water-based facial cleansers were purchased at a supermarket in Auckland, New Zealand, were produced by major cosmetic manufactures and containing Polyethylene in their ingredients. Similarly, Lei et al. [31] reported that based on the ingredient information on the packaging, Polyethylene was found in 7.1% (9 products from total 126 products) of facial cleansers, and 2.2% (3 products from total 136 products) of shower gels. Ustabashi et al. [32] has also mentioned that twenty percent of the toothpastes available in Turkey were found to contain Polyethylene at concentrations varying between 0.4 and 1%.
Although only a few names of plastics have been listed in the PCP's sold in HCMC the potential impacts of microplastic could not be neglected. Previous studies have reported that polymers could be present in additional products regardless of whether they are included in the ingredient list. Habib et al. [14] have also noted that two products did not show an ingredients list, which breaches UAE law. However, it was found later that microplastics were isolated from both products.
As mentioned above, microbeads can contribute to the total microplastic load in the aquatic system. However, rarely are these micrometer-sized primary microplastics distinguishable from secondary microplastics when detected in an environmental matrix. The microbeads are not unique; it is not easy to distinguish by shape or other indicators. Other than plastic preproduction pellets and small plastic objects <5 mm that are still recognizable, the exact origins of the tiny microbeads in the aquatic system are untraceable [6].
As indicated in previous studies, microbeads could be littered into the environment via final effluent or biosolids (sewage sludge) from wastewater treatment plants (WWTPs) [33]. Previous studies showed that 95−99.9% of the microbeads may settle out into the sludge, leaving the remaining beads in the effluent [1]. For HCMC, the total volume of domestic wastewater (the major source of microbeads) is estimated to be 1.75 million cubic meters, and 1.3 million cubic meters are collected and treated in WWTPs every day [34]. The low density of microbeads in the effluent may not sound significant but assuming all WWTPs in HCMC operate at maximum capacity and that minimum density of microbeads are found (0.1 per L of effluent, [1]) so at least 130,000 microbeads per day are emitted into the aquatic system of HCMC.
Thus, because of the large volume in production and current end-of-life strategy, microbeads have the potential to be a source of many microplastic particles to aquatic habitats. Like other microplastics, they are ubiquitous and bioavailable for injection by marine organisms [6,15,35]. Hence, it is noted that the release of microbeads of a size suitable for ingestion by marine organisms without degradation and therefore became available. Microplastics can mix with plankton and sediments, causing suspended or detritivorous organisms to ingest them by accident, since they are not always able to distinguish them from food [36]. The danger increases when these small organisms are eaten by larger organisms such as birds, marine mammals, turtles, fishes, etc. which causes microplastics to be transferred along the food chain until they reach human beings [36,37]. Hence, the high sorptive capacity of toxic contaminants has also increased microbeads' toxicity. In HCMC, besides Polyethylene, other abundant polymer types have been indicated in PCPs are Acrylates Copolymer, Styrene/Acrylates Copolymer, and Acrylates/C10-30 Alkyl Acrylate Crosspolymer. However, the toxicity of these polymers was not clear. Thus, the following research needs to explore toxicity when these polymers are released into the environment.
However, the environmental regulations and microbeads management practices in Vietnam are not well developed. Therefore, microbeads released from PCPs could impose an additional burden on the natural environment.

Community awareness of microbeads in PCPs and future actions
The usage of microbeads containing PCPs in HCMC has been obtained from a questionnaire survey. Since the beads/microbeads containing PCPs are easily found in shops and supermarkets, almost (98%) of the respondents have used at least one product. A list of beads/microbeads containing PCPs including facial cleansers (12 brands), toothpastes (3 brands), body scrubs (4 brands), and shower gel (1 brand), were identified by respondents. In fact, it was discovered the usage of microbeads containing PCPs was 8 32% (shower gel), 12.5% (facial cleanser), 12% (body scrub), and 92% (toothpaste) of respondents, respectively. There are no differences between gender for the beads containing PCPs' usage, both sexes have increased their demands for quality personal care and cosmetics products which may directly introduce a large number of microplastics (Appendix A).
In statistical analysis, Cronbach's alpha is commonly used to estimate the reliability of the Likert scale. The Cronbach's alpha coefficients were 0.829, which is above 0.60, representing good reliability [38]. Thus, the Likert scales can be considered reliable. The data showed that the majority of consumers placed great importance on product effectiveness ("microbeads containing PCPs are better to use than others") and were highly influenced by new trend of PCPs "microbeads containing PCPs represent a new trend in the cosmetic industry" (69% and 68% of total respondents, respectively). It is expected since most of the respondents are students, so they always keep up-to-date with a new trend of PCPs and therefore will follow to use beads containing PCPs. In addition, the producers always promote the effectiveness of microbeads containing PCPs as totally remove of dead skin cells, deeply embedded impurities but less irritation and damage to the skin (facial scrubs) and remove plaque and stains due to their abrasive action (toothpaste). This is similar to a survey carried out with UC Berkeley students, which showed that majority of students placed great importance on product effectiveness [39]. Furthermore, the respondents specified that they paid attention to natural materials of beads. However, a significant part of respondents (35% of total respondents) were not concerned with the potential negative impacts of beads/microbeads. It is contrary to what was with Malaysia's customers. Praveena et al. 2018 indicated that 62.6% of the respondents acknowledged the very and extremely importance of taking into consideration the environmental impacts resulting from microplastics in personal care products [40].
Therefore, the present study indicated that even students, who belong to a young and dynamic generation of HCMC, do not care about the potential environmental pollution caused by microbeads containing PCPs. In order to reduce the emission of PCP's microbeads, community awareness should be taken into account soon in HCMC. A greater sense of awareness among the general public is to inform the consumers about the negative impacts of microbeads. The campaigns coupled with hashtags such as "#banthebead" could begin in the University to generate awareness among students [39]. Furthermore, legislative action should also go into practice. For example, the consumer should be informed on whether a cosmetic product contains polymeric compounds from its packaging, as it is obligatory from the EU's legislation [41]. Nevertheless, when a cosmetic product is intended for cleansing or abrasion and simultaneously contains a polymeric compound, like Polyethylene, which is indicated high on the INCI list (meaning large quantity), it can be concluded with great certainty that the compound is a microbead [41].

Conclusions
The term 'microbeads' is used to describe plastic particles present as ingredients in personal care products and have recently created an environmental threat to ecosystems. In several developed countries (e.g. USA, Canada, France) a legislative ban on plastic microbeads-based PCPs has been proven effective to protect environment. However, other countries including Vietnam, besides the extended market for PCPs, do not take any legal action. This summary of some primary results related to the potential risks caused by microbeads-based PCPs in HCMC. Approximately 50% of respondents have frequently used facial cleansers and body scrubs, which contain plastic microbeads shown in the product package. Instead of Polyethylene, other plastics such as Acrylates Copolymer, and Styrene/Acrylates Copolymer are recent common polymers in PCP. Hence, it should be noted that although the plastic composition is not shown by the manufacturers, this does not mean that these PCPs are free of microplastics. On the other hand, it is also evident that consumers in HCMC have insufficient knowledge about the negative impacts of plastic microbeads. This fact suggests that source reduction through community awareness is the most efficient method to reducing plastic contamination in this city.