Survey of Industrial Perceptions for the Use of Nanomaterials for In-Home Drinking Water Purification Devices

Abstract

As businesses, specifically technology developers and industrial suppliers, strive to meet growing demand for higher quality drinking water, the use of engineered nanomaterials in commercial point-of-use (POU) in-home water purification devices are becoming an increasingly important option. Anecdotally, some businesses appear wary of developing and marketing nanomaterial-enabled devices because of concerns that they will face onerous regulation and consumer pushback. However, little of substance is known about business perceptions of and attitudes toward the use of engineered nanomaterials in POU water purification devices, or how these compare with consumer perceptions. To address this knowledge-gap, we administered a 14-question survey amongst 65 participants from US-based industrial companies focused on drinking water purification. Our results indicate that the dominant concerns for businesses are costs and public perceptions associated with nanomaterial-enabled POU devices for drinking water purification. Cost-specific barriers include competition from more conventional technologies, and tensions between operational versus capital costs. 57% of respondents were concerned or very concerned that public perceptions will influence the long-term viability of nanomaterial-enabled POU devices for drinking water purification. 49% of respondents stated that government regulation of nanomaterials would be the preferred approach to ensure public safety, followed by the certification of POU devices (28%). When asked about specific nanomaterials and their potential use in POU devices for drinking water purification, respondents ranked carbon nanotubes as the nanomaterial with highest concern for environmental health and safety, followed by silver, titanium dioxide, zinc oxide, and copper. Respondents ranked nanoclays as the nanomaterial with highest likelihood for public acceptance, followed by silica, cerium oxide, titanium dioxide, and aluminum oxide.

1. Introduction

Access to safe and readily-available drinking water is considered a basic human right. Yet, aging infrastructure, contaminated source waters, and low economic status of many communities worldwide, puts a heavy burden on global water systems designed to ensure safe drinking water. As of 2015, over 2 billion people worldwide relied on unmanaged drinking water services, including over 500 million people collecting drinking water from unprotected wells and springs or untreated surface water intakes from lakes, rivers, and streams [WHO, 2018a; Bain et al. 2014; Wright et al. 2004]. Typical drinking water facilities rely on a variety of unit processes to handle a multitude of drinking water contaminants. These include coagulation and sedimentation for turbidity and bulk organic removal, membranes or granular filtration to remove particles and disinfection for pathogen inactivation [Huang and Shiu, 1996; Crittenden et al. 2012]. These facilities meet all Environmental Protection Agency (EPA) and World Health Organization (WHO) guidelines for potable water. However, aging pipe and household plumbing infrastructure can release pollutants (e.g., lead, copper, bacteria) into treated water^3,4 [Tong et al. 2019; Ginige et al. 2017;. Additionally, there are over 40 million Americans who rely upon private well water [WHO 2000], which is not routinely monitored nor regulated, and can contain a range of inorganic (e.g., arsenic, nitrate), organic (e.g., pesticides) and microbial agents (e.g., virus) of health concern. Private homeowners both on- and off- the public water supply “grid” are increasing using POU systems to improve the perceived and actual water quality within their homes [Brown et al. 2017; Kidd et al. 2019]. Consumers use POU systems on whole house, tap, refrigeration, and plumbing locations to further polish potable water, remove unregulated chemicals, remove hardness that impacts washing and plumbing fixtures, and/or improve aesthetic taste and odor of drinking water [Shannon et al. 2010; Westerhoff et al. 2016; Lykens, 2018].

Nanomaterials offer an opportunity to improve performance or expand the spectrum of pollutants being removed in POU devices. POU devices often gain 3^rd party testing for material safety and/or validation of technology to remove pollutants [NSF International, 2016]. Businesses must navigate through a complex risk landscape [Maynard, 2016], where the opportunities and uncertainties associated with nanotechnologies overlap with public knowledge and concerns around the use of nanomaterials, and how their perceived risks compare to their perceived benefits. We previously explored the concerns and uncertainties of consumers around the use of nanomaterials in POU drinking water purification devices [Kidd et al. 2019]. This study highlighted a continuing paucity of knowledge amongst consumers about nanomaterials. It also highlighted concerns around the use of nanomaterials in consumer products, and preferences for alternative POU water purification devices compared to nanomaterial-enabled devices. Anecdotally, some of these concerns are reflected in attitudes within the POU water treatment manufacturing and retail sector, with businesses sometimes appearing reticent to invest in nanotechnologies for fear of a consumer backlash. However, as we report in the previous paper, consumer attitudes are nuanced, and if the benefits of nanomaterial-enabled POU devices are to be realized, businesses need to make informed decisions based on these. Specifically, where there is misalignment between consumer perceptions and attitudes, and industry assumptions of these perceptions and attitudes, there is a danger of businesses making uninformed decisions that potentially undermine their ability to effectively and safely utilize nanomaterials in POU water treatment devices.

Here, we present the results of a study examining concerns about and attitudes toward the use of nanomaterials in POU drinking water purification devices within manufacturing and retail businesses. Our objectives were to (1) determine key concerns and barriers within relevant businesses associated using nanomaterials in POU devices for drinking water purification (2) explore industry-based perceptions of major barriers to bringing nanomaterial-enabled POU devices successfully to market, (3) explore industry-based perceptions of consumer attitudes that are assumed to create barriers around bringing nanomaterial-enabled POU devices successfully to market, and (4) investigate alignments and disconnects between industry-based concerns and consumer concerns associated with nanomaterial-enabled POU drinking water purification devices.

2. Methods

2.1. Study Design and Sample Selection

A 14-question survey was conducted via an online survey platform [Evans and Mathur, 2018] and distributed to U.S. based companies between June 1^st, 2018 and July 1^st, 2018. Surveys were deployed by emailing an online link to Qualtrics^XM survey software on secure Arizona State University servers. To ensure the integrity of the survey data, we monitored the time each survey took to complete. Survey respondents that completed their survey in one-third of the time of the average time of completion were flagged for “speeding” through the survey. The average time of survey completion was 15 minutes and we found that no survey respondents were “speeding” through the survey. Data was retained on secure Arizona State University servers and respondents were given an alternative ID to ensure anonymity.

An online link to the survey was sent via email to 300 U.S. based businesses who work in both manufacturing and retail for drinking water treatment and industrial water treatment. These businesses ranged from small scale (<100 employees with $5–10mil revenue) to large enterprises (>1000 employees with > $1bil revenue). These businesses are located across all U.S. regions. These businesses were asked to distribute the link to employees at multiple levels within the organization. A total of 65 individual responses were collected. To ensure anonymity, respondents were given a unique identification number when completing the survey. Institutional Review Board approval was received from the Office of Research Integrity and Assurance at Arizona State University.

2.2. Survey Design

The survey was comprised of 14 questions that were separated into four sections and is provided in its entirety in the supplemental information. The first section consisted of 3 demographic questions. These were multiple choice close-ended questions with an option for “other” to be openly filled in. The second section consisted of 3 questions that addressed the respondent’s concerns around potential barriers to bringing nanomaterial-enabled POU drinking water purification devices to market. The third section consisted of 4 questions addressing industry-based concerns associated with public acceptance of nanomaterial-enabled POU devices for drinking water purification. The fourth and final section consisted of 4 questions that addressed broader industry-based concerns and barriers towards using nanomaterials in POU drinking water purification devices.

2.3. Survey Analysis

After the survey was completed, the data was transferred to Microsoft Excel 2016 and analyzed using the XLSTAT add-on on a secure server. Descriptive statistical analysis was carried out using ANOVA followed by a post hoc chi-square test. For Likert scale questions, a Mann Whitney U test was conducted. For all analyses the level of significance was set at 5% (p < 0.05). Ranking question analysis was carried out by determining the rank score and rank distribution for each question. A score was calculated as follows:

$$\text{Rank\hspace{0.17em}Score}={\text{X}}_1{\text{W}}_1+{\text{X}}_2{\text{W}}_2+{\text{X}}_3{\text{W}}_3\dots {\mathrm{X}}_{\text{n}}{\mathrm{W}}_{\text{n}}$$

Where X is the response count for each answer choice and W is the weight of ranked position. The respondent’s most preferred choice had the largest weight, and their least preferred choice had the lowest weight. For questions with six total responses, weights ranged from 1–6. Likewise, for questions with ten total responses, weights ranged from 1–10. Ranking questions were analyzed with the Friedman Test.

3. Results and Discussion

3.1. Response Rates and Respondent Demographics

A total of 65 fully completed surveys were returned and analyzed. Surveys that were not fully completed were discarded from the study (n=11). Table 1 provides details of respondents’ job functions within their business and their business’s role within the water treatment chain. Most survey respondents held a research and development (R&D) position within their company (38%), followed by administration/management (26%), product development (14%), marketing/sales (12%), and finance/accounting (9%). Businesses surveyed had a role in the water treatment chain as a research, development, and deployment partner (29%), followed by equipment manufacturer (26%), end user (20%), service provider (17%), and manufacturer of nanomaterials and other advanced materials (8%). Survey respondents were asked what type of water their company focuses on treating. Most respondents (57%) stated that their company addressed both commercial potable water and industrial wastewater. 26% of respondents stated that their company focuses only on treating commercial potable water and 17% of respondents stated that their company focuses only on treating industrial wastewater.

Table 1.

Comparison Between Job Function of Responders Within Company and Their Company’s Role in the Water Treatment Chain.

Role of Company in Water Treatment Chain	Job Function Within Company
	Administration / Management	Research and Development	Product Development	Finance / Accounting	Marketing / Sales	Total
Advanced Material Manufacturer	2 (3%)	0	3 (5%)	0	0	5 (8%)
R&D and Deployment Partner	5 (8%)	11 (17%)	1 (2%)	0	2 (3%)	19 (29%)
Equipment Manufacturer	4 (6%)	6 (9%)	3 (5%)	2 (3%)	2 (3%)	17 (26%)
Service Provider	4 (6%)	3 (5%)	0	1 (2%)	3 (5%)	11 (17%)
End User	2 (3%)	5 (8%)	2 (3%)	3 (5%)	1 (2%)	13 (20%)
Total	17 (26%)	25 (38%)	9 (14%)	6 (9%)	8 (12%)	65 (100%)

To assess the impact of survey respondent demographics, we investigated if there were significant differences in responses between different kinds of companies or job titles. Table S1 highlights survey respondent concerns around barriers to successful water treatment purification implementation into the marketplace. Regardless of job title or their company’s position within the water treatment sector, most survey respondents either had some concern or were concerned about barriers impacting these water purification devices and there were no significant differences in responses. Additional assessments were made to understand if survey respondent demographics influenced responses to the survey questions. We were unable to identify any statistical significance in responses to each survey question regardless of job title or their company’s position within the water treatment sector.

3.2. Perceived Concerns around Barriers to Successful Implementation of Nanomaterial-Enabled POU Devices

Respondents were asked how concerned they were about six different factors that potentially created a barrier to successfully bring nanomaterial-enabled POU devices to market. Figure 1 shows the percent response of respondents to each factor. Costs were highlighted as being of most concern to respondents followed by consumer fears and acceptance, environmental health and safety. Industrial scale manufacturability of nanomaterial-enabled POU devices was of the least concern to respondents, compared to other potential barriers.

Figure 1.

Industry response when asked “How concerned are you about the following factors creating major barriers to bringing nanotechnology water treatment devices to market successfully?”

Respondents were asked what their greatest concern was regarding the costs associated with successfully bringing nanomaterial-enabled POU devices to market (Figure S1). 35% of respondents stated that cheaper and/or alternative technologies were the greatest cost-related concern to them, followed by operational costs versus capital costs (23%), industrial scale manufacturing (20%), complying with impending governmental regulations (14%), and regeneration costs of technologies (6%).

Respondents were asked to rank by importance the information they would want from vendors supplying their company with nanomaterials to incorporate into their POU devices. Figure 2 shows the overall rank, ranked distributions and scores of the information respondents would want from nanomaterial vendors. Respondents valued environmental and human health impact assessments from vendors most highly, followed by complete material characterization, and information on the benefits and constraints of nanomaterials. These three factors had similar rankings among all survey respondents. The sustainability, life cycle assessment, viability and stability of nanomaterials had similar rankings among survey respondents as well, but were substantially less important to respondents than the three highest ranking factors.

Figure 2.

Industry response rankings when asked “In your opinion please rank the following, from 1 (most important) to 7 (least important), in terms of what information you would want from vendors supplying you with nanomaterials to incorporate into nano-enabled water treatment devices for point-of-use drinking water?”

3.3. Perceptions Around Public Acceptance and Perceptions of Nanomaterial-Enabled POU Devices

Respondents were asked what their preferred approach was to ensure nanomaterial-enabled POU devices for drinking water treatment were safe for public use (Figure S2). 49% of respondents stated that governmental regulation of nanomaterials would be their preferred approach to ensure public safety, followed by the certification of POU devices (28%), standard codes of conduct (18%), and state regulation of nanomaterials (5%).

Respondents were asked what the likelihood was that consumers would accept nanomaterial-enabled treatment devices used in a variety of different water treatment sectors. Figure 3 shows respondent perceptions of consumer concerns if nanomaterials were used to treat five different water sources. Respondents stated that the majority of consumers would have little to no concern around using nanomaterials to treat raw waters and industrial waters. However, they stated the level of concern would increase when using nanomaterials to treat water that consumers will likely come in contact with. The level of assumed concern progressively increased for municipal water treatment, point of entry (POE) systems that are installed to treat all water entering single homes, businesses, school, or facilities, and POU devices that treat water intended for direct consumption, typically at a single tap or limited number of taps [EPA 2006].

Figure 3.

Industry response when asked “In your opinion, what is the likelihood that members of public will accept nano-enabled water treatment devices used in the following water treatment sectors?”.

Respondents were asked if consumer perceptions would influence the long-term viability of nanomaterial-enabled POU devices for drinking water treatment (Table S2). Only 1% of respondents stated there was no concern around consumer perceptions influencing POU viability long-term. In contrast, 57% of respondents were concerned or very concerned (35% and 22% respectively), and 31% of respondents had some concern. 12% of respondents expressed little concern about consumer perceptions influencing POU viability long-term.

Respondents were asked to rank types of information consumers would want to know before purchasing a nano-enabled POU device to treat their drinking water. Figure 4 shows the overall rank, rank distribution and score of the information respondents stated consumers would want before purchasing a nano-enabled POU device to treat their drinking water. Respondents indicated that consumers will value a label guaranteeing the safety of the POU device, followed by them valuing a label indicating nanomaterials are present in the device, and basic information about nanomaterials used in the device. Consumer interest in the performance of nanomaterials in the POU device, the benefits of nanomaterials in the POU device, and the risks of nanomaterials in the POU device were all ranked low by respondents.

Figure 4.

Industry response rankings when asked “In your opinion please rank the following, from 1 (most important) to 6 (least important), in terms of the information you think consumers would want before purchasing nano-enabled water treatment devices for point-of-use drinking water?”

3.4. Business Concerns Around Nanomaterial-Specific Barriers, Risks and Perceptions of Using Nanomaterials in POU Devices to Treat Drinking Water

Survey respondents were given a list of ten manufactured nanomaterials released from commercial products [Keller et al. 2013] and asked to rank them from 1–10 in terms of their potential to present environmental health and safety risks, and to raise concerns with consumers. Figure 5 illustrates the breakdown of respondent rankings of these ten nanomaterials. Respondents rated carbon nanotubes (CNTs) and silver nanomaterials (Ag°) as having the highest potential to cause environmental health and safety concerns, while ranking lowest in terms of assumed consumer acceptance if used in POU drinking water devices. In contrast, nanoclays and silica (SiO₂) were ranked as having the lowest potential to cause environmental health and safety concerns, and highest in terms of anticipated public acceptance. Titanium dioxide (TiO₂) diverged slightly from this trend by being ranked relatively high in terms of both its potential to present environmental health and safety concerns, and its acceptability to consumers if used in POU drinking water devices. This may be due to TiO₂ currently being used in a wide variety of consumer products, and therefore familiar to many consumers (e.g. toothpaste, sunscreen) [Sadrieh et al. 2010; Hanigan et al. 2018; Rompelberg et al. 2016; Fadheela et al. 2020].

Figure 5.

Industry response rankings when asked “If nano-enabled water treatment devices used these materials to treat drinking water, in your opinion how would you rank them, from 1 (highest) to 10 (lowest) in terms of their potential environmental and health risks and public acceptance”.

Nanosilver (Ag°) has emerged as a potential nanomaterial for drinking water treatment [Liu et al. 2014; Kim et al. 2012; Tugulea et al. 2014; Reed et al. 2016] by businesses because its antimicrobial properties can achieve higher pathogen removal than standard disinfection systems [Heidarpour et al. 2011; WHO, 2018b] and an increase in research publications around nanosilver use for drinking water treatment (Figure S3). Survey respondents were asked specifically about the use of silver nanomaterials in water treatment devices—this being a material that has received widespread attention as a potential bactericide in water treatment products [Qu et al. 2010; Anuj et al. 2019]. Respondents were asked about major barriers associated with using the material to treat drinking waters and industrial waters. As shown in Figure 6, 42% of respondents indicated that a major barrier to treating drinking water with silver nanomaterials is consumer perceptions and acceptance, followed by cost (23%), environmental and human health risks (17%), regulations (11%), and viability (5%). In contrast, 54% of respondents indicated that the major barrier for treating industrial water with silver nanomaterials is costs, followed by environmental and human health risks (23%), viability (12%), and regulations (5%). Only 5% of respondents indicated that consumer perceptions and acceptance would present major barriers when using silver nanomaterials to treat industrial water. These results strongly suggest that perceived barriers to using nanomaterials in water treatment are substantially impacted by factors that extend beyond nanomaterial type, and include treated water type and cost.

Figure 6.

Industry response to the major barrier to successfully use silver nanomaterials to treat (A) drinking waters and (B) industrial waters when asked “Silver nanoparticles are being extensively studied for use in water treatment devices because of their antimicrobial properties. In your opinion, what is the major barrier to successfully using silver nanoparticles to treat industrial and potable water”.

3.5. Comparisons Between Industry Concerns and Public Concerns Regarding the Use of Nanomaterial-enabled POU Devices to Treat Drinking Water

We previously published the results of a survey (N=1623) on public perceptions around the use of nanomaterials for in-home POU drinking water purification devices [Kidd et al. 2019]. In that survey, the majority of respondents had little to no prior knowledge about nanomaterials (~90%), 41% of respondents used bottled water more than other sources of drinking water, they expressed greater concern about nanomaterials use in applications where there is potential for direct contact and exposure, and 64% of respondents reported they would be more likely to use nanotechnologies to treat their drinking water if they were given more information about nanomaterials before purchasing POU devices. By comparing responses to the business-oriented survey reported here, to the previous public perceptions survey, we were able to explore alignments and disconnects between consumer perceptions and attitudes toward the use of nanomaterials in POU water treatment devices, and business-based assumptions about these perceptions and attitudes.

When asked about the long-term viability of nanomaterial-enabled POU devices to treat drinking water, ~56% of industry-based survey respondents were either concerned or very concerned about public perceptions influencing the long-term viability of these devices. While the majority of public survey respondents claimed to know little to nothing about nanomaterials (~90%), when asked about the likelihood they would use nanotechnology to treat their drinking water, ~35% of respondents would likely use nanotechnology, ~42% of respondents are neutral about using nanotechnology, and only ~22% of respondents would be unlikely to use nanotechnology. Public survey respondents also stated that they would purchase nanomaterial-enabled POU devices to treat their drinking water if the device works as effectively as competitors but is half the price (~30%) or is twice as effective as competitors and is half the price (~26%). Only ~16% of public survey respondents stated they would not use nanotechnology to treat their drinking water. Additionally, ~95% of public survey respondents stated that if they were given more information about nanomaterials and their use in POU devices to treat drinking water they would likely change their opinion about nanomaterials. These results indicated that public perceptions of nanomaterial-enabled POU devices to treat drinking water are likely to influence long-term viability of these devices, but the lack of public knowledge of nanomaterials and a more neutral/positive perception towards nanotechnology by the public likely means that industry should be able to overcome consumer barriers for successful implementation of nanomaterial-enabled POU devices for drinking water purification.

Comparing both surveys, both groups of participants agree that safety of a nanomaterial-enabled POU drinking water purification device is important for consumers (Figure 7). When asked about the most important characteristics of a POU device that uses nanomaterials, public survey respondents ranked safety of the device highest (48%). Industry-based respondents indicated that, from their perspective (32%) safety of the POU device was most important, followed by potential risks of nanomaterials in POU devices (29%) and certification of nanomaterial-enabled POU products (20%). In contrast, public survey respondents stated they wanted more information about the use and benefits of nanomaterials (~19%), potential risks of nanomaterials in device (~15%), and the performance on nanomaterials in POU devices (~7%).

Figure 7.

Comparison of Industrial and Public Responses When Asked What Information Consumers Would Want Before Purchasing Nanomaterial-Enabled POU Devices for Drinking Water Treatment

4. Conclusions

This study indicated that there are many industry-related concerns around the use of nanomaterials within in-home water purification devices. Industry respondents stated the major barriers to nanomaterial-enabled POU devices to treat drinking water are costs and consumer perceptions. Regarding cost barriers for industry survey respondents, competition with conventional drinking water treatment devices is their major concern, followed by operational versus capital costs of establishing a nanomaterial-enabled POU device. Industry survey respondents were also concerned about the environmental health and safety of nanomaterials used in POU devices and the ability to fully characterize them, as they are most interested in obtaining environmental impact assessments and complete material characterization from vendors supplying them with nanomaterials to use in their POU drinking water purification devices. Industry survey respondents stated that the closer nanomaterial-enabled POU devices are to direct consumer exposure, the less likely they are willing to use the device to treat their drinking water. Industry survey respondents also stated that public perceptions will have an influence on the long-term viability of nanomaterial-enabled POU devices. Industry survey respondents stated that nanomaterials with a likelihood for environmental health and safety concern (e.g. CNTs, Ag) are less likely to be accepted by the public and vise-versa, with the exception of TiO₂ which is likely due to its abundance in a variety of different consumer products already.

There are synergies and disconnects between industry survey respondents and public survey respondents. Both stakeholders were concerned with the safety of nanomaterial-enabled POU devices for the public, but their opinions on the method for ensuring safety of the devices is different as industry would prefer governmental oversight of POU devices and the public would prefer more information on nanomaterials and their use in POU devices. Additionally, public perceptions will influence the viability of nanomaterial-enabled POU devices for drinking water purification, but ensuring that more information about nanomaterials is provided for the public or ensuring that devices are either more efficient or cost less than conventional competing technologies will likely allow for industry to overcome public concerns and ensure successful implementation of nanomaterial-enabled POU devices for drinking water purification.