Behaviorally segmented audiences for managing sunscreen chemical pollution risk in protected coastal natural resource areas

This audience segmentation of visitors at coastal parks in Hawaii and North Carolina addresses an emergent natural resource management concern and risk to aquatic ecosystems: sunscreen chemical pollution. Four audiences were identified that correspond to different behavioral profiles: sunscreen protection tourists, multimodal sun protection tourists, in‐state frequent park visitors, and frequent beachgoers who skip sunscreen. The second‐largest audience, sunscreen protection tourists, represents 29% of visitors at Cape Lookout National Seashore and 25% at Kaloko‐Honokōhau National Historical Park. This group ranks of most concern for chemical pollution because they use sunscreen, but not typically mineral formulations or other methods such as protective clothing, and they have lower levels of sunscreen chemical issue awareness. The identification of similar audience segments across regions with differing cultural characteristics and sunscreen regulation status suggests the robustness of the model and its indicator variables, with implications for both environmental protection and public health. Further, coastal visitors’ interest in enacting pro‐environmental sun protection behaviors during their next park or beach visit indicates the potential for natural resource managers to holistically address risks in both domains through targeted interventions with audiences of most concern.

behaviors (Interagency Visitor Use Management Council, 2016, 48).This study develops and assesses the validity of a behavioral typology of coastal park visitors for the management of an emergent anthropogenic threat to coastal ecosystems: sunscreen chemical pollution (Danovaro et al., 2008;Downs et al., 2014Downs et al., , 2016)).In doing so, it evaluates the extent to which audiences are willing to consider the environmental implications of sun protection, widely publicized as important public health behavior (Paulson et al., 2020).

Sunscreen chemical pollution
Little socio-behavioral research evaluates sun protection through the lens of environmental risk (National Academies of Sciences, Engineering, and Medicine, 2022).In 2022, the National Academies recommended that research on the environmental effects of sunscreen pollution should be complemented with human studies evaluating the potential implications of changing sun protection recommendations.In describing the urgent need for the US Environmental Protection Agency (EPA) to conduct ecological risk assessments, the committee emphasized that "epidemiological risk modeling and behavioral studies related to sunscreen usage should be conducted to better understand human health outcomes from changing availability and usage" (p.10).While the US EPA has yet to conduct ecological risk assessments, evidence from ecotoxicological studies demonstrating that sunscreen active ingredients can harm corals and other aquatic species (Carve et al., 2021) has already convinced some governments to restrict the use of these chemical formulations (Levine, 2021).For example, Hawaii's ban, which went into effect in January 2021, limits public access to brands containing oxybenzone and octinoxate (Gabbard & Kim, 2018).In the US Virgin Islands, the banned list also includes octocrylene (Blyden et al., 2019).
In order to both protect natural resources and maximize visitor experiences on federally managed lands and waters (Interagency Visitor Use Management Council, 2016), the National Park Service (NPS) recommends that visitors defend both their health and that of the parks by wearing protective hats and clothing and using mineral-based sunscreens, regardless of the status of local regulations (NPS, n.d.).Given that one of the most frequent forms of sun protection in the United States is use of sunscreen (Holman et al., 2018) and the majority of formulations contain nonmineral active ingredients (FDA, 2019), the success of the NPS initiative and those of other similar governmental efforts (NOAA, 2022) depends on changing visitor behaviors.As noted by the National Oceanic and Atmospheric Administration (NOAA, 2022), "protecting ourselves and marine life" includes all commonly recommended forms of sun protection-finding shade, wearing protective clothing and glasses, avoiding peak sun exposure times, and wearing sunscreen (World Health Organization, 2001)-just not using sunscreen formulations found to harm marine life.

Audience segmentation and behavior change
Marketing, public health, and risk communication scholars have long recommended that campaigns should tailor interventions to meet the needs of different audiences (Kotler & Zaltman, 1971;Rickard, 2021;Slater & Flora, 1991;Smith, 1956).By designing communication for homogenous groups that share certain characteristics-whether knowledge, attitudes, or behaviors-programs arguably can be both more effective and efficient (Slater, 1996).Audience segmentation research also can contribute to theory by further elucidating behavior change pathways (Slater, 1999).The transtheoretical model proposed by Prochaska and colleagues (1992) identifies a progression in stages of behavioral changeprecontemplation, contemplation, preparation, action, and maintenance-that aligns with general models of communication and risk information processing (Bostrom et al., 2018).Each stage is associated with differing audiences and implications for the design of effective interventions.Sunscreen use was identified early as one of the behaviors for which the approach can be generalized (Prochaska et al., 1994;Rossi et al., 1994).
Indeed, sun protection has become an increasing focus of behavior change initiatives to address health risks from exposure to ultraviolet (UV) radiation.Skin cancer is the most common cancer in the United States (CDC, 2022) and is rising, with more than double the number of new cases in 2019 than 1999 (US Cancer Statistics Working Group, 2022).In 2014, the US Surgeon General issued a call to action to address skin cancer as a "major public health problem" that is generally preventable by taking sun-protective measures (US Department of Health and Human Services, 2014).Yet, sun protection represents a complex set of behaviors in which age, gender, sun-sensitivity, and race/ethnicity all have been shown to be influential, in addition to location and other contextual variables (Holman et al., 2018;Patel et al., 2019).The World Health Organization (WHO) suggests a combination of sun-protective strategies.Instead of using sunscreen as the first line of defense, the WHO recommends: "Protection of the skin from solar damage ideally involves a number of actions which include wearing tightly woven protective clothing that adequately covers the arms, trunk and legs, a hat that provides adequate shade to the whole of the head, seeking shade whenever possible, avoiding outdoor activities during periods of peak insolation and use of sunscreens" (2001,148).
The complexity of sun protection behaviors, contextual factors, and domains (health/environment) makes the topic ideal for audience segmentation.Multivariate classification of audience segments employs large, representative samples in which data are collected on behavioral determinants or indicators (Slater, 1996).Latent class analysis (LCA) is one of the most common ways in which audience segmentations are performed (Smith, 2017).Whereas factor analysis techniques examine observed variables to detect latent constructs or factors (Kim & Mueller, 1978), LCA allows for the identification of latent subgroups of people based on similarities in observed variables, typically survey responses or other types of individual-level data (Hagenaars & McCutcheon, 2009;Weller et al., 2020).These latent groups-or "classes"-can be used to understand the behavior of specific audiences when tailoring interventions.Research has shown that behaviorally focused segmentations on sun protection may be more revealing than just demographics, especially within subsegments of the population (Silk and Parrott, 2006).They also may be more useful for the purpose of designing interventions to communicate risk and influence behavior (Connelly and Knuth, 1998).Some research demonstrates that the promotion of single, rather than multiple, sun protection behaviors may be more effective (Bleakley et al., 2020).However, that is only feasible after identifying in which behaviors audiences already engage.

Study sites
The two study locations-Cape Lookout National Seashore and Kaloko-Honokōhau National Historical Park-were selected because of their differences in ecology, state policy, and cultural context.Kaloko-Honokōhau National Historical Park is located on the western coast of the "big" island of Hawaii.To protect its marine coral reef ecosystem, the state has banned sunscreen containing oxybenzone and octinoxate (Gabbard & Kim, 2018).The shoreline park protects both natural and cultural resources.Kaloko-Honokōhau is a native Hawaiian archaeological site, featuring fish ponds, petroglyphs, and the remains of temples (NPS, 2021).By way of contrast, there are no coral reefs within Cape Lookout National Seashore (Macintyre, 2003;Necaise et al., 2010), and the state of North Carolina has not enacted policies on sunscreen chemical pollution.The park's barrier islands are only accessible by ferry or personal watercraft but were frequented for centuries by both Native Americans and early European settlers who were drawn by the region's rich fisheries (Stick, 1990).

Research questions
Given this diversity of people and places, it remains unclear how generalizable sun protection audience segmentations may be, and thus how useful for the management of natural resource risks.Grunig defined the criteria for segments as "definable, mutually exclusive, measurable, accessible, pertinent to an organization's mission, reachable with communication in an affordable way, and large enough to be substantial and to service economically" (1989,203).Segmentation studies on sun protection have found varying results by gender (Steffen et al., 2007), age group and race/ethnicity (Miller et al., 2015;Shah et al., 2017), and region (O'Riordan et al., 2008).Therefore, coastal park visitors in states with differing cultures and sunscreen environmental regulatory status might not demonstrate the same sun protection behaviors or behavioral determinants.A 2020 online study of Florida, North Carolina, and Hawaii residents found that state of residence and the location of coastal parks where the behavior was to occur related to pro-environmental sun protection preferences (Akerlof, 2023).Issue awareness of chemical sunscreen pollution and related policies has been found to be relatively low outside of regions with bans (Glanz et al., 2022;Levine, 2019), and indeed, the Hawaii ban had only been implemented approximately 6 months before the fielding of the study (Gabbard & Kim, 2018).With pro-environmental sun protection behaviors likely in the early stages of change (precontemplation/contemplation) for many, we hypothesized that the best indicators of present and future actions to reduce sun exposure were likely to be found in the past: (1) habit, that is, what people report that they typically choose as sun protection in coastal and shoreline areas, including pro-environmental measures (Allom et al., 2013); and (2) the extent to which habits are engrained and where they have been formed, that is, residents versus tourists and frequency of visits.Contextspecific measures were also included: (1) beach recreation choices and physical activity (Schneider et al., 2014;Walkosz et al., 2017); (2) motivation to visit national park wildlife as a form of recreational behavior and an indicator of nature connectedness (Martin et al., 2020); (3) visitation of the park with young children (Diehl et al., 2022); and (4) contact with NPS interventions supporting pro-environmental sun protection.
While audience segmentation techniques have been increasingly used to promote pro-environmental behavior (Hine et al., 2014;Jones et al., 2019;Shaw, 2009;Shaw et al., 2011;Wells et al., 2022), to our knowledge, this is the first research to segment audiences of concern for both sun protection and sunscreen chemical pollution.Using data from visitor intercept surveys conducted at two coastal national parks-one in North Carolina and one in Hawaii-we performed audience segmentations for each to assess: RQ 1 : Which audiences are of most concern for sunscreen chemical pollution?RQ 2 : Which of the tested indicator variables differentiate audiences of concern?RQ 3 : Are there differences in audiences of concern between North Carolina and Hawaii, areas with distinct cultural differences and sunscreen chemical regulatory status?RQ 4 : Do the audiences relate to differing levels of issue awareness, risk perception, and pro-environmental behavioral intent?

METHODS AND SEGMENTATION ANALYSIS
The research team recruited visitors of at least 18 years of age to participate in the ∼5-minute paper survey.The study protocol and datasets can be found at https://osf.io/5d9na/.The survey questionnaires are located in Supporting Information, Appendix A. The visitor intercept survey was fielded at Cape Lookout National Seashore and Kaloko-Honokōhau National Historical Park for 6 and 10 days, respectively, during July and August 2021 (Supporting Information, Tables 1a, 1b, 1c).With response rates of 41% and 77%, more than 600 surveys were completed at each location (Cape Lookout, n = 683; Kaloko-Honokōhau, n = 613) (Supporting Information, Table 2).Nonresponse bias was assessed by asking those who declined to participate in the study a brief question about their choice of sun protection at the park (Supporting Information, Table 3).At Cape Lookout National Seashore, respondents and soft refusals differed little on use of sunscreen (respectively, 88% vs. 84%).At Kaloko-Honokōhau National Historical Park, the research team was more successful in engaging visitors who intended to spend time on the beach than those passing through quickly, which likely resulted in larger differences (79% vs. 50%).

Measures
The indicator variables used in the audience segmentation included motivation to see park wildlife (coded open-ended measure), frequency of park and beach visitation, tourist status as identified from residence location, typical sun protection behavior, park sun protection behavior, park recreation behavior, young children in the group, and exposure to park pro-environmental sun protection programs (Table 1; response frequencies located in Supporting Information Tables 4-14).The audiences were assessed for validity by evaluating differences between them on measures of awareness of sunscreen environmental concerns and bans, environmental risk perception, and pro-environmental sun protection behavioral intent (Table 2).The questions were adapted from those used in an online 2020 survey of pro-environmental sun protection (Akerlof, 2023) and informed by previous questionnaires on sun protection (CDC, 2016) and coastal recreation (Tynon & Gómez, 2012).We selected the measures included in the LCA because either: (1) they directly assessed self-reported sun protection behaviors and frequency of beach visitation; or (2) the variables have been shown to relate to sun protection choices in these contexts.Sun protection decisions have been shown to vary with location (Andersen et al., 2017;Holman et al., 2015), state of residence (Akerlof, 2023), and recreational activities (Julian et al., 2023).Notably, at both parks, wildlife viewing serves as a form of recreational behavior and motivation to visit the parks.Social context can also be an important influence (Robinson & Rademaker, 1998).For example, families may engage in a unique set of sun protection behaviors focused on the needs of their young children (Robinson & Rademaker, 1998), considering that many sunscreens are specifically formulated and branded for that age group (Rastogi, 2002).
We hypothesized that exposure to NPS information on sunscreen environmental risks might influence behavior.Questions about sunscreen use specifically included categories for "reef safe" and "mineral-based" formulations.Notably, no legal requirements mandate the active ingredients in sunscreen advertised as "reef friendly," "reef safe," or "coral safe" (Calderone, 2019).They may, or may not, contain chemicals of potential concern to marine life.As a result, NPS (n.d.) recommends visitors use formulations with minerals-zinc oxide and titanium dioxide-as the active ingredients, the only ones also "generally recognized as safe and effective" (GRASE) by the Food and Drug Administration (Adamson & Shinkai, 2020;FDA, 2021).

Analysis
A latent class analysis was run in MPlus v. 8.7 using maximum likelihood (Muthén & Muthén, 2017).Dichotomous measures from the survey that characterize audience sun protection context and behaviors served as the independent variables for the analysis (Table 1).The variables were chosen for the degree to which they distinguished between groups of visitors with different characteristics.
In order to evaluate whether the audiences significantly predicted outcomes of interest, ordinal logistic regression models using SPSS v27 tested the relationship between group membership and audience environmental issue awareness, risk perceptions, and behavioral intent (Table 2; Supporting Information, Tables 17-22).We assessed whether ordinal and multinomial models produced different estimates when the parallel lines assumption did not hold (Williams, 2006).In those cases, the estimates generated using both ordinal and multinomial approaches were within the same confidence interval and hence were not different in interpretation (Supporting Information, Boxes 1-2, p. 27-29).

Sample characteristics
While demographic data alone offer limited insights as to audience behavior (Slater, 1996), information such as age, educational status, and race/ethnicity can be useful in characterizing each segment.The demographic characteristics of the survey respondents at Cape Lookout National Seashore and Kaloko-Honokōhau National Historical Park were largely similar, with the greatest difference in the percentage of respondents who identified as state residents (Supporting Information, Table 4).Cape Lookout visitors reported higher rates of in-state residence (59%), than those in Kaloko-Honokōhau (25%).Most of the survey respondents at both parks identified as female (Cape Lookout, 62%; Kaloko-Honokōhau, 62%) and as White (95%; 70%).The samples were relatively young and well-educated.A majority were under the age of 45 (57%; 51%) and had at least a bachelor's degree (59%; 61%).

Latent class solutions (RQ 1,2,3 )
Twenty-five measures were included in the final model for Cape Lookout National Seashore and 21 for Kaloko-Honokōhau National Historical Park.Differences in which variables contributed significantly to the model for each park were only slightly higher for the four-class model than the five, indicating that the addition of another audience would not greatly improve model fit.

Audience characteristics
The audiences for both parks proved remarkably similar in their sizes and characteristics.As a result, the names given to the audiences are the same across both parks (Figures 1-2).They can be characterized by the following motivations and behaviors: • Multimodal sun protection tourists: These visitors are new to the park.They are typically not in-state and are also not avid beachgoers.They use a variety of means of sun protection, which aligns with both public health and environmental recommendations, but are unlikely to use mineral sunscreen.
National Seashore] Probability of the members of each audience ranking high on each of the listed variables (each coded 0-1).
• In-state frequent park visitors: The vast majority are instate residents who visit beaches frequently, including the park where they were surveyed.They use sunscreen, but also other forms of sun protection, and have the highest probabilities of mineral sunscreen use in both parks, nearing 50%.• Frequent beachgoers who skip sunscreen: This audience is the second most likely to be in-state and frequent the park and beaches, but is unlikely to use sunscreen of any type.
For each park, two of the audiences are more likely to be local residents and two are more likely to be tourists.The groups are further differentiated by their use of sunscreen: no use, sunscreen use as the primary form of protection, and use in conjunction with other methods.The largest group in both parks is "multimodal sun protection tourists" (Cape Lookout, 43%; Kaloko-Honokōhau, 44%), followed by "sunscreen protection tourists" (29%, 25%), and "in-state frequent park visitors" (20%, 19%).The smallest audience is "frequent beachgoers who skip sunscreen" (8%, 12%).
Members of tourist audiences at both parks were more likely than those in-state to cite seeing horses and shelling (North Carolina) or seeing turtles (Hawaii) as the reason for their visit.Even so, wildlife motivation to visit the park was scored from an open-ended question that at times became obscured by the clipboard, and is likely underrepresented.The audience characteristics within each park are further described below.

3.3.1
Cape Lookout National Seashore Each audience can be described by its probability of scoring high on specific behavior-related measures used within the latent class analysis (Figure 1; Supporting Information, Table 15) and its demographic characteristics (Table 7).

Multimodal sun protection tourists (43%):
Members of this group are least likely to be from North Carolina (probability, 48%).The probability for each member is high that they will use shade at the park (61%), wear a cap (76%) and/or wide-brimmed hat (59%), and sunscreen (93%).Their probability of typically using reef safe (38%) or mineral (40%) sunscreen ranks lower.The majority of the audience identifies as female (59%) and White (97%); more than half are between the ages of 18-44 (18-34, 39%; 35-44, 21%).They are well-educated; 65% have a bachelor's degree or higher.The probability is highest that they will swim (69%) and/or walk (69%) while at the park with less likelihood of sunbathing (44%).

Sunscreen protection tourists (29%):
The probability is high that members will report wearing sunscreen typically when at the beach (98%) and at the beach the day they were surveyed (97%).They have a low probability of typically using reef safe (30%) or mineral (28%) sunscreen formulations, or using any other sun protection.While members have a moderate probability of being from North Carolina (53%), they are one of the two groups least likely to be instate.The audience tends to be young; almost half (46%) are between 18 and 34 years old.And they are well-educated.More than half (57%) have at least a bachelor's degree.They have a high probability of swimming (85%), walking (77%), and sunbathing (73%) at the park.
In-state frequent park visitors (20%): Members of this group have a high probability of being a North Carolina resident (87%), going to the beach frequently (100%), visiting the park frequently (78%), and engaging in multiple forms of sun-protection at the park (shade, 63%; cap, 83%; hat, 61%, sunscreen 87%).They also have the highest probability of typically using reef safe or mineral safe sunscreen (each, 45%) and wearing a shirt (48%).This audience has the greatest likelihood of boating at the park (45%) and fishing (18%) among the four audiences.The vast majority identifies as White (97%) and female (66%), and has at least a bachelor's degree (38%), if not also an advanced degree (21%).This audience is the oldest; three-quarters are over the age of 34 (77%).While the probability that one of this group's members has children with them at the park is low (21%), it is the highest among the audiences.Members have a high probability of swimming (86%), walking (62%), and sunbathing (64%) at the park.Frequent beachgoers who skip sunscreen (8%): A member of this group has a high probability of being from North Carolina (69%) and not typically using sunscreen (57%).As a result, they are not likely to use reef friendly or mineral variants either (7% and 0%, respectively).Of any sun protection behavior, they are most likely to wear a cap (41%).They have a moderate probability of going to the beach every week or month (48%).Just over half (51%) of the respondents in this group are male; females comprise the majority of the other three audiences.Among the generally nonracially and ethnically diverse respondents, this audience is somewhat less likely to self-describe themselves as White-only 82%-with 12% reporting that they are Black.This audience is the least educated; the majority do not have a bachelor's degree (61%).Of all the surveyed activities, members are most likely to swim (49%) or walk (46%).This group is also the most likely to say that they had received information on sun protection from NPS staff (14%).Visitor reception of any park information on sun protection was relatively low, just 15% across all Cape Lookout respondents.(The rate was somewhat higher at Kaloko-Honokōhau, 32%, but is not a distinguishing indicator variable.)

Kaloko-Honokōhau National Historical Park
Fewer visitors to this park are from in-state compared to Cape Lookout National Seashore.As a result, there are wider gaps at Kaloko-Honokōhau than at Cape Lookout between the tourist and in-state groups in probability of state residence and motivation to see park wildlife (Figure 2; Supporting Information, Table 16).Demographic characteristics of the audiences are otherwise fairly similar to those of Cape Lookout (Table 8).
Multimodal sun protection tourists (44%): Members of this group of out-of-state visitors have zero probability of visiting the park weekly or monthly and also have a low probability of being a frequent beachgoer generally (30%).When they do go to the beach, there is a high probability that they will report using a wide array of sun protection measures: shade (79%), cap (98%), wide-brimmed hat (77%), and sunscreen (93%).Members also have a high probability of saying that they typically use reef safe sunscreen (75%), but are not as likely to say it is mineral-based (47%).This group of survey respondents is largely female (60%) and White (72%) with the largest percentage of members identifying as Asian (21%).About a third of the group (32%) is between ages 18 and 34.Members are well-educated with 68% reporting a bachelor's degree or higher.Members of this audience have the highest probability of reporting that they will engage in a specific activity at the beach (beach walking, 53%).

Sunscreen protection tourists (25%):
Members from this group have a low probability of stating they are Hawaii residents (13%), but a high probability of reporting that they use sunscreen typically when at the beach (94%), including at the beach the day they were surveyed (92%).Like the previous audience, they have a lower likelihood of being frequent beachgoers (43%) than the following two audiences.Members have roughly the same probability of reporting using reef safe sunscreen as multimodal sun protection tourists (73% compared to 74%, above), and again, are more likely to cite using it than mineral-based sunscreen (44%).While they have a low probability of using most other forms of sun protection, there is one exception: shade (typical use at the beach, 53%; park use, 62%).The audience tends to be young; 48% are between 18 and 34 years old.And they are well-educated.More than half (57%) have at least a bachelor's degree.
In-state frequent park visitors (19%): Members of this group have the highest probability of being a Hawaii resident (80%), going to the beach frequently (98%), visiting the park frequently (82%), and engaging in multiple forms of sun-protection at the park (shade, 86%; cap, 62%; sunscreen 76%).They also have the highest probability of typically using reef safe and mineral sunscreen (respectively, 88% and 49%).The vast majority of this group identifies as White (70%) and female (68%), and has at least a bachelor's degree (24%), if not also an advanced degree (38%).Hawaiian or Pacific Islander respondents represent 10% of the audience.This audience is one of the oldest; three-quarters of respondents are over the age of 34 (75%).
Frequent beachgoers who skip sunscreen (12%): Members have high rates of probability of not using sunscreen (69%) and going to the beach every week or month (72%), with somewhat lower probabilities of being a Hawaiian resident (52%).This audience is least likely to report using reef safe or mineral sunscreen (respectively, 41% and 6%).More than half (58%) of the respondents in this group are male; females comprise the majority of the other three audiences.This audience is the most diverse with 19% identifying as Hispanic/Latino/Spanish heritage, 14% Asian, and 7% Hawaiian/Pacific Islander.It is also the oldest; a third of the audience is 65 years or older.And it is the least educated; the majority do not have a bachelor's degree (58%).

Latent class validation (RQ 4 )
In order to determine whether there were meaningful differences between the segments on variables of interest, we conducted ordinal logistic regression (Supporting Information, Tables 17-22).Sunscreen protection tourists served as the contrast category, compared to the other three audiences, because of the relative size of the audience (second largest) and their heavier reliance on sunscreen to protect against sun exposure with low rates of adoption of mineral formulations.The following sections describe statistically significant findings for each park's audiences, illustrated by the estimated marginal means for each question (full data available in Supporting Information, Tables 23-42).

Cape Lookout: Audience awareness, risk perceptions, behavioral intent
Issue awareness: Three audiences-multimodal sun protection tourists, in-state frequent park visitors, and frequent beachgoers who skip sunscreen-were more likely than sunscreen protection tourists to say that they were aware that sunscreen formulations containing certain types of chemicals had been banned in areas of the United States.The odds of having a higher score on issue awareness than sunscreen protection tourists on the measure were 1.74 times for multimodal sun protection tourists (95% CI, 1.18-2.57),1.91 times for in-state frequent park visitors (95% CI, 1.21-3.03),and 2.19 times for frequent beachgoers who skip sunscreen (95% CI, 1.21-3.96).While the pattern remained similar regarding respective audience awareness of potential concerns about sunscreen environmental impacts, the difference between audiences was smaller (p = 0.05).
Risk perception: In-state frequent park visitors were somewhat more likely to view the effects of human activities and sunscreen chemicals on the environment as lower risk than sunscreen protection tourists.In-state frequent park visitors had 2.12 times the odds of selecting a higher level of agreement that "human activities have little effect on ocean life" than sunscreen protection tourists (95% CI, 1.37-3.29),and 1.55 times the odds of selecting a higher level of agreement that "sunscreen chemicals are unlikely to contribute to water pollution" (95% CI, 1.04-2.32).Frequent beachgoers who skip sunscreen responded similarly to the other in-state audience regarding the question on sunscreen water pollution, but the comparison to sunscreen protection tourists was not significant (1.56 odds ratio; 95% CI, 0.91-2.68;p = 0.10).
Behavioral intent: Two of the audiences-multimodal sun protection tourists and in-state frequent park visitors-were more likely than sunscreen protection tourists to say that they would wear protective clothing the next time they visit the park again or another beach.Frequent beachgoers who skip sunscreen were the least likely audience to say that they would use mineral-based sunscreen.
• Multimodal sun protection tourists and in-state frequent park visitors had higher odds-respectively, 4.92 and 5.15 times greater-of indicating a greater likelihood of wearing sun-protective clothing when they next visit the park compared to sunscreen protection tourists (95% CI, 3.41-7.08;3.32-7.99)(Figure 3).Frequent beachgoers who skip sunscreen had odds 1.98 times greater than sunscreen protection tourists that they would select a category indicating they were less likely to use protective clothing when they next visit the park (95% CI, 1.12-3.47).• The odds for frequent beachgoers who skip sunscreen were 11.24 times that of sunscreen protection tourists to choose a less likely category for use of mineral-based sunscreen when they next visit the park (95% CI, 5.74-22.22).• Multimodal sun protection tourists and in-state frequent park visitors were more likely than sunscreen protection tourists to select a higher category indicating they would wear sun-protective clothing when they next visit another beach, with odds that were 5.38 and 5.43 times that of sunscreen protection tourists (95% CI,).• Frequent beachgoers who skip sunscreen had odds 11.11 times that of sunscreen protection tourists that they would select a less likely category for using mineral-based sunscreen when they next visit another beach (95% CI, 5.74-22.22).

3.4.2
Kaloko-Honokōhau: Audience awareness, risk perceptions, behavioral intent Issue awareness: In-state frequent park visitors and frequent beachgoers who skip sunscreen were more likely to be aware of sunscreen bans in the United States and concerns about formulation environmental risks than sunscreen protection tourists.There were no significant differences between the two tourist groups on the measures.The odds for in-state frequent park visitors and frequent beachgoers to select a category indicating greater issue awareness were 3.24 and 1.33 times as great as that of sunscreen protection tourists for bans (95% CI, 2.09-5.02;1.33-3.69)and 2.31 and 1.89 for environmental concerns (95% CI,. Risk perception: There were no significant differences between the audiences on measures of risk perception.According to the modeled estimated marginal means, each audience had a high probability of strongly disagreeing that "human activities have little effect on ocean life" (63%−77%) with a lower probability of strongly disagreeing that "sunscreen chemicals are unlikely to contribute to water pollution" (51%−59%) (Supporting Information, Tables 35-36).Behavioral intent: Demonstrating the same pattern identified with audiences from Cape Lookout National Seashore, two of the audiences-multimodal sun protection tourists and in-state frequent park visitors-were more likely than sunscreen protection tourists to say that they would wear sun protective clothing the next time they visit the park again or another beach.Frequent beachgoers who skip sunscreen were less likely than sunscreen protection tourists to say that they would use mineral-based sunscreen.
• Multimodal sun protection tourists and in-state frequent park visitors had higher odds-respectively, 3.25 and 2.65 times greater-for indicating a greater likelihood of wearing sun-protective clothing when they next visit the park compared to sunscreen protection tourists (95% CI, 2.24-4.72;1.70-4.14)(Figure 4).• The odds for frequent beachgoers who skip sunscreen were 6.67 times that of sunscreen protection tourists to choose a less likely category for use of mineral-based sunscreen when they next visit the park (95% CI, 3.68-12.05).• Multimodal sun protection tourists and in-state frequent park visitors were more likely than sunscreen protection tourists to select a higher category indicating they would wear sun-protective clothing when they next visit another beach, with odds that were 3.60 and 2.79 times that of sunscreen tourists (95% CI,).• Frequent beachgoers who skip sunscreen had odds 5.18 times that of sunscreen protection tourists that they would select a less likely category for using mineral-based sun-screen when they next visit another beach (95% CI, 2.94-9.17).

DISCUSSION
In this study of North Carolina and Hawaii coastal park visitors, we identify four audiences for sunscreen chemical pollution (RQ 1 ): sunscreen protection tourists, multimodal sun protection tourists, in-state frequent park visitors, and frequent beachgoers who skip sunscreen.Notably, indicator variables for the latent behavioral constructs are relatively consistent across visitors of both parks: shoreline sun protection habits and conditions for habit formation, park recreation choices, and motivation to visit national park wildlife (RQ 2 ).Further, the segmentation distinguishes between different audience levels of issue awareness, risk perception, and behavioral intent (R 4 ).While there are consistent patterns in regard to issue awareness and behavioral intent across the audiences of the parks in North Carolina and Hawaii (RQ 3 ), their risk perception profiles differ.In Cape Lookout, in-state frequent visitors are less likely to perceive risks to ocean life and water pollution than other audiences, but in Kaloko-Honokōhau, respondents across all groups indicate concern.While these study data do not permit us to explore why that might be the case, possible explanations include: (1) underlying differential audience perceptions of environmental risk (Kahan, 2012), which predominate especially under conditions of low specific issue awareness; and (2) processes of social amplification (Hawaii) versus attenuation (North Carolina) of environmental risk within these respective areas (Kasperson et al., 1988) due to state variations in policy focus (Gabbard & Kim, 2018).
Regardless, most of the audiences demonstrate interest in reducing their impacts on marine life and water quality, suggesting the potential to successfully promote sun protection actions to address health and environmental risks.Three of the four audiences-sunscreen protection tourists, multimodal sun protection tourists, and in-state frequent park visitors-stated a high probability of intent to use mineral sunscreen the next time they visit the park or other beaches.Two-in-state frequent beachgoers and multimodal sun protection tourists-also stated high probabilities of wearing sun-protective clothing.Limited outreach and education budgets require natural resource managers to choose which audiences to prioritize.Based on their behavioral profiles, sunscreen protection tourists represent the audience of highest concern, followed by multimodal sun protection tourists.

Highest concern audience-Sunscreen protection tourists
Sunscreen protection tourists represent only approximately a quarter of visitors, yet they rely on sunscreen as their primary form of sun protection and have just a 28% probability of saying they use mineral-based sunscreen in Cape Look-out and 44% in Kaloko-Honokōhau.These visitors also have lower levels of issue awareness and intent to engage in wearing sun-protective clothing than other audiences.They are the youngest of the groups-about half are between the ages of 18 and 34-and are well-educated.They are also less likely to be frequent beachgoers or in-state residents.Reaching this audience before they arrive in parks and other natural resource areas will help ensure that they choose the recommended sun protection options while preparing for their trip.Because they are not frequent beachgoers and are relatively young, they also may have less engrained sun protection habits and may be more open to new behaviors (National Research Council, 2006).The greater variability in the use of mineral sunscreen of this audience between the two states may be an indicator of their receptivity to new information.

Second highest concern audience-Multimodal sun protection tourists
Multimodal sun protection tourists represent the largest of the audiences in both parks with more than 40% of visitors.This audience is on average somewhat older-the majority are between 18 and 44 years old-and they are well-educated.The audience is of less concern because members already rely on more than sunscreen for protection, but their probability of saying they use mineral sunscreen remains relatively low (Cape Lookout, 40%; Kaloko-Honokōhau, 47%).Like sunscreen protection tourists, they are more than likely new to each of these parks and are not frequent beachgoers.Many of the same strategies used to reach sunscreen protection tourists will also reach this audience.Further, the need to provide information on mineral-based sunscreen is equally applicable to both.

Implications for natural resources management and public health
Multimodal sun protection-combining the use of protective clothing, shade, and staying out of the sun during the middle of the day, along with sunscreen (World Health Organization, 2001)-offers opportunities to both reduce chemical pollution and decrease skin cancer risk (Wang et al., 2010).Yet, as this study demonstrates, sizeable percentages of park visitors rely on just sunscreen with concomitant environmental risks (Downs et al., 2022).Notably, tourists represent the majority of visitors and likely sunscreen contamination, in alignment with literature on the difficulty in developing sustainable tourism models (Weaver, 2004).Leveraging national media outreach and strategically placed online information will enable management organizations to reach visitors before they arrive on site.The fact that the two tourist audiences are more likely to cite wildlife as a draw to the park than frequent visitors further suggests the potential appeal of information focused on protecting park species.
Notably, the study was conducted in collaboration with NPS and featured the logos of both the researchers' university and agency.NPS remains one of the most favorably viewed federal agencies, second only to the US Postal Service (Pew Research Center, 2019).This likely contributes to its ability to communicate sunscreen chemical pollution risk effectively with the public, including within the survey itself.
The study's findings also speak to the need for improved health risk communication.The finding that a small proportion of visitors do not use any sun protection, or very little, even while in areas of high UV exposure suggests the level of continuing difficulty in engaging the public in behaviors to reduce skin cancer risks.Frequent beachgoers who skip sunscreen are characterized by some of the higher proportions of people of color among the segments.This indicates the need for tailored interventions (Ossio et al., 2017) that address perceptions of being at low risk for skin cancer among these populations (Buchanan Lunsford et al., 2018).

Study limitations and future research
The study relies on self-report measures, which may be subject to error.However, many of the survey questions asked respondents to report on sun protection and recreation behaviors they were currently engaged in, which should have reduced these inaccuracies.While the results of this initial research are promising, the limited geographic and temporal scope range of the study-two coastal parks in different regions of the United States during summer 2021-suggests the need for further visitor surveys in other areas.As bans on some sunscreen chemical formulations become more established over time, they may spur further behavioral change among the public and alter their risk information needs.Future research should not only assess whether the audience segmentation is broadly applicable in other coastal locations but should test which messages and behavioral intervention strategies are most effective with each group.Further, people receive sunscreen information from a wide array of sources (Levine, 2019), with differing recommendations.Helping people evaluate these competing messages requires research to understand: (1) which sources and arguments different audiences are exposed to, and (2) how trustworthy or credible they perceive them to be.

CONCLUSION
As the first effort, to our knowledge, to segment the environmental and health dimensions of sun protection behaviors, this research demonstrates a potentially useful typology that may be generalizable to broader audiences of coastal park visitors.The identified audiences of concern for sunscreen chemical pollution align with Grunig's criteria (1989).Not only do they represent a significant population size that is both definable and measurable, but reachable for the purposes of natural resource managers.As awareness of pro-environmental sun protection increases, research framed on the transtheoretical model may become useful in distinguishing stages of behavioral change for these audiences.

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I G U R E 2 [Kaloko-Honokōhau National Historical Park] Probability of the members of each audience ranking high on each of the variables (each coded 0-1).

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I G U R E 3 [Cape Lookout National Seashore] Estimated marginal means: Behavioral intent if you were to visit this park again.

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I G U R E 4 [Kaloko-Honokōhau National Historical Park] Estimated marginal means: Behavioral intent if you were to visit this park again.

criteria Models Smallest class count (n) Smallest class size (%) Entropy LL (parametric bootstrapped likelihood ratio test) 2x LL difference p
Ordinal regression variable descriptions and coding TA B L E 1 LCA variable descriptions and coding included: wildlife of interest (Cape Lookout, horses and shelling; Kaloko-Honokōhau, sea turtles), forms of physical recreation(Cape Lookout, swim, sunbathe, walk, fish, boat;  Kaloko-Honokōhau, sunbathe, snorkel, walk), young children within the group (Cape Lookout only), and NPS staff contact regarding sun protection (Cape Lookout only).Models ranging between 2 and 7 classes were tested with each of the park datasets.A four-class model provided the most parsimony and explanatory value in both cases (Tables3-6).Log-likelihood statistics are likely to be significant when sample sizes are large; as a result Bayesian information criterion (BIC) and Akaike information criterion (AIC) model fit criteria are generally more likely to be used(Hagenaars &  McCutcheon, 2009).In each case, the BIC and AIC valuesTA B L E 2Abbreviations: AIC, Akaike information criterion; BIC, Bayesian information criterion; LL, log-likelihood; SABIC, sample-size adjusted BIC.TA B L E 4 [Cape Lookout National Seashore] Diagnostic

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Sunscreen protection tourists: This group of out-of-state visitors uses sunscreen, but not typically other methods, such as protective clothing.This audience demonstrates low mineral sunscreen use as well, but with more variability in the probabilities of the two park samples.