Environmental health literacy (EHL) refers to the understanding and use of information about potentially harmful environmental exposures and how those exposures influence health [1
]. EHL encompasses a range of knowledge, attitudes, and behaviors that influence how individuals and communities use environmental information in making decisions about health [2
]. EHL is often viewed as a dynamic process through which individuals and communities are increasingly able to apply a more nuanced understanding of environmental health (EH) risks, exposures, outcomes, and strategies to reduce adverse environmental exposures and promote health [1
]. Given the diversity of potential environmental exposures, it is also important to note that EHL is often specific to personal and community context and the contaminated environmental media involved. The term “environmental media” refers to parts of the environment, such as soil, water, air, plants and animals, that can contain contaminants, potentially resulting in individual or community exposure. EHL may be increased through multiple strategies [3
]. Often, the desired outcome of addressing EHL is to increase knowledge and promote action among individuals and communities, especially in situations where past exposures to hazardous substances may lead to both current and future adverse health effects [2
Recently, the literature has emphasized the importance of information-seeking and decision-making skills that raise awareness and knowledge of EH and could result in health-protective actions [1
]. There is also recognition that the sources of environmental exposures are often outside an individual’s control and that health disparities can heighten community concerns [7
]. Furthermore, socioeconomic and contextual factors influence EHL, including language, education, community networks, and news media [3
]. Accordingly, it is necessary to address EH concerns utilizing a culturally competent, interdisciplinary, and context-specific approach [3
]. Gray [1
] presents three interrelated dimensions of EHL, including awareness and understanding, skills and self-efficacy to reduce harmful environmental exposures and make decisions that protect health, and community change to reduce or remove environmental exposures that are harmful to health. A range of activities are required to improve EHL across these dimensions. It is thus important to address EHL at both individual and community levels, ensuring that baseline awareness and knowledge is coupled with skills to ignite actions that promote health and reduce adverse exposure [2
The field of EHL emerged in the 1970s from the American movements to promote literacy, including health literacy, science literacy, and environmental literacy, as well as risk communication and environmental justice [2
]. Since 2014, there have been increasing efforts to define, measure, and improve EHL [1
]. Some progress has been made in measuring EHL [8
], with most studies 1) describing the perceived relationship between environmental exposures and health outcomes; 2) focusing on a specific exposure (e.g., pesticides, lead in drinking water, arsenic in soil); 3) assessing the impacts of interventions, and/or 4) examining results dissemination of biomonitoring studies [1
]. For example, in a systematic literature review of 31 articles related to EHL, Gray [1
] highlighted numerous studies that employed pre-/post-assessments to measure changes in EHL in response to an intervention or environmental exposure at both individual and community levels. Many of the studies utilized community-based participatory research approaches and examined community participation in results dissemination for biomonitoring studies [4
]. Several of these “report-back” studies concluded that engagement in research can advance participants’ EHL [1
A validated scale that measures individual EHL is a foundational step to improving EHL at both individual and community levels [3
]. Standardized measurement of EHL has the potential to inform needs assessments, measure national EHL trends, guide policy and planning, and assess the impact of educational initiatives and other interventions that aim to improve EHL [3
]. While several EHL tools exist, few have been validated [1
]. To date, there are only two peer-reviewed studies [8
] focused on the development and validation of tools to measure EH knowledge, behaviors, and attitudes. Dixon and colleagues [8
] validated the Environmental Health Engagement Profile, which examines how individuals engage with EH issues, including their experience with EH hazards, assumptions of risks, and actions taken both individually or collectively. Although this study utilized a systematic process to generate the EHL scale, it was only validated via phone with community members located in New Haven, Connecticut, and statistical analyses lacked confirmatory factor analysis. Ratnapradipa et al. [14
] used a modified Delphi technique to develop and validate core EH categories and corresponding topics, creating an assessment tool with 443 potential questions. Given the number of potential items included in this scale, the researchers were unable to validate the entire survey with community members, instead receiving validation on topic-specific survey sections through focus groups [10
]. Additionally, feedback from participants highlighted the difficulty of creating a general EHL survey due to the context-specific and technical nature of some EH issues, highlighting the importance of validating a general EHL scale across geographic areas. While these studies represent advancements in the field, the currently published EHL scales lack environmental media-specific assessments of knowledge, attitudes, and behaviors and have not been validated with community members in more than one geographic area.
To fill this gap, this study aims to develop a validated survey instrument to assess an individual’s knowledge, attitudes and behaviors related to EHL. The design reflects the multidisciplinary nature of EH, as evidenced by the creation of scales encompassing both general EH and three environmental media; food, air, and water. These media were deliberately selected since individuals have daily contact with them and contamination of these media is often the focus of community concerns. The four scales were validated with distinct samples in two geographic areas using advanced multivariate statistical methods, including exploratory and confirmatory factor analyses. Using the scales in community-based participatory research (CBPR) can strengthen community engagement, research translation, and health promotion, ultimately advancing the implementation of environmental epidemiological studies.
The purpose of this study was to develop a psychometrically sound, multidimensional scale of independent factors to assess specific environmental media and general EHL. The survey instrument uses five-point Likert scales to assess respondents’ knowledge, attitudes, and behaviors related to EH issues. The four scales, with a total of 42 items, were developed using the results of exploratory and confirmatory factor analyses completed on data collected from distinct exploratory and test samples of public health students and community members, respectively.
The ten-item Air scale comprises a three-factor solution with three knowledge, three attitude, and four behavior items. All three subscales explain adequate amount of variability ranging from 13.3% to 17.6%. The Cronbach’s alpha for this scale was 0.70, indicating good internal consistency. The nine-item Food scale comprises a three-factor solution with five knowledge, two attitude, and two behavior items. All three subscales explain variance ranging from 2.6% to 38.1%. The Cronbach’s alpha for this scale was 0.67. The 14-item Water scale comprises a three-factor solution with five knowledge, two attitude, and two behavior items explaining 15.6–26.4% of the variance. Reliability of this scale was measured with a Cronbach’s alpha of 0.63. The nine-item General EH scale also resulted in a three-factor solution with three knowledge, three attitude, and three behavior items with the subscales explaining 9.1–17.6% of the variance. The Cronbach’s alpha for this scale was 0.70. Although all three factors of the four scales are distinct, they do have an implicit relationship, indicating some interdependence among them. Significant associations were found between the attitudes and knowledge subscales for all four scales. No significant associations were seen between any of the behaviors and knowledge subscales and the attitudes and behaviors subscales. All four scales show good fit statistics, with the Air scale and the General EH scale showing good absolute fit and all four scales showing good to adequate practical fit with RMSEA values ranging from 0.05 to 0.11.
The validated survey instrument developed in this study represents an important contribution towards evaluating individual EH knowledge, attitudes, and behaviors. The scales could be used to measure the effectiveness of a relevant intervention, however, the value of the scales does not lie in scoring or rating an individual’s EHL. Rather, the scales are best utilized in CBPR settings to a) gauge community partners’ general knowledge, attitudes, and behaviors related to EH, b) identify specific EH concerns among community partners, c) identify constraints that community partners might face in reducing adverse environmental exposures, d) inform research translation and dissemination, or e) serve as starting point for discussing EH issues and EHL among research partners. The four scales can also serve as a gap analysis to inform strategies to bolster community resilience [26
] and tailor health promotion and education actions, further enabling community members to participate in both CBPR and environmental epidemiology studies.
Given the complex nature of many environmental exposures, it is important that community research partners have general knowledge of the completed exposure pathway and the biological plausibility of linking adverse health conditions to environmental exposures, using appropriate and well-accepted criteria [27
]. For example, to advance effective community–academic partnerships in environmental health research, there must be common understanding that environmental exposure must precede disease for there to be a possible causal relationship between the two. Using the scales as a means for researchers and community members to meaningfully engage with each other about EH and EHL will lead to more sustained community–academic partnerships and build trust in the research findings. This, in turn, will benefit research translation, dissemination, and community action. The scales will be of interest to university-based research centers (e.g., Superfund Research Program Centers, Environmental Health Sciences Core Centers) and investigators engaged in environmental epidemiology studies. In addition to expanding the EH knowledge base, the scales can also strengthen CBPR and related educational products and curricula [28
There are some limitations for this study. The exploratory sample cannot be classified as a probability sample since data were collected from students enrolled in public health degree programs. These participants, however, were appropriate for testing knowledge, attitudes, and behaviors associated with EH. Furthermore, the factor structure developed on the exploratory sample was confirmed on a different population of community participants. Other limitations include the lack of data to test the convergent and divergent validity of the scales, and the Cronbach’s alpha values of the Water scale (0.63) and the Food scale (0.67) just approach the recommended 0.70 minimum [25
]. The expert review of the scales for face validity likely reflected the specific expertise of the reviewers within the broad field of EH. The four scales also reflect a content-driven approach to assessing individual EHL. This approach does not necessarily assess individual self-efficacy or account for contextual drivers of EHL. However, this validated instrument does consider behaviors and attitudes in addition to knowledge, and it represents an important vehicle for community-engaged research and action that addresses other dimensions of EHL. Considering the breadth of the EH field, the scales do not cover all possible environmental media (e.g., soil) or EH issues (e.g., radon, disasters, and climate change). However, the scales can serve as a blueprint for creating more detailed scales in additional EH domains. Finally, the survey items were intentionally written at a 5th grade literacy level to ensure that the validated instrument could be effectively administered to the general public. However, reducing complex EH topics to a brief set of items necessarily involved the loss of some nuance and detail in the instrument, which is an ongoing challenge in the EHL field [29