Environmental health has been described as the area of public health that addresses all external physical, chemical, and biological parameters that affect a person's health and quality of life, as well as any associated factors that have an impact on behaviors [5, 44]. The built and natural environments are increasingly being recognized as fundamental health determinants by public health and planning professionals [45]. Hence, in the present study, we created a brief self-report measure for evaluating the perceived level of EDH comprising two factors (natural environment and built environment) among university undergraduate students. The EDH-Q had five rating options, ranging from 1 (strongly disagree), 2 (disagree), 3 (somewhat agree), 4 (agree), and 5 (strongly agree). At the macro level, the natural environment assesses essential factors, including natural resources [12]. At the level of the community, the built environment assesses physical factors that safeguard and support chances for a living, good health, and sustainable development [12].
In the present study, the natural environment encompasses physical exposures like extreme weather conditions, the quality and accessibility of drinking water and food, exposure to air pollutants, and ensuring a secure work environment. On the other hand, the built environment includes an evaluation of diverse factors such as housing, land use, infrastructure, transportation, public spaces, schools, and healthcare facilities. According to various studies, numerous health risks can result from our indoor, outdoor, and work environments, such as the risk of injuries from moving vehicles, unsafe living and working conditions, pollution of the air we breathe, the water we drink, and the food we eat [1, 2, 7]. The natural environment consists of physical exposures (like noise and radiation), anthropogenic changes (like climate change and vector breeding grounds), exposure to toxins and chemicals (like in the air, water, soil, and food products), associated behaviors, and the work environment [5, 46, 47]. The built environment includes factors like housing, land use, infrastructure, transportation, and public places [2, 47]. These environment-related factors have an influence on human health and have been one of the primary objectives in raising public awareness of the importance of better environmental management [1, 15].
Given that individuals have either created or extensively altered parks and waterways in urban areas, there is no isolated natural environment per se; rather, these spaces are now considered part of the built environment [11]. Nevertheless, it is crucial to recognize that the natural environment remains indispensable for all life, including those residing in urban environments [11]. Having examined research in the observational public health literature regarding hazards in residential structures, Alidoust and Huang [48] identified fires, radon exposure, falls, house dust mites, and environmental tobacco smoke as the primary health risks associated with such situations. Addressing the influence of substandard housing on physical health, a systematic review concluded that residing in cramped spaces, especially in temporary accommodations, heightens the risk of injuries, violence, respiratory diseases, and gastrointestinal issues related to cold, damp conditions and mold growth [49].
Researchers have proposed many mechanisms to explain the disproportionate risk experienced by residents of economically underdeveloped urban communities, such as limited access to nutritious food and an abundance of high-fat fast food options [50], high crime rates and poorly maintained public spaces that limit opportunities for recreational activity [51], informal socializing among neighbours [52], and the ability of neighbours to enforce collective social norms [52], as well as reduced educational and employment opportunities and quality [15]. Furthermore, educational institutions and medical facilities in poor regions often experience suboptimal physical conditions and face increased demands [15, 53]. The interplay between elements of the built environment and the social context may lead to exposure to various stressors, encompassing noxious odours, emissions from local industries, illegal dumping, occupational hazards, financial stressors, and anxieties related to crime and safety [15].
The results of content validity reveal that the I-CVIs and S-CVIs of all 18 items were 1. For face validity, the results reveal that the I-FVI values ranged from 0.90 to 1, and the S-FVIs were 0.99 and 1. These results indicate sufficient content validity and face validity [31-33]. Further, two separate samples of undergraduate students—mostly adolescents—were used to test the EDH-Q for EFA (300 respondents) and CFA (430 respondents). The development of economies across countries and the general well-being of the population depend on how these environmental determinants affect adolescents health [54, 55]. This is because there is a strong correlation between health and health behaviors throughout adolescence and adulthood. The transition from adolescence to adulthood also has an impact on the way individuals develop in regard to their well-being and quality of life. The environmental and financial factors that exist in each nation have an impact on these changes [56].
In the EFA, two factors (natural environment and bult environment) were identified (KMO = 0.937; p-value < 0.001), containing all 18 items with satisfactory factor loadings (above 0.50) on their respective constructs. The EFA model was further tested using the CFA. The final model showed adequate fit indices, and all the items had sufficient factor loading on their respective constructs. The two constructs had acceptable internal consistency, composite reliability, and discriminant validity. Overall, the results show that the EDH scale has sufficient psychometric properties and may be used to evaluate individuals perceived environmental determinants of health [36, 39-41]. In addition, six pairs of error covariances were included in the final model (2 for the natural environment and 4 for the built environment) after taking enough theory into account. These residual covariances were added by referring to the MI values reported in the Mplus output. In social psychology, residual covariances can be added to the model when they have a significant meaning [57].
The present study is not without some limitations. First, given that the survey was carried out at one university, it is essential to tread cautiously when drawing inferences from the results. However, the size of the sample might give the study's findings and conclusions more weight. Second, using a self-reported survey may result in response bias and reduce the accuracy of the data collected. To address this issue, all participants were assured that their information would be kept private and were advised to respond to all of the questions accurately and truthfully, as well as avoid discussing the survey with their friends. Thirdly, we employed a convenience sample method to select the study participants, which may have limitations inherent to this sampling approach. Furthermore, the study's focus on undergraduate students only limits the generalizability of its findings to the general population. Researchers should conduct future studies to test the EDH-Q in a more diverse population with diverse sociodemographic characteristics.