**4. Conclusions**

This study analyzed both the real and perceived impact of lighting among vendors and non-vendors in night markets. The methodology was based on a field survey in one typical night market in Surin province (Thailand).

Given the importance of night markets as a source of complementary income and even as unique livelihood, and their critical role in maintaining the traditional economy in many urban and rural environments around Asia, the health and well-being of both vendors and visitors is a key factor to achieving sustainable development in such a quickly growing zone like Southeast Asia and, in general, in the whole continent. Hence, the higher the sense of well-being among people making their living from night markets, the higher their attachment to their land and way of life. This is especially critical to avoid depopulation in rural zones and uncontrolled shifts to unsustainable economies and massive migrations toward big cities.

On the other hand, the extremely important role of lighting as a transversal factor in every human activity, and the necessity to keep it in mind when talking about sustainable development, is without doubt. Thus, the need for accurate policies for lighting, in order to gran<sup>t</sup> health and well-being to the users of lighting installations, as well as the need to design and maintain these installations with the minimum consumption of energy, raw materials, and financial resources, makes it necessary to apply the current knowledge on this matter to night markets.

From the well-known perspective of installations, excessive levels of lighting, spectral distribution producing scattering toward the sky, or emission of light beams toward inaccurate directions, disturbing people, is considered light pollution. Night markets are outdoor places, and, hence, they can produce light pollution, but they are also places where people work. Most countries in Europe and North America regulate light pollution and also lighting levels in work places.

The results of this work, proving more health problems among vendors, confirm the necessity of regulating the lighting of night markets in Thailand and most countries in Southeast Asia.

This higher impact among vendors can be explained by their more continuous exposure to higher levels of illumination during inappropriate hours, at night. This impact is real (higher incidence of eye- and sleep-related problems) and also perceived.

Besides the considerations above, a careful analysis of the results leads to some very interesting conclusions:


In summary, night markets are key sources of incomes and traditional economy at local levels, in many Asian countries, like Thailand. The impact of their peculiar lighting on vendors' health, well-being, and perceived problems is a real threat for their long-term survival, with a consequent influence on sustainable development.

Although this study was conducted with a small vendor population from a seven-hour night-market in a remote province, it provided the first empirical insight into the health impacts caused by excessive lighting in night markets in Thailand. It is suggested that further research should be conducted in other types of night markets (i.e., 24-h night markets, e.g., in Bangkok) and/or integrated with medical statistics reporting vendors with circadian-rhythm disturbances and other health problems associated with excessive illumination, in order to provide more accurate evidence. These research findings speak to the need for policies regulating sustainable lighting in night markets to not only ensure livelihoods for local vendors and save energy, but also to reduce the lighting impacts on vendors and health-care costs.

**Author Contributions:** T.P.L.N. designed the research, conducted the survey, and analyzed the data. Both T.P.L.N. and A.P.-G. equally contributed to the writing and revision of the paper.

**Funding:** This research received no external funding.

**Acknowledgments:** This research was conducted during the field activity of a Master regular course "Regional and Rural Development Planning Workshops" of Asian Institute of Technology. The authors thank vendors and clients of Surin province night market who participated in this survey. Special thanks are given to Wilawan, B. Prathaithep, and students from Rajamanjala University of Technology Isan Surin Campus who supported the implementation of the survey, Nitchakan Inkong and Vu Thanh Bien, AIT Master students for their assistance in data input and analysis.

**Conflicts of Interest:** The authors declare no conflict of interest.

### **Appendix A Questionnaire Survey (Thai Language was the Original Language of the Survey)**

Survey on awareness, attitude, and perception of excessive lighting effects on human health.

Dear participants, This is a survey regarding users' awareness, attitude, and perception of excessive lighting effects on human health. It is implemented by Dr. Thi Phuoc Lai Nguyen, Assistant Professor at the Department of Development and Sustainability, School of Environment, Development, and Resources, Asian Institute of Technology (Thailand). Your participation is voluntary and may be discontinued at any time. Your responses are anonymous, and the individual study results will be confidential and only used for the research purpose. Data will not be traceable to you and will not be shared with anyone.

Thank you for your time. If you have any questions, or if you want the study's final report, please contact me at phuoclai@ait.asia.

I. Respondent's general information


II. Information on Respondent's circadian rhythm and eye health

1. Do you suffer any problems with sleeping associated with excessive lighting?

 Yes No If yes, what are the problems and how long have you suffered with this problem?**Problems When** —————————– ————————- —————————– ————————- —————————– ————————- —————————– ————————- Do you have any eye related problem associated with excessive lighting? Yes No

If yes, what are the problems and how long have you suffered with this problem?

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**Problems**

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2.

III.Respondent'sattitudetowardnightmarkets

 **When**



### IV. Respondent's awareness of excessive light effects on human health
