**1. Introduction**

Nowadays, there is wide agreemen<sup>t</sup> that many of the most dramatic problems of humankind directly deal with sustainable development. Although the sustainable use of energy and natural resources, as well as the decrease in the emissions of contaminant and greenhouse gases, are major concerns, fostering the well-being of people and sustainable progress, without substantial disruptions to traditional ways of life, are key factors to gran<sup>t</sup> a fair distribution of resources and ensure their

availability to future generations. Appropriate lighting has proven to be a transversal factor of sustainable development, with a high importance in human activities, granting safety, well-being, efficacy, profitability, and a healthy environment. Although the primary target of lighting should be to gran<sup>t</sup> the safety of people and their goods [1], its impact on other activities, like commerce, leisure, or both, is also essential for personal well-being, as well as economic and social development. In spite of this positive influence on human life, the impact of night lighting, from other perspectives, also has negative aspects. Thus, light pollution [2], or the very high consumption in terms of energy, raw materials for the manufacture of luminaries, CO2 emissions due to the production of electrical energy, and the manufacture of the luminaries, auxiliary devices, wiring, etc. are major concerns for public administrations [3–5]. Although the massive introduction of LED lighting has resulted in a lower consumption per luminary, the continuous growth of cities and population makes lighting a main challenge for sustainable development.

Furthermore, the effects of no-appropriate lighting during nighttime on human health are proven [6–10], as well as its effects on animal life [11–13], plants [14–18], and astronomical observations [19,20]. More specifically, the effects of light on human physiology and psychology have been well-known for ages. For the purposes of this research, the most important effects of lighting are those produced on the circadian rhythms (oscillations in some rhythms of our body lasting about a day, such as the sleep–wake cycle, the cycle of body temperature) [21].

In summary, all the advantages and shortcomings of lighting must be carefully considered when planning all kinds of facilities and installations [22], with special attention to sustainable development, when considered from its wider perspective. Night markets are a good example of necessary facilities in many countries of the world where inappropriate lighting can be a source of problems in spite of other benefits.

### *Night Markets and Excessive Illumination in Thailand*

Night markets are typical opencast facilities for both local inhabitants and tourists to shop and spend time working during the night. They are very popular and indispensable to people in many Asian countries.

Thailand is home to some of the biggest and best ones across South East Asia. This country has a long history of night markets, which are teeming all over the country, in every corner of cities and villages, and usually on every night of the week. Thus, night markets of all shapes, sizes, and types of businesses are present in every village and town in Thailand, and they are open on a daily basis. These facilities are sources of livelihoods for many Thai people, especially for the poor, women, and unskilled people, as the vending activities in the night markets require low capital and investment.

For instance, the Talad Neon market in Bangkok (Figure 1) is open during the whole night. Food, clothes, and other goods are sold, and there are also stands to have a drink and chill out. Jumbo Klongsam market in Pathum Thani province (Figure 2) is open from 5:00 p.m. to 12:00 a.m. and mainly sells food. Night markets provide jobs and income for a large Thai population and are also considered to be a platform for creating new entrepreneurs [23].

Shops in night markets in Thailand are easily recognizable for their neon signs and intense illumination, which are used to attract customers. The reason is that shop owners perceived that more illumination is better, and, in addition, the lighting of night markets is not regulated in that country. However, continuous exposure to high levels and/or types of lighting during nighttime could have adverse effects on vendors' health, as mentioned above.

The dimensions of a standard shop are around 1.0–1.5 m x 2.0–2.5 m, and the number of lamps range from 4 to 12, depending on the shop's size and power of light sources. The majority of them use LED lamps, in order to save energy.

This study aims to understand people's perceptions of night markets' lighting and the impact of its excessive use on vendors' health and well-being. Its results and conclusions are expected to

contribute to important aspects of sustainable development, such as local policy, rural development, and attachment to the traditional economy.

**Figure 1.** Talad neon market (Bangkok).

**Figure 2.** Jumbo Klongsam market (Pathumthani).
