Project Leader	Tomita Shinsuke (Nagoya University , Asian Satellite Campuses Institute)
Collaborators	Sakamoto Ryota (Kyoto University,  Center for Southeast Asian Studies) Umezaki Masahiro (The University of Tokyo , S School of International Health, Graduate School of Medicine,) Honda Masato (Kanazawa University, Institute of Nature and Environmental Technology) Hattori Hiroyuki (Nagoya University, Graduate School of Bioagricultural Sciences) Mizuno Yuki ( The University of Tokyo, School of International Health,Graduate School of Medicine) Kibe Mihoko ( The University of Tokyo, School of International Health,Graduate School of Medicine)
Research Project	A study of the inherent health risks of livelihoods in montane mainland Southeast Asia
Countries of Study	Laos

Outline of Research

Previous studies have alleged that padi state or valley state at the lowlands exerted political influence over upland communities due to their higher rice productivity and carrying capacity. In fact, it is evident that upland villages often do not have enough rice to survive. It has become apparent, however, that differences in agricultural productivity alone do not explain the health of the local population. Our research indicates that lowland people face greater health risks than their upland counterparts. In our opinion, such health risks are inherent to livelihoods rather than a consequence of modernization. An analysis of the relationship between health, and chemical substances and trace elements related to the ecological setting and livelihoods is presented in this study, which evaluates the health risks among people living in lowland and upland environments. 

Purpose of Research, Its Significance and Expected Results, etc.

Wet rice farming has been often implicitly or explicitly regarded as the source of political power of the chieftains of the region, not least because its higher agricultural productivity allows for the raising of a larger population than that of swidden farming which is employed by upland people. Upland people had to be subordinate or try to escape from authority. However, recent studies showed that there have been other relationships which could not be explained by agricultural productivity. Upland people had led, created and protected padi states (Badenoch and Tomita 2013). In Lan Xang kingdom, lowland and upland people built the relationship through NTFPs trading (Masuhara 2011). Investigating the effect of chemicals and trace elements pertaining to livelihoods on health, this study rethinks the relationship between lowland and upland societies beyond agricultural productivity-based discourse.

There are two common rice farming systems in montane mainland Southeast Asia: wet rice farming in the lowlands and swidden rice farming in the uplands. In contrast to wet rice farming, swidden farming usually produces lower rice yields. Hanks (1972) estimated that wet rice farming yields 1.5 times more rice than swidden rice farming. Due to the lack of irrigation systems, rice yield in swidden farming fluctuates to a greater extent every year. People in the uplands often face rice shortages because of the lower productivity and instability of dry rice production.    

A swidden farming system is considered to have greater health risks than wet rice farming. Burning trees is seen as one of sources of air pollution in Southeast Asia (e.g. Mostafanezhad, 2019). Small particles in the air easily bind to polycyclic aromatic hydrocarbons (PAHs), a hazardous chemical emitted from burning.

Experiencing malnutrition and exposure to noxious chemicals may increase oxidative damage to cells, thus increasing health risks. According to our studies, lowland and upland people do not differ significantly in height or BMI. A lower level of oxidative stress was also observed among upland people.

A key question is why upland people have lower health risks than lowland people, despite lower agricultural productivity and frequent exposure to noxious chemicals. Considering the influence of modernization, the study examines 1. The socioeconomic factors that influence health status, 2. Noxious chemicals and trace elements related to ecological settings and livelihoods, 3. Plausible factors which increase health risks among lowland people, and 4. Plausible factors which decrease health risks among upland people.