Migration, Human, and Environmental Health
This dissertation is an examination of the environmental and health impacts of the migration process at multiple scales: individual, muncipio, biome, national, and regional/continental. It seeks to address the questions: Whose health benefits or worsens when people migrate? Under what conditions? Through this, I hope to further the understanding of the complex effects of migration upon the places and people who participate in this process.
Migration affects the natural environment directly through the changes produced in sending communities: Rural depopulation occurs as people migrate to seek wage labor in urban and international destinations. This can lead to a diverse set of outcomes: forest cover returning on abandoned small farms, or forest cover declining as remissions allow for investment in agriculture or as empty smallholdings are replaced with large industrial farms. Migration also contributes to changes in the natural environment indirectly: Most migration occurs up the development continuum from rural to urban, and/or developing to the developed world. As people move up the development continuum they almost invariably consume more resources, including high-resource food in the form of meat, animal products, and prepared and processed foods. Migration also directly affects the health of the individual. In addition to the stresses and dangers of the migration process itself, changes in location result in changes in access to health related resources, changes in health behaviors, and health-related acculturation. As Mexican migrants move from rural to urban places, and to the U.S., they often move to less stable or less family based living environments, and they commonly eat in a less healthy manner, resulting in higher risk for nutrition-related chronic diseases such as obesity, diabetes, cardiovascular disease, and cancer.
This dissertation consists of a four chapters that seek to explore this complex relationship. A ‘theoretical’ or ‘literature’ chapter, three ‘empirical’ chapters, and a conclusion. Each chapter has been formatted as stand-alone, publication-ready manuscripts, and each contain their own literature sections. The first chapter makes two principal arguments: first, that research on migration should be included in the emerging academic topic of “Planetary Health”, and second, that this dissertation is part of an emerging theme within the subfield of nutritional geography, “the geography of malnutrition”. Chapter 2 is an examination of the relationship between population trends (including migration), agricultural land use, and food at multiple scales, using data from the Food and Agriculture Organization (FAO). The chapter examines trends from recent decades in population change and distribution, as well as patterns of agricultural expansion and intensification at the global region scale and the national scale for Latin America. We also examine agricultural intensification vs production in Latin America, and discuss three case studies to highlight how space and place context are critical in understanding the population-food-environment nexus. Chapter 3 is an examination of the relationships between migration, population, and economic processes, and forest cover change in Mexico from 2000 to 2010. Using multiple regression analyses with remotely-sensed, significant (p > 0.10) change in woody vegetation from 2000 to 2010 as our dependent variable, we explore the effects of a suite of environmental, demographic, and economic indicators at the national and regional biome scales. Results highlight the importance of international migration on forest change across various scales, and that internal migration and other demographic and economic variables contribute at particular scales and regions. Chapter 4 examines how migration history influences diet and diet-related health among recent internal migrants to Tijuana, Mexico. We investigate characteristics of migrants’ origin influence their health and diet, finding that migrants from rural places and of indigenous status have better diet-related health, but have undergone more diet change than other groups. These results indicate the importance of migration history and geographic variables in health related research with migrants.