Migration, Population Mobility and Health:

International Movement, Urbanization and Health

Douglas W. MacPherson MD, MSc(CTM), FRCPC, Director, Office for Public Health Security, Centre for Emergency Preparedness and Response, Population and Public Health Branch, Health Canada.

Brian D. Gushulak MD, Director General, Medical Services Branch, Citizenship and Immigration Canada.

Paper prepared for the Workshop: "Is your city making migrants healthy or sick?" at the Sixth International Metropolis Conference, Rotterdam, The Netherlands, November 26-30, 2001.

Introduction:

This paper will provide a brief overview of some of the relationships associated between modern migration and population mobility and health.

Overview

The forces of globalization, largely represented by trade and economic forces, and the development of more integrated global systems are accompanied and sustained by growing population mobility and increased human migration. In spite of increasing interconnection and interdependence between trade and economic globalization and population mobility, the process of globalization is occurring against a background of persistent disparities[i] in health determination between regions of the world. Many of these disparities exist in or influence health sectors.

Coincident with these regional health determinant disparities, are the advances in transportation technology and procedures that facilitate travel and allow for the relatively rapid movement of communities from very diverse origins. This combination of cheap, rapid movement and wide disparities in health determination creates an environment where the health and well being of migrant communities is influenced by both new challenges (prevalence gaps) and new opportunities (drivers for mobility).

The implications of globalization extend across the spectrum of all human activities and as the issues become more widely studied, knowledge of the specific impacts is generating increasing discussion and analysis in the health field[ii]. The direct relationship between mobility, migration and globalization allow for increasing recognition that these are important health determinants for individuals, communities and populations. As the concepts and constructs of population health assume greater prominence in the formulation of health policies and actions at the national and international level the importance of migration population mobility in those deliberations will continue to expand.

Description of Population Mobility : Moving from administrative to functional considerations as a basis of migrant health.

It has been common to consider migrants and other mobile populations in terms of specific defined groups delineated by their legal immigration status. Generic application of classifications of mobile populations such as immigrants, refugees, and migrant worker, irregular and illegal migrants, based on an administrative classification, commonly refer to groups of people from markedly different "health determinant" backgrounds and environments. This becomes more complicated when specific administrative classification terminology such as convention refugee, asylum seeker, and visitor are used which are not clear functional health descriptors.

The variations in characteristics, background histories and health determinants between populations of migrants and refugees can be extensive. Health-related investigation and subsequent recommendations based on studies of some cohorts may have limited application or relevance to others, in spite of similar immigration status or administrative classification. For example, health parameters and determinants in communities of immigrants originating in rural areas of the develleoping world migrating to join families, may be much different from populations of business immigrants or skilled workers. Conclusions and recommendations regarding health prevention and promotion designed for one group may have limited relevance for the other. Health service providers with limited experience in the process and dynamics of population movements and migration may have difficulty in transferring the results of studies in cohorts of "immigrants" or "refugees" to the migrant communities they serve. The practice of reporting immigration status as a determinant of health may be less important than type of migratory journey itself. The migratory journey includes three phases: pre-departure, transit period, and post-arrival, which will be discussed later in this paper.

a. Migration Patterns - an evolving issue.

Modern migration patterns have changed significantly over the past 3 decades and some of the traditional aspects of international population exchange reflect these changes. Refugee movements that have traditionally been based on patterns of permanent resettlement, such as observed during the Cold War, now encompass temporary relocation and return following the geopolitical stabilization, such as recently observed in the South East Balkans. Ease of travel has allowed resettled immigrants repeated access to their place of origin, a pattern of movement markedly different from earlier migratory movements where return visits were uncommon. International labour migration has become much more dynamic with large numbers of workers following global market shifts during their working lifetime.

Recognizing that health is more directly related to the origin, behaviour, environment, educational and social make up of the population in question rather than their technical immigration status, this paper reflects a functional approach to population mobility. Migrants and other mobile populations in this context, are considered in relation to the migratory journey itself, not simply in relation to specific legal immigration definitions. This approach compensates for many of the important differences between communities that may have the same formal immigration designation.

b. The Migratory Phases

Through this functional approach, the multiple relationships between population mobility, migration health can be described in terms of three discrete, but connected, and inter-dependent components. Those components are the pre-departure phase, the migratory journey itself, and the post-arrival phase at the journey's completion. Each of these components influences specific health determinants that are subsequently reflected in the health of migrants on the individual and population level. These influences may result in appreciable health concerns and issues during each of the phases of mobility. Additionally, some of the health-related consequences may not be realized or appreciated until the individual is much further along the "migration" process and may have in fact settled and integrated into the new host environment. It has also been observed that some of the migration-associated health effects and outcomes will continue manifest themselves in the locally born offspring of migrants.

Health Related Aspects of Population Mobility

As noted above, the process of population mobility and migration can be considered in three related but distinct functional components. Each of these components has specific influences and impacts on the health of both the individual and the community[iii]. Overlaying the process of mobility and migration are the disparities between health sectors that are known as "prevalence gaps". Individuals and populations who move between disparate health systems in effect transit across gaps in socio-economic development and public health practices. The net result can be considered as a bridging of differential in health risks between two locations or situations by the migratory process.

Common examples are seen in the differential epidemiology of infectious diseases such as observed in the prevalence rates of tuberculosis between Eastern Europe and North America[iv]. Prevalence gaps however, are not limited to geographic differences in disease distribution.

Figure I. Tuberculosis Prevalence in Canada

[source: Dr. Linda Panaro,Tuberculosis program, Health Canada]

Similar disparities can be observed between populations in situations where individual behaviour can affect health risk or exposure activity. Examples can include culturally or socially influenced characteristics that impact on the use of or access to health care. Other health risk prevalence gaps can be observed in situations where pre-existing health characteristics are influenced by behavioural or physiological factors such as the use of alcohol or tobacco or dietary practices that affect health outcomes.

The Process of Mobility

a. The Pre-departure Phase

In considering the health of migrants and many other mobile populations it has been traditional to examine and deal with health issues in these communities after they have arrived at their destination. The understanding of the health issues present after arrival however, may be improved though more detailed consideration of the migrant's pre-existing health profile. The health of the migrant at the beginning of the process of relocation reflects community and public health environments present at the migrants' home. Aspects of the health environment include disease epidemiology at the place of origin, factors related to social equity such as poverty, housing, nutrition, education, access to and availability of health care services.

b. The Migratory Journey phase

The type and nature of the migratory journey itself may affect the health and well being of some migrant and mobile populations. The health effects of the journey are often more pronounced in refugee and other forced displacements, trafficked and illegal migrants and other irregular population flows. The health status of the migrant during the journey can be affected and influenced by the duration of the journey itself, the nature of the transportation used and whether or not the terminal stage of the passage involves a licit or illicit entry to the destination. Two specific migratory journeys may be associated with significant risk of mortality and morbidity. Refugee and forced migratory movements are often accompanied by violence, hardship and lack of basic necessities while trafficked migrants often risk death, violence and environmental exposure during this phase of their mobility.

c. Post-arrival phase

i. Reception and Integration

There are several factors that combine to influence and modify the health of mobile populations after arrival at the destination. Depending on their origin, education and experience, many of these individuals may not be aware of, familiar with or have access to health programs and services[v]. This can be a significant problem in irregular, trafficked or illegal migrants who may have reached the destination outside of the regular migration procedures[vi].

ii. Prevalence gap in health determination

The health characteristics of new arrivals will compare to those of the population in which they will settle in one of three ways. Some determinants will be less favorable than those in the receiving population. A common example is the incidence of certain infectious diseases; such as tuberculosis, where migrants often represent a higher risk for the disease than the local population. Some migrant communities will have health determinants that are more favorable than those observed in at the destination[vii]. Nutritional status and dietary habits are commonly noted to be less problematic in migrant communities on arrival in North America, for example. Finally the health characteristics of the mobile population may be the similar to or identical to those of the communities in which they settle making the movement neutral in health terms.

iii. Demographic Considerations

The demographic make up migrants and mobile populations, has been and remains a fluid and evolving process. Global geopolitical, social and economic events influence the characteristics of groups seeking new futures as well as influencing the involuntary displacement of refugees. In parallel to the broader events, national policies and selection criteria change over time reflecting national economic and labour considerations. Yet behind the evolution and change in the demographics of population mobility, there are some fixed characteristics that influence the process of migration. Each demographic factor can be considered in relation to the above defined three phases of mobility.

As a current snapshot of migration to Canada, as an example, displays some major differences as well as some common similarities when compared to one taken two decades ago. There have been shifts in size of the classes of immigrants arriving in Canada. In 2000, 58% granted permanent residence in Canada were immigrants of the skilled worker and business classes. During the same year 27% of migrants were family class immigrants. Twenty years ago the ratios were practically inverted. In 1986, 42% of those arriving permanently were family class immigrants while business and independent classes represented 29% of those arriving.

Other changes are apparent in the geographical origin of migrants destined to Canada. Currently, individuals arriving in Canada from Asia and the Pacific make up the largest cohort of new migrants. Patterns of mobility prior to 1975 were different with the majority of new arrivals originating in Western Europe and the United States. Many challenges facing the improvement of global health are rooted in disparities caused by poverty, underdevelopment and geographic imbalances in disease prevalence. Large population movements from areas adversely affected in terms of health can produce significant and sustained impacts at the migrants' destination.

Figure II Migration to Canada as a Function of Migrant Origin

[source: Citizenship and Immigration Canada Statistics]

Both the nature of the community and their geographic origin can be considered in relation to the pre-movement phase of mobility.

One of other significant factor influencing populatiiton mobility and indirectly health, is the post arrival demography. Migration in the Canadian context is predominantly a process centered on large urban centers. The health implications of the urban concentration of new arrivals can be complex. Uncommon or previously geographically isolated illness may be more commonly encountered in metropolitan areas than in the rest of the province or the nation. This fact may influence the development of national health screening or prevention programs as threshold effects will vary dramatically across the country.

Figure III Arrivals by Province

[Source: Citizenship and Immigration Canada]

A secondary and often hidden component are the effects of rural/urban migration which may the ultimate result of migration related population mobility. Movements to large urban centers from rural areas have been shown to affect health in both positive and negative manners[viii]. Many migratory journeys also comprise rural/urban components and corresponding health consequences are not unexpected, although they are poorly studied.

Figure IV Arrivals by Metropolitan Area

[Source: Citizenship and Immigration Canada]

The general demographic characteristics of mobile populations described above may have important health considerations. Economic and social factors are clearly defined determinants of health and the economic stresses often associated with the migration of populations who may be marginalized in terms of economic status can affect health and well being. Mobile populations who during their journey bridge or cross gaps in the incidence or prevalence of disease or illness may create some challenges for the health care system at their destination.

Recommendations for Future Study

As the world moves towards an integrated approach that links population mobility to the ongoing process of globalization a better understanding of global public health may result. This perspective has the potential to assist international development activities as well. Developmental and economic disparity are the major factors that create and sustain many of the current prevalence gaps that are bridged by mobile populations.

Studies that identify methods of reducing the health prevalence gaps will support and sustain development. Better development and economic status will support and improve the prospects for health protection and disease prevention in mobile populations. Together these activities will moderate many of the impacts created by the mass movement of people between disparate health environments.

Other research issues:

1. human capital approach to immigration policy development and receiving vs. donor nationskill"gaps";

2. international ethics in immigration policy - is raping the developing nations of their human capital in support of western nations sustainable in a growing ideological stressed world;

3. mobile populations vs. mobile jobs- globaltele-working works in some sectors, but who will raise our kids?, pick our crops, walk our dogs, drive our taxis . . .

4. is amulti-culturalpopulation base sustainable in the current nationalperspective on population demographic on aging and birth, job market, rural-urban migration.