Sabine Henry

What do we know about effects of desert dust on air quality and human health in West Africa compared to other regions

This study aims to compare, on the one hand, the geographical distribution of the desert dust source areas, their contribution to quantities emitted into the atmosphere, the trajectories and the quantities deposited, with on the other hand the areas of research interest focused on the desert dust impacts on air quality and/or human health. Based on a systematic review of the literature using the ISI Web of Knowledge database, we found 231 articles published over the last decade on the desert dust impacts on air quality. Of these, 48% concerned Asian dust and 39% Saharan dust, with the remaining 13% divided between the other dust source areas. However, only one of these studies addressed the worsening air pollution in West Africa, even though it is very close to the Sahara, the greatest contributor to the global dust budget. Moreover, there have been very few studies (41) looking at the direct links between desert dust and human health; in this context too, no interest has been shown in West Africa. Yet this region is also among the areas in which morbidity rates have been noted to be far higher than those found in other regions of the world, and where respiratory infections alone account for more than 20% of the causes of infant mortality. This survey highlights a clear imbalance between those areas most exposed to dust and the most studied areas in terms of dust impacts. Given these findings and the often alarming results published about other regions of the world, we advocate a revival of interest in research on West Africa in order to achieve a better understanding of the desert dust impacts on air quality and health among the populations of this region.

Desert dust impacts on human health: an alarming worldwide reality and a need for studies in West Africa.

High desert dust concentrations raise concerns about adverse health effects on human populations. Based on a systematic literature review, this paper aims to learn more about the relationship between desert dust and human health in the world and to analyse the place of West Africa as a study area of interest. Papers focussing on the potential relationship between dust and health and showing quantitative analyses, published between January 1999 and September 2011, were identified using the ISI Web of Knowledge database (N = 50). A number of adverse health effects, including respiratory, cardiovascular and cardiopulmonary diseases, are associated with dust. This survey highlights obvious dust impacts on human health independently of the study area, health outcomes and method. Moreover, it reveals an imbalance between the areas most exposed to dust and the areas most studied in terms of health effects. None of these studies has been conducted in West Africa, despite the proximity of the Sahara, which produces about half of the yearly global mineral dust. In view of the alarming results in many parts of the world (Asia, Europe, America), this paper concludes by stressing the importance of carrying out impact studies of Saharan dust in West Africa, where dust events are more frequent and intense than anywhere else.

Saharan dust impacts on air quality: What are the potential health risks in West Africa?

ABSTRACT Despite the proximity of the Sahara, very few studies about dust impact on air quality and human health have been conducted in West Africa. The lack of data is a major constraint on our understanding of the impacts on human health in this area. We analyzed PM10 concentrations and horizontal visibility recorded in four West African stations. The pollution levels often exceed the standards defined by many countries/regulatory authorities and have been associated with serious health risks outside Africa. Over the Sahelian stations, 45.6% of the days between November 2006 and March 2007 were likely to impact human health and the studied Sudanian population was exposed to potential health effects every 5 days.

Monitoring land-use change by combining participatory land-use maps with standard remote sensing techniques: Showcase from a remote forest catchment on Mindanao, Philippines

Abstract This paper combines participatory activities (PA) with remote sensing analysis into an integrated methodology to describe and explain land-cover changes. A remote watershed on Mindanao (Philippines) is used to showcase the approach, which hypothesizes that the accuracy of expert knowledge gained from remote sensing techniques can be further enhanced by inputs from vernacular knowledge when attempting to understand complex land mosaics and past land-use changes. Six participatory sessions based on focus-group discussions were conducted. These were enhanced by community-based land-use mapping, resulting in a final total of 21 participatory land-use maps (PLUMs) co-produced by a sample of stakeholders with different sociocultural and ecological perspectives. In parallel, seven satellite images (Landsat MSS, Landsat TM, Landsat ETM+, and SPOT4) were classified following standard techniques and provided snapshots for the years 1976, 1996, and 2010. Local knowledge and collective memory contributed to define and qualify relevant land-use classes. This also provided information about what had caused the land-use changes in the past. Results show that combining PA with remote-sensing analysis provides a unique understanding of land-cover change because the two methods complement and validate one another. Substantive qualitative information regarding the chronology of land-cover change was obtained in a short amount of time across an area poorly covered by scientific literature. The remote sensing techniques contributed to test and to quantify verbal reports of land-use and land-cover change by stakeholders. We conclude that the method is particularly relevant to data-poor areas or conflict zones where rapid reconnaissance work is the only available option. It provides a preliminary but accurate baseline for capturing land changes and for reporting their causes and consequences. A discussion of the main challenges encountered (i.e. how to combine different systems of knowledge), and options for further methodological improvements, are also provided.

RURAL-URBAN LINKAGES AND THE IMPACT OF INTERNAL MIGRATION IN ASIAN DEVELOPING COUNTRIES

As an integral part of development and one of the most important aspects of socioeconomic transformation, internal migration in developing countries has been extensively studied in the decades since the second half of the last century. In the early stages of this research, effort was primarily devoted to identifying the scale, patterns, and determinants of migration flows, especially those from rural to urban areas. More recent research has shifted to the study of migration consequences*for the migrants themselves, for their families and for communities, both at the destinations and at the origins. Recognising the importance of this shift in perspective, the Council of the International Union for the Scientific Study of Population (IUSSP) established a Scientific Panel on the Impact of Internal Migration and Urbanization in Developing Countries in early 2010. The Panel enjoyed a wide-ranging brief, charged with advancing understanding both the measurement and dynamics of population movement within countries, and their diverse impacts, at the individual, household and community level. One of the major initiatives of the Panel was to organise a seminar on ‘Internal Migration and Urbanization and Their Socioeconomic Impacts in Developing Countries: Challenges and Policy Responses’, in collaboration with Fujian Normal University, held in Fuzhou, China on December 10 12, 2011. The seminar was funded by the International Development Research Centre of Canada (IDRC), United Nations Population Fund (UNFPA), Asian Development Bank (ADB), and Fujian Normal University. Some 50 participants from 16 countries attended the seminar, and 36 papers were presented, covering a wide range of issues relating to the theme. While the presentation of and discussion on all the papers served the purpose of advancing knowledge about the impact of internal migration and urbanisation in developing countries in general, the topic of rural-urban linkages and their roles in the development of Asian countries attracted particular attention of both participants and Panel members. By courtesy of Asian Population Studies, the Panel decided to publish a special section in this issue of the journal to highlight this important new area of migration investigation, and the four papers presented here offer some major findings on this topic from different perspectives. The publication of these four papers is timely because they represent an important emergent direction in our efforts to advance research on the impacts of internal migration and urbanisation in developing countries. Although some progress has been made on this Asian Population Studies, 2013 Vol. 9, No. 2, 119 123, http://dx.doi.org/10.1080/17441730.2013.797296