BMC Psychiatry BioMed Central Research article Illness causal beliefs in Turkish immigrants

Background People hold a wide variety of beliefs concerning the causes of illness. Such beliefs vary across cultures and, among immigrants, may be influenced by many factors, including level of acculturation, gender, level of education, and experience of illness and treatment. This study examines illness causal beliefs in Turkish-immigrants in Australia. Methods Causal beliefs about somatic and mental illness were examined in a sample of 444 members of the Turkish population of Melbourne. The socio-demographic characteristics of the sample were broadly similar to those of the Melbourne Turkish community. Five issues were examined: the structure of causal beliefs; the relative frequency of natural, supernatural and metaphysical beliefs; ascription of somatic, mental, or both somatic and mental conditions to the various causes; the correlations of belief types with socio-demographic, modernizing and acculturation variables; and the relationship between causal beliefs and current illness. Results Principal components analysis revealed two broad factors, accounting for 58 percent of the variation in scores on illness belief scales, distinctly interpretable as natural and supernatural beliefs. Second, beliefs in natural causes were more frequent than beliefs in supernatural causes. Third, some causal beliefs were commonly linked to both somatic and mental conditions while others were regarded as more specific to either somatic or mental disorders. Last, there was a range of correlations between endorsement of belief types and factors defining heterogeneity within the community, including with demographic factors, indicators of modernizing and acculturative processes, and the current presence of illness. Conclusion Results supported the classification of causal beliefs proposed by Murdock, Wilson & Frederick, with a division into natural and supernatural causes. While belief in natural causes is more common, belief in supernatural causes persists despite modernizing and acculturative influences. Different types of causal beliefs are held in relation to somatic or mental illness, and a variety of apparently logically incompatible beliefs may be concurrently held. Illness causal beliefs are dynamic and are related to demographic, modernizing, and acculturative factors, and to the current presence of illness. Any assumption of uniformity of illness causal beliefs within a community, even one that is relatively culturally homogeneous, is likely to be misleading. A better understanding of the diversity, and determinants, of illness causal beliefs can be of value in improving our understanding of illness experience, the clinical process, and in developing more effective health services and population health strategies.


Preface
The hydrologic cycle describes the continuous transport of water through the atmosphere and the different zones of the subsurface. Through the hydrologic cycle, waters in the atmosphere are linked with waters in surface impoundments such as lakes and streams and with ground waters in the subsurface. In its transport through different zones of the subsurface, water is stored in reservoirs called confined and unconfined aquifers. Subsurface reservoirs represent important water resources for drinking water, irrigation of crops and industrial uses. In this issue, attention is focused through case studies and field trials on human activities and practices that have been carried out in different zones of the subsurface and that have added constituents to subsurface aquifers that effect water quality. Research programs are described that have been carried out to understand the many processes that transport and transform pollutants in the subsurface and to develop methods of describing these many processes with mathematical models. In the subsurface, water, nonaqueous fluids, and dissolved constituents move through both partially saturated and completely saturated porous media, making this an exceedingly complex transport situation to understand conceptually and to describe mathematically.
In May 1987, experts in different areas of water quality of the subsurface were asked to contribute articles for this issue of Environmental Health Perspectives that reviewed the present state of knowledge and provided guidance on future directions of needed research.
Contributing authors addressed topics that covered contamination of both the partially saturated and completely saturated zones of the subsurface and covered the following four broad categories: practices and activities that lead to contamination of the subsurface by chemical substances; methods for describing transport mathematically and for calculating chemical concentrations in different zones of the subsurface; processes that transport and transform contaminants; and health implications of contaminants in the subsurface. The 12 articles from nine different countries provide an important sampling of papers that address the many issues contained in each of these topic areas.
Worldwide, the increasing emphasis on monocultures in agriculture has produced higher than normal levels of nitrates, herbicides, and pesticides in both the unsaturated and saturated zones. Case studies from Czechoslavakia and the Soviet Union have examined the impact of this practice on nitrate levels in the subsurface. Efforts of State programs to monitor levels of contaminants in groundwater systems and to establish groundwater protection zones to prevent contamination of vulnerable groundwater resources are reported. Problems with modeling transport mathematically, with using laboratory studies to determine values for important transport variables, and with applying these models and laboratory results to field situations are described. High levels of nitrates, herbicides, pesticides, and toxic metals have also been reported in the subsurface in many parts of Nigeria and other developing countries and have been associated with agricultural practices and other human activities.
For many years in industrial countries, chemical wastes were disposed of in the unsaturated zone of the subsurface. In addition, large quantities of liquid chemicals and fuels have been stored in metal tanks in the unsaturated zone. Over a long time, chemicals from waste burial sites and deteriorating storage tanks have gradually released their contents to the unsaturated zone. Eventually these chemicals migrate into the groundwater zone creating many long-lasting contamination incidences of groundwater aquifers that are very difficult situations to cleanup.
In developing mathematical models to describe chemical transport, sets of mathematical equations are developed that must be solved simultaneously. Equations must be written that describe transport of chemicals in the aqueous phase and the nonaqueous phase, particularily when describing transport in the unsaturated zone of the subsurface or when there has been an oil spill or leakage of gasoline or other water-insoluble chemical into the subsurface. Several authors have described the difficulties not only of describing multiphase transport in complex aquifers, but also the mathematical problems of solving these equations to give reliable results. Not only are flow patterns difficult to describe, but many of the processes are not well understood, and mechanisms of action are incomplete. In this situation where process rules and mechanisms of action are not clearly defined, it is very important for the mathematical modeler to identify those components in the numerical method that could cause the method to produce erroneous calculations of important system dependent variables such as chemical concentration, moisture content, and water temperature. Without this information, the model is incomplete because the conditions when it will fail have not been properly identified. Model failure to predict concentrations accurately due to inadequate or incomplete data is certainly a problem, but model failure due to mathematically induced errors should not happen. Several authors have dealt with this problem by developing models to describe transport of chemicals in saturated flow and for describing multiphase flow as would be experienced in the leakage of gasoline from an underground storage tank. One author also described how mathematically induced errors can be minimized.
As discussed earlier, the mechanisms of many processes that transport and transform chemicals in different zones of the subsurface are either incomplete or are not well understood. Sorption of chemicals to different solid substrates in the subsurface is an important process that retards transport. The strength of the sorptive interaction is a strong function of the molecular characteristics of the chemical and the solid substrate. Three authors have written on sorption. One presents the physical-chemical aspects of sorption; the second examines the molecular characteristics of humic substances in organic matter and the importance of these substances in sorption; and the third presents a correlation equation for the sorption coefficient that is based on the molecular properties of the chemical.
Transformation of chemicals in the subsurface usually refers to degradation of the chemical into one or more substances that are different from the parent compound. The most important chemical transformation process is hydrolysis and the most important biologi-cally mediated transformations are oxidation or reduction of the parent chemical. Again, which mechanism is appropriate is a strong function of the chemical characteristics of the molecules, and for aromatic chemicals includes the chemical characteristics and positiqn of ring constituents. Transformations of chemicals are not always degradation reactions, however. One author describes how clay minerals have the capacity to catalyze the polymerization of aromatic chenlicals, producing molecules with greater molecular weights than the parent chemical.
In summary, the authors who have contributed to this issue of Environmental Health Perspectives on groundwater quality have examined the present knowledge on many important areas of groundwater quality and have identified many areas needing additional research. Certainly the topics that have been covered do not represent the full scope of activities on chemical transport in the subsurface. However, the ultimate goal of research in the areas described is to provide understanding and methods that can be used to understand how groundwater resources become contaminated, how this process can be prevented from happening, and once contamination has occurred, how appropriate and effective remedial actions to cleanup the aquifer can be developed.