| 英文摘要: | The purpose of this study is to investigate Yup'ik Alaska Native subsistence storage and preservation techniques - an absolutely essential component of Yup'ik food preparation - and their potential mitigating influence on persistent organic pollutant (POP) concentrations in subsistence foods in two village communities in southwestern Alaska (Tununak and Chefornak). The Yup'ik are an arctic hunter-gatherer population living in southwestern Alaska in 70 villages dispersed throughout the delta of the Yukon and Kuskokwim rivers. Despite a recent shift toward the inclusion of store-bought foods in the diet, Yup'ik people still depend on locally harvested resources, primarily fish and sea mammals. They retain and continue to utilize their extensive knowledge of ocean hunting, coastal fishing, tundra gathering, and, most importantly for this project, the processing and long-term storage of large marine mammals and sizeable catches of fish. As a result of their marine-based diet, the Yup'ik have health profiles that have attracted the attention of health researchers, such as low rates of diabetes and good cardiovascular health. However, recently, the diets of many Alaska Native groups have come under scrutiny because of concern over persistent organic pollutants (POPs) that are commonly present in seafoods.
POPs are chemicals that were produced by humans during the chemical revolution in agriculture for their use as pesticides. Despite discontinuation of the production of most POPs, they remain dangerous to human health because they persist in the environment (for decades or more), can travel long distances, and accumulate up the food chain. Although far from major agricultural sites, arctic regions accumulate particularly high concentrations of leftover POPs. This is due to a number of factors including the ability of POPs to travel with ocean currents, the wildlife species that pass through the arctic, and the fact that POPs accumulate in the bodies of animals highest up on the food chain such as arctic seals, whales, and bears. The result has been a mixed message regarding the safety of eating marine-based foods: nutritionists promote their consumption because they are "heart healthy?"(i.e., high in polyunsaturated fatty acids) and environmental toxicologists caution their consumption because they accumulate POPs significantly more so than many other foods. Unfortunately, the primary source of data for the toxicological and nutritional profiles of fish and sea mammals that are frequently consumed by Alaska Native peoples comes from unprocessed muscle samples (i.e., species that are harvested, sampled, frozen for transport, and thawed for lab analysis). However, Yup?ik people not only consume many other parts of animals aside from the muscle tissue (blubber, organs, blood, small bones), but they rarely consume freshly caught species and have a vast array of methods for processing, storing, and preparing foods before they are consumed (for example, ninamayuk is a popular food that involves one month of sun-drying and two to three months of fermentation in rendered seal blubber before it is consumed). Nevertheless, the potential effects of processing, storage, and local dietary traditions on the nutritional and toxicological profiles of foods have received little attention. The Yup'ik community is not only eager to know about the potential benefits and hazards of the foods they eat, but also this information can shed light on processes that may impact the safety of foods in general.
An examination of how Yup'ik food preparation and storage affects the nutritional and toxicological profile of subsistence foods will be achieved by 1) laboratory tests of foods that are prepared by Yup'ik people in Yup'ik communities and of the unprepared tissues of the origin subsistence species and 2) investigation, via direct observation and documentation (where possible), interviews, and semi-qualitative surveys, the ways in which the two staple marine foods in the study region (seal and herring) are cleaned, processed, stored, prepared, and eaten by the Yup'ik today and in the recent past. Alaska Native food processing and storage techniques have generally been overlooked in contaminant research, particularly in food risk assessments intended for present-day Yup'ik communities. However, there is evidence in other contexts that processing technique, storage time and conditions, and diet can have an effect on levels of various food toxicants and/or their bioavailability. The many diverse techniques of processing and storing foods in the circumpolar north have generally been limited to early descriptions in historical documents, sparse traveler accounts and more recent ethnographic (purely descriptive) accounts. The viability or recent memory of many traditional subsistence practices in Yup'ik communities today presents researchers with a unique opportunity to systematically investigate some of these processes on which, until only very recently, the survival of people absolutely depended. To date, no subsistence data on seal or herring exists for the village of Chefornak and the data that exists for Tununak dates no later than the 1990s. This study will provide new and needed subsistence data for both villages and add to ongoing debates about the role of small-scale food storage in human evolution.
A general assumption in research on indigenous health is that once hunter-gatherer populations become involved in the market economy or become "Westernized" there is no turning back, and full integration will soon follow. Alaska Native peoples, because of their continued reliance on local subsistence hunting and gathering, question this assumption. Nevertheless, there are many real concerns for them, and this research project will make a risk assessment of Alaska Native foods by investigated the potential mediating effects of food processing and storing. This research will contribute to a better understanding and appreciation of Alaska Native life-ways, as well as add to knowledge about a primary health concern in the region and contribute to an understanding of key global health issues in general. |