Today there are many signs recommending that we consume locally produced foods, and many people try to raise as much food of their own as possible. There are a number of reasons to do so (to reduce food costs by obviating transportation costs; to diversify the local economy; to preserve a pastoral way of life in the face of suburbanization; etc.) and creating a clean food supply is certainly one of them.
In the US, many Native American peoples attempt to follow traditional food-ways and seek to consume locally produced foods. In fact, forty-three percent of the Indian population resides in rural areas and there are some 79,703 American Indian or Alaskan Native operators on farms and ranches across the US (U.S. Environmental Protection Agency, 2009
). Diet and food preparation are singular markers of cultural identity and adhering to traditional food-ways are often a means of maintaining cultural identity in the face of a multitude of mainstream/western cultural influences. Furthermore, raising, gathering, or hunting traditional foods in traditional ways would seem to be an excellent strategy to reduce exposure to pesticides and pollutants generally, given the risks of consuming commercially produced foods as just described. However, the degree of contamination of a food depends on the degree of contamination of the habitat, and particularly the food supply, in which that food is produced. As such, Native Americans and other consumers of locally raised food are at particular risk of exposure to contaminants if the local habitat is polluted.
A case in point is the Akwesasne Mohawk Nation. The Nation exists on the St. Regis Mohawk Reservation (known as a Reserve in Canada) and in many communities in close proximity to the reserve. It has a population of approximately 13,000 people although the nation is not censused by US or Canadian governments (Fitzgerald et al., 1998). The territory straddles the St. Lawrence River, and as a sovereign nation, it abuts New York State, Ontario and Quebec, Canada. The Nation is adjacent to and downstream from one federal superfund site and two New York state superfund sites. Contamination of the St. Lawrence River, and some of its tributaries that cross the reservation, has led to the contamination of local fish and wild life particularly with polychlorinated biphenyls (PCBs).
In industries neighboring the Akwesasne Mohawk Nation, PCBs were used in hydraulic fluid that was raised to high temperatures in the manufacturing process. Leakages and improper disposal of the PCB laden fluids introduced PCBs to the waterways and life within. In the mid 1980's contamination of local fish was reported (Lacetti, 1993
; Sloan and Jock, 1990
), and fish advisories were issued warning people not to consume, or to limit consumption, of local fish.
Many non-occupational studies have found that diet is the primary route of exposure to PCBs. Other sources are breastfeeding and transplacental passage. Due to the persistence of many PCB congeners, a woman's PCB exposure while growing up influences her PCB level as an adult, and thus her transference of PCBs while pregnant and breastfeeding.
The fish advisories issued in the mid 1980's may be an influence on the levels of PCBs in the nation. Before the advisories, pregnant and lactating women were not aware that locally caught fish posed any risks to health and they consumed fish as a healthy food choice. Indeed, breast milk is considered one of the cornerstones of the traditional subsistence system (Cook, personal communication). Breast milk contributes to immunological, psychological and socializing functions in Mohawk society. Environmental health is inextricably linked through breastfeeding to the status of women in Mohawk society which traditionally is matrilineal. The importance of breast milk and its role in Mohawk society may be seen in the high rates of breast feeding initiation (84%) among women attending the WIC clinic at the St. Regis Mohawk Health Services. This is possibly the highest rate in the Nashville (provision) Area of the Indian Health Service (Cook, personal communication).
Akwesasne youth born before the advisories against eating local fish are likely to have had prenatal exposure from transplacental passage. In addition, if breastfed, they would have early postnatal exposure. Breastfeeding adds substantial exposure to all lipophilic compounds at a crucial stage of development. Youth “born-before” the advisories would also have postnatal exposure through their own diet. In contrast, youth “born-after” the advisories were issued would be expected to have less postnatal exposure through their own diet. “Born-after” youth may also have prenatal and lactational exposure depending on their mother's PCB levels and their breastfeeding history. Thus, we devolve three exposure components: prenatal (via transplacental passage), early postnatal (via lactation) and later postnatal (via offspring's own diet). The greatest contrast would be between born-before youth who were breastfed and consumed locally raised food items versus born-after youth who were not breastfed and did not consume locally raised foods.
Our first study was conducted in partnership with the Akwesasne Mohawk Nation from 1995–2000 and focused on adolescents 10–16.9 years of age who resided in Mohawk households located on the St. Regis Reservation/Reserve (reserve is the Canadian equivalent of reservation) or in Mohawk households within 10 miles of the reserve/reservation. (More complete details are available from several publications (Gallo et al., 2005
; Gallo et al., 2011
; Schell et al., 2008
; Schell et al., 2009b
; Schell et al., 2003
)). Mohawk data collectors identified the Mohawk households and collected all data without knowledge of participants' exposure status. Data collectors were trained by the principal investigator and co-investigators and underwent routine re-training. A fasting blood specimen was collected by venipuncture on first rising and was analyzed for PCBs by the University at Albany, School of Public Health, Exposure Assessment Laboratory. PCBs were measured in serum by high-resolution, congener-specific analysis that yielded the delineation of 101 PCB congeners, as well as p,p'
-DDE, HCB, and mirex (DeCaprio et al., 2005
; DeCaprio et al., 2000
). This permitted the classification of congeners into groups of persistent and less persistent classes, the first representing all past exposure and the latter more current exposure. Sociodemographic information and knowledge of the consumption of local foods was obtained by questionnaire to the adolescent if over 13 years of age, or from the mother if 13 or younger. Information on breastfeeding history, and diet during pregnancy was obtained from the mother.
Between 2000 and 2005 these adolescents were invited to participate in a follow up study. Of the 271 participants in the first study, 152 young adults (61 males, 91 females) with an average age of 18.1 years participated. Again blood was collected and participants completed questionnaires concerning diet and behaviors that might have constituted exposure pathways, especially behaviors involving the consumption of locally caught or raised foods, as well as several other outcomes not related to the focus of this analysis.
Information on dietary intake over the past year was collected by interview using a number of questionnaires. In order to capture the most information about traditional food intake, questionnaires focused on the consumption and preparation of any locally grown consumables (eggs, meat, poultry, dairy products, etc.) and caught, hunted, or trapped fish (bass, bullhead, catfish, northern pike, perch, salmon, sturgeon), game or wildlife (deer, rabbit, frog, goose, muskrat, turtle, duck, goose, partridge, pheasant) in the past year, or more than a year ago.