Mercury Levels in Barbadian Fisher Folk and Commonly Caught Fish Species

Ocean fish are an important staple food for many Caribbean persons. Some species, however, have high Hg concentration levels and represent a significant source of Hg exposure. This study assessed Hg concentrations in fish species commonly caught and consumed in Barbados as well as Hg exposure of those who work in the fishing industry. Total Hg concentrations were measured in 100 fish samples. Human Hg concentrations were determined from hair snippets taken from 46 fisher folk and fish consumption habits evaluated using interview-administered questionnaires. Mercury levels varied by fish species with predatory fish species having the highest concentrations. Low Hg concentrations were found in dolphinfish (Coryphaena hippurus) and flyingfish (Hirundichthys affinis). Reported fish consumption rates were high and varied significantly between men and women, 2675 ± 1600 and 1275 ± 600 (g/week), respectively (p = 0.01). The median hair Hg concentration was 3.1 ± 2.3 μg/g (range: 0.01–15.6 μg/g) and significantly associated with consumption of “high-risk” fish species (p = .02). These results show that it is possible to make informed choices concerning fish consumption habits in order to maximize benefits while minimizing the effect of Hg exposures, especially for sensitive groups such as pregnant women and infants.     

Population-Based Fish Consumption Survey and Probabilistic Methylmercury Risk Assessment

A fish consumption survey was developed and administered by telephone to 820 Wyoming fishing license holders. Survey respondents provided the frequency, species, and quantity of Wyoming-caught and store-bought fish consumed for license holder and household members. Deterministic and probabilistic methylmercury exposure distributions were estimated by multiplying fish consumption by species-specific mercury concentrations for each household member. Risk assessments were conducted for children, women of childbearing age, and the rest of the population by comparing methylmercury exposure distributions to levels of concern. The results indicate that probabilistic risk assessment likely provides a more realistic view of the risk to the study population. The results of this study clearly indicate that: (1) there is no level of fish consumption that is without risk of methylmercury exposure, (2) fish advisories may be warranted for children and women of childbearing age, and (3) that store-bought fish generally contribute more to methylmercury exposure than do Wyoming-caught fish.     

Human Exposure to Mercury Through Fish Consumption: Risk Assessment of Riverside Inhabitants of the Urrá Reservoir,Colombia

This study evaluated the risk to human health from mercury exposure through fish consumption in three riverside populations: Children (CH, 2–15 years old), women of childbearing age (WCHA, 16–49 years old), and the rest of the population (RP) from the Urrá reservoir area, Colombia. Questionnaire-based surveys were used to collect data and information about the weekly amount of fish consumed (WAFC) and the relative importance of each fish species in the diet of the study participants. There were no significant differences in WAFC between population groups. CH recorded the highest weekly intake of total Hg (WIT-Hg) (0.6–55.4 μg/kg bodyweight/week), with significant differences (p < .05) from WCHA (0.2–26.7 μg/kg bw/w) and RP (0.1–23.6 μg/kg bw/w). A high percentage (90%) of estimated WIT-Hg values exceeded the provisional tolerable weekly intake (PTWI) established in order to protect the embryo and fetus. Results suggested that sensitive subgroups, such as pregnant women or those who may become pregnant and young children should limit or avoid consumption of certain fish of higher trophic levels due to their high total Hg (T-Hg) concentrations (up to 2.73 μg/g). In sum, the high values of WIT-Hg in children and women of childbearing age revealed a worrying situation, which should be reviewed carefully in order to prevent a potential public health crisis.     

Indigenous Studies in the Elementary Curriculum: A Cautionary Hawaiian Example

This article uses a Native Hawaiian example to raise difficult questions about the role and responsibility of non-Indigenous educators in teaching and supporting Indigenous studies. It challenges educators and educational researchers to think closely about how they might serve as allies in Indigenous struggles for self-determination.     

Cancer mortality in a population-based cohort of American Indians – The strong heart study

BackgroundCancer mortality among American Indian (AI) people varies widely, but factors associated with cancer mortality are infrequently assessed.MethodsCancer deaths were identified from death certificate data for 3516 participants of the Strong Heart Study, a population-based cohort study of AI adults ages 45–74 years in Arizona, Oklahoma, and North and South Dakota. Cancer mortality was calculated by age, sex and region. Cox proportional hazards model was used to assess independent associations between baseline factors in 1989 and cancer death by 2010.ResultsAfter a median follow-up of 15.3 years, the cancer death rate per 1000 person-years was 6.33 (95 % CI 5.67–7.04). Cancer mortality was highest among men in North/South Dakota (8.18; 95 % CI 6.46–10.23) and lowest among women in Arizona (4.57; 95 % CI 2.87–6.92). Factors independently associated with increased cancer mortality included age, current or former smoking, waist circumference, albuminuria, urinary cadmium, and prior cancer history. Factors associated with decreased cancer mortality included Oklahoma compared to Dakota residence, higher body mass index and total cholesterol. Sex was not associated with cancer mortality. Lung cancer was the leading cause of cancer mortality overall (1.56/1000 person-years), but no lung cancer deaths occurred among Arizona participants. Mortality from unspecified cancer was relatively high (0.48/100 person-years; 95 % CI 0.32−0.71).ConclusionsRegional variation in AI cancer mortality persisted despite adjustment for individual risk factors. Mortality from unspecified cancer was high. Better understanding of regional differences in cancer mortality, and better classification of cancer deaths, will help healthcare programs address cancer in AI communities.     

Native Language Teachers in a Struggle for Language and Cultural Survival

Language shift among New Mexico Pueblo Indians threatens the loss of their oral-based cultures. Language revival for many Pueblos has resulted in school programs in which students are easily accessible and teachers are accountable to tribes rather than the state. Finding "Pueblo space" for the Native language in school, where it was previously targeted for extinction, poses unique challenges. Personal histories and ethnographic interviews provide language teacher perspectives on teaching in four separate school programs.     

Mercury in tigerfish (Hydrocynus vittatus, Castelnau), green happy (Sargochromis codringtonii, Boulenger) and kapenta (Limnothrissa miodon, Boulenger) from Lake Kariba, Zimbabwe

Concentrations of total mercury were determined in Hydrocynus vittatus (Castelnau), Sargochromis codringtonii (Boulenger), and Limnothrissa miodon (Boulenger) from two localities in Lake Kariba, Zimbabwe.
The mean concentrations of total mercury in H. vittatus from Basin 5 and Basin 2 were 0.08 mg kg⁻¹ and 0.094 mg kg⁻¹, respectively. In S. codringtonii, mean concentrations were 0.004 mg kg⁻¹ and 0.026 mg kg⁻¹ for Basins 5 and 2, respectively. No mercury was detected in L. miodon from Basin 2 while samples from Basin 5 had a mean concentration of 0.069 mg kg⁻¹ (wet weight). Total mercury concentrations were also determined on a dry weight basis.
Within each sampling area, total mercury concentrations were significantly different among species ( P  < 0.05). For H. vittatus and S. codringtonii, total mercury concentrations (in the same species) were not significantly different between the two localities ( P  < 0.05).
The factors causing the observed differences in total mercury between similar species from different localities and among different species in the same locality (sampling area) are discussed. From the observed low levels of mercury in all three species, it was concluded that the mercury constituted 'background levels'. These levels are below the maximum concentrations permissible in human fish foods.     

The Role of Education in American Indian Self-Determination: Lessons from the Ramah Navajo Community School

Since 1975 the Indian Self-Determination and Educational Assistance Act has enabled American Indian communities to enact self-determination through community-based schooling. In this study conducted by a Navajo researcher, the Ramah Navajo community defined self-determination and how it was operationalized within the community and school. The study demonstrates how education based on Navajo epistemology has been integral to self-determination at Ramah, underscoring the importance of incorporating Native American epistemologies in schooling for Indigenous students.     

Health Hazard Assessment for Native Americans Exposed to the Herbicide Fluridone via the Ingestion of Tules at Clear Lake,California, USA

This study addresses concerns expressed by Native Americans regarding exposure via the consumption of aquatic vegetation to the herbicide fluridone (active ingredient) used by the California Department of Food and Agriculture (CDFA) Hydrilla Eradication Program in Clear Lake, California. In 2005, the Department monitored lakeshore vegetation, water, and sediment at four locations, before and after seasonal applications of fluridone. Subchronic and chronic exposures were evaluated, and hazard quotients calculated for a worst-case exposure (WCE) scenario. Ingestion rates and other exposure factors were developed in public meetings with tribal members. Environmental sampling found fluridone present at extremely low levels in tule vegetation, water, and sediment. Exposures were four times greater in subchronic timeframes than chronic timeframes; however, hazards were less due to the 25-fold larger reference dose (RfD) used for subchronic calculations: RfD_(subchronic) = 2.0 mg/kg-day, RfD_(chronic) = 0.08 mg/kg-day. Conservative, child, total daily ingestion (TDI) doses were calculated to be 8.3 × 10^?5 mg/kg-day (subchronic) and 2.1 × 10^?5 mg/kg-day (chronic). Hazard quotients (HQ) for subchronic and chronic exposures were on the order of 10^?5 and 10^?4, respectively, indicating that at current application regimes, there is little to no hazard of adverse effects from fluridone exposure via ingesting Clear Lake tules.