A framework and information needs for the management of the risks from consumption of self-caught fish

Governmental agencies deal with the potential risk from consuming fish contaminated with toxic chemicals by issuing fish consumption advisories. Yet such advisories are often ignored by the general public, who continue to fish and consume self-caught fish that are the subject of advisories and are from contaminated waters. Further, people are often unaware of specific warnings (which species to avoid, who is vulnerable, when they are vulnerable). In this paper we propose a more inclusive framework for examining consumption behavior of self-caught fish and identify information needs for effective communication. We include not only the usual variables that are used for calculating risk from fish consumption (meal frequency, meal size, contaminant levels) but also other aspects of behavior that contribute to risk. These include attitudes (trust, risk aversion, environmental concerns), behavior (sources of information, cultural mores, personal preferences), exposure (physical proximity, ingestion rates, bioavailability, target tissues), contaminant levels, individual host differences, and hazards (levels of contaminants). We suggest that attitudes and behavior shape risk as much as exposure and hazards and that all four of these factors must be considered in risk management. Factors such as gender, age, pregnancy status, and nutrition all influence who is at risk, while other consumption factors affect these at-risk populations, including meals/week, meal size, cooking method, fish species and sizes eaten, and years of fish consumption. Similarly, contaminant levels in fish vary by fish species, fish size and age, part of the fish, and collection location. Elucidating the risk to individual consumers involves integrating this range of factors, and managing the risk likewise involves incorporating these factors. We suggest that development of appropriate advisories and compliance with advisories will occur only if managers, risk assessors, and public policy makers consider this whole range of factors and not just the traditional fish consumption rate (often underestimated) and contaminant levels in fish (often undersampled). Merely informing the public of contaminant levels or the risk from contaminants will not ensure a public that has enough information to make informed decision, or to be in compliance with consumption advisories, or to effect changes in consumption behavior where public health is at risk.     

Maternal recall of children's consumption of commercial and sport-caught fish: findings from a multi-state study

A randomized telephone survey of 3015 women was conducted in an effort to assess the effectiveness of local sport-fish consumption advisories. Survey participants were between the ages of 18 and 45 and lived in the states of Arkansas, California, Connecticut, Florida, Maine, Minnesota, Montana, New Jersey, New Mexico, North Carolina, and Wisconsin. At the time of the women's interview, fish and shellfish consumption information was obtained for children under 18 years of age living in the household. One child (aged 2-17) from each household (1852) was randomly selected to evaluate fish consumption among children. Based on maternal recall, 84% of these children had consumed fish or shellfish at least once during the previous 12 months. This percentage ranged from 73% in New Jersey to 94% in Louisiana and was higher among children who lived with a licensed angler compared to those who did not. Eight percent of the children ate fish and/or shellfish more than twice a week. Of the total number of fish and shellfish meals eaten by children, 67% was commercial finfish, 22% was shellfish, and 11% was sport-caught finfish. Among those who ate fish, the average consumption rate was 47 meals per year-slightly less than one meal per week. This consumption frequency rate varied by state of residence ranging from 37 meals per year in Montana and Wisconsin to 62 in Florida. Because of these regional differences, the use of national average fish consumption rates may over- or under-estimate consumption in localized areas. This survey suggests that targeting information to women who eat fish may also protect children; more than 80% of children have fish consumption patterns that are similar to that of their mothers. Additional research and biomonitoring is needed to improve our understanding of the risk and benefits associated with childhood consumption of fish and shellfish.     

The role of sport-fish consumption advisories in mercury risk communication: a 1998-1999 12-state survey of women age 18-45

BACKGROUND: In 2002, in the United States, 48 states issued advisories for sport-fish consumers that included 39 chemical contaminants. The most commonly identified chemical was methyl mercury, which is linked to reproductive and developmental effects. Advisories to reduce consumption of contaminated fish have been issued by states since the early 1970s. Advisories are being integrated to include both sport and commercial fish. METHODS: As part of a comprehensive risk-communication project, from December 1998 through August 1999 the Wisconsin Division of Public Health and the State of Maine Bureau of Health conducted a 12-state random-digit-dial telephone survey of 3015 women of childbearing age (ages 18-45). The goal was to assess the prevalence of fish consumption, understanding of mercury toxicity, and awareness of state sport-fish consumption advisories for mercury. We gathered information concerning respondents' demographic characteristics, understanding of mercury toxicity, fish consumption during the preceding 12 months, and sport-fish consumption advisory awareness. RESULTS: The overall survey completion rate was 57% with a Council of American Survey Research Organizations (CASRO)-calculated response rate of 50%. Completion rates varied from 37% in New Jersey to 73% in Minnesota. Fish consumption during the previous 12 months was reported by 87% of respondents (range by state of 82-90%). Nearly 10% of women reported consuming two or more fish-meals per week over the prior 12 months. Twenty-nine percent reported sport-fish consumption during the same time period, with a greater state-to-state variability (14-43%). Most women (71%) were aware of mercury's toxicity to a developing child (87% among those aware of an advisory and 67% among those unaware of an advisory). However, awareness of state advisories was only 20%, ranging by state from 8% to 32%. Women who were older, had more than a high school education, and had a household member with a fishing license were the most informed about mercury and fish-consumption advisories. CONCLUSIONS: Most women of childbearing age consume commercial fish and a substantial number also consume sport-caught fish. Despite this potential exposure to dietary mercury, most are unfamiliar with their state's mercury fish-consumption advisory. Most women were aware of the most toxic effects of mercury but less informed about mercury and its relationship to types of fish and fish characteristics. Minorities, women over age 30, family incomes above 25,000 US dollars, and those with some collage education were more likely to be consuming two or more fish-meals per week. Until source control and environmental remediation efforts can reduce the environmental burden of mercury below levels of concern, combined sport and commercial fish consumption advisories will remain the primary means of reducing human exposure to methylmercury. Assuring and assessing the effectiveness of such advisories is paramount. Our survey documents that current efforts to inform vulnerable populations are far from optimal.     

An examination of the trade-offs in public health resulting from the use of default exposure assumptions in fish consumption advisories

Efforts to provide for public health protection from environmental contaminants in fish have resulted in various advisories or recommendations with regard to fish consumption from local, state, and federal agencies. These advisories are based on measured levels of contaminants in fish that are combined with values for body weight and portion size to produce an estimate of an "acceptable" consumption frequency (e.g., eat no more than once per month). Because values for body weight and portion size are generally generic default values, they do not necessarily relate to a specific population or to any individual in that population. Thus, the use of default values may result in underprotection or overprotection in any given case. Given the benefits of fish consumption and the risks from overexposure to various toxicants, vigilance is required by custodians of public health to ensure that populations are protected while being cautious not to over- or underprotect them. In this analysis, we examine the "acceptable" consumption limits derived for fish species/groups consumed by three specific populations and determine the extent of public health protection afforded by these limits. To accomplish this, the "acceptable" consumption frequencies are derived based, in part, on default assumptions and are compared to intakes calculated from empirically derived species-specific individual consumption and demographic data. Sensitivity analyses and population-specific probabilistic assessments of exposure are conducted to identify those values and/or assumptions which might significantly influence the resulting fish consumption advisories. Three populations were chosen for study based on their ability to represent populations of greatest concern: those most sensitive and/or those most exposed. We conclude from this investigation that consumption pattern data, contaminant data and body weight data together can be used to make fish consumption advisories more focused and, therefore, less likely to be under- or overprotective.     

Mercury levels and fish consumption practices in women of child-bearing age in the Florida Panhandle

The southeastern United States, and in particular the coastal areas along the Gulf of Mexico (Gulf Coast) in Florida, experience some of the highest levels of mercury deposition in the country. Although the State of Florida's coastal border is among the longest in the United States, and the State has issued fish consumption advisories due to mercury on multiple fish species, few data have been systematically collected to assess mercury levels in the human population of the state or to assess the efficacy of the consumption advisories. Because of the generally high rate of seafood consumption among coastal populations, the human population in the Florida Panhandle, near Pensacola, FL is potentially exposed to elevated levels of mercury. In the present study, we analyzed hair mercury levels in women of child-bearing age (16-49 years) who had resided near Pensacola, FL for at least 1 year. We also surveyed the fish consumption practices of the cohort and evaluated awareness of the Florida Fish Consumption Advisory. Hair mercury levels were significantly higher in women who consumed fish within the 30 days prior to sampling (p<0.05) and in those women who were unaware of the consumption advisory (p<0.05). Only 31% of the women reported knowledge of the consumption advisory and pregnant women exhibited lower awareness of the advisory than non-pregnant women. The data suggest that public health interventions such as education and fish advisories have not reached the majority of women in the counties surrounding Pensacola who are most at risk from consumption of fish with high levels of mercury.     

Fish consumption and PCB-associated health risks in recreational fishermen on the James River, Virginia

Consumption of sport-caught fish contaminated with high levels of polychlorinated biphenyls (PCBs) may pose human health risks. To obtain estimates of fish consumption and fishing behaviors in recreational fishermen in Virginia, on-site interviews (n=143; 134 men and 9 women) were conducted at seven public boat landings along the James River. Using existing PCB concentration data from James River fish tissue samples collected from 1997, and 1999 to 2001, default and point estimates were calculated and Monte Carlo analyses conducted to estimate potential risks under different consumption scenarios. A mean of 55 fish meals/yr and 14 James River sport-caught fish (JRSCF) meals/yr were reported. Caucasians fished less often (mean of 58 d), consumed less fish (mean of 43 meals/yr) and had smaller portion sizes (mean of 11.7 oz) compared to other races combined (130 d; 82 meals/yr; and 15.6 oz). On average, respondents reported consuming 10 meals of James River catfish a year (5 kg/yr). Risk estimates produced from Monte Carlo analysis were consistently lower than the default and point estimates. Several individuals exceeded acceptable risk levels and the mean cancer and non-cancer risks among catfish consumers exceeded acceptable levels. Eighteen percent of individuals had no knowledge of fish advisories in Virginia and 4% of the subjects indicated they would consume fish under advisory. Based on reported consumption, a significant risk to recreational fishermen, as a result of consuming PCB-contaminated catfish, was found. Risks associated with consuming other species were within acceptable limits.     

Fish and shellfish consumption estimates and perceptions of risk in a cohort of occupational and recreational fishers of the Chesapeake Bay

Exposure to persistent, bioaccumulating substances, through the consumption of contaminated fish is of concern in human populations. Consumption may be particularly high for subsistence, commercial, and recreational fishers, so it is important to obtain accurate consumption estimates to assess risks in these groups. The objectives of the work reported here were: to obtain estimates of fish and shellfish consumption (meals and portion size) in an occupational cohort; to determine what percentage of the consumption was from local fish; to evaluate reliability of two methods of reporting fish and shellfish consumption; and to examine risk perceptions in relation to consumption. Subjects included 99 recreational and occupational fishers in the Chesapeake Bay area, Virginia, who were recruited for a cohort study of estuary-associated syndrome. Subjects reported average fish and shellfish consumption (all species) on a weekly, monthly or yearly basis, and were asked species-specific information, which was summed. The median number of fish meals consumed a year was significantly different depending on the method used, 52 (interquartile range, IQR:24-104) (average method) and 65 (IQR:30-117) (sum of species-specific), respectively. Shellfish estimates were 24 (IQR:12-52) (average) and 47 (IQR:31-84) (sum) meals a year. Of those who consumed fish, participants reported an average meal size of 8.9±3.38 oz. (median 8 oz, range 4-16) with close to 70% of fish consumed self-caught and 50% from Virginia waters. Using multiple regression, occupation, and risk perceptions were found to be significantly correlated with fish consumption levels, and consumption of fish from locations under advisory.     

An ecosystem approach to the health effects of mercury in the Great Lakes basin ecosystem

New concerns about the global presence and human health significance of mercury have arisen as a result of recent epidemiological data demonstrating subtle neurological effects from consumption of mercury-contaminated fish. In the Great Lakes Basin, the complexity of the diverse sources, pools, and sinks of mercury and of the pathways of distribution, fate, and biotransformation requires an ecosystem approach to the assessment of exposures of Great Lakes' human populations. Further epidemiological research is needed to verify preliminary indications of harmful effects in people living near the Great Lakes. Great Lakes fish are valuable resources for subsistence nutrition, recreation, and commerce, but the benefits of fish consumption must be balanced by concern for the hazards from the contaminants that they may contain. The efficacy of fish consumption advisories in reducing exposures should continue to be evaluated while planning continues for remedial actions on contaminated sediments from historic industrial activities and for regulatory action to control sources.     

Temporal variation of blood and hair mercury levels in pregnancy in relation to fish consumption history in a population living along the St. Lawrence River

Fish consumption from the Great Lakes and the St. Lawrence River has been decreasing over the last years due to advisories and increased awareness of the presence of several contaminants. Methylmercury (MeHg), a well-established neurotoxicant even at low levels of exposure, bioaccumulates to differing degrees in various fish species and can have serious adverse effects on the development and functioning of the human central nervous system, especially during prenatal exposure. Most studies on MeHg exposure have focussed on high-level consumers from local fish sources, although mercury (Hg) is also present in fresh, frozen, and canned market fish. Moreover, little information exists on the temporal variation of blood and hair Hg in pregnant women, particularly in populations with low levels of Hg. The aim of the present study was to characterize the temporal variation of Hg during pregnancy and to investigate the relation between fish consumption from various sources prior to and during pregnancy and maternal cord blood and mother's hair Hg levels. We recruited 159 pregnant women from Southwest Quebec through two prenatal clinics of the Quebec Public Health System. All women completed two detailed questionnaires concerning their fish consumption (species and frequency) prior to and during pregnancy. The women also provided blood samples for all three trimesters of pregnancy and hair samples after delivery of up to 9 cm in length. Blood and hair Hg levels were analyzed by cold-vapor atomic-absorption and -fluorescence spectrometry methods, respectively. Results showed that maternal blood and hair Hg levels decreased significantly between the second and third trimesters of pregnancy. However, cord blood Hg was significantly higher than maternal blood at birth. Maternal hair was correlated with Hg blood concentration and was highly predictive of the organic fraction in cord blood. A strong dose relation was observed between the frequency of fish consumption before and during pregnancy and Hg exposure in mothers and newborns. Fish consumption prior to and during pregnancy explained 26% and 20% of cord blood Hg variance, respectively. For this population, detailed multivariate analyses showed that during pregnancy market fish (fresh, canned, and frozen) were more important sources of Hg exposure than were fish from the St. Lawrence River. These results should be taken into account for future advisories and intervention strategies, which should consider Hg levels in different species from all sources in order to maximize the nutritional input from fish and minimize the toxic risk.     

Risk to consumers from mercury in bluefish (Pomatomus saltatrix) from New Jersey: Size, season and geographical effects

Relatively little attention has been devoted to the risks from mercury in saltwater fish, that were caught by recreational fisherfolk. Although the US Food and Drug Administration has issued advisories based on mercury for four saltwater species or groups of fish, there are few data on how mercury levels vary by size, season, or location. This paper examines total mercury levels in muscle of bluefish (Pomatomus saltatrix) collected from coastal New Jersey, mainly by recreational fishermen. Of primary interest was whether there were differences in mercury levels as a function of location, weight and length of the fish, and season, and in what risk mercury posed to the food chain, including people. Selenium was also measured because of its reported protective effects against mercury. Mercury levels averaged 0.35±0.02 (mean and standard error) ppm, and selenium levels averaged 0.37±0.01 ppm (N=206). In this study, 41% of the fish had mercury levels above 0.3 ppm, 20% had levels above 0.5 ppm, and 4% had levels above 1 ppm. Size was highly correlated with mercury levels, but not with selenium. While selenium levels did not vary at all with season, mercury levels decreased significantly. This relationship was not due to differences in the size of fish, since the fish collected in the summer were the smallest, but had intermediate mercury levels. Mercury levels declined from early June until November, particularly for the smaller-sized fish. While there were significant locational differences in mercury levels (but not selenium), these differences could be a result of size. The levels of mercury in bluefish are not sufficiently high to cause problems for the bluefish themselves, based on known adverse health effects levels, but are high enough to cause potential adverse health effects in sensitive birds and mammals that eat them, and to provide a potential health risk to humans who consume them. Fish larger than 50 cm fork length averaged levels above 0.3 ppm, suggesting that eating them should be avoided by pregnant women, children, and others who are at risk.     

Hair mercury concentration and fish consumption: Risk and perceptions of risk among women of childbearing age

The purposes of this study were to assess the hair mercury concentration of women of childbearing age in Taiwan, and to calculate a hazard quotient (HQ) to evaluate the risk of fish consumption for these women. We also examined perceptions of risk associated with fish consumption and whether women in our study changed their habits in response to such risks. The average concentration of mercury was 1.73±2.12 μg g⁻¹ (range: 0.02-16.34 μg g⁻¹), exceeding the US EPA reference dose of 1 μg g⁻¹ in 52.9% of study subjects. The WHO tolerance limit of 10 μg g⁻¹ was exceeded in 1.5% of study subjects. Hair mercury concentration in groups who consumed fish was significantly higher than in groups who never consumed fish (p<0.05). The hazard quotient (exposure estimate/oral reference dose) exceeded 1.0 for 29% of subjects, based on the US EPA’s reference dose (0.1 μg kg⁻¹ d⁻¹), and the average HQ equaled 1.26. When told that some fish contain high levels of mercury that may be harmful for unborn babies, 67.6% of women still indicated that they would not change their amount of fish intake. The high hair mercury concentrations among women of childbearing age in Taiwan are a cause for concern, due to the effect on babies’ brain development. The government should provide specific information about risks and benefits of fish consumption for women to make risk-balancing decisions.     

The structure of Canadians' health risk perceptions: Environmental,therapeutic and social health risks

Numerous studies have examined health risk perception through public ratings of health hazards, comparing them across lists, across time or across subpopulations. Yet, few have unveiled people's mental organization and representation of the factors affecting health risk. In order to better understand how the construct of health risk is conceptualized by the public, a principal components analysis was conducted on data from a previous national survey in which Canadians rated a series of hazards with respect to perceived level of health risk. Canadians conveyed their concerns as falling into three broad components: Environmental (e.g., nuclear waste, PCBs or Dioxins, etc.), Therapeutic (e.g., contact lenses, medical X-rays, etc.), and Social health risks (e.g., motor vehicle accidents, street crime, etc.). Generally, hazards perceived as posing the most health risk were those belonging to Social health risks. Perceptions of Environmental, Therapeutic and Social health risks were higher among women, respondents with lower education or income, and among residents of Québec. Results are discussed in relation to the population health approach (Evans et al. 1994 Evans, R. G., Barer, M. L. and Marmor, T. R. 1994. Why are Some People Healthy and Others Not?, New York: Aldine de Gruyter.  [Google Scholar]), in which the physical environment, biology, lifestyle, social environment and health care represent major determinants of the health of populations and population subgroups.     

Risk to consumers from mercury in Pacific cod (Gadus macrocephalus) from the Aleutians: fish age and size effects

While there has been considerable attention devoted to the risks to high level consumers from mercury in freshwater fish, relatively little attention has been devoted to saltwater fish. Although the U.S. Food and Drug Administration has issued advisories based on mercury for four saltwater species or groups of fish, there are few data on mercury levels generally, or on the risk these levels pose to the fish themselves or to consumers of marine fish. We examined total mercury levels in liver and muscle of Pacific cod (Gadus macrocephalus) collected from the northern Pacific and Bering Sea waters around Nikolski, Amchitka, and Kiska Islands in the Aleutian Chain (Alaska). We were interested in whether there were differences in mercury levels as a function of location, weight, length, and age of the fish, and what risk mercury posed to the food chain, including people. Fish were aged by examining otoliths, and we measured selenium because of its reported protective effects against mercury. Regression models indicated that 27% of the variation in levels of mercury was due to tissue examined and age, while 67% of the variation in levels of selenium was due to tissue, length, and age. Mercury levels were significantly higher in the muscle than the liver, and the reverse was true for selenium. Mercury levels were negatively correlated with selenium levels, and positively correlated with length, weight, and age. There were no gender differences in mercury or selenium levels. The mean levels of mercury in muscle (0.17 ppm wet weight) are within the range known to cause adverse effects in sensitive birds and mammals. Only 4% of the Pacific cod samples had mercury levels above 0.5 ppm, the action level promulgated by many states and countries, and none were above the 1 ppm action level of the U.S. FDA.     

Ranking the contributions of commercial fish and shellfish varieties to mercury exposure in the United States: Implications for risk communication

Fish and shellfish have important nutritional benefits, and US per capita seafood consumption has increased substantially since 2002. Recent research has reinforced concerns about adverse effects of methylmercury exposure, suggesting that methylmercury doses associated with typical US rates of fish consumption may pose measurable risks, with no threshold. These converging trends create a need to improve risk communication about fish consumption and mercury. The analysis performed here identifies the relative importance of different fish and shellfish as sources of mercury in the US seafood supply and proposes improved consumer advice, so that the public can benefit from fish consumption while minimizing mercury exposure. I have quantified contributions to total mercury in the US seafood supply by 51 different varieties of fish and shellfish, then ranked and sorted the 51 varieties in terms of relative impact. Except for swordfish, most fish with the highest mercury levels are relatively minor contributors to total inputs. Tuna (canned light, canned albacore and fresh/frozen varieties) accounts for 37.4 percent of total mercury inputs, while two-thirds of the seafood supply and nine of the 11 most heavily consumed fish and shellfish are low or very low in mercury. Substantial improvement in risk communication about mercury in fish and seafood is needed; in particular, several population subsets need better guidance to base their seafood choices more explicitly on mercury content. I have sorted the 51 seafood varieties into six categories based on mercury levels, as a framework for improving risk communication in this regard.     

Differences in water consumption choices in Canada: the role of socio-demographics, experiences, and perceptions of health risks

In 2000 and 2001 Canadians were shocked by water contamination events that took place in two provinces. In 2004 we undertook an internet-based survey across Canada that asked respondents to identify in percentage terms their total drinking water consumption according to one of three sources: tap water, bottled water, and home-filtered water (either some type of container or an in-tap filter device). In this paper we investigate the factors that influence these choices and whether choosing to either filter or purchase water is linked to perceptions of health concerns with respect to tap water. A series of one-way analysis of variance (ANOVA) tests suggest that the presence of children in a household and self-reported concern that tap water causes health problems lead to significantly greater consumption of bottled water or filtered water and significantly less tap water consumption. In order to examine these choices in a multivariate framework, we estimate a multinomial logit model. Factors yielding higher probabilities of a respondent being primarily a bottled water drinker (relative to the choice of tap water) include: higher income, unpleasant taste experiences with tap water, non-French-speaking, and being a male with children in one's household. Similar factors yield higher probabilities of a respondent being primarily a filtered tap water drinker. An important finding is that two key variables linking a person's health perceptions regarding tap water quality are significant factors leading to the choice of either filtered tap water or bottled water over tap water. They are: a variable showing the degree of health concerns a respondent has with respect to tap water and a second variable indicating whether the respondent believes bottled water is safer than tap water.     

Accumulation of toxic elements in an invasive crayfish species (Procambarus clarkii) and its health risk assessment to humans

The accumulation and potential health risks of eight trace elements (Cu, Cd, Cr, Mn, Zn, Pb, Hg and As) were analyzed in the commercially important crayfish and oriental river prawn species from the Zhenjiang City, Jiangsu Province, China. The accumulation sequence of elements in different tissues were as gill > walking leg > muscle. Among the analyzed elements, majority of the elements were accumulated in the gill tissue, while Hg was concentrated in abdominal muscle and Zn in walking leg tissues. The elements Zn (95.9 μg g⁻¹) and Cd (0.02 μg g⁻¹) were the most and the least accumulated elements in the abdominal muscle tissue. The calculated estimated daily intake (EDI) and hazard indices (HI) of the analyzed elements in the tissue organs of Procambarus clarkii and Macrobrachium nipponense species were lower than the Chinese Food Health Criterion and international guideline values and results in no acute toxicities and thus, safe for human consumption. This study also suggests that Procambarus clarkii species can be used as an effective bio-indicator organism for examining the toxic heavy metals in the freshwater ecosystems.     

Creeping edgework: carnivalesque consumption and the social experience of health risk

This article contributes to an understanding of voluntary health risk based on the regular, excessive intake of food and alcohol in the micro‐cultural setting. By drawing on and extending edgework theory our aim is to conceptualise the riskiness of carnivalesque consumption as a medium for expression and performance in two separate community contexts. Using ethnographic research methods, we explore the consumption of calorie‐dense, low nutrient food for gamers and the use of alcohol for hipsters. Our findings are reported over four key themes. The first and last consider how carnivalesque consumption provides sensations for multi‐sensory loss of self and a shared emancipation from day‐to‐day moderation. The second and third explore how community members prepare and exercise control over their consumption to manage risks related to an ‘immediate edge’. We discuss how carnivalesque behaviour, when ritualised, establishes a trajectory that creeps towards a more ‘distant edge’ characterised by longer term health consequences. We argue that the transcendental experiences that are part and parcel of edgework can be enacted by products that are traditionally conceptualised as mundane and that the risks of consuming them are largely accumulative rather than instantaneous. Implications for health interventions are included.     

Radiological risk from consuming fish and wildlife to Native Americans on the Hanford Site (USA)

Historical operations at the Hanford Site (Washington State, USA) have released a wide array of non-radionuclide and radionuclide contaminants into the environment. As a result of stakeholder concerns, Native American exposure scenarios have been integrated into Hanford risk assessments. Because its contribution to radiological risk to Native Americans is culturally and geographically specific but quantitatively uncertain, a fish and wildlife ingestion pathway was examined in this study. Adult consumption rates were derived from 20 Native American scenarios (based on 12 studies) at Hanford, and tissue concentrations of key radionuclides in fish, game birds, and game mammals were compiled from the Hanford Environmental Information System (HEIS) database for a recent time interval (1995-2007) during the post-operational period. It was assumed that skeletal muscle comprised 90% of intake, while other tissues accounted for the remainder. Acknowledging data gaps, median concentrations of eight radionuclides (i.e., Co-60, Cs-137, Sr-90, Tc-99, U-234, U-238, Pu-238, and Pu-239/240) in skeletal muscle and other tissues were below 0.01 and 1 pCi/g wet wt, respectively. These radionuclide concentrations were not significantly different (Bonferroni P>0.05) on and off the Hanford Site. Despite no observed difference between onsite and offsite tissue concentrations, radiation dose and risk were calculated for the fish and wildlife ingestion pathway using onsite data. With median consumption rates and radionuclide tissue concentrations, skeletal muscle provided 42% of the dose, while other tissues (primarily bone and carcass) accounted for 58%. In terms of biota, fish ingestion was the largest contributor to dose (64%). Among radionuclides, Sr-90 was dominant, accounting for 47% of the dose. At median intake and radionuclide levels, estimated annual dose (0.36 mrem/yr) was below a dose limit of 15 mrem/yr recommended by the United States Environmental Protection Agency (USEPA), as well as below a dose limit of 100 mrem/yr proposed by the International Commission on Radiation Protection (ICRP). Similarly, lifetime cancer risk (1.7E−5), calculated with median inputs, was below risk levels corresponding to these dose limits. However, our dose and risk estimates apply to only one pathway within a multidimensional exposure scenario for Native Americans. On the other hand, radiation dose and risk corresponding to onsite tissue concentrations were not significantly different from those corresponding to offsite (background) concentrations. Recognizing uncertainties in exposure and toxicity assessments, our results may facilitate informed decision making and optimize resource allocation within a risk assessment framework at the Hanford Site.     

Biomonitoring of mercury and persistent organic pollutants in Michigan urban anglers and association with fish consumption

The 32-mile Detroit River and surrounding tributaries have been designated as a Great Lakes Area of Concern due to pollution from decades of municipal and industrial discharges, sewer overflows and urban development. Key pollutants in fish samples from the Detroit River include mercury, polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), dioxins and furans. A biomonitoring study was conducted to assess exposures to these persistent toxic substances in Detroit urban shoreline anglers who may be at high exposure risk due to consumption of locally caught fish. Using a modified venue-based sampling approach, 287 adult shoreline anglers along the Detroit River were recruited and participated in the program. Study participants provided blood and urine specimens and completed a questionnaire following informed consent. We examined percentile estimates for total blood mercury, PCBs, DDE, and dioxin-like total toxic equivalency (TEQ) concentrations among study participants. Multiple linear regression was used to identify important predictors of contaminant concentrations. Participants consumed a median of 64 Detroit River caught fish meals in the past year. The Detroit urban anglers’ median total blood mercury concentrations was 3.2 times higher than that for the general adult U.S. population. PCB concentrations among the Detroit anglers aged 18–39 years were higher than the U.S. population of the same race/ethnicity. Elevated levels of DDE and total TEQ concentrations were not observed in the cohort. Eating more locally caught fish was associated with higher total blood mercury and serum PCB concentrations. The biomonitoring data served to inform public health officials and help guide environmental public health actions to reduce harmful exposures.