Sport fish consumption and body burden levels of chlorinated hydrocarbons: a study of Wisconsin anglers

Sport-caught fish consumption is the major source of polychlorinated biphenyls (PCBs) exposure for the general population. To assess this and 2,2'-bis-(p-chlorophenyl)-1,1-dichloroethylene (DDE) exposure, we surveyed 801 Wisconsin anglers for fishing and consumption habits and comprehension of and compliance with the Wisconsin fish consumption health advisory. The mean annual number of sport-caught fish meals was 18. Seventy-two percent of anglers were familiar with the health advisory and 57% had changed their fishing or fish consumption habits as a result of the advisory. The mean PCB serum congener sum level for 192 anglers was 2.2 micrograms/l (range = nondetectable to 27.1 micrograms/l); mean DDE was 6.3 micrograms/l (range = nondetectable to 40.0 micrograms/l). Statistically significant positive Spearman correlations were observed between sport-caught fish meals and PCB and DDE sera levels (R = .21 and .14, respectively) and between kilograms of fish caught and PCB sera levels (R = .25). These results demonstrate that anglers may provide a population for assessment of PCBs and DDE associated morbidity and mortality.     

A longitudinal examination of factors related to changes in serum polychlorinated biphenyl levels

Consumption of sport-caught fish from the Great Lakes is a recognized source of human exposure to polychlorinated biphenyls (PCBs). Understanding temporal changes in PCB body burden is crucial for evaluating exposure levels and augmenting validity of studies investigating their relationship to adverse health effects. Using data collected from 1980 to 1995, we evaluated longitudinal changes in serum PCB levels among 179 fisheaters and non-fisheaters of the Michigan Fisheater Cohort. Participants identified as fisheaters in 1980 ate 26 lb or more of sport-caught fish per year, whereas non-fisheaters ate less than 6 lb per year. We found a monotonic decline in serum PCB levels among all participants from a mean value of 24 ppb in 1980 to 12 ppb in 1994. This was paralleled by an 83% decrease in mean fish consumption among all participants over the same period. We combined demographic, lifestyle, and fish consumption information with PCB data and evaluated the data using regression models to identify predictors of PCB body burden over a 16-year period. Results of the mixed-effects linear regression model suggest that consumption of Lake Michigan fish before 1980, amount of sport-caught fish eaten in the past year, age, and year of data collection were significant determinants of current PCB body burden over the 16-year study period. PCB levels were particularly elevated for males who were classified as fisheaters in 1980, which may reflect higher levels of sport-caught fish consumption compared with female fisheaters.     

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 consumption and advisory awareness in the Great Lakes Basin

More than 61 million adults live in the eight U.S. states bordering the Great Lakes. Between June 2001 and June 2002, a population-based, random-digit-dial telephone survey of adults residing in Great Lakes (GL) states was conducted to assess consumption of commercial and sport-caught fish and awareness of state-issued consumption advisories for GL fish. On the basis of the weighted survey data, approximately 84% of the adults living in these states included fish in their diets. Seven percent (an estimated 4.2 million adults) consumed fish caught from the Great Lakes. The percentage of residents who had consumed sport-caught fish (from any water source) varied regionally and was highest among those who lived in Minnesota (44%) and Wisconsin (39%). Consumption of GL sport fish was highest among residents of Michigan (16%) and Ohio (12%). Among residents who had eaten GL fish, awareness of consumption advisories varied by gender and race and was lowest among women (30%) and black residents (15%). However, 70% of those who consumed GL sport-caught fish twice a month or more (an estimated 509,000 adults across all eight states) were aware of the advisories. Findings from this survey indicate that exposure to persistent contaminants found in GL fish is likely limited to a relatively small subpopulation of avid sport-fish consumers. Results also underscore the public health importance of advisories for commercial fish because an estimated 2.9 million adults living in these states consume more than 104 fish meals per year and may be at risk of exceeding the reference doses for methylmercury, polychlorinated biphenyls, and other bioaccumulative contaminants.     

Comprehension of Fish Consumption Guidelines Among Older Male Anglers in Wisconsin

Although awareness of Wisconsin’s fish consumption guidelines is high among older male anglers, little is known about comprehension of guideline content, and many anglers have levels of contaminants high enough to be associated with adverse health outcomes. The Environmental Protection Agency Great Lakes Restoration Initiative supported evaluation and revision of Wisconsin’s fish consumption guideline program, using a web based survey of male Wisconsin anglers over the age of 50. A total of 3740 men completed the online survey; the median age of respondents was 62 years, and nearly all had lived and fished in Wisconsin for over 10 years. Comprehension of guideline content was relatively high, although two knowledge gaps were identified, one relating to mercury exposures and fish preparation, and the other to polychlorinated biphenyl content of certain fish species. The fishing regulations booklet distributed with annual fishing licenses and warning signs posted at fishing locations were commonly reported sources of guideline information in Wisconsin. Residents of coastal counties and consumers of Great Lakes fish were more likely to report guideline knowledge and behavior changes reflective of guideline knowledge, when compared to inland residents and those not consuming Great Lakes fish, respectively. In general, Wisconsin’s consumption guidelines do not appear to discourage men from eating the fish they catch; rather, the most common behavioral changes included modifying the species eaten or the water body source of their meals. Continued efforts to educate anglers about the risks and benefits of fish consumption are needed.     

The good, the bad, and the ugly: weighing the risks and benefits of seafood consumption

The health benefits that long chain omega-3 fatty acids contribute in the reduction of coronary heart disease are well established through a number of scientific publications. A number of studies are also examining their potential role in mitigating other diseases and health conditions such as Alzheimer's and mental disorders. Some of the latest research have shown the importance of omega-3 fatty acids such as docosahexaenoic acid in cognitive development in infants. Extensive scientific research and recommendations to consume fish regularly from professional societies, health organizations, and government agencies consistently support dietary guidance to consume fish regularly. Nevertheless, increasingly consumers are being warned to eliminate or minimize their consumption of certain species. The warnings, which have been issued due to risks associated with chemical contaminates such as mercury, PCB, and dioxin in fish, have received extensive coverage in news articles and stories in popular magazines. There have been a series of mixed messages to the consumer about the benefits or risks in eating seafood. In some cases, the warnings have been issued by government agencies such as the Food and Drug Administration and Environmental Protection Agency's Joint Fish Advisory on methylmercury. In other cases, the warnings have come from advocacy groups and others. Unfortunately, the advice is often miscommunicated and misunderstood by consumers. The emerging news about the benefits and risks of fish consumption will be discussed in the context of their impacts on consumer's health and well-being.     

Assessment of methylmercury exposure in Wisconsin

Between January 2004 and June 2005 the Wisconsin Department of Health and Family Services recruited more than 2000 adults for a methylmercury (MeHg) exposure assessment study. Study participants, including 978 men and 1050 women who ranged in age from 18 to 92 years, completed a fish consumption and advisory awareness survey and provided hair samples for mercury analysis. Fish intake estimates ranged from 0 to 60 meals/month (mean 7.7). Hair mercury levels ranged from 0.012 to 15.2 microg/g and were positively correlated with monthly fish meals. Despite reporting similar fish consumption rates, men tended to have higher hair mercury levels than women. Mercury levels exceeded 1 microg/g in 29% of the men and 13% of the women and increased with age. Approximately, half of the study volunteers were licensed anglers and 77% were familiar with Wisconsin's sportfish consumption advisory. Among consumers of sport-caught fish, 37% of the men and 18% of the women had a hair mercury concentration above 1 microg/g. These findings suggest that exposure to MeHg is widespread and that men may be a previously unrecognized high risk population.     

Potential exposure to PCBs, DDT, and PBDEs from sport-caught fish consumption in relation to breast cancer risk in Wisconsin

In Wisconsin, consumption of Great Lakes fish is an important source of exposure to polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), polybrominated diphenyl ethers (PBDEs), and other halogenated hydrocarbons, all of which may act as potential risk factors for breast cancer. We examined the association between sport-caught fish consumption and breast cancer incidence as part of an ongoing population-based case-control study. We identified breast cancer cases 20-69 years of age who were diagnosed in 1998-2000 (n = 1,481) from the Wisconsin Cancer Reporting System. Female controls of similar age were randomly selected from population lists (n = 1,301). Information about all sport-caught (Great Lakes and other lakes) fish consumption and breast cancer risk factors was obtained through telephone interviews. After adjustment for known and suspected risk factors, the relative risk of breast cancer for women who had recently consumed sport-caught fish was similar to women who had never eaten sport-caught fish [relative risk (RR) = 1.00; 95% confidence interval (CI), 0.86-1.17]. Frequency of consumption and location of sport-caught fish were not associated with an increased risk of breast cancer. Recent consumption of Great Lakes fish was not associated with postmenopausal breast cancer (RR = 0.78; 95% CI, 0.57-1.07), whereas risk associated with premenopausal breast cancer was elevated (RR = 1.70; 95% CI, 1.16-2.50). In this study we found no overall association between recent consumption of sport-caught fish and breast cancer, although there may be an increased breast cancer risk for subgroups of women who are young and/or premenopausal.     

Exposure assessment and initial intervention regarding fish consumption of tribal members of the Upper Great Lakes Region in the United States

The Ojibwe Health Study (OHS) has concluded 10 years of data collection and exposure assessment. Eight hundred and twenty-two participants from tribes in the states of Wisconsin, Michigan, and Minnesota (USA) completed fish consumption and environmental risk perception questionnaires. Many participants provided hair and blood samples for mercury and polychlorinated biphenyl (PCB) residue analyses as body burden indicators of these persistent environmental pollutants. Fish were collected by the tribal organizations and contaminants were analyzed for numerous tribal reports and professional environmental journal articles, these data were used by the Great Lakes Indian Fish and Wildlife Commission to produce tribal-specific geographic information systems maps as part of a public health intervention strategy. These maps are currently available at for six Wisconsin tribes that regularly harvest walleye. To determine the health impacts (if any) of pollutants on cancer, diabetes, and reproduction, it was necessary to know the recent trends in key indicators such as cancer mortality ratios and birth gender ratios. The Great Lakes Inter-Tribal Council provided the OHS and each participating tribe in Wisconsin and Michigan with a health profile. Total fish consumption (estimated by recall) for 720 tribal participants was self-reported as 60 g/day, but the highest actual consumption was measured as 11.2 g/day in one of the tribal groups. The highest blood concentrations in tribal participants were 18.6 ppb total serum PCBs and 11.8 ppb total blood mercury. Ninety percent of the participants had less than 3.8 ppb total serum PCBs and 2.6 ppb total blood mercury. Compared to other studies of subsistence fishing populations, these exposures were only moderately elevated and not high enough to warrant widespread restrictions on diets. Furthermore, the benefits of eating a fish diet must be continually emphasized. However, sport fishermen and their families who consume larger and more contaminated fish should abide by their state fish consumption advisories to minimize their health risks.     

Contaminated fish consumption in California’s Central Valley Delta

Extensive mercury contamination and angler selection of the most contaminated fish species coincide in California’s Central Valley. This has led to a policy conundrum: how to balance the economic and cultural impact of advising subsistence anglers to eat less fish with the economic cost of reducing the mercury concentrations in fish? State agencies with regulatory and other jurisdictional authority lack sufficient data and have no consistent approach to this problem. The present study focused on a critical and contentious region in California’s Central Valley (the Sacramento-San Joaquin Rivers Delta) where mercury concentrations in fish and subsistence fishing rates are both high. Anglers and community members were surveyed for their fish preferences, rates of consumption, the ways that they receive health information, and basic demographic information. The rates of fish consumption for certain ethnicities were higher than the rates used by state agencies for planning pollution remediation. A broad range of ethnic groups were involved in catching and eating fish. The majority of anglers reported catching fish in order to feed to their families, including children and women of child-bearing age. There were varied preferences for receiving health information and no correlation between knowledge of fish contamination and rates of consumption. Calculated rates of mercury intake by subsistence anglers were well above the EPA reference dose. The findings here support a comprehensive policy strategy of involvement of the diverse communities in decision-making about education and clean-up and an official recognition of subsistence fishers in the region.     

Mortality among frequent consumers of Great Lakes sport fish

Commercial and sport-caught fish provide a healthy source of dietary protein, omega-3 fatty acids, and other micronutrients. Regular fish consumption has been associated with decreased risk of heart disease and health professionals encourage adults to include fish in their weekly diets. However, fish harvested from contaminated waters can contain higher levels of persistent, bioaccumulative chemicals such as methylmercury, PCBs, dieldrin, and DDT. To assess the beneficial effects of fish intake and the adverse effects of contaminant exposure, underlying and contributing causes of death were obtained from the National Death Index for 342 deceased members of a cohort of 2538 Great Lakes charterboat captains, 180 Wisconsin anglers, and 1141 referents who were established in 1993-1995. Multivariate analysis of death rates confirmed a dose-related protective effect of fish intake against all-cause and cardiovascular disease mortality, including coronary heart disease, among the referent group. This effect was not observed among consumers of Great Lakes sport fish, however. Cancer mortality was not associated with fish intake in either exposure group. While the number of deaths among this cohort is currently too small to support rigorous statistical analysis, these preliminary findings are consistent with other studies that have shown a protective effect of commercial fish on human health and longevity and raise concerns regarding the effect of persistent environmental contaminants that continue to be detected in fish from the Great Lakes Basin. It is hoped that continued monitoring of this cohort will improve our understanding of the complex interactions that exist between nutrients and contaminants found in fish harvested from the Great Lakes.     

Fishing, fish consumption, and awareness about warnings in a university community in central New Jersey in 2007, and comparisons with 2004

Fish are a healthy source of protein, but the risks from consuming fish have become a national concern. Over the past 7 years, there have been a number of national advisories regarding saltwater fish. Fish consumption patterns and public knowledge about advisories and warnings have been examined for at-risk populations, but there is little information about the latter for a general population, or of temporal trends in such information acquisition. Information about the benefits and health risks of consuming fish, health warnings from the New Jersey Department of Environmental Protection and the Food and Drug Administration, belief in these warnings, and trust in different sources of information were examined in a sample of 460 people within a university community in central New Jersey in 2007. The null hypothesis of no differences in fishing, consumption, and knowledge about advisories as a function of age, gender, ethnicity, and education was tested. In 2007, only 30% of the study population fished, and 83% of the study population ate fish, either commercial or self-caught. There were differences in fishing behavior, consumption patterns, and awareness of advisories as a function of gender, ethnicity, age, and education. Most notably, nearly twice as many men as women fished, Whites fished more and Blacks and Indian/Pakistanis fished less than other ethnic groups, and people aged 23-35 fished more than did others. About 8% of fish meals were from self-caught fish, 32% were eaten in restaurants, and 60% were of fish bought in stores and cooked at home. Men ate more meals of self-caught fish than did females, and Asians ate more meals of fish in restaurants, and Blacks ate more meals of store-bought fish than other ethnic groups. The total number of fish meals consumed per month increased significantly with age. Overall, more people had heard about the benefits (92%) than the risks (78%) of fish consumption. When asked whom they trust for information about health benefits and risks from eating fish, doctors were rated the highest, followed by professors; friends and fishermen were rated the lowest. We then examined whether there were any changes from 2004 to 2007 in the knowledge of the health benefits and warnings about fish consumption, and the trustworthiness of different sources of information. In other words, have communication efforts of the state and federal agencies resulted in any appreciable increase in overall awareness of the benefits or risks of fish consumption. The greatest change in the parameters examined from 2004 to 2007 was an overall decrease in fish consumption from an average of 7.9 meals per month in 2004 to about six meals per month in 2007. This suggests that the unintended effect of some of the warnings and advisories is to decrease overall fish consumption, rather than to switch from fish species with high levels of contaminants to those with low levels.     

Identification of sport fish consumption patterns in families of recreational anglers through factor analysis

This paper reports on the identification of sport fish consumption patterns in angler families through the factor analysis technique. New York State recreational anglers and their spouses or partners were surveyed in 1991 about their consumption of Lake Ontario and Lake Erie sport fish. Respondents were surveyed again in 1997 to report the number of sport fish consumed by their children aged 5-10 years. Parental report revealed that 60% of children had consumed at least one sport fish meal over their lifetime. Anglers', partners', and children's variables were entered into three separate factor analysis models to assess consumption patterns. Factors for anglers and partners accounted for 65 and 59% of variance in consumption scores, respectively. Factors dealing with trout and salmon consumption accounted for the most variance. Children's factors accounted for 82% of variance in consumption scores, showing separation in relation to type of fish, body of water, and age at consumption. Children's factors were then used as dependent measures of separate multiple regression runs in which parental factors were entered stepwise as predictors. Significant associations between parental and children's factors were noted, suggesting that sport fish consumption patterns in parents are predictive of similar consumption patterns in children. Results suggest that sport fish consumption advisories do not fully prevent consumption of contaminated sport fish during childhood. Therefore, risk communicators may need to modify the current strategy of informing anglers and their families about sport fish consumption recommendations.     

Levels of polychlorinated biphenyls (PCBs) in fish: the influence on local decision making about fish consumption

In 1989, the level of Aroclor 1254 (a mixture of polychlorinated biphenyls with 42 percent chlorine by weight) in fish collected from a recreational pond in Toledo, Ohio, was reported to be 44.4 milligrams per kilogram (mg/kg), prompting local health officials to declare a "no fishing advisory" for the pond. A second study conducted in 1990 did not identify elevated levels of polychlorinated biphenyls (PCBs) in fish tissue. In other words, the two studies gave conflicting results. The purpose of this study was to determine the level of Aroclor in fish tissues and then evaluate whether consumption of fish from the pond would pose a serious health risk. Fish samples collected on several occasions in 1998 and 1999 were filleted, and tissues were analyzed, as composite or individual samples, with gas chromatography. The levels of Aroclor 1254 ranged from 0.2 mg/kg in white crappies to 1.0 mg/kg in carp. These levels, while far less than the level reported in 1989, nevertheless were greater than 0.05 mg/kg, which is the maximum level established by the Great Lakes Fish Advisory Task Force for "no restriction in fish consumption." Levels of other Aroclor formulations ranged from less than the 0.02 mg/kg (the minimum detectable limit) to 0.1 mg/kg. Given current knowledge about the potential health consequence of exposure to PCBs and the results of this study, the authors have recommended that local health officials develop a new fish consumption guideline for PCBs. Any decisions about maintaining or lifting the restrictions on the pond, however, should be based on additional studies that determine the levels of other chemicals that are present in the pond and deemed hazardous to human health.     

Impairments of memory and learning in older adults exposed to polychlorinated biphenyls via consumption of Great Lakes fish.

An association between in utero polychlorinated biphenyl (PCB) exposure and impaired childhood intellectual functioning has been reported, but the potential impact of PCB exposure during adulthood on intellectual functioning has received little attention. We assessed the impact of PCBs and other fish-borne contaminants on intellectual functioning in older adults. The subjects were 49- to 86-year-old Michigan residents recruited from an existing cohort. Fish eaters ate > 24 lb of sport-caught Lake Michigan fish per year and non-fish eaters ate < 6 lb of Lake Michigan fish per year. A battery of cognitive tests including tests of memory and learning, executive function, and visual-spatial function was administered to 180 subjects (101 fish eaters and 79 non-fish eaters). Blood samples were analyzed for PCBs and 10 other contaminants. We evaluated cognitive outcomes using multiple regression. PCBs and dichlorodiphenyl dichloroethene (DDE) were markedly elevated in fish eaters. After controlling for potential confounders PCB, but not DDE, exposure was associated with lower scores on several measures of memory and learning. These included the Weschler Memory Scale verbal delayed recall (p = 0.001), the semantic cluster ratio (p = 0.006), and list A, trial 1 (p = 0.037), from the California Verbal Learning Test. In contrast, executive and visual-spatial function were not impaired by exposure to either PCBs or DDE. In conclusion, PCB exposure during adulthood was associated with impairments in memory and learning, whereas executive and visual-spatial function were unaffected. These results are consistent with previous research showing an association between in utero PCB exposure and impairments of memory during infancy and childhood.     

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.     

Consumption of fish from polluted waters by WIC participants in East Harlem

To minimize exposure to neurotoxins such as mercury, polychlorinated biphenyls (PCBs), dioxins, and pesticide residues, the New York State Department of Health issues health advisories about consumption of certain fish and shellfish caught from polluted local waters. Fetal exposure causes cognitive developmental deficits in children. Consumption of fish was assessed. We surveyed 220 WIC (Special Supplemental Nutrition Program for Women, Infants, and Children) participants. Of the participants, 10% ate fish and shellfish caught in local polluted waters. Statistically significant factors associated with eating local, noncommercial fish included male gender and knowledge of the health advisory. Locally caught fish and crabs are consumed; thus, in utero and childhood exposure to these neurotoxins occurs. Interventions to promote safer choices of fish are needed.     

Fish consumption patterns,knowledge and potential exposure to mercury by race

Objective: Compared fish consumption patterns, fish advisory/benefit awareness and risk factors of consuming high-mercury (Hg) fish between Chinese and non-Chinese adults. Methods: 301 Chinese and 120 non-Chinese participated in this cross-sectional study. Participants self-reported demographics, fish consumption behavior, and awareness of warnings/benefits of fish consumption. Results: non-Chinese (62.5%) ate more high-Hg fish than Chinese (35.9%) although more Chinese ate fish in the last year. Over 90% of both groups knew general benefits of consuming fish; fewer knew specific benefits. Chinese were less aware of fish warnings (49.8%) than non-Chinese (86.7%); knowledge did not appear to affect their fish consumption. Conclusions: There were significant differences in fish consumption patterns and fish benefit/warning knowledge between the two groups. A higher proportion of non-Chinese reported consumption of high-Hg fish. Fish knowledge did not affect fish consumption behavior for either group. Public education efforts regarding fish consumption should emphasize details such as species and amounts.     

Public health guidance on cardiovascular benefits and risks related to fish consumption

Historically, concerns with fish consumption have addressed risks from contaminants (e.g., methylmercury (MeHg), and PCBs). More recently public health concerns have widened in appreciation of the specific benefits of fish consumption such as those arising from polyunsaturated fatty acids (PUFAs) in fish oil. Fish contains varying levels of PUFAs and MeHg. Since both address the same health outcomes (in opposite directions) and occur together in fish, great care must be exercised in providing public health guidance. Mozaffarian and Rimm in a recent article (JAMA. 2006, 296:1885–99) have made a strong case for the beneficial effects of PUFAs in reducing the risk of coronary heart disease, but at the same time, have also broadly discounted the increased risks of coronary heart disease posed by MeHg in fish, stating that "... among adults... the benefits of fish intake exceed the potential risks." This conclusion appears to be based on an inaccurate and insufficiently critical analysis of the literature. This literature is re-examined in light of their conclusions, and the available and appropriate public health options are considered.     

Biomonitoring as an intervention against methylmercury exposure

Objectives

We evaluated the effectiveness of biomonitoring as an intervention against methylmercury exposure.

Methods

During 2004, the Wisconsin Department of Health Services assessed fish consumption and methylmercury exposure among 2,031 men and women who responded to a statewide press release. People whose hair mercury levels exceeded 1 microgram per gram (μg/g) were advised to reduce their intake of large, predatory fish. Others were informed that mercury exposure was not an issue for them and were encouraged to continue to eat fish as part of a healthy diet. In 2008, follow-up questionnaires and hair sampling kits were mailed to all 2004 study participants.

Results

Completed surveys and hair samples were received from 1,139 individuals. While overall fish intake for this group increased slightly, from 8,561 to 8,785 servings per month between 2004 and 2008, the intake rate was significantly reduced among people whose 2004 hair mercury levels were >1 μg/g, and 30% of the cohort reported eating different types of fish or smaller fish in 2008. The number of people who had a hair mercury level >1 μg/g fell from 300 in 2004 to 206 in 2008.

Conclusions

Hair mercury analysis and explanatory result letters appear to have had a long-term effect on methylmercury exposure and the selection of fish. These findings support the public health benefit of methylmercury screening in conjunction with results-based education among frequent consumers of commercial and sport-caught fish.Eating a diet that includes a variety of fish, especially fatty marine species such as herring, mackerel, and sardines, has been associated with a reduced risk of cardiovascular disease.^1–4 However, consumption of methylmercury-contaminated fish or grain has been linked to a variety of health problems ranging from developmental delays in prenatally exposed infants to neurological problems and heart disease.^5–11 Most state health departments advise children and women of childbearing age to reduce their intake of large, predatory sport fish, which are frequently high in mercury. Following publication of the 2000 National Research Council report on the toxicological effects of methylmercury,¹² the Wisconsin Department of Health Services began to offer hair mercury testing to concerned citizens and broadened its advisory to include dietary guidance for men and older women.The Great Lakes Regional Collaboration (GLRC) has set a goal of protecting the public from toxic substances through effective outreach and education, including protective fish consumption advice throughout the Great Lakes Basin Ecosystem.¹³ In addition, the GLRC has encouraged stakeholders to identify and fill knowledge gaps that limit our ability to manage public health risks posed by substances found in the Great Lakes and has recommended the use of consistent, easily accessible messages on fish consumption to protect human health. By 2010, the GLRC hoped to establish a regional biomonitoring program for persistent contaminants, and this initiative was recently funded through grants offered by the U.S. Agency for Toxic Substances and Disease Registry.In 2004, the Wisconsin Department of Health Services assessed methylmercury levels in 2,031 residents.¹⁴ Volunteers recruited using statewide press releases completed questionnaires that requested information about sport-caught and commercial fish consumption, and provided hair samples for analysis. Compared with responses from a fish consumption module included in the 2004 Wisconsin Behavioral Risk Factor Surveillance System (WBRFSS) survey, participants in this study ate more fish and were more likely to be licensed anglers. Nearly 20% of the hair samples exceeded the federal advisory level of 1 microgram per gram (μg/g). Levels were highest in male anglers and lowest in women of childbearing age. These results suggested that the advisory used prior to 2005, which advised women who were pregnant or were planning a pregnancy to avoid eating large, predatory fish, had been effective in reducing mercury exposure among this group and highlighted the need to provide consumption advice to men.To assess the effectiveness of the 2004 biomonitoring effort as an outreach and intervention tool, a follow-up investigation was conducted in 2008. The follow-up study was designed to evaluate the participants'' recall of their 2004 hair mercury level, as well as any changes in their fish intake and hair mercury level. This article presents findings from the follow-up study.