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- McMichael, A.J. and Butler, C.D. Promoting global population health while constraining the environmental footprint. Annual Review of Public Health 32: 179-197, 2011.
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Populations today face increasing health risks from human-induced regional and global environmental changes and resultant ecological nonsustainability. Localized environmental degradation that has long accompanied population growth, industrialization, and rising consumerism has now acquired a global and often systemic dimension (e.g., climate change, disrupted nitrogen cycling, biodiversity loss). Thus, the economic intensification and technological advances that previously contributed to health gains have now expanded such that humanity's environmental (and ecological) footprint jeopardizes global population health. International data show, in general, a positive correlation of a population's health with level of affluence and size of per-person footprint. Yet, beyond a modest threshold, larger footprints afford negligible health gain and may impair health (e.g., via the rise of obesity). Furthermore, some lower-income countries have attained high levels of health. Many changes now needed to promote ecological (and social) sustainability will benefit local health. Continued improvement of global health could thus coexist with an equitably shared global environmental footprint.
- Novak, P.J. et al. On the need for a national (U.S.) research program to elucidate the potential risks to human health and the environment posed by contaminants of emerging concern. Environmental Science and Technology 45(9): 3829-3830, 2011.
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- Davidson, P.W. et al. Fish consumption and prenatal methylmercury exposure: Cognitive and behavioral outcomes in the main cohort at 17 years from the Seychelles child development study. NeuroToxicology 32(6): 711-717, 2011.
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Introduction People worldwide depend upon daily fish consumption as a major source of protein and other nutrients. Fish are high in nutrients essential for normal brain development, but they also contain methylmercury (MeHg), a neurotoxicant. Our studies in a population consuming fish daily have indicated no consistent pattern of adverse associations between prenatal MeHg and children's development. For some endpoints we found performance improved with increasing prenatal exposure to MeHg. Follow up studies indicate this association is related to the beneficial nutrients present in fish. Objectives To determine if the absence of adverse outcomes and the presence of beneficial associations between prenatal MeHg and developmental outcomes previously reported persists into adolescence. Methods This study was conducted on the Main Cohort of the Seychelles Child Development Study (SCDS). We examined the association between prenatal MeHg exposure and subjects' performance at 17 years of age on 27 endpoints. The test battery included the Wisconsin Card Sorting Test (WCST), the California Verbal Learning Test (CVLT), the Woodcock-Johnson (W-J-II) Achievement Test, subtests of the Cambridge Neuropsychological Test Automated Battery (CANTAB), and measures of problematic behaviors. Analyses for all endpoints were adjusted for postnatal MeHg, sex, socioeconomic status, maternal IQ, and child's age at testing and the child's IQ was added for problematic behavioral endpoints. Results Mean prenatal MeHg exposure was 6.9 ppm. There was no association between prenatal MeHg and 21 endpoints. Increasing prenatal MeHg was associated with better scores on four endpoints (higher W-J-II math calculation scores, reduced numbers of trials on the Intra-Extradimensional Shift Set of the CANTAB), fewer reports of substance use and incidents of and referrals for problematic behaviors in school. Increasing prenatal MeHg was adversely associated with one level of referrals to a school counselor. Conclusions At age 17 years there was no consistent pattern of adverse associations present between prenatal MeHg exposure and detailed domain specific neurocognitive and behavioral testing. There continues to be evidence of improved performance on some endpoints as prenatal MeHg exposure increases in the range studied, a finding that appears to reflect the role of beneficial nutrients present in fish as demonstrated previously in younger subjects. These findings suggest that ocean fish consumption during pregnancy is important for the health and development of children and that the benefits are long lasting.
- Valera, B., Dewailly, E., and Poirier, P. Impact of mercury exposure on blood pressure and cardiac autonomic activity among Cree adults (James Bay, Quebec, Canada). Environmental Research 111(8): 1265-1270, 2011.
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Aboriginal populations from Quebec (Canada) are exposed to higher mercury levels than southern regions since these populations consume high quantities of fish. Epidemiological evidence suggests a detrimental impact of mercury on cardiovascular risk factors such as heart rate variability (HRV) and blood pressure (BP). The objective of this study was to assess the impact of mercury exposure on BP, resting heart rate (HR) and HRV among Cree adults. Data were collected among 791 adults ≥18 years old living in seven communities of the James Bay. Blood mercury and hair levels were used as biomarkers of recent and long-term exposure. BP was measured through a standardised protocol while HRV was derived from a 2-h Holter monitoring assessment. The relationship between mercury and the outcomes was studied using ANOVA and ANCOVA analysis. Geometric mean of blood mercury and hair mercury concentration was 17.0 nmol/L (95%CI: 6.1–44.0) and 2.36 nmol/g (95%CI: 2.09–2.65); respectively. After adjusting for confounders, blood mercury was associated with HRV parameters such as LF (β = 0.21, P = 0.0002), HF (β = 0.15, P = 0.004) and LF/HF (β = 0.06, P = 0.003). Similar associations were observed with hair mercury. In contrast, no significant association was observed between blood mercury or hair mercury and BP after adjusting for confounders. In conclusion, mercury exposure seems to affect HRV among Cree adults even after considering fish nutrients (n-3 fatty acids and selenium) and other contaminants (lead and polychlorinated biphenyls) that are also present in the traditional diet of this population.
- Armitage, J.M., Quinn, C.L., and Wania, F. Global climate change and contaminants – an overview of opportunities and priorities for modelling the potential implications for long-term human exposure to organic compounds in the Arctic. Journal of Environmental Monitoring 13(6): 1532-1546, 2011.
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This overview seeks to provide context and insight into the relative importance of different aspects related to global climate change for the exposure of Northern residents to organic contaminants. A key objective is to identify, from the perspective of researchers engaged in contaminant fate, transport and bioaccumulation modelling, the most useful research questions with respect to projecting the long-term trends in human exposure. Monitoring studies, modelling results, the magnitude of projected changes and simplified quantitative approaches are used to inform the discussion. Besides the influence of temperature on contaminant amplification and distribution, accumulation of organic contaminants in the Arctic is expected to be particularly sensitive to the reduction/elimination of sea-ice cover and also changes to the frequency and intensity of precipitation events (most notably for substances that are highly susceptible to precipitation scavenging). Changes to key food-web interactions, in particular the introduction of additional trophic levels, have the potential to exert a relatively high influence on contaminant exposure but the likelihood of such changes is difficult to assess. Similarly, changes in primary productivity and dynamics of organic matter in aquatic systems could be influential for very hydrophobic contaminants, but the magnitude of change that may occur is uncertain. Shifts in the amount and location of chemical use and emissions are key considerations, in particular if substances with relatively low long range transport potential are used in closer proximity to, or even within, the Arctic in the future. Temperature-dependent increases in emissions via (re)volatilization from primary and secondary sources outside the Arctic are also important in this regard. An increased frequency of boreal forest fires has relevance for compounds emitted via biomass burning and revolatilization from soil during/after burns but compound-specific analyses are limited by the availability of reliable emission factors. However, potentially more influential for human exposure than changes to the physical environment are changes in human behaviour. This includes the gradual displacement of traditional food items by imported foods from other regions, driven by prey availability and/or consumer preference, but also the possibility of increased exposure to chemicals used in packaging materials and other consumer products, driven by dietary and lifestyle choices.
- Pizzol, M., Christensen, P., Schmidt, J., and Thomsen, M. Impacts of "metals" on human health: a comparison between nine different methodologies for Life Cycle Impact Assessment (LCIA). Journal of Cleaner Production 19(6-7): 646-656, 2011.
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This paper looks into the differences and uncertainties in determining the impact of "metals'" emissions on human health, in Life Cycle Impact Assessment (LCIA). Metals are diverse substances, with different properties and characteristics, considered important in LCIA because of their toxicity to humans and ecosystems. First, we defined a list of the most significant metals in terms of impacts on human health. This was done according to precise criteria accounting for both physical and toxic properties of the metals. Second, we performed an LCIA on different key processes using various existing LCIA methodologies and including also USEtox: the recently developed consensus-model for LCIA. Last, we compared the results in relative terms using a contribution analysis. The analysis showed poor or no agreement between the methods: the relative contribution of each metal and of the metals in total to the total impact on human health changes greatly according to the LCIA method used. These differences are due mainly to the number of metals included in each method and to the technique used to calculate the characterization factors. Results obtained with USEtox show no apparent correlation with results calculated with other methods. At present time USEtox is recommended as the best model for LCIA on human toxicity, but mainly because of the large consensus behind it, because its uncertainties regarding metals are still high. The study gives a good and simple overview regarding the way different methods address the impact assessment for metals, and helps in the interpretation of LCIA results for actual LCA studies where metal emissions are involved.
- Mnif, W., Hassine, A.I.H., Bouaziz, A., Bartegi, A., Thomas, O., and Roig, B. Effect of endocrine disruptor pesticides: a review. International Journal of Environmental Research and Public Health 8(6): 2265-2303, 2011.
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Endocrine disrupting chemicals (EDC) are compounds that alter the normal functioning of the endocrine system of both wildlife and humans. A huge number of chemicals have been identified as endocrine disruptors, among them several pesticides. Pesticides are used to kill unwanted organisms in crops, public areas, homes and gardens, and parasites in medicine. Human are exposed to pesticides due to their occupations or through dietary and environmental exposure (water, soil, air). For several years, there have been enquiries about the impact of environmental factors on the occurrence of human pathologies. This paper reviews the current knowledge of the potential impacts of endocrine disruptor pesticides on human health.
- Cannon, J.R. and Greenamyre, J.T. The role of environmental exposures in neurodegeneration and neurodegenerative diseases. Toxicological Sciences 124(2): 225-250, 2011.
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Neurodegeneration describes the loss of neuronal structure and function. Numerous neurodegenerative diseases are associated with neurodegeneration. Many are rare and stem from purely genetic causes. However, the prevalence of major neurodegenerative diseases is increasing with improvements in treating major diseases such as cancers and cardiovascular diseases, resulting in an aging population. The neurological consequences of neurodegeneration in patients can have devastating effects on mental and physical functioning. The causes of most cases of prevalent neurodegenerative diseases are unknown. The role of neurotoxicant exposures in neurodegenerative disease has long been suspected, with much effort devoted to identifying causative agents. However, causative factors for a significant number of cases have yet to be identified. In this review, the role of environmental neurotoxicant exposures on neurodegeneration in selected major neurodegenerative diseases is discussed. Alzheimer's disease, Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis were chosen because of available data on environmental influences. The special sensitivity the nervous system exhibits to toxicant exposure and unifying mechanisms of neurodegeneration are explored.
- Love, D.C., Rodman, S., Neff, R.A., and Nachman, K.E. Veterinary drug residues in seafood inspected by the European Union, United States, Canada, and Japan from 2000 to 2009. Environmental Science and Technology 45(17): 7232-7240, 2011.
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Veterinary drugs are used to treat or prevent a wide array of production-related diseases in aquaculture. Residues of these drugs in seafood products may pose risks to consumers, prompting governments to set drug residue tolerance levels and inspect seafood for violations of these standards. This study characterizes veterinary drug inspection policies and violations among four inspecting bodies (European Union (E.U.), United States (U.S.), Canada, and Japan), using government-collected veterinary drug violation data from 2000 to 2009. Most veterinary drug violations were detected in species that are commonly farm-raised. Asian seafood products, including shrimp and prawns, catfish (or fish sold as catfish), crab, tilapia, eel, and Chilean salmon were most frequently in violation of veterinary drug residue standards. Vietnam had the greatest number of violations among exporting countries. Concentrations of most veterinary drugs in seafood found in violation did not differ between inspecting bodies that reported drug concentrations. Transparency in seafood inspection reporting varied widely among inspecting bodies. Estimation of violations in the untested fraction of seafood was precluded by a lack of information from inspecting bodies regarding the distinction between targeted and random sampling. Increased transparency could facilitate a more rigorous characterization of public health risks from consuming imported seafood.
- Alam, L. and Mohamed, C.A.R. Natural radionuclide of Po210 in the edible seafood affected by coal-fired power plant industry in Kapar coastal area of Malaysia. Environmental Health 10: art. 43, 2011.
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Po210 can be accumulated in various environmental materials, including marine organisms, and contributes to the dose of natural radiation in seafood. The concentration of this radionuclide in the marine environment can be influenced by the operation of a coal burning power plant but existing studies regarding this issue are not well documented. Therefore, the aim of this study was to estimate the Po210 concentration level in marine organisms from the coastal area of Kapar, Malaysia which is very near to a coal burning power plant station and to assess its impact on seafood consumers. Methods Concentration of Po210 was determined in the edible muscle of seafood and water from the coastal area of Kapar, Malaysia using radiochemical separation and the Alpha Spectrometry technique. Results The activities of Po210 in the dissolved phase of water samples ranged between 0.51 ± 0.21 and 0.71 ± 0.24 mBql-1 whereas the particulate phase registered a range of 50.34 ± 11.40 to 72.07 ± 21.20 Bqkg-1. The ranges of Po210 activities in the organism samples were 4.4 ± 0.12 to 6.4 ± 0.95 Bqkg-1 dry wt in fish (Arius maculatus), 45.7 ± 0.86 to 54.4 ± 1.58 Bqkg-1 dry wt in shrimp (Penaeus merguiensis) and 104.3 ± 3.44 to 293.8 ± 10.04 Bqkg-1 dry wt in cockle (Anadara granosa). The variation of Po210 in organisms is dependent on the mode of their life style, ambient water concentration and seasonal changes. The concentration factors calculated for fish and molluscs were higher than the recommended values by the IAEA. An assessment of daily intake and received dose due to the consumption of seafood was also carried out and found to be 2083.85 mBqday-1person-1 and 249.30 μSvyr-1 respectively. These values are comparatively higher than reported values in other countries. Moreover, the transformation of Po210 in the human body was calculated and revealed that a considerable amount of Po210 can be absorbed in the internal organs. The calculated values of life time mortality and morbidity cancer risks were 24.8 × 10-4 and 34 × 10-4 respectively which also exceeded the recommended limits set by the ICRP. Conclusions The findings of this present study can be used to evaluate the safety dose uptake level of seafood as well as to monitor environmental health. However, as the calculated dose and cancer risks were found to cross the limit of safety, finding a realistic way to moderate the risk is imperative.
- Yu, H.Y., Zhang, B.Z., Giesy, J.P., and Zeng, E.Y. Persistent halogenated compounds in aquaculture environments of South China: Implications for global consumers' health risk via fish consumption. Environment International 37(7): 1190-1195, 2011.
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This study examined the potential sources of persistent halogenated compounds (PHCs), including organochlorine pesticides, mainly DDXs (sum of o,p'- and p,p'-DDT, -DDD, and -DDE and p,p'-DDMU) and polybrominated diphenyl ethers, to typical aquaculture environments of South China, determined the relative importance of gill diffusion and fish feeding for exposure of fish to these contaminants and assessed potential health risk for global consumers via consumption of fish from South China. Fish feed is generally a direct and important source of PHCs in both freshwater and seawater aquaculture. In addition, gill diffusion is the predominant uptake route for PHCs (except p,p'-DDMU, o,p'-DDD and -DDT) in farmed freshwater fish, whereas accumulation from the diet is the major route for farmed marine fish. Risks to health of global consumers via consumption of fish from South China are minimal. However, increased risk can be foreseen due to continuous use of brominated fire retardants and electronic waste importation to China.
- Ololade, I.A., Lajide, L., Olumekun, V.O., Ololade, O.O., and Ejelonu, B.C. Influence of diffuse and chronic metal pollution in water and sediments on edible seafoods within Ondo oil-polluted coastal region, Nigeria. Journal of Environmental Science and Health, Part A 46(8): 898-908, 2011.
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The bioconcentration levels of 3 non-essential elements (Pb, Cd and Ni) have been investigated in three different seafoods; fish (Tilapia zilli), crab (Callinectes sapidus) and periwinkle (Littorina littorea), to investigate the ecosystem health status in Ondo oil-polluted coastal region, Nigeria. The seafood samples were chosen based on their popularity as a food source and the potential of the species to contain high levels of metals based on past research results. Metal concentrations in the biota showed marked interspecific differences with C. sapidus recording the highest concentrations of all the metals. The bioconcentration factor (BCF) showed that C. sapidus and T. zilli have the greatest potential to concentrate Cd (BCF = 3–10) and Pb (BCF = 11–84) respectively. Lead uptake from both water and sediment (BCF is almost equal to BSAF: 0.003–0.018) were abysmally low in L. littorea as compared with other organisms. The high concentrations of Pb in fish species, effective bioaccumulation of Cd in species of crab and periwinkles, as well as very high BSAF of Ni found in species of crab indicated a strong influence from anthropogenic pollutant source on the biotic community. Oil pollution appears to be a major source of bioavailable metal contaminants for the selected biota. The study shows that C. sapidus and L. littorea can effectively compartmentalize potentially toxic metals such as Cd, Pb and Ni within their tissues. In terms of toxicity, C. sapidus had Cd concentrations greater than the 3,000 ng/g limit set by the Commission of the European Communities while Pb concentration exceeded their limits in both C. sapidus and T. zilli. All levels of Ni were below the U.S. Food and Drug Administration action levels for these metals in fish, crustaceans and shellfish. The study revealed anthropogenic enrichment of the metals studied which can possibly pose potential threats to the ecology of the area.
- Dabeka, R.W., McKenzie, A.D., and Forsyth, D.S. Levels of total mercury in predatory fish sold in Canada in 2005. Food Additives and Contaminants: Part A 28(6): 740-743, 2011.
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Total mercury was analysed in 188 samples of predatory fish purchased at the retail level in Canada in 2005. The average concentrations (ng g-1, range) were: sea bass 329 (38–1367), red snapper 148 (36–431), orange roughy 543 (279–974), fresh water trout 55 (20–430), grouper 360 (8–1060), black cod 284 (71–651), Arctic char 37 (28–54), king fish 440 (42–923), tilefish 601 (79–1164) and marlin 854 (125–2346). The Canadian standard for maximum total mercury allowed in the edible portions of fish sold at the retail level is 1000 ng g-1 for shark, swordfish, marlin, orange roughy, escolar and both fresh and frozen tuna. The standard is 500 ng g-1 for all other types of fish. In this study, despite the small number of samples of each species, the 1000 ng g-1 maximum was exceeded in five samples of marlin (28%). The 500 ng g-1 maximum was exceeded by six samples of sea bass (20%), four of tilefish (50%), five of grouper (24%), six of king fish (40%) and one of black cod (13%).
- Fang, G.C., Nam, D.H., and Basu, N. Mercury and selenium content of Taiwanese seafood. Food Additives and Contaminants: Part B 4(3): 212-217, 2011.
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Fish consumption is avid in Taiwan (and other Asian nations), but little is known about the mercury and selenium content in local seafood. This paper reports on total mercury, methylmercury and selenium levels from 14 commonly consumed seafood items obtained from Taichung, Taiwan. Mean total mercury concentrations varied nearly 100-fold across species. Fifty per cent of the marlins sampled and 35% of the sharks exceeded the 0.3 µg g-1 US Environmental Protection Agency (USEPA) guideline. Methylmercury comprised a majority of the total mercury in all species. In all species studied there was a molar excess of selenium over mercury. The rank order of mean selenium-mercury molar ratios was red tilapia (166.8) > abura (87.9) > river prawn (82.4) > whiteleg shrimp (64.2) > butterfish (44.6) > milkfish (37.0) > tuna (15.6) > grouper (13.9) > ayu (13.4) > coral hind (13.0) > weever (11.8) > saury (9.0) > shark (7.8) > marlin (4.2).
- Maulvault, A.L., Machado, R., Afonso, C., Lourenço, H.M., Nunes, M.L., Coelho, I., Langerholc, T., and Marques, A. Bioaccessibility of Hg, Cd and As in cooked black scabbard fish and edible crab. Food and Chemical Toxicology 49(11): 2808-2815, 2011.
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Regular consumption of seafood has been widely recommended by authorities. Yet, some species accumulate high levels of contaminants like Hg, Cd and As. In addition, the risks associated to the consumption of such seafood may increase if consumers use cooking practices that enhance the concentration of contaminants and their bioaccessibility. In this study, the bioaccessibility of Hg, Cd and As was assessed with in vitro human digestion of raw and cooked black scabbard fish (Hg; steamed, fried and grilled) and edible crab (Cd and As; steamed and boiled) tissues. Additionally, the toxicological hazards associated with the consumption of these products were also discussed. Generally, Hg, Cd and As bioaccessibility increased throughout the digestion process. Cadmium and As revealed high bioaccessibility rates in raw and cooked samples (up to 100%), whereas lower bioaccessible fractions of Hg was observed (up to 40%). Furthermore, this study pointed out the importance of food matrix, elemental chemical properties and cooking practices in the bioaccessibility of Hg, Cd and As. The toxicological hazards revealed that edible crab brown meat (Cd) and grilled black scabbard fish (MeHg) consumption in children should be moderated. In contrast, edible crab muscle (Cd) and fried or steamed black scabbard fish (MeHg) should be consumed to minimize exposure. The use of bioaccessible contaminant data strongly reduced the toxicological risks of MeHg, whereas less risk reduction occurred with Cd and inorganic As.
- He, M. and Wang, W.X. Factors affecting the bioaccessibility of methylmercury in several marine fish species. Journal of Agricultural and Food Chemistry 59(13): 7155-7162, 2011.
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Bioaccessibility refers to the maximum bioavailability of pollutant ingested with food, and its measurements can lead to a more accurate risk assessment as compared to the measurements of total concentrations of pollutant in food. This study examined the factors affecting the bioaccessibility of methylmercury (MeHg) in nine species of marine fish with an aim to identify ways of reducing MeHg bioaccessibility. MeHg bioaccessibility without any treatment in the nine species of marine fish ranged from 16.0 to 67.7%. Steaming, grilling, and frying reduced MeHg bioaccessibility by 29.4–77.4% for rabbitfish and 74.6–95.8% for grouper. Co-consumption of phytochemical-rich foods such as green tea decreased the bioaccessibility of MeHg by 72.2% for rabbitfish and 74.0% for grouper, whereas meso-2,3-dimercaptosuccinic acid increased it by 39.2–108% for rabbitfish and 45.3–75.7% for grouper. The bioaccessibilities of both MeHg and inorganic mercury were independent of the total Hg concentration and the exposure route (dietary vs dissolved). In eight of the nine species studied, bioaccessibility was negatively correlated with the extent to which MeHg was partitioned into the metal-rich granule fraction and the trophically available fraction. It was positively correlated with partitioning into the cellular debris fraction. This study demonstrated the important control of subcellular distribution in MeHg bioaccessibility.
- Kelly, B.C., Ikonomou, M.G., Higgs, D.A., Oakes, J., and Dubetz, C. Flesh residue concentrations of organochlorine pesticides in farmed and wild salmon from British Columbia, Canada. Environmental Toxicology and Chemistry 30(11): 2456-2464, 2011.
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The present study reports measured levels of organochlorine pesticides (OCPs) in commercial salmon feed (n = 8) and farmed Atlantic, coho, and chinook salmon (n = 110), as well as wild coho, chinook, chum, sockeye, and pink salmon (n = 91). Flesh residue concentrations (ng/g wet weight) of dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), chlordanes, chlorobenzenes (CBz) and cyclodiene pesticides (e.g., dieldrin, mirex) were 2 to 11 times higher (p < 0.05) in farmed salmon compared with wild salmon. Concentrations were positively correlated with flesh lipid levels. Farmed Atlantic salmon (12–15% lipid) typically exhibited the greatest OCP burdens compared with other salmon species. However, when expressed on a lipid weight basis, concentrations of OCPs (ng/g lipid weight) in wild salmon, in many cases, exceeded those levels in farmed salmon. Observed interspecies and site-specific variations of OCP concentrations in farmed and wild salmon may be attributed to divergent life history, prey/feed characteristics and composition, bioenergetics, or ambient environmental concentrations. Calculated biomagnification factors (BMF = CF/CD, lipid wt) of OCPs in farmed salmon typically ranged between two and five. Biomagnification of chemicals such as DDTs, chlordanes, and mirex was anticipated, because those compounds tend to exhibit high dietary uptake and slow depuration rates in fish because of relatively high octanol–water partition coefficients (K OWs > 105). Surprisingly, less hydrophobic pesticides such as hexachlorocyclohexanes and endosulfans (K OWs < 105) consistently exhibited a high degree of biomagnification in farmed salmon species (BMFs > 5). This is contrary to previous laboratory and field observations demonstrating fish BMFs less than 1 for low K OW chemicals, because of efficient respiratory elimination of those compounds via gills. The results suggest that ambient seawater concentrations and bioconcentration-driven accumulation may play a key role in the bioaccumulation of these relatively more water-soluble contaminants in farmed salmon. Finally, OCP exposure through consumption of British Columbian salmon is found to be low relative to United States national average per capita total exposure levels and provisional tolerable daily intakes.
- Welfinger-Smith, G., Minholz, J.L., Byrne, S., Waghiyi, V., Gologergen, J., Kava, J., Apatiki, M., Ungott, E., Miller, P.K., Arnason, J.G., and Carpenter, D.O. Organochlorine and metal contaminants in traditional foods from St. Lawrence Island, Alaska. Journal of Toxicology and Environmental Health Part A 74(18): 1195-1214, 2011.
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Marine mammals (bowhead whale, walrus, and various seals) constitute the major component of the diet of the Yupik people of St. Lawrence Island, Alaska. St. Lawrence Island residents have higher serum concentrations of polychlorinated biphenyls (PCB) than in the general U.S. population. In order to determine potential sources, traditional food samples were collected from 2004 to 2009 and analyzed for PCBs, three chlorinated pesticides, and seven heavy metals (mercury, copper, zinc, arsenic, selenium, cadmium, and lead). Concentrations of PCB in rendered oils (193–421 ppb) and blubber (73–317 ppb) from all marine mammal samples were at levels that trigger advisories for severely restricted consumption, using U.S. Environmental Protection Agency (EPA) fish consumption advisories. Concentrations of pesticides were lower, but were still elevated. The highest PCB concentrations were found in polar bear (445 ppb) and the lowest in reindeer adipose tissue (2 ppb). Marine mammal and polar bear meat in general have PCB concentrations that were 1–5% of those in rendered oils or adipose tissue. PCB concentrations in organs were higher than meat. Concentrations of metals in oils and meats from all species were relatively low, but increased levels of mercury, cadmium, copper, and zinc were present in some liver and kidney samples. Mercury and arsenic were found in lipid-rich samples, indicating organometals. These results show that the source of the elevated concentrations of these contaminants in the Yupik population is primarily from consumption of marine mammal blubber and rendered oils.
- Paredes, I., Rietjens, I.M.C.M., Vieites, J.M., and Cabado, A.G. Update of risk assessments of main marine biotoxins in the European Union. Toxicon 58(4): 336-354, 2011.
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This review is an up-to-date compilation of the available literature, including scientific papers, reviews, and EFSA's opinions, on toxicity and risk assessment data on the main marine biotoxins of importance in the European Union, including the legislated ones and the ones of recent appearance which are not legislated. Information about the hazard identification and hazard characterisation of okadaic acid, dynophysistoxins, pectenotoxins, yessotoxins, azaspiracids, domoic acid, saxitoxins, tetrodotoxins, brevetoxins, ciguatoxins, cyclic imines and palytoxins is reviewed and presented in the form of a collection of risk assessments. It is concluded that the importance of having an appropriate exposure assessment reiterates the urgency of establishing a database with representative and comparable data on exposure to food items possiby containing marine biotoxins. It is also concluded that a revision of the present regulation of marine biotoxins in the EU legislation could be considered, as some regulated toxins have been shown not to pose a risk for EU's population (as yessotoxin) and some non regulated toxins have been shown to be harmful and/or to occur in the EU (as tetrodotoxin, palytoxin, and some cyclic imines) while they are not regulated.
- Clua, E., Brena, P.F., Lecasble, C., Ghnassia, R., and Chauvet, C. Prevalence and proposal for cost-effective management of the ciguatera risk in the Noumea fish market, New Caledonia (South Pacific). Toxicon 58(6-7): 591-601, 2011.
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Ciguatera fish poisoning (CFP) is a common intoxication associated with the consumption of reef fish, which constitutes a critical issue for public health in many countries. The complexity of its epidemiology is responsible for the poor management of the risk in tropical fish markets. We used the example of the Noumea fish market in New Caledonia to develop a cost-effective methodology of assessing the CFP risk. We first used published reports and the knowledge of local experts to define a list of potentially poisonous local species, ranked by their ciguatoxic potential. Based on two 1-month surveys in the market, conducted in winters 2008 and 2009, we then calculated the consolidated ratio of biomass of potentially poisonous species vs. total biomass of fish sold on the market. The prevalence of high CFP-risk species in the market was 16.1% and 18.9% in 2008 and 2009, respectively. The most common high CFP risk species were groupers (serranids), king mackerels (scombrids), snappers (lutjanids), barracudas (sphyaraenids), emperors (lethrinids) and wrasses (labrids). The size (age) of the fish also plays a critical role in the potential ciguatoxic risk. According to proposals of average size thresholds provided by experts for high-risk species, we were also able to assess the additional risk induced by the sale of some large fish on the market. The data collected both from experts and from the market allowed us to develop a cost-effective proposal for improving the management of the CFP risk in this market. However, the successful implementation of any regulation aiming to ban some specific species and sizes from the market, with an acceptable economical impact, will require the improvement of the expertise in fish identification by public health officers and, ideally, the commitment of retailers.
- Hinder, S.L., Hays, G.C., Brooks, C.J., Davies, A.P., Edwards, M., Walne, A.W., and Gravenor, M.B. Toxic marine microalgae and shellfish poisoning in the British isles: history, review of epidemiology, and future implications. Environmental Health 10: art. 54, 2011.
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The relationship between toxic marine microalgae species and climate change has become a high profile and well discussed topic in recent years, with research focusing on the possible future impacts of changing hydrological conditions on Harmful Algal Bloom (HAB) species around the world. However, there is very little literature concerning the epidemiology of these species on marine organisms and human health. Here, we examine the current state of toxic microalgae species around the UK, in two ways: first we describe the key toxic syndromes and gather together the disparate reported data on their epidemiology from UK records and monitoring procedures. Secondly, using NHS hospital admissions and GP records from Wales, we attempt to quantify the incidence of shellfish poisoning from an independent source. We show that within the UK, outbreaks of shellfish poisoning are rare but occurring on a yearly basis in different regions and affecting a diverse range of molluscan shellfish and other marine organisms. We also show that the abundance of a species does not necessarily correlate to the rate of toxic events. Based on routine hospital records, the numbers of shellfish poisonings in the UK are very low, but the identification of the toxin involved, or even a confirmation of a poisoning event is extremely difficult to diagnose. An effective shellfish monitoring system, which shuts down aquaculture sites when toxins exceed regularity limits, has clearly prevented serious impact to human health, and remains the only viable means of monitoring the potential threat to human health. However, the closure of these sites has an adverse economic impact, and the monitoring system does not include all toxic plankton. The possible geographic spreading of toxic microalgae species is therefore a concern, as warmer waters in the Atlantic could suit several species with southern biogeographical affinities enabling them to occupy the coastal regions of the UK, but which are not yet monitored or considered to be detrimental.
- Picot, C., Nguyen, T.A., Roudot, A.C., and Parent-Massin, D. A preliminary risk assessment of human exposure to phycotoxins in shellfish: A review. Human and Ecological Risk Assessment 17(2): 328-366, 2011.
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Over the past few decades, phycotoxins, secondary metabolites produced by toxic phytoplankton, have seen an increase in their frequency, concentrations, and geographic distribution. As shellfish accumulate phycotoxins making them unfit for human consumption, they are considered as an important food safety issue. Thus, a consumer exposure assessment on phycotoxins is necessary. Exposure assessment requires two types of information: contamination and consumption data. Shellfish contamination data on major toxins encountered by at-risk populations (Domoic Acid group, Okadaic Acid group, and Saxitoxin group) have been reviewed. Consumption data have been reviewed for both general and potential high-consumer populations. Then, we undertook acute and chronic exposure assessments, combining available French contamination data and our own consumption data. Studies including exposure assessment were then reviewed. Lastly, risk characterization was undertaken. It can be concluded that both acute and chronic exposure to phycotoxins via shellfish consumption is a matter of concern, mainly for high consumers identified in this review (specific populations and shellfish harvesters). However, the results for risk characterization must be improved. There is a need for (i) toxicological data to establish a Tolerable Daily Intake; (ii) an assessment of consumption and contamination data, undertaken at the same time, so as to assess exposure.
- Goater, S., Derne, B., and Weinstein, P. Critical issues in the development of health information systems in supporting environmental health: A case study of ciguatera. Environmental Health Perspectives 119(5): 585-590, 2011.
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Background: Emerging environmental pressures resulting from climate change and globalization challenge the capacity of health information systems (HIS) in the Pacific to inform future policy and public health interventions. Ciguatera, a globally common marine food-borne illness, is used here to illustrate specific HIS challenges in the Pacific and how these might be overcome proactively to meet the changing surveillance needs resulting from environmental change. Objectives: We review and highlight inefficiencies in the reactive nature of existing HIS in the Pacific to collect, collate, and communicate ciguatera fish poisoning data currently used to inform public health intervention. Further, we review the capacity of existing HIS to respond to new data needs associated with shifts in ciguatera disease burden likely to result from coral reef habitat disruption. Discussion: Improved knowledge on the ecological drivers of ciguatera prevalence at local and regional levels is needed, combined with enhanced surveillance techniques and data management systems, to capture environmental drivers as well as health outcomes data. Conclusions: The capacity of public HIS to detect and prevent future outbreaks is largely dependent on the future development of governance strategies that promote proactive surveillance and health action. Accordingly, we present an innovative framework from which to stimulate scientific debate on how this might be achieved by using existing larger scale data sets and multidisciplinary collaborations.
- Islam, M.S., Luby, S.P., Rahman, M., Parveen, S., Homaira, N., Begum, N.H., Khan, A.K.M.D., Sultana, R., Akhter, S., and Gurley, E.S. Social ecological analysis of an outbreak of pufferfish egg poisoning in a coastal area of Bangladesh. American Journal of Tropical Medicine and Hygiene 85(3): 498-503, 2011.
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Recurrent outbreaks of marine pufferfish poisoning in Bangladesh highlight the need to understand the context in which the outbreaks occurred. In a recent outbreak investigation, a multidisciplinary team conducted a mixed-method study to identify the demography and clinical manifestation of the victims and to explore different uses of pufferfish, and local buying, selling, and processing practices. The outbreak primarily affected a low income household where an elderly woman collected and cooked pufferfish egg curry. Nine persons consumed the curry, and symptoms developed in 6 (67%) of these persons. Symptoms included vomiting, diarrhea, paresis, and tingling sensation; 2 (22%) persons died. The unstable income of the affected family, food crisis, and the public disposal of unsafe pufferfish byproducts all contributed to the outbreak. A multi-level intervention should be developed and disseminated with the participation of target communities to discourage unsafe discarding of pufferfish scraps and to improve the community knowledge about the risk of consuming pufferfish.
- Rongo, T. and van Woesik, R. Ciguatera poisoning in Rarotonga, southern Cook Islands. Harmful Algae 10(4): 345-355, 2011.
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The central Pacific Ocean has arguably more ciguatera poisoning than any other place on earth. Here we tested two competing hypotheses that outline the primary causes of ciguatera outbreaks: (1) the 'new surface hypothesis' and (2) the 'climate oscillation hypothesis'. Our findings indicated that in Rarotonga, from 1994 to 2010, the annual incidence of ciguatera poisoning ranged from 204 to 1,058 per 10,000 population per year. We found that the widest reefs of Rarotonga elicited the most cases of ciguatera poisoning, but found no relationship between ciguatera outbreaks and reef exposure. We also found strong correlations between cases of ciguatera poisoning and (i) the positive phase of the Pacific Decadal Oscillation, (ii) El Niño years, and (iii) periods with frequent disturbances. Yet, most disturbances occurred during the above-mentioned climate phases. This study links the two supposedly, mutually exclusive hypotheses. Moreover, as predicted by the 'climate oscillation hypothesis', the Pacific Ocean is now, in 2010, experiencing a negative phase of the Pacific Decadal Oscillation, and Rarotonga is reporting few cases of ciguatera poisoning.
- Davidson, R., Simard, M., Kutz, S.J., Kapel, C.M.O., Hamnes, I.S., and Robertson, L.J. Arctic parasitology: why should we care? Trends in Parasitology 27(6): 239-245, 2011.
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The significant impact on human and animal health from parasitic infections in tropical regions is well known, but parasites of medical and veterinary importance are also found in the Arctic. Subsistence hunting and inadequate food inspection can expose people of the Arctic to foodborne parasites. Parasitic infections can influence the health of wildlife populations and thereby food security. The low ecological diversity that characterizes the Arctic imparts vulnerability. In addition, parasitic invasions and altered transmission of endemic parasites are evident and anticipated to continue under current climate changes, manifesting as pathogen range expansion, host switching, and/or disease emergence or reduction. However, Arctic ecosystems can provide useful models for understanding climate-induced shifts in host–parasite ecology in other regions.
- Collin, B. and Rehnstam-Holm, A.-S. Occurrence and potential pathogenesis of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus on the south coast of Sweden. FEMS Microbiology Ecology 78(2): 306-313, 2011.
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During the summer of 2006, several wound infections – of which three were fatal – caused by Vibrio cholerae were reported from patients who had been exposed to water from the Baltic Sea. Before these reports, we initiated a sampling project investigating the occurrence of potential human pathogenic V. cholerae, Vibrio vulnificus and Vibrio parahaemolyticus in The Sound between Sweden and Denmark. The blue mussel (Mytilus edulis) was used as an indicator to follow the occurrence of vibrios over time. Molecular analyses showed high frequencies of the most potent human pathogenic Vibrio spp.; 53% of mussel samples were positive for V. cholerae (although none were positive for the cholera toxin gene), 63% for V. vulnificus and 79% for V. parahaemolyticus (of which 47% were tdh+ and/or trh+). Viable vibrios were also isolated from the mussel meat and screened for virulence by PCR. The mortality of eukaryotic cells when exposed to bacteria was tested in vivo, with results showing that the Vibrio strains, independent of species and origin, were harmful to the cells. Despite severe infections and several deaths, no report on potential human pathogenic vibrios in this area had been published before this study.
- Murugaiah, C. The burden of cholera. Critical Reviews in Microbiology 37(4): 337-348, 2011.
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Cholera is an acute secretory diarrheal disease that is perceived by World Health Organization (WHO) to be a highly contagious threat. Firstly discovered by an Italian physician, Filippo Pacini, the disease gains a reputation as the most feared epidemic diarrheal disease encountered in developing countries. Despite effort taken by WHO to reduce the incidence rate, cholera-endemic prevail in certain regions. Factors that contribute to the disease transmission and ongoing spreading in cholera-prone areas remain as elusive. Should an awareness and knowledge of cholera be developed, it is the residents of developing nation that stand to benefit the most. This review gives insight into the disease prevalence, pandemic, epidemiology, pathogenesis, disease transmission, major strategies and steps to be pursued toward controlling cholera.
- Jutla, A.S., Akanda, A.S., Griffiths, J.K., Colwell, R., and Islam, S. Warming oceans, phytoplankton, and river discharge: Implications for cholera outbreaks. American Journal of Tropical Medicine and Hygiene 85(2): 303-308, 2011.
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Phytoplankton abundance is inversely related to sea surface temperature (SST). However, a positive relationship is observed between SST and phytoplankton abundance in coastal waters of Bay of Bengal. This has led to an assertion that in a warming climate, rise in SST may increase phytoplankton blooms and, therefore, cholera outbreaks. Here, we explain why a positive SST-phytoplankton relationship exists in the Bay of Bengal and the implications of such a relationship on cholera dynamics. We found clear evidence of two independent physical drivers for phytoplankton abundance. The first one is the widely accepted phytoplankton blooming produced by the upwelling of cold, nutrient-rich deep ocean waters. The second, which explains the Bay of Bengal findings, is coastal phytoplankton blooming during high river discharges with terrestrial nutrients. Causal mechanisms should be understood when associating SST with phytoplankton and subsequent cholera outbreaks in regions where freshwater discharge are a predominant mechanism for phytoplankton production.
- Akanda, A.S., Jutla, A.S., Alam, M., de Magny, G.C., Siddique, A.K., Sack, R.B., Huq, A., Colwell, R.R., and Islam, S. Hydroclimatic influences on seasonal and spatial cholera transmission cycles: Implications for public health intervention in the Bengal Delta. Water Resources Research 47: art. W00H07, 2011.
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Cholera remains a major public health threat in many developing countries around the world. The striking seasonality and annual recurrence of this infectious disease in endemic areas remain of considerable interest to scientists and public health workers. Despite major advances in the ecological and microbiological understanding of Vibrio cholerae, the causative agent of the disease, the role of underlying large-scale hydroclimatic processes in propagating the disease for different seasons and spatial locations is not well understood. Here we show that the cholera outbreaks in the Bengal Delta region are propagated from the coastal to the inland areas and from spring to fall by two distinctly different transmission cycles, premonsoon and postmonsoon, influenced by coastal and terrestrial hydroclimatic processes, respectively. A coupled analysis of the regional hydroclimate and cholera incidence reveals a strong association of the space-time variability of incidence peaks with seasonal processes and extreme climatic events. We explain how the asymmetric seasonal hydroclimatology affects regional cholera dynamics by providing a coastal growth environment for bacteria in spring, while propagating the disease to fall by monsoon flooding. Our findings may serve as the basis for "climate-informed" early warnings and for prompting effective means for intervention and preempting epidemic cholera outbreaks in vulnerable regions.
- Morris, J.G. Cholera – Modern pandemic disease of ancient lineage. Emerging Infectious Diseases 17(11): 2099-2104, 2011.
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Cholera has affected humans for at least a millennium and persists as a major cause of illness and death worldwide, with recent epidemics in Zimbabwe (2008-2009) and Haiti (2010). Clinically, evidence exists of increasing severity of disease linked with emergence of atypical Vibrio cholerae organisms that have incorporated genetic material from classical biotype strains into an El Tor biotype background. A key element in transmission may be a recently recognized hyperinfectious phase, which persists for hours after passage in diarrheal feces. We propose a model of transmission in which environmental triggers (such as temperature) lead to increases in V. cholerae in environmental reservoirs, with spillover into human populations. However, once the microorganism is introduced into a human population, transmission occurs primary by "fast" transmission from person to person (taking advantage of the hyperinfectious state), without returning to the aquatic environment.
- Sabino, R. et al. Pathogenic fungi: An unacknowledged risk at coastal resorts? New insights on microbiological sand quality in Portugal. Marine Pollution Bulletin 62(7): 1506-1511, 2011.
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Whilst the potential impact on beach users from microorganisms in water has received considerable attention, there has been relatively little investigation into microbial contaminants in sand. Thirty three beaches across Portugal were analyzed during a five year period (2006-2010) to determine the presence of yeasts, pathogenic fungi, dermatophytes, total coliforms, Escherichia coli and intestinal enterococci in sand. Our results showed that 60.4% of the samples were positive for fungi and that 25.2% were positive for the bacterial parameters. The most frequent fungal species found were Candida sp. and Aspergillus sp., whereas intestinal enterococci were the most frequently isolated bacteria. Positive associations were detected among analyzed parameters and country-regions but none among those parameters and sampling period. Regarding threshold values, we propose 15 cfu/g for yeasts, 17 cfu/g for potential pathogenic fungi, 8 cfu/g for dermatophytes. Eighty four cfu/g for coliforms, 250 cfu/g for E. coli, and 100 cfu/g for intestinal enterococci.
- Mahaffey, K.R., Sunderland, E.M., Chan, H.M., Choi, A.L., Grandjean, P., Mariën, K., Oken, E., Sakamoto, M., Schoeny, R., Weihe, P., Yan, C.-H., and Yasutake, A. Balancing the benefits of n-3 polyunsaturated fatty acids and the risks of methylmercury exposure from fish consumption. Nutrition Reviews 69(9): 493-508, 2011.
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Fish and shellfish are widely available foods that provide important nutrients, particularly n-3 polyunsaturated fatty acids (n-3 PUFAs), to many populations globally. These nutrients, especially docosahexaenoic acid, confer benefits to brain and visual system development in infants and reduce risks of certain forms of heart disease in adults. However, fish and shellfish can also be a major source of methylmercury (MeHg), a known neurotoxicant that is particularly harmful to fetal brain development. This review documents the latest knowledge on the risks and benefits of seafood consumption for perinatal development of infants. It is possible to choose fish species that are both high in n-3 PUFAs and low in MeHg. A framework for providing dietary advice for women of childbearing age on how to maximize the dietary intake of n-3 PUFAs while minimizing MeHg exposures is suggested.
- Teisl, M.F., Fromberg, E., Smith, A.E., Boyle, K.J., and Engelberth, H.M. Awake at the switch: Improving fish consumption advisories for at-risk women. The Science of The Total Environment 409(18): 3257-3266, 2011.
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Eating fish provides health benefits; however, nearly all fish contain at least some methylmercury which can impair human health. While government agencies have been issuing fish consumption advisories for 40 years, recent evaluation efforts highlight their poor performance. The benefit of an advisory can be measured by its ability to inform consumers as to both the positive and negative attributes of their potential choices, leading to appropriate changes in behavior. Because of the health benefits, fish advisories should not reduce fish consumption, even among at-risk individuals, but should lead consumers to switch away from highly contaminated fish toward those less contaminated. Although studies document how advisories reduce fish consumption (a negative outcome), no study indicates whether they lead to switching behavior (a positive outcome). We explore the effects of Maine Center of Disease Control and Prevention's advisory aimed at informing women who may become pregnant, nursing mothers and pregnant women about the benefits and risks of fish consumption. We examine how the advisory changes consumption, especially related to switching behavior. We demonstrate such changes in behavior both during and after pregnancy and compare the advisory-induced changes with those induced by other information sources. Although we find the advisory reduced some women's consumption of fish, we find the decrease is short-lived. Most importantly, the advisory induced appropriate switching behavior; women reading the advisory decreased their consumption of high-risk fish and increased their consumption of low-risk fish. We conclude a well-designed advisory can successfully transform a complex risk/benefit message into one that leads to appropriate knowledge and behavioral changes.
- Roman, H.A., Walsh, T.L., Coull, B.A., Dewailly, E., Guallar, E., Hattis, D., Mariën, K., Schwartz, J., Stern, A.H., Virtanen, J.K., and Rice, G. Evaluation of the cardiovascular effects of methylmercury exposures: Current evidence supports development of a dose-response function for regulatory benefits analysis. Environmental Health Perspectives 119(5): 607-614, 2011.
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Background: The U.S. Environmental Protection Agency (U.S. EPA) has estimated the neurological benefits of reductions in prenatal methylmercury (MeHg) exposure in past assessments of rules controlling mercury (Hg) emissions. A growing body of evidence suggests that MeHg exposure can also lead to increased risks of adverse cardiovascular impacts in exposed populations. Data extraction: The U.S. EPA assembled the authors of this article to participate in a workshop, where we reviewed the current science concerning cardiovascular health effects of MeHg exposure via fish and seafood consumption and provided recommendations concerning whether cardiovascular health effects should be included in future Hg regulatory impact analyses. Data synthesis: We found the body of evidence exploring the link between MeHg and acute myocardial infarction (MI) to be sufficiently strong to support its inclusion in future benefits analyses, based both on direct epidemiological evidence of an MeHg-MI link and on MeHg's association with intermediary impacts that contribute to MI risk. Although additional research in this area would be beneficial to further clarify key characteristics of this relationship and the biological mechanisms that underlie it, we consider the current epidemiological literature sufficiently robust to support the development of a dose-response function. Conclusions: We recommend the development of a dose-response function relating MeHg exposures with MIs for use in regulatory benefits analyses of future rules targeting Hg air emissions.
- Stern, A.H. and Korn, L.R. An approach for quantitatively balancing methylmercury risk and omega-3 benefit in fish consumption advisories. Environmental Health Perspectives 119(8): 1043-1046, 2011.
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Background: Nearly all fish consumption advisories for methylmercury (MeHg) are based only on risk. There is a need to also address benefits, especially those from polyunsaturated fatty acids (PUFAs), in neurodevelopmental function and cardiovascular health. However, because MeHg and PUFA generally act on these same end points, disentangling risk and benefit is challenging. Objectives: We propose an approach for balancing risk and benefit that is based on the use of statistically dissociated measures of risk and benefit. Discussion: Because of mutual coexposure of MeHg and PUFAs in population-based studies and their opposite effect on many of the same end points, MeHg risk and PUFA benefit are tightly linked statistically, which results in mutual (negative) confounding. Thus, neither MeHg risk nor PUFA benefit can be accurately quantified without taking the other into account. A statistical approach that generates unconfounded risk and benefit coefficients for each end point can permit their subsequent recombination to describe the overall risk-benefit profile of each species of fish or fish diet. However, it appears that some end points may be adversely affected by MeHg without experiencing counterbalancing benefit from PUFAs. Such end points may drive consumption advisories and may preclude balancing of risk and benefit on the basis of other end points. Conclusions: Our thinking about fish consumption advisories now recognizes the need to balance risk and benefit. However, although statistical analysis of the appropriate data can eliminate mutual confounding, care is required to address the most sensitive end points that may be sensitive to risk and not benefit.
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