Letters to the editor: Risks and Benefits of Seafood Consumption (original) (raw)
Related papers
Environmental Health Perspectives, 2005
We reported recently that several organic contaminants occurred at elevated concentrations in farmed Atlantic salmon compared with concentrations of the same contaminants in wild Pacific salmon [Hites et al. Science 303:226-229 (2004)]. We also found that polychlorinated biphenyls (PCBs), toxaphene, dieldrin, dioxins, and polybrominated diphenyl ethers occurred at higher concentrations in European farm-raised salmon than in farmed salmon from North and South America. Health risks (based on a quantitative cancer risk assessment) associated with consumption of farmed salmon contaminated with PCBs, toxaphene, and dieldrin were higher than risks associated with exposure to the same contaminants in wild salmon. Here we present information on cancer and noncancer health risks of exposure to dioxins in farmed and wild salmon. The analysis is based on a tolerable intake level for dioxin-like compounds established by the World Health Organization and on risk estimates for human exposure to dioxins developed by the U.S. Environmental Protection Agency. Consumption of farmed salmon at relatively low frequencies results in elevated exposure to dioxins and dioxin-like compounds with commensurate elevation in estimates of health risk. Key words: dioxins, risk-based consumption advice, salmon. Environ Health Perspect 113:552-556 (2005). doi:10.1289/ehp.7626 available via http://dx.doi.org/ [Online 9 February 2005]
Consumption advisories for salmon based on risk of cancer and noncancer health effects
Environmental Research, 2006
The levels of dioxins/furans, polychlorinated biphenyls (PCBs), and chlorinated pesticides were determined in farmed salmon for eight regions in Europe, North America, and South America, in salmon fillets purchased in 16 cities in Europe and North America, and in five species of wild Pacific salmon. Upon application of US Environmental Protection Agency (USEPA) methods for developing fish consumption advisories for cancer from mixtures of all of these substance for which USEPA has reported a cancer slope factor, the most stringent recommendation, for farmed salmon from northern Europe, was for consumption of at most one meal every 5 months in order to not exceed an elevated risk of cancer of more than 1 in 100,000. Farmed salmon from North and South America triggered advisories of between 0.4 and one meal per month. Retail market samples, in general, reflected levels found in regionally farmed fish, although much of the US salmon comes from Chile, which had somewhat lower contaminant levels than the North American farmed samples. Upon consideration of all of these organochlorine compounds as a mixture, even wild Pacific salmon triggered advisories of between one and less than five meals per month. The advisories are driven by the nondioxin-like PCBs and pesticides and not by dioxins/furans and coplanar PCBs. For noncancer effects for contaminants where USEPA has provided a reference dose only endrin and PCBs triggered any significant advisory. For both of these in the worst case, farmed salmon from northern Europe, the advice was not more than three meals per month. r
Environmental Toxicology and Chemistry, 2007
Assimilation and elimination rate constant of dietary polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DLPCBs) with a World Health Organization toxic equivalency factor (WHO-TEF) were estimated in market-size Atlantic salmon (Salmo salar) using fish that were previously fed vegetable oil-based (low in PCDD/Fs and DLPCBs) or fish oil-based (high in PCDD/Fs and PCBs) diets. At the start of the kinetic trial, half the fish that were fed fish oils were fed vegetable oil feeds and inverted (cross-over design) for five months. The assimilation efficiencies of the PCDD/F congeners were more variable (3-89%) and, generally, were lower than those of the DLPCBs (70-80%). Among the PCDD/F congeners, the assimilation efficiency of the most toxic tetra-and pentachlorinated PCDD/Fs was greater than that of higherchlorinated PCDD/Fs. Elimination rates for DLPCBs were higher than those for PCDD/Fs. Lower-chlorinated PCDDs had a lower elimination rate than the higher-chlorinated PCDDs, but no differences were observed among PCDF congeners or DLPCB congeners. Kinetic parameters were used to predict the level of WHO-TEF dioxins and DLPCBs in Atlantic salmon reared in a large-scale facility under commercial conditions. Predictions were based on preanalyzed levels of these organochlorines in feeds with three different replacement levels (0, 30, and 60%) of vegetable oil. A simple one-compartmental, first-order kinetic model was used to predict the level of sum WHO toxic equivalents for PCDD/Fs and DL-PCBs. The predicted values varied by 0 to 11% from the measured values in the commercially reared salmon.
Contribution of PCB exposure from fish consumption to total dioxin-like dietary exposure
Regulatory Toxicology and Pharmacology, 2004
Polychlorinated biphenyls (PCB) are the second greatest cause of fish advisories, and are often the greatest contributors to dioxin-like toxic equivalency (TEQ) in fish and seafood. Because fish consumption is associated with both contaminant risks and health benefits, incremental health risks from PCBs in fish should be considered within the context of overall TEQ associated dietary risk to enable consumers to make informed decisions about choosing to eat fish or alternate foodstuffs. In this paper, potential TEQ exposure from PCBs in fish for adults with a variety of consumption patterns and consuming fish from a variety of sources are calculated using recent consumption and fish contaminant data from the literature and compared to total TEQ exposure from all sources. For high-level consumers and individuals eating fish from relatively contaminated sites, PCB TEQ exposure from fish consumption alone may exceed the 1 pg TEQ/kg/day average adult daily intake estimated by EPA, which itself carries an upper bound cancer risk of 1 in 1000. PCB TEQ risk for average consumers of commercial fish is expected to be far less, but is highly uncertain, since there is a dearth of congener specific PCB data for commercial fish and seafood.
Contaminant Concentrations are Higher in Farm-raised Salmon as Compared to Wild Salmon
2002
The concentrations of over 30 contaminants were measured in farm-raised and wild salmon. Eighteen composite samples of 180 farm-raised and wild salmon were measured; there were lO fish per composite. The fish were purchased from commercial distributors in the United States and Canada but included fish farmed or caught in Canada, Chile, Norway, and the United Sates. All measurements were made using gas chromatographic mass spectrometry with isotopic internal standards. On a wet weight basis, the concentrations of polychlorinated biphenyls (PCB), dioxins, almost all pesticides (including toxaphene), polybrominated diphenyl ethers (PBDE, flame retardants), and organic arsenic were significantly higher in the farm-raised fish as compared to their wild colleagues. In fact, the PCB and PBDE concentrations were about nine times higher in the farm-raised fish compared to the wild fish. On a lipid adjusted basis, many of these differences disappeared, but PCBs and PBDEs were still significantly elevated by about a factor of three.
Environmental Science & Technology, 2005
We have shown recently that levels of persistent, bioaccumulative contaminants (polychlorinated biphenyls, dioxins, and several chlorinated pesticides) are significantly higher in farmed than in wild salmon and that European farmraised salmon have significantly greater toxic contaminant loads than those raised in North and South America. In this paper, we extend these results to polybrominated diphenyl ethers (PBDEs) and show that farm-raised salmon have higher levels of these compounds than wild salmon. We also show that farm-raised salmon from Europe have higher PBDE levels than those raised in North America and that both European and North American farm-raised salmon have higher PBDE levels than those farm-raised in Chile. Among the species of wild salmon, chinook had significantly elevated PBDE levels relative to the other wild species. These elevated PBDE levels may be related to chinook's feeding behavior and trophic level. Among all of the wild species we studied, chinook tend to feed higher in the food web throughout their adult life and grow to be larger individuals.
Environmental …, 2006
Farmed Atlantic salmon (Salmo salar) from Maine and eastern Canada, wild Alaskan Chinook salmon (Oncorhynchus tshawytscha), and organically farmed Norwegian salmon samples were analyzed for the presence of polychlorinated biphenyls (PCBs), dioxin-like PCBs, polychlorinated dibenzop-dioxins (PCDDs), dibenzo-p-furans (PCDFs), and chlorinated pesticides. PCDD and PCDF congeners were not detected in >80% of the samples analyzed. Total PCB concentrations (7.2-29.5 ng/g, wet weight, ww) in the farmed salmon were significantly higher than those in the wild Alaskan Chinook samples (3.9-8.1 ng/g, ww). Concentrations of PCBs, WHO PCB TEQs, and chlorinated pesticides varied significantly by region. PCB and WHO PCB TEQ concentrations in farmed salmon from eastern Canada were lower than those reported in samples collected two years earlier, possibly reflecting recent industry efforts to lower contaminant concentrations in feed. Organically farmed Norwegian salmon had the highest concentrations of PCBs (mean: 27 ng/g, ww) and WHO PCB TEQs (2.85 pg/g,ww); their TEQ values are in the higher range of those reported in farmed salmon from around the world. Removal of skin from salmon fillets resulted in highly variable reductions of lipids and contaminants, and in some skin-off samples, contaminant levels were higher, suggesting that skin removal does not protect the consumer from health risks associated with consumption of farmed salmon.
Environment International, 2015
Background: Environmental pollutants such as dioxins and PCBs, heavy metals, and organochlorine pesticides are a global threat to food safety. In particular, the aquatic biota can bioaccumulate many of these contaminants potentially making seafood of concern for chronic exposure to humans. Objectives: The main objective was to evaluate trends of contaminant levels in Norwegian farmed Atlantic salmon in light of the derived tolerable intakes. Methods: Through an EU-instigated surveillance programme, the Norwegian Food Safety Authority (NFSA) has between 1999 and 2011 collected more than 2300 samples of Norwegian farmed Atlantic salmon (Salmo salar) for contaminant analyses. The fillets of these fish were homogenised and analysed for dioxins, PCBs, heavy metals and organochlorine pesticides. Results: The levels of the contaminants mercury, arsenic, dioxins, dioxin-like PCBs and DDT in Norwegian farmed salmon fillet have decreased during our period of analyses. The levels of cadmium, lead and several organochlorine pesticides were too close to the limit of quantification to calculate time trends. For PCB 6 and quantifiable amounts of pesticides, except DDT, stable levels were observed. Conclusion: The contaminant levels in Norwegian farmed salmon have generally decreased between 1999 and 2011. Excluding other dietary sources, the levels of dioxins and dioxin-like PCBs in 2011 allowed consumption of up to 1.3 kg salmon per week to reach the tolerable weekly intake. The group of contaminants which was the limiting factor for safe consumption of Norwegian farmed salmon, based on currently established TWI values, is the sum of dioxins and dioxin-like PCBs.