Aquaculture practices and potential human health risks: current knowledge and future priorities

Annual global aquaculture production has more than tripled within the past 15 years, and by 2015, aquaculture is predicted to account for 39% of total global seafood production by weight. Given that lack of adequate nutrition is a leading contributor to the global burden of disease, increased food production through aquaculture is a seemingly welcome sign. However, as production surges, aquaculture facilities increasingly rely on the heavy input of formulated feeds, antibiotics, antifungals, and agrochemicals. This review summarizes our current knowledge concerning major chemical, biological and emerging agents that are employed in modern aquaculture facilities and their potential impacts on public health. Findings from this review indicate that current aquaculture practices can lead to elevated levels of antibiotic residues, antibiotic-resistant bacteria, persistent organic pollutants, metals, parasites, and viruses in aquacultured finfish and shellfish. Specific populations at risk of exposure to these contaminants include individuals working in aquaculture facilities, populations living around these facilities, and consumers of aquacultured food products. Additional research is necessary not only to fully understand the human health risks associated with aquacultured fish versus wild-caught fish but also to develop appropriate interventions that could reduce or prevent these risks. In order to adequately understand, address and prevent these impacts at local, national and global scales, researchers, policy makers, governments, and aquaculture industries must collaborate and cooperate in exchanging critical information and developing targeted policies that are practical, effective and enforceable.     

Environmental health impacts of feeding crops to farmed fish

Half of the seafood consumed globally now comes from aquaculture, or farmed seafood. Aquaculture therefore plays an increasingly important role in the global food system, the environment, and human health. Traditionally, aquaculture feed has contained high levels of wild fish, which is unsustainable for ocean ecosystems as demand grows. The aquaculture industry is shifting to crop-based feed ingredients, such as soy, to replace wild fish as a feed source and allow for continued industry growth. This shift fundamentally links seafood production to terrestrial agriculture, and multidisciplinary research is needed to understand the ecological and environmental health implications. We provide basic estimates of the agricultural resource use associated with producing the top five crops used in commercial aquaculture feed. Aquaculture's environmental footprint may now include nutrient and pesticide runoff from industrial crop production, and depending on where and how feed crops are produced, could be indirectly linked to associated negative health outcomes. We summarize key environmental health research on health effects associated with exposure to air, water, and soil contaminated by industrial crop production. Our review also finds that changes in the nutritional content of farmed seafood products due to altered feed composition could impact human nutrition. Based on our literature reviews and estimates of resource use, we present a conceptual framework describing the potential links between increasing use of crop-based ingredients in aquaculture and human health. Additional data and geographic sourcing information for crop-based ingredients are needed to fully assess the environmental health implications of this trend. This is especially critical in the context of a food system that is using both aquatic and terrestrial resources at unsustainable rates.     

Radionuclides from past uranium mining in rivers of Portugal

During several decades and until a few years ago, uranium mines were exploited in the Centre of Portugal and wastewaters from uranium ore milling facilities were discharged into river basins. To investigate enhancement of radioactivity in freshwater ecosystems, radionuclides of uranium and thorium series were measured in water, sediments, suspended matter, and fish samples from the rivers Vouga, D?o, Távora and Mondego. The results show that these rivers carry sediments with relatively high naturally occurring radioactivity, and display relatively high concentrations of radon dissolved in water, which is typical of a uranium rich region. Riverbed sediments show enhanced concentrations of radionuclides in the mid-section of the Mondego River, a sign of past wastewater discharges from mining and milling works at Urgeiri?a confirmed by the enhanced values of (238)U/(232)Th radionuclide ratios in sediments. Radionuclide concentrations in water, suspended matter and freshwater fish from that section of Mondego are also enhanced in comparison with concentrations measured in other rivers. Based on current radionuclide concentrations in fish, regular consumption of freshwater species by local populations would add 0.032 mSv a(-1) of dose equivalent (1%) to the average background radiation dose. Therefore, it is concluded that current levels of enhanced radioactivity do not pose a significant radiological risk either to aquatic fauna or to freshwater fish consumers.     

Vietnam’s seafood boom: Economic growth with impoverishment?

By 2050 most seafood will be sourced through aquaculture, with a range of production intensities being required to sustain livelihoods and to meet future needs from seafood. This makes Vietnam a particularly insightful case, since Vietnam is at the forefront of the trend toward greater aquaculture production. Our aim in this paper is to examine the social-ecological sustainability of small producer livelihoods contributing to Vietnam’s seafood boom. This paper uses original survey data to understand the range of fishery-based livelihoods that have contributed to Vietnam being a leading global exporter of seafood. We investigate the kinds of fishery-based livelihood activities that households are engaged in, consider the type and amount (kilograms) of species caught or farmed annually, and examine household perceptions’ of change in species quantity. We find that Vietnam’s seafood sector is facing real sustainability challenges: Nearly 30 % of small producers—fishers and fish farmers—within our sample rest at or below Vietnam’s rural poverty line. Ecological decline and disease in farmed fish is perceived to be a serious issue for all fishers. In this context, policy and management interventions need to better reflect social and ecological variability, adopt an integrated coastal systems perspective across fisheries and aquaculture, and consider the most impact-effective poverty interventions.     

Risk characterization and exposure assessment in arseniasis-endemic areas of Taiwan

This paper examines the age-specific human health risks exposed to inorganic arsenic through arsenic-contaminated farmed fish/shrimp and groundwater consumptions in arseniasis-endemic areas of blackfoot disease (BFD)-endemic area and Lanyang Plain in Taiwan, based on an probabilistic integrated risk assessment framework. We employ an age-dependent predictive physiologically-based pharmacokinetic model to account for arsenic concentrations in target organs. We reconstruct age-specific dose-response profiles for arsenicosis and arsenic-induced cancers by best fitting a pharmacodynamics-based three-parameter Hill equation model to published epidemiological data from West Bengal and Taiwan. The predicted median arsenic concentrations in age group-specific skin, lung, and bladder ranged from 2.24-5.70, 3.76-9.46, and 5.11-20.71 micro g g(-1) in BFD-endemic area, whereas 4.98-12.04, 8.23-19.92, and 11.07-43.45 micro g g(-1) in Lanyang Plain, respectively. Risk analysis indicates that consumption of arsenic-contaminated farmed fish/shrimp and groundwater in arseniasis-endemic areas may increase threat to prevalence of arsenicosis for all age groups, whereas adults may undergo potential risks of arsenic-induced skin, lung and bladder cancers. We show that peoples in Lanyang Plain are more readily associated with higher morbidities for arsenicosis and skin cancer as well as fatalities for lung and bladder cancers than that of peoples in BFD-endemic area. Here we report the first case in which theoretical human health risks for consuming As-contaminated farmed fish/shrimp and groundwater in the arseniasis-endemic areas are alarming under a conservative condition based on a probabilistic risk assessment framework.     

Extracted and farmed shrimp fisheries in Brazil: economic, environmental and social consequences of exploitation

This paper analyses shrimp caught from the wild and farmed shrimp in Brazil, focusing on production, amounts exported and earnings, with comparisons drawn to all of South America and the world in general. We show that wild caught shrimp still comprises the majority of what is produced and exported in Brazil, although aquaculture has been taking a relevant role in the internal and external scenario, reaching similar levels of extraction in recent years. Despite some fluctuations in the amount of extracted shrimp, Brazil increased its production from 15,000 tons in 1950 to 80,000 in 2004. The money earned with shrimp product exportation, which includes farmed shrimp as well, followed a similar tendency. Shrimp aquaculture began late in Brazil, in 1974, and grew slowly until 1995, initiating an accelerated growing process; current estimates assume 50,000 people are employed in this activity, producing about 76,000 tons of shrimp every year. Although still incipient in relation to the world shrimp farmed production, Brazil has been assuming a relevant role in South America, yielding 44% of its total production, in 2004. Despite the importance of shrimp to the country, no studies have been conducted to explore the interrelations between the environmental and social consequences of such unplanned aquaculture growth or uncontrolled wild shrimp fishing. Based on previous observations, conflicts exist between different fishing scales. However, the consequences of shrimp farming on society (displacement from their lands, changes in the life quality, etc.) have not yet been explored. Both activities, shrimp exploitation and aquaculture, deserve better control and structure toward sustainable shrimp fishing and farming. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Rice consumption contributes to low level methylmercury exposure in southern China

Fish consumption is considered as the primary pathway of human methylmercury (MeHg) exposure. However, recent studies highlighted that, rice, rather than fish, is the main route of human MeHg exposure in Guizhou, inland China. China is considered as the largest anthropogenic source of mercury (Hg) emission in the world, which has led to serious environmental Hg pollution. But there are no comprehensive studies regarding this environmental health problem to evaluate human Hg exposure and associated health effects. This study aimed to estimate daily MeHg intake and health risk in 7 provinces in southern China, and to assess the relative contribution from rice and fish consumption. The average levels of total mercury (THg) and MeHg in rice samples were generally low at 10.1 ng·g^− 1 and 2.47 ng·g^− 1, respectively. But a total of 36 rice samples (12.7%) had THg concentration exceeding the national limit (20 ng·g^− 1). Generally, rural population had significantly higher Probable Daily Intakes (PDIs) of MeHg than urban population from rice consumption and its relative contribution to MeHg exposure increased significantly from coastal to inland area. The averages of PDIs of MeHg were 0.020 μg·kg^− 1·d^− 1 and 0.028 μg·kg^− 1·d^− 1 for urban and rural population in southern China, respectively. Despite the serious environmental Hg pollutions in China, the general population in southern China had low risk of MeHg exposure. But rice is an important route of human MeHg exposure in southern China, especially for the rural population in inland area. The findings indicate that rice consumption should be considered when evaluating MeHg exposure in rice eating population in southern China.     

Fetal methylmercury exposure as measured by cord blood mercury concentrations in a mother-infant cohort in Hong Kong

This study was designed to examine newborn infants in Hong Kong prenatally exposed to levels of methylmercury considered to increase risk of neurotoxic effects and to examine subject characteristics that modify the degree of prenatal mercury exposure. Mercury concentrations in 1057 sets of maternal and cord blood samples and 96 randomly selected maternal hair samples were measured. Subject characteristics were measured or collected by questionnaire. Of the 1057 cord blood samples collected only 21.6% had mercury concentrations less than 29 nmol/L (5.8 micro g/L). Median maternal hair mercury concentration was 1.7 ppm. The geometric mean cord to maternal blood mercury ratio was 1.79 to 1. Increasing maternal fish consumption and maternal age were found to be associated with increased cord blood mercury concentrations. Marine fish consumption increased cord blood mercury concentrations more than freshwater fish (5.09%/kg vs 2.86%/kg). Female babies, maternal alcohol consumption and increasing maternal height were associated with decreased cord blood mercury concentrations. Pregnant women in Hong Kong consume large amounts of fish and as a result, most of their offspring have been prenatally exposed to moderately high levels of mercury. In this population, pregnant women should choose freshwater over marine fish and limit fish consumption.     

Are Chinese consumers at risk due to exposure to metals in crayfish? A bioaccessibility-adjusted probabilistic risk assessment

Freshwater crayfish, the world's third largest crustacean species, has been reported to accumulate high levels of metals, while the current knowledge of potential risk associated with crayfish consumption lags behind that of finfish. We provide the first estimate of human health risk associated with crayfish (Procambarus clarkii) consumption in China, the world's largest producer and consumer of crayfish. We performed Monte Carlo Simulation on a standard risk model parameterized with local data on metal concentrations, bioaccessibility (φ), crayfish consumption rate, and consumer body mass. Bioaccessibility of metals in crayfish was found to be variable (68–95%) and metal-specific, suggesting a potential influence of metal bioaccessibility on effective metal intake. However, sensitivity analysis suggested risk of metals via crayfish consumption was predominantly explained by consumption rate (explaining > 92% of total risk estimate variability), rather than metals concentration, bioaccessibility, or body mass. Mean metal concentrations (As, Cd, Cu, Ni, Pb, Se and Zn) in surveyed crayfish samples from 12 provinces in China conformed to national safety standards. However, risk calculation of φ-modified hazard quotient (HQ) and hazard index (HI) suggested that crayfish metals may pose a health risk for very high rate consumers, with a HI of over 24 for the highest rate consumers. Additionally, the φ-modified increased lifetime risk (ILTR) for carcinogenic effects due to the presence of As was above the acceptable level (10^− 5) for both the median (ILTR = 2.5 × 10^− 5) and 90th percentile (ILTR = 1.8 × 10^− 4), highlighting the relatively high risk of As in crayfish. Our results suggest a need to consider crayfish when assessing human dietary exposure to metals and associated health risks, especially for high crayfish-consuming populations, such as in China, USA and Sweden.     

Toxicokinetics/toxicodynamics of arsenic for farmed juvenile milkfish Chanos chanos and human consumption risk in BFD-endemic area of Taiwan

This paper presents a toxicokinetic/toxicodynamic analysis to appraise arsenic (As) bioaccumulation in farmed juvenile milkfish Chanos chanos at blackfoot disease (BFD)-endemic area in Taiwan, whereas probabilistic incremental lifetime cancer risk (ILCR) and hazard quotient (HQ) models are also employed to assess the range of exposures for the fishers and non-fishers who eat the contaminated fish. We conducted a 7-day exposure experiment to obtain toxicokinetic parameters, whereas a simple critical body burden toxicity model was verified with LC50(t) data obtained from a 7-day acute toxicity bioassay. Acute toxicity bioassay indicates that 96-h LC50 for juvenile milkfish exposed to As is 7.29 (95% CI: 3.10-10.47) mg l(-1). Our risk analysis for milkfish reared in BFD-endemic area indicates a low likelihood that survival is being affected by waterborne As. Human risk analysis demonstrates that 90%-tile probability exposure ILCRs for fishers in BFD-endemic area have orders of magnitude of 10(-3), indicating a high potential carcinogenic risk, whereas there is no significant cancer risk for non-fishers (ILCRs around 10(-5)). All predicted 90%-tiles of HQ are less than 1 for non-fishers, yet larger than 10 for fishers which indicate larger contributions from farmed milkfish consumptions. Sensitivity analysis indicates that to increase the accuracy of the results, efforts should focus on a better definition of probability distributions for milkfish daily consumption rate and As level in milkfish. Here we show that theoretical human health risks for consuming As-contaminated milkfish in the BFD-endemic area are alarming under a conservative condition based on a probabilistic risk assessment model.     

Contaminant levels in Norwegian farmed Atlantic salmon (Salmo salar) in the 13-year period from 1999 to 2011

BackgroundEnvironmental 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.ObjectivesThe main objective was to evaluate trends of contaminant levels in Norwegian farmed Atlantic salmon in light of the derived tolerable intakes.MethodsThrough 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.ResultsThe 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 PCB₆ and quantifiable amounts of pesticides, except DDT, stable levels were observed.ConclusionThe 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.     

淡水鱼类种质资源信息系统的研制

采用人工智能和多媒体技术、建成了淡水鱼类种质资源信息系统。本系统完整、准确地保存了鲢、鳙、草鱼、团头鲂、方正银鲫、兴国红鲤、散鳞镜锂、尼罗罗非鱼、奥利亚罗非鱼等十种淡水鱼类种质标准参数及其性状图形、图像集、,包括鱼类可量和可数性状;鱼类年龄与生长特征;鱼类性成熟和怀卵量特征;鱼类耗氧量、耗氧率和窒息点指标;鱼类肌肉成份;鱼类染色体核型图像;鱼类同工酶酶谱组成指标,为进行种质鉴别和保存探索了一条新路     

PCDD/Fs and DL-PCBs intake from fish caught in Polish fishing grounds in the Baltic Sea — Characterizing the risk for consumers

Fish and fishery products are among the primary sources of dietary exposure to dioxins. It is known that some fish species caught in the Baltic Sea contain elevated level of those compounds. Levels of dioxins and DL-PCBs in 236 Baltic fish samples (including 65 salmon, 14 sea trout, 63 sprat, 63 herring, 31 cod), and 20 cod liver samples from the Polish fishing grounds (the ICES zones 24–27), collected in the time frame of 2006–2011 as part of Polish monitoring survey have been used for risk assessment. To characterize potential health risk associated with dioxins intake, doses ingested in a single portion of fish and cod liver by adults (200 g for fish, 125 g for cod liver), and children (100 g for fish, 25 g for cod liver) were expressed as percent of Tolerable Weekly Intake (TWI) and Provisional Tolerable Monthly Intake (PTMI).Average dioxins intake estimated for fatty fish species was about 250% TWI for children, and about 170% TWI for adults, with maximum values of 436.3 and 288.0% TWI, respectively. Maximum exposure expressed as percent of PTMI was below 90% for children and below 60% in adults. For sprat and herring, mean dioxins intakes were lower, but still not at “safe” level: 100–150% TWI for children and about 70–100% for adults, with the maximum values of about 250 and 180%, respectively. Maximum exposure expressed as percent of PTMI was approximately 50% for children and 35% for adults.Intakes values calculated for practically “dioxin-free” cod are just theoretical because in calculating toxic equivalents (TEQs) an upperbound approach was applied, and vast majority of TEQs originates from the limit of quantification (LOQ) values of all non-quantified congeners.Frequent consumption of cod liver seems to be a health risk as, according to assumed scenario, dioxins intake of 100% PTMI for adults would be achieved by the 65th percentile, while for children by approximately 90th percentile of results.Serving sizes of salmonids, cod liver, and even sprat, and herring that lead to total dioxins intake equal to TWI, and PTMI were relatively small. Thus, one can easily exceed those toxicological reference values consuming above Baltic fish species available on the Polish market.Taking into account low fish consumption in Poland and, additionally, low share of Baltic fish in total consumption of marine fish, potential risk of high dioxins intake does not apply to general population. Occasionally elevated dioxins intake above TWI or PTMI is not necessarily related to health risk, because of uncertainty factors embedded in these toxicological reference values. However, some sub-populations in Poland that habitually consume fatty fish originating from the Baltic Sea or Baltic cod liver may be at an elevated health risk of potential consequences of chronic exposure to dioxins. Dietary recommendations based on risk-benefit analysis for consumers of such fish and fishery products from the Baltic Sea would be the most effective tool for risk management.     

长江水系四大家鱼种质资源的保护和合理利用

四大家鱼是我国淡水养殖和捕捞的主要对象，本文从影响长江水第四大家鱼种质资源的主要因素出发，对目前鱼类养殖场普遍存在的四大家鱼种质退化的原因进行了分析，提出了保护长江水系四大家鱼天然产卵场，利用长江故道保护和合理利用长江四大家鱼种质资源，保护四大家鱼人工养殖群体的遗传性能，建立长江水系四大家鱼种质资源监测体系等对策。     

Does climate change matter for freshwater aquaculture in Bangladesh?

Freshwater aquaculture plays an important role in the economy of Bangladesh, providing food, income, livelihoods and export earnings. However, freshwater aquaculture in the Mymensingh area of north-central Bangladesh has been accompanied by recent concerns over climate change. Field survey revealed that different climatic variables including flood, drought, rainfall variation and temperature fluctuation have had adverse effects on pond-fish culture. These climatic variables have detrimental effects on the ecosystem of ponds and thus affect survival, growth and production of fish. Changes in climatic variables have adverse effects on fish reproduction, grow-out operation, parasite infestation and disease occurrence. Considering vulnerability to the effects of climate change on pond-fish culture, we propose adaptation strategies that need to be introduced to cope with the challenges.     

Determination of toxic elements (mercury,cadmium, lead,tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers

Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead).     

太湖流域沉积物中有机氯农药空间分布特征及风险评价

为了解太湖流域表层沉积物中有机氯农药的空间分布和污染特征,采集全流域111个表层沉积物样品,用GC-μECD分析了20种有机氯农药的含量,并基于沉积物质量基准法对沉积物污染风险进行评价。结果表明:太湖流域沉积物中20种有机氯农药(OCPs)的总含量介于16. 3～96. 9 ng/g dw之间,平均值为35. 0ng/g dw,其中HCHs和DDTs是主要的检出成分,平均含量分别为12. 1、7. 6 ng/g dw,两者含量之和占总OCPs的25. 5%～85. 5%。特征化合物指数法分析结果表明,HCHs主要来源于林丹,而且该区域仍然有新的DDT输入,并且大部分p,p’-DDT通过好氧生物降解为p,p’-DDE。沉积物质量基准法评价结果显示,γ-HCH、DDTs潜在生物毒性较大。     

Balancing the health benefits and environmental risks of pharmaceuticals: Diclofenac as an example

Pharmaceuticals are designed to improve human and animal health, but even the most beneficial pharmaceuticals might raise some questions concerning the consequences of exposure to non-target organisms. To illustrate this situation and using diclofenac as a case-study, we analyze global consumption and occurrence data to identify hot spots of consumption without occurrence data, review the scientific literature on the harmful environmental effects to determine whether the observed concentrations in freshwater are of environmental concern, summarize the current pharmaceutical and environmental policies to highlight policy gaps, and suggest a series of research and policy recommendations, which can be summarized as follows: we need to improve the current knowledge on occurrence in freshwaters to properly implement environmental policies (i), diclofenac might pose a risk to non-target organisms in freshwater (ii); the harmful effects that some pharmaceuticals may have on the environment are not always addressed by environmental policies (iii).     

A critical review of measures to reduce radioactive doses from drinking water and consumption of freshwater foodstuffs.

Following a radioactive fallout event, there are a number of possible intervention measures to reduce radioactive doses to the public via the surface water pathway. We have critically reviewed the options available to decision-makers in the event of radioactive contamination of surface waters. We believe that the most effective and viable measures to reduce radioactivity in drinking water are those which operate at the water treatment and distribution stage. Intervention measures to reduce concentrations of radioactivity in rivers and reservoirs are expected to be much less viable and efficient at reducing doses via the drinking water pathway. Bans on consumption of freshwater fish can be effective, but there are few viable measures to reduce radioactivity in fish prior to the preparation stage. Lake liming and biomanipulation have been found to be ineffective for radiocaesium, although the addition of potassium to lakewaters appears promising in some situations. Lake liming may be effective in reducing radiostrontium in fish, though this has not, to our knowledge, been tested. De-boning fish contaminated by strontium is probably the most effective food preparation measure, but salting and freezing can also reduce radiocaesium concentrations in fish. The provision of accurate information to the public is highlighted as a key element of countermeasure implementation.     

A review and model assessment of (32)P and (33)P uptake to biota in freshwater systems

Bioaccumulation of key short-lived radionuclides such as ¹³¹I and ^32,33P may be over-estimated since concentration ratios (CRs) are often based on values for the corresponding stable isotope which do not account for radioactive decay during uptake via the food chain. This study presents estimates for bioaccumulation of radioactive phosphorus which account for both radioactive decay and varying ambient levels of stable P in the environment. Recommended interim CR values for radioactive forms of P as a function of bioavailable stable phosphorus in the water body are presented. Values of CR are presented for three different trophic levels of the aquatic food chain; foodstuffs from all three trophic levels may potentially be consumed by humans. It is concluded that current recommended values of the CR are likely to be significantly over-estimated for radioactive phosphorus in many freshwater systems, particularly lowland rivers. Further research is recommended to field-validate these models and assess their uncertainty. The relative importance of food-chain uptake and direct uptake from water are also assessed from a review of the literature. It can be concluded that food-chain uptake is the dominant accumulation pathway in fish and hence accumulation factors for radioactive phosphorus in farmed fish are likely to be significantly lower than those for wild fish.