Agency publishes surveys of fish, shellfish and fish oils

Thursday 27 October 2005

Ref: 2005/0614

The Food Standards Agency has today published surveys looking at the levels of a number of contaminants in fish. The levels have been found to be low and the Agency continues to advise that as part of a healthy balanced diet the majority of people should eat more fish.

FSA advice is that people should eat at least two portions of fish a week, one of which should be oily. Fish and shellfish are rich in protein and minerals, and oily fish is rich in long-chain omega 3 fatty acids, which reduce the risk of death from heart disease.

The five surveys, which were carried out as part of routine monitoring, show that, where comparisons are possible, levels of contaminants are similar to or have decreased since they were previously measured.

Fish and shellfish were collected or harvested from a range of locations around the UK and retail samples were also taken. A range of contaminants were analysed, including lead, mercury and cadmium, organotins, which are present in sea water from marine paints, and polycyclic aromatic hydrocarbons (PAHs), which come from oil and combustion processes. Some of these substances can occur naturally at low levels, while others are present as a result of environmental pollution.

Scientific experts from the Food and Agriculture Organization/World Health Organization Joint Expert Committee on Food Additives and the European Food Safety Authority have considered these contaminants and set guidelines (for all except PAHs) as to how much can be consumed without posing a risk to consumer health.

In addition, the European Commission has set legal limits for some contaminants in food that take into account safety and other considerations, such as measures that should be taken by industry to reduce the levels. Occasional consumption of products that slightly exceed these limits would not be a concern for health.

The results of the surveys have been considered by the Agency, alongside data about consumption levels, to estimate consumer exposure. The summary of findings is as follows:

Survey of cadmium, lead and mercury in shellfish

• Lead, mercury and cadmium can be present in fish naturally at low levels. They can also be found at higher levels as a result of pollution from industrial processes.
• Samples in the survey included mussels, cockles, oysters, clams, whelks, winkles, scallops and razor shells.
• Out of the 125 samples in the survey, three mussel samples exceeded the legal limit for lead and two scallop samples for cadmium.
• The samples that exceeded the legal limit do not present a health concern because even people who eat well above average amounts of shellfish would still be below the safety guidelines taking into account the rest of the diet.

Survey of mercury in fish oil supplements

• A range of fish oil dietary supplements were considered in the survey, including cod liver oil, salmon oil and shark liver oil.
• Out of 100 samples only 9 products contained detectable levels of mercury, and none of these were over legal limits.
• For the product with the highest concentration of mercury, omore than 500 capsules would need to be consumed per day in addition to levels in the rest of the diet before the safety guidelines would be exceeded.

Survey of organotins in shellfish

• Organotins can be present in seawater mainly from previous use in marine paints and can be taken up by fish and shellfish.
• Samples included in the survey were mussels, cockles, oysters, clams, winkles, scallops and razor shells.
• Organotins were detected in 50 shellfish out of 155 samples.
• In 48 of these, this would contribute less than 7% of the safety guideline for average consumers. One sample of mussel and one of oyster contained higher levels of organotins, but exposure would still be less than half of the safety guideline for average consumers.

Survey of arsenic in fish and shellfish

• Arsenic is present in the environment from natural sources, such as rocks and sediments, and as a result of human activities such as coal burning and copper smelting.
• A range of fish, e.g. salmon, tuna and mackerel, and shellfish, such as oysters, mussels and clams, were analysed.
• All samples had detectable levels of total arsenic. Inorganic arsenic, which has the potential to cause cancer, was detected in 68% of bulk fish and shellfish samples and 100% of individual shellfish samples.
• There is no regulatory limit for arsenic in fish and shellfish. People's estimated maximum intake of inorganic arsenic would be below 5% of the safety guideline set previously by the World Health Organization, although the guideline is due to be reviewed.

Survey of polycyclic aromatic hydrocarbons (PAHs) in shellfish

• PAHs come from oil and combustion processes and only occur in raw shellfish as a result of environmental pollution.
• Samples of cockles, mussels, oysters, scallops and one clam were included in the survey.
• Out of 72 samples, all contained detectable levels of benzo(a)pyrene and other PAHs.
• Mean levels of PAHs are lower by between 40 and 80% since a survey in 1995-6, although the sampling locations are not identical.
• Some PAHs have the potential to cause cancer and experts advise that it is not possible to set a level that would pose no risk. However, at the levels detected the estimated intake of PAHs from the consumption of shellfish and the rest of the diet is at a level the World Health Organization considered to be of low concern for human health.