Number 53      February 1995

MAFF UK - ANALYSIS OF BEE PRODUCTS FOR HEAVY METALS

Index to MAFF UK Food Surveillance Information Sheets, 1995

see also:
93: MAFF,UK - Multi element analysis of infant foods - follow-up survey (August 1996)
146: MAFF UK - Concentrations of metals and other elements in selected snack and convenience foods (March 1998)
156: MAFF UK - Metals and Other Elements in Dietary Supplements and Licensed Medicinal Products (November 1998)
190: MAFF UK - Metals and other elements in infant foods (November 1999)

Background

In March 1994 MAFF became aware of a problem of elevated concentrations of lead in dietary supplements containing propolis, (Bulletin Number 48, April 1994). Propolis is a mixture of plant exudates, beeswax and pollen produced by bees. Following discussions between the Department of Health, MAFF representatives and the product manufacturers/distributors, all products which contained lead concentrations above the legal limit of 1 mg/kg laid down in the Lead in Food Regulations 1979 (as amended) were immediately withdrawn, and action taken to prevent the marketing of further products that did not conform with the legal limit. Additionally, the Health Food Manufacturers Association which represents most of these companies undertook to prepare a specification for propolis to which their members must adhere and which would ensure that contamination of future products would be minimised. To ensure that other bee products were not similarly contaminated and to obtain further information as to the likely source of the contamination, MAFF undertook a small survey of bee products which included honey, pollen and raw UK harvested propolis for lead and cadmium. The results of these analyses are now available.

Results

Honey samples were obtained from retailers (16 samples - all imported) and apiarists throughout England (17 samples) and analysed using inductively coupled plasma-mass spectrometry (ICP-MS). Samples included both set and clear honey, one sample of which contained a piece of honey comb. The results of the analyses were reassuring since the lead concentrations reported were low, ranging from 0.01 to 0.2 mg/kg. These values are comparable with previously reported MAFF surveillance data. There was no apparent difference between the lead concentrations observed for English honey and those of the pure and blended imported products. Cadmium concentrations for these samples were also low, lying between the limit of determination (0.04 mg/kg) and 0.18 mg/kg.

Five pollen samples provided by members of the British Bee Keepers Association (BBKA), (four English and one of Spanish origin) were found to contain lead concentrations ranging from 0.1 to 1.5 mg/kg. The samples were analysed in duplicate and found to be inhomogeneous, with a mean lead concentration for all ten analyses of 0.62 mg/kg. One sample of imported organic bee pollen grains (a dried granulated pollen product) produced for human consumption was also analysed in duplicate and the mean lead concentration found to be 0.2 mg/kg. The cadmium concentrations reported for all pollen samples analysed were unexceptional and very low, ranging from 0.06 to 0.13 mg/kg.

Analysis of 20 propolis samples, also donated by the BBKA members from locations throughout England revealed widely varying lead and cadmium concentrations. Repeat analyses indicated the extremely inhomogeneous nature of the propolis. The concentrations varied by as much as 118 mg/kg - between 343 and 461 mg/kg - for a single sample. Overall the lead concentrations of all 38 analyses ranged between 2.3 and 461 mg/kg and these results are illustrated by a histogram shown in Figure 1. The concentrations found are similar to previous surveillance data and literature values reported for both UK and imported samples. The elevated lead concentrations appear to be inherent in this product and reflect the diverse sources from which the bees forage material to produce propolis. Likewise the cadmium concentrations reported for these samples also showed considerable variation and concentrations ranged between the limit of determination (<0.07 mg/kg) and 3.8 mg/kg. The cadmium concentrations were generally higher than would be found in most foods. These results indicate that the previously reported contamination of dietary supplements can be attributed to their propolis content.

Interpretation

The survey results show that honey and pollen contain low concentrations of lead and cadmium and their consumption is not a hazard to health. Although the propolis samples analysed for this survey all contained lead concentrations in excess of the 1 mg/kg permitted in foods, none of these samples was intended for use in food supplement capsules. Manufacturers and suppliers of these supplements are aware of the inherent problem of elevated lead concentrations in propolis and have agreed to ensure that all their propolis products contain levels of lead of 1 mg/kg or less. The Lead in Food Regulations 1979 (as amended) apply to all propolis products intended for human consumption and as such should not contain lead concentrations in excess of 1 mg/kg. The elevated lead concentrations reported for this survey indicate the need for manufacturers to purify the raw propolis to an acceptable quality such that its use in foods does not lead to a breach in the regulation.

Contact point

For further information, please contact:

Dr Gillian Ysart
MAFF, Joint Food Safety and Standards Group
Food Contaminants Division
Rm 238, Ergon House c/o Nobel House
17 Smith Square
London SW1P 3JR.

Tel: +44 (0)20 7238 6064
Fax: +44 (0)20 7238 5331

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These pages were last updated on 1 October 1996