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MAFF UK - MULTI-ELEMENT SURVEY OF WILD EDIBLE FUNGI AND BLACKBERRIES

Index to MAFF UK Food Surveillance Information Sheets, 2000

Key Points

This survey was carried out to measure the concentrations of arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, platinum, tin, titanium and zinc in two types of food found in the wild; fungi and blackberries.
The concentrations of these elements found in these foods were consistent with previous studies where available. Concentrations of lead were higher in urban fruit and platinum levels were higher in blackberry samples taken from locations close to main roads reflecting the emissions of these metals from road traffic.
Estimated dietary exposures to these elements by consumers of wild blackberries and fungi have been considered by the independent Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT). It concluded that ‘the concentrations of the elements arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, platinum, tin, titanium and zinc in fungi and blackberries collected from the wild do not provide any cause for concern for individuals eating these foods’.

Summary

The JFSSG undertook a survey of the concentrations of 12 metals and other elements in edible fungi and blackberries collected from the wild to assess the risks to health of consumers of these foods.

The metals and other elements in this survey include those of interest as contaminants (e.g. arsenic, cadmium, lead and mercury) and those which are known to have the potential to accumulate in wild fungi and blackberries (e.g. cadmium, copper, mercury and lead). Platinum was included in this survey as it is known to be released from the catalytic converters fitted to many cars. ^1-3 The results of the survey showed that the concentrations of the metals and other elements were consistent with previous studies where available. Concentrations of titanium, tin and platinum were significantly higher at urban sites than at rural sites in both the wild fungi and blackberries. Platinum concentrations in blackberries were significantly higher at roadside locations. The estimated dietary exposures were within relevant guidelines on safe exposures, even for above average adult consumers of wild foods.

Background

Metals in Food

Some metals and other elements (e.g. zinc, selenium, cobalt, copper) can act as nutrients and are essential for health, while others (e.g. mercury, cadmium, lead) have no known beneficial health effects. ^4,
5 All may be harmful if excessive amounts are consumed. Metals and other elements are present in foods either naturally, as a result of human activities (e.g. agricultural practices, industrial emissions, car exhausts), from contamination during manufacture/processing and storage, or may be added directly. ^4,
5

Purpose

The JFSSG undertakes each year a number of surveys of contaminants in foods. These surveys tend to focus on commercial foods as they are the main source of food for most consumers. Few surveys have been specifically carried out on foods that consumers collect from the wild. ^6,
7 As some wild foods, for example, some fungi, can accumulate contaminants that are present in the environment, ^1-3,
8-12 they could be important additional sources of exposure to these contaminants for consumers of wild foods. This survey was therefore undertaken to quantify the possible risks to consumers of such foods.

This survey aimed to reflect the most popular types of wild food collected and eaten in the UK. It was designed to include food which grows in the wild, but not game which is now often farmed and is included in other MAFF surveys. ¹³ Therefore, the chosen wild foods were fungi and blackberries. Edible wild fungi were selected because they can accumulate contaminants from the soil (e.g. cadmium, mercury and lead). The principle factors influencing the accumulation of contaminants by fungi are not only environmental factors, such as metal concentrations in the soil and pH, but also factors such as fungal structure. ⁹ Several studies have shown that the fruiting bodies (i.e. mushrooms) of many fungal species can accumulate mercury, cadmium and lead, ^8,
9,
10 with some very high lead concentrations being reported in mushrooms growing in the vicinity of highways or other sources of lead. ⁸

Wild blackberries were analysed as indicators of surface pollution e.g. from traffic exhausts. There have been recent concerns about the potential for increases in the levels of platinum in the environment due to emissions from catalytic converters in car exhausts. ^1-3 Currently, it is believed that approximately half of cars registered in the UK have catalytic converters fitted, whereas virtually none were fitted before 1993. Therefore, platinum was included in this survey to compare the levels of contamination of wild foods growing close to roads with those grown away from traffic.

Manganese was also included in this survey in order to provide baseline data against which any increase in contamination can be compared should manganese-based fuel additives be used in the future as replacements for leaded fuel. Titanium was analysed as an indicator of soil contamination. Titanium is not taken up internally by plants, and so any titanium concentrations in plant samples can be used as indicators of the presence of soil or dust on the outer surface of the plant sample.

Samples of wild fungi and blackberries were taken from both rural and urban locations, and from roadside sites and those distant from roads around the UK in order to reflect potential localised sources of contamination.

Although there are no comparative data for wild foods from previous surveys, the results may be compared with results from surveys in which commercial mushrooms and blackberries were analysed. ^14-19 However, these commercial samples are likely to be produced under much more controlled conditions and, for fungi, will comprise different species to some of the wild fungi in this survey.

All details of the samples tested are reported in the sampling report for this survey which is available for public access in MAFF’s library. ²⁰

Brand Names

As this survey was undertaken on foods collected directly from the wild, the MAFF policy on the release of brand names when reporting the results of food chemical surveillance is not applicable. ²¹

Methodology

Sampling

The survey was undertaken on behalf of JFSSG by the University of Bristol’s Department of Food Animal Science between June 1998 and July 1999. Analyses were performed by Central Science Laboratory (CSL), norwich.

Fungi

Members of the British Mycological Society undertook the majority of sample collection as types of edible fungi can sometimes be difficult to identify. They routinely collect wild fungi for their own consumption and are familiar with commonly eaten species. Volunteers were provided with written instructions on how to collect the samples. Sample collection took place between June and november 1998. The sample plan required 24 samples of wild fungi to be collected, split between urban and rural locations, 8 samples (4 urban and 4 rural) from each of the three broad regions, the ‘north’, the ‘Midlands’ and the ‘South’ of Great Britain respectively. In the event, a total of 34 samples of wild fungi were collected, and all samples were analysed in order to give a better representation of results. The volunteers were asked to obtain mushrooms, mainly of ‘ Agaricus’ species, which are the most commonly eaten wild fungi but, where this was not possible, volunteers were asked to take samples of other common edible species which they would also normally collect. The common names for the mushrooms collected may be found in Table 1. They were asked to note the date of collection, the Ordnance Survey grid reference and whether the sample was from a ‘rural’ or ‘urban’ location. Once collected, the fresh samples were sealed in air and watertight plastic bags and dispatched to CSL.

Blackberries

The sample plan aimed to collect 48 samples of wild blackberries. Samples (ideally at least 200g ) were collected by staff of the University of Bristol from the ‘north’, the ‘Midlands’ and the ‘South’ of Great Britain although there was some difficulty obtaining samples from the north. Within each region, four samples each came from ‘rural’ sites, ‘urban’ sites, ‘beside a rural road’ and ‘beside an urban road’. ‘Rural’ was defined as being greater than 20 metres from the road, to distinguish from ‘rural road’. Once collected, the samples were washed with distilled water, dried using sterile absorbent paper wipes to remove the excess water from washing and then sealed in plastic bags and dispatched to CSL.

Soil

The uptake of elements from the soil is dependent upon many factors, including soil type and pH. A soil sample was collected from each site of fungi and blackberry collection and this was composed of random sub-samples taken from within the area of the site to a depth of 15 cm, using a soil auger. The soil samples were stored in sealed plastic sample bags. The soil samples were not analysed for this survey, but were stored against the need for analysis to investigate any unexpected or unusual results. Titanium was determined as an indicator of contamination of the surface of food samples by soil.

Analysis

The wild fungi and blackberry samples were prepared and analysed for arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, platinum, tin, titanium, and zinc by CSL.

All samples were washed thoroughly with distilled water and the edible portions prepared. Aliquots of the homogenised edible portion of each sample (equivalent to approximately 0.5 g dry weight) were digested with nitric acid by microwave heating in a CEM MDS 2000 UDV system. All elements were measured by inductively coupled plasma-mass spectrometry (ICP-MS) using a Perkin Elmer Elan 6000. All measurements were covered by the United Kingdom Accreditation Service (UKAS) accreditation, except titanium which was used as a screen only and thus outside the scope of UKAS accreditation, and platinum which was analysed by a different method in order to obtain a lower limit of detection (LOD). For the platinum samples, aliquots of each sample (equivalent to approximately 0.5 g dry weight) were digested in aqua regia by microwave heating in a Perkin Elmer Multiwave microwave digestion system. This method was chosen because platinum that is emitted from car exhausts fitted with catalytic converters is likely to be in resilient forms that are difficult to digest fully by nitric acid digestion alone. However, this method was outside the scope of UKAS accreditation.

Quality Control

CSL norwich had UKAS accreditation for trace element analysis although platinum and titanium were analysed outside the scope of accreditation.

The approach for quality control in multi-element analyses at CSL has been discussed elsewhere. ²² Every multi-element analysis in this study included the following quality control checks:

Measurement of a calibration standard at the start and end of each ICP-MS run – values to be within plus or minus 20 per cent of each other;
Spiked reagent blank recoveries to be within plus or minus 20 per cent of the expected value (and all results are corrected for spike recovery);
Replicate determinations to give a relative standard deviation of less than or equal to 20 per cent or twice the LOD; and
Certified Reference Material (CRM) results.

Every microwave digestion batch included a National Institute of Standards Technology (NIST) certified reference material (CRM) (BCR 60 – Aquatic Plant; BCR 61 – Aquatic Moss; NIST 1547 – Peach leaves; NIST 1570 – Spinach; NIST 1573 – Tomato leaves) and a duplicate sample. Each batch also contained reagent blanks and a reagent blank spiked with a known amount of each element for recovery estimate purposes. Rhodium and indium were added to the digests as internal standards before element concentrations were measured by ICP-MS.

The LODs obtained in this survey are shown in Table 2.

Results

The results for each element, together with details for each individual sample analysed are shown in Table 3a for wild fungi and Table 3b for wild blackberries. Full details of the foods analysed and the concentrations measured are also given in the final report for this project ²⁰ which is available in MAFF’s library. All results are reported on a fresh weight basis.

The mean and ranges of the concentrations of each element found in wild fungi and blackberries are shown in Table 4a and Table 4b. Several of the samples for both fungi and blackberries contained high concentrations of some elements and highly skewed distributions of results were obtained. Again, this is consistent with previous studies. ^8-12

Fungi

Several samples of wild fungi showed the ability to accumulate some relatively high concentrations of certain elements, especially cadmium, copper, arsenic, mercury, zinc and lead. This is consistent with earlier studies which show that certain fungi can accumulate very high concentrations of metals. ^1-3,
8-12

Overall, there appeared to be few significant differences between concentrations from the rural and urban sites but statistical analysis showed significantly higher concentrations of titanium, tin and platinum observed in samples from urban sites. Zinc concentrations were found to be significantly lower at urban sites.

Blackberries

Generally, the concentrations of the chemical elements in the samples of blackberries were low, with many falling below the LODs. Manganese concentrations were significantly higher in samples from rural locations. Higher concentrations of lead, platinum and also titanium were found in samples by major roads and at urban sites. These results for lead and platinum are as expected as road traffic represents a significant localised source of emissions of these elements to the environment.

Results for individual elements are discussed in turn, below. Dietary exposures to the 12 elements for consumers of these foods are discussed in the subsequent section.

Interpretation

Arsenic

Several samples of fungi showed high arsenic levels, the highest being in Agaricus macrosporus (0.97 mg/kg), Lepiota procera (0.83 mg/kg) and Agaricus arvensis (0.73 mg/kg). These concentrations are below the statutory limit of 1 mg/kg for arsenic in commercial foods set by The Arsenic in Food Regulations 1959, as amended ²³ although those Regulations do not apply to wild foods collected for personal consumption. There was no significant difference between arsenic concentrations in urban and rural samples.

All of the blackberry samples were well below the statutory limit of 1 mg/kg,23 the highest concentration being 0.069 mg/kg. The results show significantly (at a 5 per cent level) higher concentrations in urban samples (mean 0.01 mg/kg, range 0.0015 mg/kg to 0.069 mg/kg) than rural samples (mean 0.0032 mg/kg, range 0.0011 mg/kg to 0.0079 mg/kg)( Table 3b). However, there were no significant differences between roadside and non-roadside samples.

Cadmium

Cadmium concentrations in wild fungi ranged from 0.02 mg/kg to 20 mg/kg with a mean of 1.6 mg/kg. High concentrations of cadmium were found in several species ( Agaricus macrosporus, 20 mg/kg; Agaricus campestris, 8.7 mg/kg; and Agaricus arvensis, 5.3 mg/kg). This could reflect either a higher rate of cadmium accumulation in these species, or it could be that these samples happened to be growing in soil that had higher levels of cadmium. However, soil analysis was not pursued for the reasons given below, see ‘Titanium’.

Some results from this study are somewhat higher than those from a study of wild fungi undertaken in Croatia ²⁴(mean 1.2 mg/kg, range 0.3 mg/kg to 4.87 mg/kg dry weight) although different species were analysed. The mean concentration of 1.6 mg/kg from this study is greater than the mean concentration of 0.018 mg/kg found in samples of commercial fungi tested in a JFSSG survey of ‘Lead and Cadmium in Foods’, ¹⁴ and also in 4 samples of mushroom in an earlier study of background levels of cadmium in foods ¹⁷ where the mean concentration was 0.06 mg/kg (0.02 mg/kg to 0.08 mg/kg).

Cadmium concentrations in the blackberry samples ranged from 0.0007 mg/kg to 0.094 mg/kg with a mean concentration of 0.011 mg/kg ( Table 4b). There was no significant difference between the urban and rural samples or between roadside and non-roadside samples. A MAFF study analysing foods grown in the Shipham area ¹⁷ where elevated levels of cadmium are found as a result of historic mining activity, found a commercial sample of blackberry with a cadmium level of 0.08 mg/kg which is at the higher end of the range found in samples from this survey. Although not a direct comparison, strawberries analysed in a Finnish study ²⁵ had a mean cadmium concentration of 0.007 mg/kg which is similar to concentrations in this survey ( Table 3b).

Chromium

Chromium was not detected in 4 of the 34 wild fungi samples. The mean concentration was 0.084 mg/kg which is much lower than samples of retail fungi analysed in a MAFF survey in which the mean concentration was 0.25 mg/kg. ¹⁸ Concentrations of chromium were undetectable in a quarter of the wild blackberry samples ( Table 3b).

Copper

The concentrations of copper in wild fungi were all above the LOD of 0.002 mg/kg ( Table 2), with a mean concentration of 9 mg/kg and a range of 2.7 mg/kg to 35 mg/kg. The highest concentrations were found in 2 samples which were ‘ Agaricus’ species ( Agaricus campestris-25 mg/kg and Agaricus macrosporus-35 mg/kg), and 1 sample of Lepiota procera (25 mg/kg).

All the blackberry samples were above the LOD of 0.002 mg/kg (mean 1 mg/kg, range 0.6 mg/kg to 3.3mg/kg). There was no significant difference between samples taken from urban sites and rural sites. Similarly, no significant difference was found between roadside and non-roadside samples.

Lead

Lead was detected in all of the wild fungi samples (mean 0.7 mg/kg, range 0.012 mg/kg to 6 mg/kg)( Table 4a). The majority of the samples had lead concentrations below the statutory limit of 1 mg/kg for lead in commercial fungi as set by ‘ The Lead in Food Regulations 1979 as amended’, ²⁶ although, as noted above for arsenic, these statutory limits do not apply to wild foods collected for personal consumption. Five samples with higher lead concentrations were found with the greatest (6 mg/kg) being in a sample of ‘Wrinkled Club’ ( Clavaria species). Statistical analysis showed there to be no significant difference between urban and rural samples.

The mean concentration from this survey (0.7 mg/kg) is greater than results for commercial fungi tested in an earlier JFSSG study, ¹⁴ where a mean concentration of 0.01 mg/kg was obtained. However, this result is expected as commercial fungi are different species, are grown in controlled conditions and are unlikely to be subject to the contamination as those growing in the wild. This has been shown in a previous study. ²⁷ Lead concentrations in edible wild fungi from a study in Croatia ranged up to 7.72 mg/kg. ²⁴

none of the wild blackberry samples had lead concentrations above 1 mg/kg. ²⁶ There was no significant difference between the samples taken from urban sites and urban road sites. However, the mean concentration of lead in urban samples (0.093 mg/kg) was significantly greater (at a 0.01 per cent level) than in the rural samples (0.012 mg/kg)( Table 4b) which suggests that localised environmental contamination in urban areas does contribute to higher lead levels in wild blackberries. The mean concentration of lead found in blackberries in this survey (0.05 mg/kg) is less than that found in commercial fresh blackberries (0.07 mg/kg) in a previous MAFF survey. ¹⁶

Manganese

The highest concentration of manganese was found in a sample of ‘ Corprinus atramentarius’ (8.8 mg/kg). All other samples were also well above the LOD of 0.01 mg/kg. The mean concentration for urban fungi was higher than for rural fungi (2.6 mg/kg and 1.9 mg/kg respectively) ( Table 4a).

There were several high concentrations of manganese in the blackberry samples (92 mg/kg, 43 mg/kg, 27 mg/kg) and one very high concentration (153 mg/kg) ( Table 3b). These very high concentrations resulted in a skewed distribution and statistical analysis showed that the mean concentration of manganese at urban locations was significantly lower (at a 0.1 per cent level) than samples from rural locations. Further, urban roadside samples of wild blackberries had greater levels of manganese (5.9 mg/kg) than did blackberries taken from non-roadside locations (2.4 mg/kg).

Mercury

The concentrations in all of the wild fungi samples were above the LOD of 0.0006 mg/kg (mean 0.64 mg/kg, range 0.006 mg/kg to 4.2 mg/kg) ( Table 4a). This is greater than samples of commercial fungi analysed in a survey of individual foods (mean 0.02 mg/kg). ¹⁹ However, as noted above, commercial fungi samples may be different species and are grown in controlled conditions and so this difference is not surprising. There were three samples with higher concentrations of mercury ( Table 3a). There was no significant difference between urban and rural samples.

Mercury concentrations in wild blackberries were very low (mean 0.00088 mg/kg, range 0.0006 mg/kg to 0.0079 mg/kg) with only 8 samples having mercury concentrations above the LOD of 0.0006 mg/kg.

Nickel

Nickel concentrations in the wild fungi samples showed no unusually high results although most had concentrations above the LOD (0.002 mg/kg). The mean concentration of nickel in the blackberry samples was 0.13 mg/kg (range 0.025 mg/kg - 0.7 mg/kg)( Table 4b). There was no significant difference between urban and rural blackberry samples.

Platinum

Ten samples of wild fungi had platinum concentrations below the LOD of 0.00001 mg/kg. The mean concentration was 0.00003 mg/kg with a range up to 0.0002 mg/kg ( Table 4a). Statistical analysis showed that platinum concentrations were significantly higher (at a 5 per cent level) in samples from urban sites than from rural sites (0.00005 mg/kg and 0.00002 mg/kg respectively).

The aqua regia method used to digest the wild blackberries resulted in a lower LOD of 0.000006 mg/kg. There was no significant difference between rural and urban concentrations of platinum in blackberries. However, statistical analysis showed a significant difference (at a 5 per cent level) between platinum concentrations in mean urban samples (0.000007 mg/kg) and mean urban roadside samples (0.00001 mg/kg). This difference is likely to reflect platinum contamination from emissions from catalytic converters and the much heavier traffic on urban main roads compared with rural roads.

Tin

All the tin concentrations in both the wild fungi and blackberry samples were well below the UK legal limit of 200 mg/kg ²⁸ ( Table 3a & Table 3b) although, as with arsenic and lead, this limit does not apply to wild foods collected for personal consumption.

Concentrations of tin were undetectable in 4 samples of wild fungi. Tin levels were significantly greater (1 per cent level) in the urban fungi samples. The concentrations of tin in the wild blackberries were very similar to the concentrations in wild fungi with over half of the samples below the LOD of 0.001 mg/kg ( Table 2 & Table 3b). Tin levels were higher in urban samples but there were no significant differences between tin levels in urban and urban road samples and rural and rural road samples.

Titanium

Titanium was analysed as an indicator of soil or dust on the surface of samples. Titanium was detected in all samples of wild fungi (mean 0.73 mg/kg, range 0.033 mg/kg to 6.1 mg/kg)( Table 4a). All samples had titanium concentrations higher than the LOD of 0.001 mg/kg ( Table 2). Titanium concentrations in urban fungi samples (1.4 mg/kg) were found to be significantly higher (at a 5 per cent level) than in rural samples (0.35 mg/kg).

Wild blackberry samples all had titanium concentrations higher than the LOD ( Table 2). The highest concentration of 1.8 mg/kg was found in an urban roadside sample. From the mean concentrations of both the urban and rural samples (0.2 mg/kg and 0.066 mg/kg respectively), it was found that titanium was significantly higher (at a 1 per cent level) in the urban samples, particularly in urban roadside locations compared with urban non-roadside locations. This was not the case for rural locations and rural roadside locations where there was no significant difference in the concentrations of titanium.

The results for titanium suggest that, not surprisingly, significant levels of soil and dust may remain in the wild fungi and berry samples even after washing with clean water. Any surface soil remaining in samples would have contributed to the titanium concentrations reported. However, since none of the reported concentrations gave rise to exposures above the guideline limits, this has not been pursued further.

Zinc

Zinc was detected in all fungi samples (mean 14 mg/kg, range 3.6 mg/kg to 35 mg/kg) with some samples showing relatively high concentrations in some species [ Agaricus bisporus (21 mg/kg), Agaricus campestris (23 mg/kg), Agaricus macrosporus (35 mg/kg), Lepista nuda (22 mg/kg), Langermannia gigantea (34 mg/kg), Lepiota procera (30 and 34 mg/kg) - Table 3a]. Statistical analysis showed the mean concentration of zinc in rural mushroom samples (16 mg/kg) was significantly greater (at a 5 per cent level) than that of urban mushroom samples (9.6 mg/kg).

Concentrations of zinc in the wild blackberries were much lower than those in the wild fungi. Differences between urban and rural, and roadside and non-roadside locations were minimal and not significantly different.

Dietary exposures of consumers of wild mushrooms and wild blackberries.

Calculation of dietary exposures

Dietary exposures of adult consumers of wild fungi and blackberries were estimated using the mean concentrations of each element found in this survey, with data on the patterns and levels of consumption of wild foods derived from MAFF surveys of actual consumption habits among local populations in different areas of the UK. ⁷

Exposures from wild foods have been estimated both for average consumers and for consumers who eat above average (97.5th percentile) amounts of both wild fungi and fruit. To estimate total dietary exposures, the mean exposure for adults from the 1997 TDS was added to the exposures from these free foods. ²⁹

The significance to health of the element concentrations found in these wild foods may be assessed by comparing the estimated exposures with exposures from the normal diet and with the internationally agreed exposure guidelines where these exist. These guidelines are the Provisional Tolerable Weekly Intakes (PTWIs) or Provisional Maximum Tolerable Daily Intakes (PMTDIs) set by the Joint Expert Committee on Food Additives of the Food and Agriculture Organization of the United Nations and the World Health Organization (JECFA). Such guidelines exist for six of the elements considered in this study: cadmium, copper, lead, mercury, tin and zinc. JECFA has also set a PTWI for inorganic arsenic (but not for organic or for total arsenic). The World Health Organization (WHO) has set a Tolerable Daily Intake (TDI) for nickel. These guidelines are shown in Table 5.

Significance of estimated exposures for adults’ health.

Estimated dietary exposures of these elements are within the relevant PMTDIs, PTWIs and TDIs in all cases where they exist, even for consumers eating above average (97.5th percentile) amounts of both wild fungi and blackberries. Although lead concentrations were considerably higher in urban blackberry samples compared with those from rural samples, the highest estimated exposure would not cause even an above average consumer’s total dietary exposure of these foods to exceed the normal range estimated from the 1997 Total Diet Study. ²⁹ However, the estimated ‘total’ exposure to lead by a high level adult consumer (i.e. taking into account the average exposure from the rest of the diet) is greater than the 97.5th percentile exposures for adults from the 1997 TDS but still well below the PTWI for lead ( Table 5). The estimated ‘total’ exposures for cadmium are also greater than the 97.5th percentile exposures for adults from the 1997 TDS but do not exceed the PTWI ( Table 5).

Arsenic is present in food in different forms (species) which vary in toxicity with inorganic forms being the most toxic. The JECFA PTWI applies to inorganic arsenic only. Most of the arsenic in the diet comes from fish and seafood and is present in the less toxic organic forms. ^30,
31 However, it is difficult to distinguish analytically between the different forms of arsenic in food, and for this reason, most surveys including this one, have measured total arsenic. Therefore, the overall arsenic exposure of 0.13 mg/day shown in Table 5 represents ‘total’ arsenic and the contribution of inorganic arsenic to this total figure should not exceed the PTWI of 0.12 mg/day ( Table 5).

As noted above, lead concentrations were higher in urban blackberry samples (mean 0.093 mg/kg) than in those from rural locations (mean 0.012 mg/kg). The estimated lead exposures for a 97.5th percentile consumer of urban blackberries (0.0063 mg/day) is higher than that for rural blackberries only (0.0008 mg/day), but remains small compared with the exposure from the normal diet (0.024 mg/day). The total estimated exposure for an above average (97.5th percentile) consumer of both wild mushrooms and urban wild blackberries, together with the rest of the diet (0.047mg/day) remains well below the PTWI of 0.21 mg/day. ³⁰

These estimated dietary exposures were considered by the COT. This Committee gives the Government independent expert advice on food safety. The COT concluded that, ‘the concentrations of the elements arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, platinum, tin, titanium and zinc in fungi and blackberries collected in the wild do not provide any cause for concern for individuals eating these foods’.

The COT’s full statement on this survey is attached at Annex 1.

Conclusion

The aims of this survey were to produce baseline concentrations for twelve metals and other elements in two types of commonly eaten wild foods, to allow a comparison between urban and rural samples of wild foods and also to allow a comparison between roadside and non-roadside samples of wild foods. These aims were all achieved and the survey was successful in allowing dietary exposures from the consumption of free foods to be estimated. As with previous studies, ^1-3 this survey also found higher concentrations of platinum in wild foods from roadside areas compared with non-roadside areas, which supports the view that the use of catalytic converters can result in platinum residues in food, but at very low levels. Titanium concentrations were found to be higher in urban main road areas.

Future Action

This survey has provided baseline concentrations for arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, platinum, tin, titanium and zinc in wild fungi and blackberries. These data can be used to monitor and compare concentrations of elements in future surveys of wild foods, for example, to determine whether concentrations of platinum in wild foods increase as more vehicles on the road use catalytic converters, or whether lead concentrations decrease in wild foods as a result of the replacement of leaded fuel with other fuel additives.

Acknowledgements

The JFSSG is grateful to the members of the British Mycological Society for their assistance in the identification and collection of the wild fungi samples for this survey.

Units

kilogram (kg): one thousand grams (g)
milligram (mg): one thousandth of a gram (g)
mg/kg: milligrams per kilogram (equivalent to parts per million)
mg/day: milligrams per day

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Ministry of Agriculture, Fisheries and Food/ Department of Health (1997). Food Safety Information Bulletin no. 88.
Baxter, M.J., Crews, H.M., Robb, P., Strutt, P. (1997). Quality Control in the Multi-Element Analysis of Foods using ICP-MS. In Plasma Source Mass Spectrometry: Developments and Applications (Ed Holland, G. and Tanner, S.D.). The Royal Society of Chemistry, London.
The Arsenic in Food Regulations 1959 (S.I. [1959] no. 831), as amended by The Arsenic in Food (Amendment) Regulations 1960 (S.I. [1960] no. 2261) and The Arsenic in Food (Amendment) Regulations 1973 (S.I. [1973] no. 1052). The Stationery Office, London.
Mandic, M.L., Grgic, J., Grgic, Z., Servga, M. (1992). The natural levels of Aluminium, Cadmium and Lead in Wild Mushrooms in Eastern Croatia. Deutsche Lebensmittel-Rundschau 88, 76-77.
Tahvonen, R., Kumpulainen, J. (1995). Lead and Cadmium in some Berries and Vegetables on the Finnish Market in 1991-1993. Food Additives and Contaminants 12, 263-279.
The Lead in Food Regulations 1979 (S.I. [1979] no. 1254), as amended by The Lead in Food (Amendment) Regulations 1985 (S.I.[1985] no. 912). The Stationery Office, London.
Borella, P., Caselgrandi, E., Fabio, G., Gibertoni, C. (1994). Risk of Intake for Cadmium and Lead with Consumption of fresh mushrooms on sale. L’Igiene Moderna 101, 323-331.
The Tin in Food Regulations 1992 (S.I. [1992] no. 496). The Stationery Office, London.
Ministry of Agriculture, Fisheries and Food (1999). 1997 Total Diet Study: Metals and Other Elements. Food Surveillance Information Sheet no. 191.
Edmonds, J.S. and Francesconi, K.A. (1993). Arsenic in seafoods: human health aspects and regulations. Marine Pollution 26, 665-674.
Buchet, J.P., Pauwels, J. and Lauwerys, R. (1994). Assessment of exposure to inorganic arsenic following ingestion of marine organisms by volunteers. Environmental Research 66, 44-51
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Contact points

Further information on this survey can be obtained from:

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

Tel: +44 (0) 20 7238 5751
Fax: +44 (0) 20 7238 5331
e-mail: pf.miller@fsci.maff.gov.uk

Further copies of this Information Sheet can be obtained from:

Joint Food Safety and Standards Group, MAFF
Publicity and Information Section
Room 303b, Ergon House, c/o Nobel House
17 Smith Square
London, SW1P 3JR .

Tel: +44 (0) 20 7238 6223
Fax: +44 (0) 20 7238 6330
e-mail: s.h.fssginfo@fssg.maff.gov.uk

Further information on the COT and copies of COT statements can be obtained from:

Mr Jonathan Lighthill
COT Secretariat, Joint Food Safety and Standards Group, DH
Room 652C, Skipton House
80 London Road
London, SE1 6LH.

Tel: +44 (0) 20 7972 5007
Fax: +44 (0) 20 7972 5134
e-mail: jonathan.lighthill@doh.gsi.gov.uk

Further Information

A copy of the full report of this survey has been placed in the MAFF Library, nobel House, London, SW1P 3JR, Tel. no. +44 (0) 20 7238 6575. If you wish to consult it, please contact the library for an appointment giving at least 24 hours notice or alternatively, copies can be obtained from the library: a charge will be made to cover photocopying and postage.

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These pages were last updated on 29 February 2000