PESTICIDE RESIDUES IN FOOD - 1981
Sponsored jointly by FAO and WHO
Food and Agriculture Organization of the United Nations
FAO PLANT PRODUCTION AND PROTECTION PAPER 42
pesticide residues in food:
data and recommendations
of the joint meeting
FAO panel of experts on pesticide residues
in food and the environment
WHO expert group on pesticide residues
Geneva, 23 November-2 December 1981
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
The 1968 Meeting reviewed bromide ion, and data relevant to this
material are also included in the various reviews of brominated
fumigants, especially bromomethane, carried out in 1965, 1966, 1967,
1968, 1971 and 1979*. At the 1980 Meeting it was considered that a
general review of bromide residues in relation to dietary intake
should be considered in 1981 or at a future meeting. This monograph
addendum sets out some data on intake as measured in total diet
studies and some information on 'natural' crop levels.
RESIDUES IN FOOD
RESIDUES IN COMMODITIES IN COMMERCE OR AT CONSUMPTION
Manske and Corneliussen (1974) reported that bromide ion residues
were present in 81 out of 120 food composites examined in their total
diet survey carried out in the USA in June and August 1970; the range
of results reported was from 0.5 to 51 mg/kg. Bromide analysis of the
total diet samples was subsequently discontinued and has not been
resumed. Results reported are shown in Table 1; comparable data had
been obtained in earlier years.
TABLE 1. Bromide ion residues in total diet food composite groups,
Food group Residues found (mg/kg) Average
Dairy products 1.5, 2.0, 3.0, 4.0, 5.0, 5.0, 5.5 3.7
Meat, fish and
poultry 2.0, 3.5, 4.5, 5.5, 6.5, 7.5, 8.0 5.4
Grain and cereal 7.0, 9.0, 14, 14, 14, 22, 25, 30 17
Potatoes 1.0, 1.0, 2.0, 4.0, 13, 16 6.2
Leafy vegetables 0.5, 1.0, 1.5, 2.5, 2.5, 3.0,
4.0, 4.0, 5.1 7.8
Legume vegetables 1.5, 1.5, 2.0, 2.0, 4.0, 5.5 2.8
Root vegetables 0.5, 1.5, 3.5, 4.0, 4.0, 5.0, 6.0 3.5
Garden fruits 0.5, 3.0, 3.5, 3.5, 4.5, 5.0, 6.0 3.7
Fruits 0.5, 1.5, 1.5, 5.5, 6.0, 6.5 3.6
Oils and fats 2.5, 5.5, 12, 12, 12 8.8
Sugars, etc. 0.5, 3.5, 5.5, 6.0, 7.5, 9.5, 12, 23 8.4
Beverages 1.5, 2.0, 2.0, 2.5, 3.0 2.2
* See Annex II for FAO and WHO documentation.
A report on total bromine residues observed in a total diet
survey carried out in the United Kingdom in 1978-79 was made available
to the Meeting (UK 1981). Table 2 shows the results obtained on each
food group; five complete sets of food composites were examined.
Levels are broadly similar to those shown in the survey by Manske and
Corneliussen (1974) in the USA.
TABLE 2. Total bromine content of total diet samples, 1978-79, UK
Food Group Total bromine residues Daily intake
(mg/kg) of bromine
Cereals 6 to 11 7.4 1.7
Meats 4 to 5 4.4 0.7
Fish 3 to 6 4.6 0.1
Fats <5 5 < 0.4
Fruits and sugars 1 to 5 2.4 0.4
Root vegetables 2 to 4 2.6 0.5
Other vegetables 6 to 40 19.2 2.1
Beverages <1 1 < 0.1
Milk 3 to 10 6 2.4
Data on the bromine ion content of summer and winter duplicate
24-hour diets of workers were received from the Netherlands (Greve and
Verschraagen 1977, 1978). Table 3 shows the ranges and means of the
bromide ion content of the diets and the corresponding daily intakes
TABLE 3. Bromide ion content of duplicate diets in the Netherlands
Bromide ion content Daily bromide ion intake
No. in Season (mg/kg) per person (mg)
Range Mean Range Mean
100 Summer, 1976 1.2-11.7 3.6 2.9-15 7.8
101 Winter, 1978 1.1-8.2 3.2 1.8-17 7.6
A further report from the Netherlands gave details of a two-year
total diet (market basket) study based on the diets of 16 to 18-year-
old boys (de Vcs and van Dokkum 1980). Table 4 shows the detailed
results on the 12 samples in each of the 12 groups into which the
diets were divided. Maximum intake per person has been calculated from
these results to be 13.4 mg, with a mean figure of 9.4 mg. In the
Netherlands, the maximum permissible daily intake is regarded as being
10 mg per person.
TABLE 4. Bromide ion content of total diet groups
Food Group Range Mean Median
(mg/kg) (mg/kg) (mg/kg)
Grain products 10-19 13 12
Potatoes and potato
products 0.55-16 3.4 2.4
Green vegetables 0.9-5.8 2.1 1.7
Root vegetables 0.36-3.2 2.0 2.1
Leguminous vegetables 0.70-5.0 1.7 1.4
Fruits 0.07-4.9 0.82 0.28
Meat and meat
products 2.1-4.0 3.1 3.1
Fish 4.6-8.0 6.6 6.7
Milk and milk
products 1.7-5.5 3.6 3.9
Oils and fats 5-22 11 10
Sugar and preserves 0.7-2.2 1.3 1.3
Beverages and drinking
water 0.09-0.30 0.19 0.20
Inorganic bromine in soils in the United Kingdom do not normally
exceed 5 mg/kg dry weight, except for coastal soils which can attain
levels of 100 mg/kg. Levels in rain water and surface waters generally
do not exceed 1 mg. Information drawn from a review of the literature
indicates that natural bromine levels in fresh fruit and vegetables
can generally be expected to be below 10 mg/kg fresh weight and will
not normally exceed 50 mg/kg fresh weight. Table 5 gives some UK
'natural' levels of total bromine, which were found from the analysis
of a limited survey on the elemental composition of field crops,
undertaken in 1976 (UK 1981).
TABLE 5. 'Natural' levels of total bromine in crops grown in
Crop1 Range of total bromine levels in five different
cultivars of each crop
(mg/kg fresh weight)
Wheat 0.6 - 1.0
Barley 1.9 - 3.7
Cabbage 0.3 - 2.0
Potatoes 0.3 - 1.0
Broad beans 0.5 - 1.1
Peas 0.5 - 3.0
1 Grain and vegetable samples were obtained from various
experimental stations, prepared as for cooking or eating, sliced or
shredded, air dried and analysed by neutron activation techniques.
In 1979, 10 samples of wheat flour intended for human consumption
were analysed for bromide ion content. Levels found ranged from 1.4 to
9.0 mg/kg, with a mean value of 4.5 mg/kg (UK 1981).
The use of bromomethane as a soil sterilant in glasshouses can
give rise to bromide ion residues in subsequent crops. Retail samples
of tomatoes, cucumbers and lettuces, home produced and imported, have
therefore been examined for total bromine levels. In tomatoes, levels
were generally below 5 mg/kg, but exceeded 30 mg/kg in 12 of the
samples. Of 107 samples of cucumbers, 102 had less than 5 mg/kg of
total bromine, but two had more than 100 mg/kg. Residue levels in
lettuce were much more evenly spread, ranging up to 2 000 mg/kg;
although the majority were below 100 mg/kg, 20 percent of the samples
examined exceeded this figure (UK 1981).
A range of 22 samples of bottled, canned and draught beers was
examined for bromide ion content; results are shown in Table 6. Levels
are remarkably consistent and generally low, with a maximum of
2.1 mg/kg (UK 1981).
TABLE 6. Bromide ion content of various beers
Bromide ion concentration
Commodity No. of 1 (mg/kg)
Bottled beers 32 0.37 to 1.5 0.8
Canned beers 20 0.85 to 2.1 1.4
Draught beers 36 0.53 to 1.3 0.9
1 Each sample was analysed four times.
The use of organobromine fumigants in food storage practice and
in the treatment of soil used for the production of glasshouse crops
has resulted in bromine residues in foodstuffs being raised above
Cereals, vegetables (other than root vegetables) and milk are the
most important contributors to bromine residues in the average diet.
Extensive data on bromine residues in milk are not available, apart
from the data obtained in the analysis of the UK total diet samples
where the levels found ranged between those found in other dietary
items. Further work is desirable to study levels of bromine in milk
and milk products, because the consumption of milk is high and this
item of the diet can contribute significantly to the overall intake of
bromine. The high bromine contribution from the cereals group is
probably a reflection both of the extensive use of bromomethane as a
cereal fumigant and of the large daily consumption of such foods as
bread or breakfast cereals.
The 'other vegetables' group of the total diet includes lettuces,
which appear to be items most likely to give rise to high dietary
intakes of bromine. Average consumption of lettuce containing average
amounts of bromine residues is not likely to lead to a daily intake in
excess of the present ADI.
METHODS OF RESIDUE ANALYSIS
Methods for the determination of bromine in foods, as organic,
inorganic or total, have been reviewed by Getzendaner (1975). The gas-
liquid chromatographic procedure developed for bromide ion in grain
(Heuser and Scudamore 1970), has been adapted for use on lettuce as
reported by Greve and Grevenstuck (1979), and versions of this method
are now widely accepted for use on various foodstuffs.
Some data on dietary intakes of bromide ion in USA (1970), UK
(1978-79) and the Netherlands (1976-80) have been reviewed, together
with some additional information regarding 'natural' and post-
treatment levels in some crops. The average daily intakes of 8.4 mg
(UK) and 9.4 (Netherlands) compare favourably with the calculated
allowable daily intake for a 60 kg adult of 60 mg.
FURTHER WORK OR INFORMATION
1. Data on dietary intake of bromide ion from countries other than
the Netherlands, USA and UK, especially those with different
2. Further data on the bromide ion content of milk and dairy
de Vos, R.H. and van Dokkum, W. Kwantitatief onderzoek naar de
1980 aanwezigheid van additieven in chemische contaminanten in
totale dagvoedingen. Rapport nr. R. 6331 (CIVO/TNO).
Getzendaner, M.E. A review of bromine determination in foods. Journal
1975 of the Association of Official Analytical Chemists, 58:
711 - 716.
Greve, P.A. and Grevenstuck, W.B.F. Gas-liquid chromatographic
1979 determination of bromide ion in lettuce: interlaboratory
studies. Journal of the Association of Official Analytical
Chemists, 62: 1155 - 1159.
Greve, P.A. and Verschraagen, C. Anorganisch bromide in totale dieten.
1977 Intern rapport nr. 75/77 Tox-RoB (RIV). (Unpublished)
1978 Anorganisch bromide in duplicaat 24-unrsvoedingen. Intern.
rapport nr. 162/78 RA (RIV). (Unpublished)
Heuser, S.G. and Scudamore, K.A. Selective determination of ionised
1970 bromide and organic bromides in foodstuffs by gas-liquid
chromatography. Pesticide Science, 1: 244 - 249.
Manske, D.E. and Corneliussen, P.E. Pesticide residues in total diet
1974 samples (VII) Pesticides Monitoring Journal, 8: 110 - 124.
UK Information on bromide ion residues from the United Kingdom.