Document Y9Vb5JNjrxRY3GLndYaymR1xO

origin. In (he Australian samples, residues derived from DDT (dicophene) were at levels broadly similar to those in homeproduced mutton'Tat, but in the New Zealund samples these residues were markedly, higher. Beef fot from home-killed nnimali tended to have lower residues of BHC and dieklrin than did the corresponding mutton fat samples over the period 1963-69. The cattle examined were approximately evenly divided between store-fed animals and those predomi nantly grass-fed. This might have given some indication as to the source of the residues detected, but in fact the mean residue levels for the two sets of samples were wy similar. Imported beef samples examined were mainly of Argentinian origin until 1969. Residues in these samples tended to be variable, but in general BUC and dicldrin levels were some what higher than in home-produced beef fat, white DDT- derlved residues were slightly lower. The results for mutton and beef fats are summarized in Table 11; (hose for butter are listed In Table III. By 1970 the high concentrations of dicldrin, at one time so characteristic of home-produced mutton fat, were no longer found, and the annual arithmetic mean was down to 0.01 mg/kg. It was also apparent that the residue levels in homeproduced beef, and in (he major imports of beef and mutton, were either stable or tending to decrease, and continuous monitoring was suspended. The examination of New Zealand mutton fat was continued at a reduced level and Yugoslav and Irish beef fats were also sampled at a low rate. With the entry or the UK into the European Economic Community (EEC) in January 1973, up-to-date data were needed to provide evidence on which the merits or otherwise of alternative control procedures could be discussed. In conse quence, the sampling of home-produced mutton and beef fats was resumed towards the end of 1973, a limited sampling scheme for (he fat of these and other meats imported from within the EEC having been started somewhat earlier. Residues of hcxachlorobctuene are normally negligible in IJK-produced animal fats and no serious attempt had been made in the earlier surveys to record die trace quantities some times encountered. However, this compound assumes more importanceamong (hose residues found in the produccofsome oilier countries. Thcie Is also strong presumptive evidence for the presence of traces of polychlorobiphenyls (PCTI) in the fatty products and these have also been estimated. As early as 1963, a series Harold Egan A A. W. Hubbard of unknown comixnmdi was observed during the course of residue analyses; subsequently these were recognized as indicating the presence of PCB compounds (New ScitMist, 1966). Peaks suggestive of the presence of PCB were recog nized on the chromatograms given by occasional samples of bulk milk early in 1967; whilst originally relatively insignifi cant in sire, more prominent peaks appeared as the year progressed. Two samples of the 19 examined between July and September 1967 contained an estimated 0.002.mg PCB/I, calculated on n whole-milk basis, white two out of 18 samples examined between October and December of the same year contained 0.003 mg PCB/I and 0.01 Sing PCB/I. The bulk samples continued to give occasional PCB-type chromato graphic traces during 1968, but no sample contained an amount of PCB in excess of an estimated 0.002 mg/I. Again, during 1969, PCB-type (races occurred erratically, the esti mated maximum PCB content for the year being 0.003mg/I. Some results obtained as part of the 1970-72 Total Diet Study are shown in Table IV; in this, 33 samples of each of the seven food groups comprising the total diet were examined, making 383 samples in all. PCBs were detected in only the 13 samples of milk and cereals indicated. The only other food in which PCBs were noted consistently was Ash within the meat and lish group. The results for samples taken in 16 in dividual towns und cities in the UK and the Channel Islands during the period between April and September 1971 arc shown in TaNe V. The levels of PCB compounds when they occur in foods are thus very low. The highest value found in the milk samples in 1967, if converted to an "in fat'* bests, is 0.5 mgPCB/kg. which is well below the temporary tolerance level set in the USA. i. Othrr Pr.ttieUhs Limited surveys have also been made of specific organophosphorus insecticide residues in particular crops, including demeton-methyl and dimethoate residues in Brussels sprouts, lettuce, green pens. French-beans, potatoes and strawberries (Lee, 1968a), and malathion In imported cereals (Hill A Thompson, 1968; Thompson A Hill, 1969b). Similarly, potatoes and carrots have been examined for aklna and dieklrin residues (Lee, 1968b), as have welfare foods (dried full-cream milk, cod-liver oil and concentrated orange juice) (Ruzicka, Simmons A Tatton, 1967), eggs and poultry (Findlay A Hamilton, 1968; -Holmes, Simmons A Tatton, 1961), and Tam.! IV. Estimated concentrations of polychlorobiphenyls (PCS), expressed in mg/kg, in total diet samples In the UK, in 1970-71 re r timpU *rs*S Ort. to Otc. 1970 Lectiten, eviMiMsS ssecswrstiei* ! rCBt In ttw sr>e: /*. is M*r. 1971 A*r. i June* *7 J )vir is if*. H7i 'Ctrtlll heat* Green vegetables Milk /Norwich,0,10 \ \ Newcastle, 0.01 / ND NO (Aberdeen, 0.002 Glasgow. 0.002 (Sheffield. 0.002 Norwich, 0.0$ London, 0.02 Torquay, 0.01 Aberdeen, 0.002 \ Brighton, 0.002 ) Liverpool, 0.002 1 Norwich, 0.04 ND NO NO Norwich. 0.02 NO NO NO NO: PCBi not delected in any temple, nor were they detected tn these four periods in the three remaining groups; fats, fruits and preserve*, and root vegetables HONS QbZZZQ 204 Br Med 8tdL 19H ANALYTICAL SURVEYS OF FOOD Harold Egan & A. W. Hubbard ABU V. Estimated PCS concentration (mg/kf) of tho compositi fish component lamplai of the total dlat In tha British Isles, in If7l iMMlea Apr. in )** 1*71 Mr i*7l bargain Him Ngtaeft ardt* eafcstawn diafeurgh ksgaw klay (verges! Oftgon -Jewcattla Harwich t Hailar (lariay) HtAeM hrawibvry faramy <0.01 0.02 <0.01 0.01 0.06 <0.01 <0.01 <0.01 <0.01 <0.01 0.03 9.02 0.01 <0.01 <0.01 o.os Abbreviation: NS: No tampl* received <0.01 <001 NS <0.01 <001 0.H NS <0.01 o.os 0.01 0.03 NS NS <0.01 <0.01 cereals, pulws and nuts (Hill, Fishwick A Thompson, 1973). Oth'* limited surveys have been made of bromide residues In vet and pulses (Thompson A Hill, 1969a; Hill A Thompson, 1973) and of triphcnyltin residues in potatoes (Thomas A Tann, 1971). h. Toxic Metal* Ruiicka A Egan (1971) have recently reviewed the occur rence of traces of mercury, lead, cadmium, arsenic and sele nium in food. I. Mercury1 The two reports on mercury published (o dale by (he Working Party on Use Monitoring of Foodstuffs for Heavy Metals have indicated an average dietary intake or 5-10m nwreury/day and that this intake is largely determined by the Ash component of the diet (Ministry of Agriculture, Fisheries and Food, 1971. 1973b). Most food-stuff*, with Use exception of certain coastal Ash and shell-fish, contain very low concen trations of mercury, mainly in the form ofmethylmercury com pounds. After publication of the supplementary report it wax recommended that monitoring for mercury should be confined to periodic total diet studies duringthe following five years and that particular arcus ofcontamination by mercury, notably dis charges into waters where Ash might be affected, should be sought out. Total diet studies are thus in progress, with those for 1974 currently being cvaiuuied; at the same lime, fisii me being monitored continuously for traces of heavy metals by the Ministry of Agriculture, Fisheries nnd Food. The tolciable weekly intake of mercury by adults was pro* visional))- | at 0 3mg by the Joint l-'AO/W} IO Lxpcrt Committee on Food Additives in 1971 (World Health Organi sation, 1972), the corresponding figure for methylmercury < oundt (included in the above) being 0.2 mg for cuch a.-.i, as shown in Table VI. tt. Cadmium* Three thousand, five hundred samples of food-stuff-* were examined for the survey described in tire report (Ministry of ft* Mm<>V pp. 241-247 or (tiii Bulkltn--Ft). * SM W<bt>, pp. 24*-270 of llik fliillfini.- I p. Agriculture, Fisheries and Food, 1973a); in most of these the concentrations of cadmium were below the limit of detection (0.01 mg/kg). In those samples in which cadmium was de tected, the concentrations generally did not exceed 0.04 mg/kg. Higher concentrations were, however, found in some animal kidneys and fresh vegetables, but these were significantly lower than those found in cerluin sheii-Ash. The brown body meat of crabs has been found to contain a relatively high concen tration of cadmium, ranging from 0.78mg/kg to 21 mg/kg. compared with that of the while claw rtwat In which the average was 0.24mg/kg and the range was O.I3mg/kg to 0.33mg/kg. Crawfish, lobsters and nephrops, of which only the white meal Is eaten, contained relatively small concentra tions, with a maximum of 0.75mg/kg. With few exceptions, molluscs generally contained only small concentrations. The total diet studies conducted as described above also showed that few of the samples contained concentrations above the limit of detection and practically all the milk samples had less than 0.005mg cadmium/l. As a result, the cadmium content of the total diet sample cannot be estimated precisely and is better expressed in terms of the likely range of concentrations. On this basil, the cadmium concentration of the average diet is probably between 0.01 mg/kg and 0.02 mg/kg, corresponding to a weekly intake by each person of about 0.1 mg to 0.2mg. The survey was able to distinguish areas (hat were particularly polluted, by means of the range of values found in locally grown crops or in local shell-fish. Crops grown near to a metal refinery were found to contain higher than average values of cadmium, and coastal estuaries used for the dumping of reftnery waste contained molluscs with above average levels of cadmium. Because the consumption of sheil-fish by people in the l/K ts low, the contribution of cadmium to the average diet from this source is negligible. In general, it was felt that cadmium intake in the country as a whole posed no hazard to health and it was recommended (hat no statutory limits for the amounts of cadmium in food were necessary. The moni toring of cadmium in (he UK continues through the Total Diet Study. iii. LewI* The Working Party on the Monitoring of Foodstuffs for Heavy Metals completed (he survey of lead in food in 1972 (Ministry of Agriculture, Fisheries and Food, 1972). Unlike mercury, lead is widely distributed in foods (Egan, 1972), al though lire amounts found are dependent on the nature of the Tails VI. Amount of the weekly intake of trace metals (expressed in mg/person) in the total diet 1 < tc inml Fro-lilon*! lelrrtbf* wttklf <M*kt ' W*#kl. intik* Mint** Sr tillin' Mercury Total mercury Methylmercury (expressed a* mercury) lead Cadmium 0.) 0.2 3.0 (AdullJ only) 0.4-0.S _0,035-0.070 14 0.10-0.21 Data (rofn World Health Organization (1772) < Site Clarion, pp. 2l6-24l>oftM Dolinin.--! D 205 PONS 062221