Assuring food safety: the complementary tasks and standards of the World Organisation for Animal Health and the Codex Alimentarius Commission.

The Agreement on the Application of Sanitary and Phytosanitary Measures of the World Trade Organization specifically recognises the international standards developed by the World Organisation for Animal Health (OIE) and the Codex Alimentarius Commission (CAC). OIE standards focus on animal health and zoonoses and those of the CAC on food safety, but since zoonoses can affect food safety, it is vital that the two organisations cooperate closely to avoid duplication of effort, gaps and conflicting standards. The OIE has established an Animal Production Food Safety Working Group to promote cooperation with the CAC and to act as a steering committee for the OIE's work programme on the development of standards aimed at protecting consumers from foodborne hazards arising from animals at the production level of the food chain. This paper describes briefly how standards are developed by the OIE and the CAC and gives examples of how the tasks and standards of the two organisations complement each other in helping to assure food safety. The areas covered include meat hygiene, the identification and traceability of live animals, model certificates for international trade, antimicrobial resistance, veterinary drugs, animal feed, and salmonellosis.

Organochlorine pesticides, polychlorinated biphenyls and dioxins in human milk from Swedish mothers.

Ten human milk samples, collected from two towns, Uppsala and Sundsvall, in Sweden in 1994 were analysed for selected chlorinated pesticides (HCB, alpha- and gamma-HCH, DDT, DDD and DDE) and PCB congeners (PCBs 28, 77, 101, 105, 118, 126, 138, 153, 156, 158, 167, 169 and 180), PCDDs and PCDFs. The levels found in this study, including the toxic equivalent (TEQ) values, showed a slight downward trend between 1986 and 1994 and are somewhat lower than levels reported from other countries. The contribution of both the mono- and non-ortho PCBs, together with that of PCDD/Fs to the total TEQ values was assessed. Over 70% of the TCDD equivalents was derived from PCBs, PCB 126 being the major contributor. Other high PCB contributors were PCBs 156 and 118. The levels of HCB, alpha- and gamma-HCH, and sigma DDT were generally higher in Uppsala than in Sundsvall. They were, however, over 50% lower in 1990 than in 1986 and have since changed little. For the PCDD/Fs the results show a marked decrease (ca 50%) in levels between 1986 and 1994. There is an indication that PCB 153 and PCB 126 may be good indicators for total PCB and TEQ levels respectively.

Organochlorine contaminants in Swedish human milk: studies conducted at the National Food Administration 1981-1990.

The concentrations of selected organochlorine contaminants in Swedish human milk have been determined in a number of studies conducted at the National Food Administration during the 1980s. It was shown that the time of sampling post-partum (subsequent to childbirth) had little effect on the levels of the DDT complex, beta-HCH, HCB and PCBs in breast milk fat. However, the levels of these compounds decreased with increasing parity (number of children born). For this reason it is recommended that primiparae (women nursing their first child) be sampled when comparing levels over time and in milk from mothers from different geographical areas. The levels of organochlorine compounds in the fat of breast milk from primiparae living in different parts of Sweden were similar. Finally, a study on time trends in concentrations of these compounds in milk from mothers living in Uppsala showed that a marked decline in levels has taken place during the 1980s.

Integrated personal monitoring of cadmium exposure in Sweden.

Methods for the personal monitoring of human exposure to cadmium from air, food and beverages were studied in a group of 15 non-smoking women in Stockholm. Particles in the breathing zone air and duplicates of all food and beverages ingested were collected during seven consecutive days, as were faeces corresponding to the food ingested. Spot samples of blood and urine were also taken. The main sampling problems were caused by the noise of the personal air monitors and the short operation time of the batteries. On average, dietary cadmium (8.5 micrograms per day) contributed 99% of the total cadmium absorbed. There were large day-to-day variations in intake, most peaks corresponding to the consumption of seafood. Faecal cadmium was shown to reflect the total amount of cadmium ingested. There was a significant (p < 0.05) correlation between cadmium concentrations in blood (median 0.3 microgram/l) and average daily dietary intake of cadmium, but the blood cadmium levels could vary by a factor of four at one and the same average daily intake. The median urinary cadmium level was 0.2 microgram/l.

Methods for integrated exposure monitoring of lead and cadmium.

An international pilot monitoring study on exposure to lead (Pb) and cadmium (Cd) has been implemented in Beijing, Yokohama, Stockholm, and Zagreb as part of the UNEP/WHO human exposure assessment locations (HEAL) Program. The main objective was to develop and test methods, including methods for quality assurance, for monitoring of personal exposure to Pb and Cd. The study included analytical training for Pb and Cd in blood, air filters, dust, diets, and feces, as well as exposure monitoring activities in small groups of nonsmoking women, 23-53 years of age, during 7 consecutive days. Airborne particulates, duplicate diets, feces, and blood were collected. An extensive quality assurance program was implemented in order to assure the reliability and comparability of the monitoring data. The main problem in the sample collection was associated with the air monitoring. The pumps were noisy, and the batteries had to be recharged every 6-8 hr. Collection of duplicate diets during 1 week gave good estimates of average dietary intakes of Pb and Cd. The metal contents in feces were found useful for evaluation of total peroral intakes. The methods used made it possible to demonstrate that the diet was the main source of Cd exposure at all the HEAL sites.

Lead, cadmium, arsenic and mercury in meat, liver and kidney of Swedish pigs and cattle in 1984-88.

During the period 1984-88 several hundred samples of meat, liver and kidney from Swedish pigs and cattle were analysed for lead, cadmium, arsenic and mercury. Analysis was performed by AAS and extensive quality assurance was carried out. The mean lead levels in pig meat, liver and kidney were less than 0.005, 0.019 and 0.016 mg/kg, respectively: the mean levels in the corresponding bovine tissues were less than 0.005, 0.047 and 0.097 mg/kg. The mean cadmium levels in pig meat, liver and kidney were 0.001, 0.019 and 0.11 mg/kg, whilst those in the corresponding bovine tissues were 0.001, 0.070 and 0.39 mg/kg. The mean arsenic levels in pig meat, liver and kidney were 0.024, 0.023 and 0.019, respectively and those in the corresponding bovine tissues were lower, none exceeding 0.015 mg/kg. The mean mercury levels in pig meat, liver and kidney were 0.009, 0.015 and 0.019 mg/kg respectively, while those in the corresponding bovine tissues were 0.005, 0.006 and 0.010 mg/kg. A decrease in the levels of both arsenic and mercury in pig tissues was found during the period studied, which may be due to a decrease in the use of fish meal in pig feed.

Personal monitoring of lead and cadmium exposure--a Swedish study with special reference to methodological aspects.

Methods for determining personal exposure to lead and cadmium were tested in Stockholm in 1988. Lead and cadmium in breathing-zone air, 24-h duplicate diets, and feces of 15 nonsmoking women (27-46 years of age) were studied. Blood was collected at the beginning of and immediately after the test period (seven consecutive days). An extensive quality assurance program was included. Most technical problems were encountered in the 24-h collection of airborne particles. The pumps were noisy, and the batteries had to be recharged every 6-8 h. The lead and cadmium levels in feces were found to be useful indicators of the total ingested amounts of these metals. Because of the large day-to-day variation in the dietary intake of lead and cadmium, the sampling period for duplicate diets and feces should be at least 5-6 d.

Effects of the immunomodulator LS 2616 on lymphocyte subpopulations in murine Coxsackievirus B3 myocarditis.

Quinoline-3-carboxamide (LS 2616) is a broadly acting immunostimulator with anti-inflammatory effects in Coxsackie virus B3-induced myocarditis in female BALB/c mice. This infection caused extensive inflammatory and necrotic lesions in the myocardium 7 days after inoculation (6.8% of tissue section area). The damaged area was reduced (to 3.7% (p less than 0.05] and the lethality decreased when LS 2616 was administered over 14 days, starting 7 days before the inoculation. The response pattern of lymphocyte subsets in situ in myocardial inflammatory lesions was elucidated by a newly developed immune histochemical staining technique. LS 2616 increased the number of class II-expressing cells 3-fold (p less than 0.01) and the CTL, Ts:Th cell ratio by 55% (p less than 0.05), whereas Lyt-1+ and TIB+ cells were unaffected. After 7 days of LS 2616 treatment, spleen lymphocyte activity tended to increase (T cells by 21% (NS) and B cells by 60% (p less than 0.05), respectively). The activity of NK cells increased by 51% (p less than 0.01). LS 2616 may thus have potential in therapy of human inflammatory disorders, such as myocarditis.

Tobacco-specific N-nitrosamines in the saliva of habitual male snuff dippers.

Saliva was collected every ten minutes from habitual male snuff dippers and analysed for tobacco-specific N-nitrosamines (TSNA). Detectable levels of at least two TSNA were found in all samples collected between 10 and 30 minutes after the snuff had been placed in the mouth. Total concentrations of TSNA up to 241 ng/g were found in the saliva. Trace levels of TSNA were still found in the saliva 20 minutes after the snuff had been removed.

Lead in table wines on the Swedish market.

The levels of lead in 67 different table wines on the Swedish market in 1982 and 1986 have been determined by atomic absorption spectrophotometry. The mean level found was 73 micrograms/l (range 16-170 micrograms/l). Little difference was found between the levels in red, white and rosé wines (mean levels 76, 75 and 65 micrograms/l, ranges 16-120, 34-170 and 35-120 micrograms/l respectively). The average daily dietary intake of lead by adults in Sweden has been estimated to be about 30 micrograms, excluding any contribution from wines and spirits. The average adult per capita consumption of wine is about 45 ml per day. This would thus give an additional intake of about 3 micrograms of lead and the intake of lead could be doubled by consuming half a litre of wine daily.

Lead, chromium, tin, iron and cadmium in foods in welded cans.

The levels of lead, chromium, tin, iron and cadmium in fruit and vegetables in welded tinplate cans were determined by atomic absorption spectrophotometry. The levels found were compared with those in foods in soldered tinplate cans and fresh foods. The results show that the lead levels in foods in welded cans were much lower than those in similar foods in soldered cans. Foods in unlacquered welded cans contain much more lead, chromium and tin than foods in lacquered welded cans. The cadmium and iron levels in canned fruit and vegetables in welded cans were similar to those found in the corresponding fresh foods.

Dietary citric acid enhances absorption of aluminum in antacids.

Ten healthy men ingested, twice daily between meals, during each of the seven-day experimental periods: (a) citric acid (as lemon juice), (b) Al(OH)3, or (c) Al(OH)3 + citric acid. Whole blood sampled after each dietary period was analyzed electrothermally after digestion with nitric acid. Moderate, but significant, increases in mean Al concentrations as compared with pretreatment values [5 (SD 3) micrograms of Al per liter] were seen after ingestion of either citric acid or Al(OH)3: 9 (SD 4) and 12 (SD 3) micrograms/L, respectively. Ingestion of both Al(OH)3 and citric acid resulted in a more pronounced, highly significant (p less than 0.001) increase in Al concentrations, to 23 (SD 2) micrograms Al/L, probably owing to formation and absorption of Al-citrate complexes.

PCB levels in breast milk: data from the UNEP/WHO pilot project on biological monitoring and some other recent studies.

The levels of polychlorinated biphenyls (PCBs) in human milk provide an index of exposure of the mother to these compounds and enable the intake by the breast-fed child to be estimated. For valid comparisons between different studies, concentrations should be expressed on a milk fat basis. In a recently completed UNEP/WHO pilot project on monitoring of organochlorine compounds in human milk in ten countries, great emphasis was placed on analytical quality assurance. To obtain comparable data, a common procedure, that of Sawyer, was adopted for quantitation of PCBs, using Aroclor 1260 as standard. In addition, certain criteria (e.g., age and parity) were established for selection of the mothers to be sampled. In contrast to the situation with p,p'-DDT and p,p'-DDE, the levels of PCBs in human milk fat were higher in the European countries and Japan than in China, India and Mexico. In fact, PCBs were not detected in human milk in the latter three countries. Although PCBs were detected in some samples in the USA, the median level was below the limit of detection of the method used there (1 mg/kg fat). The median PCB levels reported from Belgium, Israel, Japan and Yugoslavia were 0.81, 0.45, 0.35 and 0.63 mg/kg fat, respectively. Higher median levels were reported from Sweden and the Federal Republic of Germany (0.97 and 2.1 mg/kg fat, respectively). The German samples were not analyzed by the Sawyer method.

N-nitrosamines in snuff and chewing tobacco on the Swedish market in 1983.

Snuff and chewing tobacco on the Swedish market in 1983 were analysed for tobacco-specific and volatile N-nitrosamines using gas chromatography--thermal energy analysis. All 36 samples of snuff analysed were found to contain detectable levels of N'-nitrosonornicotine, N'-nitrosoanatabine, N'-nitrosoanabasine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. Total tobacco-specific N-nitrosamine levels between 2.5 and 51 mg/kg wet weight were found, the mean level being 8.8 mg/kg. Detectable levels of at least two of the four tobacco-specific N-nitrosamines were found in all 18 samples of chewing tobacco analysed. The total concentration of tobacco-specific N-nitrosamines found in chewing tobacco was between 0.1 and 7.8 mg/kg, the mean level being 2.1 mg/kg. The levels of volatile N-nitrosamines found in the 54 samples of snuff and chewing tobacco were very much lower--most of the samples contained less than 10 micrograms/kg and the highest concentration found was 550 micrograms/kg. Since snuff and chewing tobacco contain relatively high levels of carcinogenic N-nitrosamines and there is evidence of an association between the use of these tobacco products and human cancer, snuff and chewing tobacco users should be warned about the possible cancer risk involved in their habit. In addition, efforts should be made to reduce the levels of N-nitrosamines in snuff and chewing tobacco and the formation of these substances in the body from precursors originating from these tobacco products.

Volatile N-nitrosamines in snuff and chewing tobacco on the Swedish market.

Snuff and chewing tobacco on the Swedish market in 1981-82 were analysed for volatile N-nitrosamines using gas chromatography-thermal energy analysis. Detectable levels of N-nitrosodimethylamine and N-nitrosopyrrolidine were found in nearly all of the 36 samples analysed. N-nitrosopiperidine and N-nitrosomorpholine were also found in some samples. The total concentration of volatile N-nitrosamines found in any sample was between 0.5 and 145.9 micrograms/kg wet weight. Storage of snuff in unopened boxes for 20 wk at -20, +2 or +23 degrees C resulted in small but statistically insignificant changes in the volatile N-nitrosamine content. Storage for 20 wk at +2 degrees C in boxes that had been opened and resealed led to a larger but statistically insignificant increase in the mean level of total volatile N-nitrosamines. The levels of volatile N-nitrosamines found in Swedish snuff in 1981 and 1982 were significantly (P less than 0.05) lower than those found in 1979. It is estimated that in Sweden today the use of snuff can increase the normal intake of the N-nitrosamines studied here by about 10 to 100%.

The WHO/UNEP Pilot Project on Assessment of Human Exposure to Pollutants through Biological Monitoring.

The objectives, development and current status of the WHO/UNEP Pilot Project on Assessment of Human Exposure to Pollutants through Biological Monitoring are described. The project is being carried out within the framework of UNEP's Global Environmental Monitoring System (GEMS) and is supported by funds from UNEP. The long-term objective is to develop and strengthen national, regional and global biological monitoring programmes that will make it possible to accurately assess human exposure to selected toxic pollutants by measuring their concentrations in human tissues and body fluids. In this pilot project the levels of lead and cadmium in venous blood, cadmium in kidney cortex and certain organochlorine compounds in breast milk are being determined in selected population groups in 10-12 countries in different parts of the world. Each participating laboratory has been required to achieve satisfactory results in the quality assurance phase of the project before starting to analyse the human samples and quality assurance has been continued during the monitoring phase. The project started in 1978 and is scheduled for completion by July 1982.

WHO collaborative breast feeding study. I. Organochlorine contaminants in individual samples of Swedish human milk, 1978--1979.

Individual samples of human milk collected in Uppsala at 3 months post-partum (18 samples) or 6 months post-partum (23 samples) were analysed for chlorinated insecticides and polychlorinated biphenyls (PCBs) by gas chromatography. The mean levels of the organochlorine compounds in the 3- and 6-month groups were similar. The mean content of DDE, the major metabolite of DDT, in all the samples was 54 micrograms/kg fresh weight (1.3 mg/kg on a fat basis) with a range of 8.4--220 micrograms/kg (0.49--3.0 mg/kg fat). The results confirm that the decline since 1967 in the levels of DDT and its metabolites in Swedish human milk reported by other authors is continuing. The levels of dieldrin and beta-hexachlorocyclohexane found are lower than those reported earlier in Sweden, whereas the levels of hexachlorobenzene are about the same. On the other hand, the levels of PCBs (mean 64 micrograms/kg, range 15--150 micrograms/kg, fresh weight, equivalent to 1.6 mg/kg, range 0.84--2.9 mg/kg, on a fat basis) are higher than those reported earlier in Swedish human milk. Although the calculated intake of the DDT complex (DDT + DDE + DDD) by some of the suckling infants exceeds the acceptable daily intake proposed by a FAO/WHO expert group, it does not constitute a reason for recommending any restrictions on breast feeding--for nutritional, immunological and other reasons it should be encouraged.

WHO collaborative breast feeding study. II. Levels of lead and cadmium in Swedish human milk, 1978-1979.

Individual samples of human milk collected in Uppsala at 3 months post partum (18 samples) and 6 months post partum (23 samples) from 21-35-year-old healthy mothers were analysed for lead and cadmium by flameless atomic absorption spectrometry. The median lead content in the 41 samples was 2 microgram/kg fresh weight (range 0.5-9.0 microgram/kg), and the median cadmium level was 0.1 microgram/kg. There were no appreciable differences between the 3-month and 6-month samples as regards lead or cadmium levels. The calculated median weekly intakes of lead and cadmium by the 3-month-old infants (who received nothing else except breast milk) were approx. 2 microgram and 0.1 microgram/kg body-weight, respectively. There is no reason to believe that these low intakes of lead and cadmium constitute any risk to the health of the child. The intake of these metals by the breast-fed infant is likely to be the same as or somewhat lower than that of infants fed human milk substitutes and certainly less than that of children fed cereal-based infant foods.