Lars Jorhem

Lead and cadmium levels in human milk and blood

Lead and cadmium levels were determined (with AAS) in blood and milk obtained at 6 weeks after delivery from women living in the vicinity of a copper and lead metal smelter and in a control area. Analysis of lead and cadmium were also performed in blood samples obtained at delivery. Accuracy of the analysis was confirmed by the analysis of quality control samples. In general, blood and milk levels of lead and cadmium were low in both areas. At 6 weeks after delivery the lead levels in blood and milk were 32 +/- 8 and 0.7 +/- 0.4 micrograms Pb/l, respectively (total mean +/- S.D., n = 75). Cadmium levels in blood and milk were 0.9 +/- 0.3 and 0.06 +/- 0.04 microgram Cd/l, respectively (n = 75). At delivery the lead levels in blood of women in the smelter area were higher, 38.7 micrograms Pb/l, than the blood lead levels in women from the control area, 32.3 micrograms Pb/l, (P < 0.001). At 6 weeks after delivery there was no difference in blood lead levels between the two groups. In contrast, the lead levels in milk were higher in women from the smelter area, 0.9 microgram Pb/l, than in women from the control area, 0.5 microgram Pb/l, (P < 0.001). No differences in blood cadmium levels were found between the two groups. Milk cadmium levels in women from the control area, 0.07 microgram Cd/l, were somewhat higher (P < 0.01) than in women from the smelter area, 0.05 microgram Cd/l.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Elements in rice from the Swedish market: 1. Cadmium, lead and arsenic (total and inorganic)

A survey of the levels of cadmium, lead and arsenic in different types of rice available on the Swedish retail market was carried out in 2001–03. The types of rice included long and short grain, brown, white, and parboiled white rice. The mean levels found were as follows: total As: 0.20 mg kg−1, inorganic As: 0.11 mg kg−1; Cd: 0.024 mg kg−1; and Pb: 0.004 mg kg−1. ICP-MS was used for the determination of As (total and inorganic) after acid digestion. Lead and cadmium were determined using graphite furnace atomic absorption spectrometry (GFAAS) after dry ashing. In countries where rice is a staple food, it may represent a significant contribution in relation to the provisional tolerable weekly intake for Cd and inorganic As.

The levels of zinc, copper, manganese, selenium, chromium, nickel, cobalt, and aluminium in the meat, liver and kidney of swedish pigs and cattle.

ZusammenfassungEs wurde der Gehalt an Zink, Kupfer, Mangan, Selen, Chrom, Nickel, Kobalt und Aluminium in Fleisch, Leber und Nieren vom Schwein und Rind aus schwedischen Schlachthäusern bestimmt. Diese Ergebnisse wurden mit denen anderer Untersuchungen verglichen. Die Durchschnittswerte für Zink, Kupfer, Mangan und Selen in verschiedenen Geweben waren ungefähr die gleichen wie in früheren Untersuchungen; die für Chrom und Nickel lagen alle im Intervall <0,010 bis zu 0,015 mg/kg, unabhängig von der Art der Gewebe, und die für Kobalt zwischen 0,001 und 0,043 mg/kg, mit den höchsten Werten in der Leber. Für Aluminium ergaben sich Durchschnittswerte zwischen 0,024 und 0,068 mg/kg, wobei die Gewebe vom Rind ungefahr doppelt so viel Aluminium enthalten wie die Gewebe vom Schwein. Die analytische Qualitätskontrolle wurde mit Referenzmaterial durchgeführt. Viel Arbeit wurde zur Minimierung und Kontrolle der Kontamination aufgewendet. Das kann zu einem Teil erklären, daß die Werte von Chrom, Nickel und Aluminium unserer Untersuchung zu den niedrigsten bisher veröffentlichten Werten gehören.SummaryThe levels of zinc, copper, manganese, selenium, chromium, nickel, cobalt, and aluminium were determined in samples of meat, liver and kidney from pigs and cattle from Swedish slaughterhouses. The results have been compared with those reported from other investigations carried out in recent years. For zinc, copper, manganese and selenium, the mean levels found in the different tissues were very similar to those reported in previous studies. The mean levels of chromium and nickel were found to be in the range <0.010–0.015 mg/kg, regardless of the type of tissue. Cobalt levels ranged from 0.001 to 0.043 mg/kg, the highest levels being in the liver samples. The mean levels of aluminium were between 0.024 and 0.068 mg/kg. Tissues from cattle contained approximately twice as much aluminium as tissues from pigs. Analytical quality assurance was carried out by analysing standard reference materials. A great effort was made to minimize and check contamination. This may partly explain the fact that the levels of chromium, nickel, and aluminium found in the present study are among the lowest reported.

Lead poisoning in cattle — transfer of lead to milk

The transfer of lead to milk in cattle in relation to blood lead levels and the uptake of lead in edible tissues was studied for an accidental exposure over 1 or 2 days to lead in excessive amounts from the licking of burnt storage batteries. The degree of exposure was monitored by determination of blood lead levels. Milk and blood samples were taken from eight cows, without acute symptoms of lead poisoning, during a period of 18 weeks. Two weeks after the accidental exposure, lead levels (mean +/- SD) in milk were 0.08 +/- 0.04 mg kg-1 and in blood 0.36 +/- 0.04 mg kg-1 in six of the cows. The relationship between lead concentration in blood and those in milk was found to be exponential and could be expressed by the equation: log y = 3.19x - 2.36 (r = 0.85, p less than 0.001), where y and x are the lead concentrations in milk and blood, respectively. The lead level in milk was relatively constant up to a blood lead level of 0.2-0.3 mg kg-1, and increased sharply at higher blood levels. The biological half-life of lead in blood was shown to be approximately 9 weeks. In eight acutely sick cows, which were emergency slaughtered, the range of lead levels in edible muscle tissue was 0.23-0.50 mg kg-1 wet weight. Very high concentrations were found in the kidneys, with a range of 70-330 mg kg-1, and in the livers, with a range of 10-55 mg kg-1. Four of the cows were pregnant, in the first or second month of gestation, during the episode of exposure. The lead exposure was not found to disturb the gestation or development of the fetuses.

Levels of some trace elements in edible fungi

A number of common edible fungi were analysed for their contents of Pb, Cd, Cr, Ni, Co, Zn, Cu, Mn and Se. The results indicate that the Cd level in the speciesRozites caperata can be as high as several mg/kg fresh weight. InLycoperdon perlatum andMacrolepiota procera the Pb level was found to be up to 2.5 mg/kg. The Ni level was at or below 0.1 mg/kg in all species, with the exception ofAlbatrellus ovinus, which had a mean concentration of 0.72 mg/kg. The level of Cr was highest inM. procera with a mean of 0.091 mg/kg. In a single sample of the speciesAgaricus augustus, the concentration of Co was found to be exceptionally high at 0.28 mg/kg. Zn and Cu levels were highest inL. perlatum andM. procera. Mn levels were fairly similar in the different species. The results of several surveys show that there can be large differences in the concentrations of the same metal (e.g. Pb) in the same species. The Se level was found to be very high in the speciesBoletus edulis, as has been shown by others. In the other species analysed the level of Se was low.

Placental and lactational transfer of lead in rats: a study on the lactational process and effects on offspring.

The effects of placental and lactational exposure to lead (Pb) were studied in suckling rats after long-term exposure of their dams to Pb in drinking water. Dams were given 12 mM Pb-acetate in the drinking water 8 weeks prior to mating and during gestation. One group of dams was also continuously exposed during lactation until day 15. Neonates from Pb-treated dams were cross-fostered at birth to control dams treated with Na-acetate (12 mM) in the drinking water. In the same way, neonates from dams receiving control water were in the same way cross-fostered to Pb-exposed dams. All animals were killed at day 15 of lactation, when measurements were performed. Continuous Pb exposure during gestation and lactation resulted in milk Pb levels approximately 2.5 times higher than the blood Pb levels. When Pb exposure was terminated at parturition the milk Pb levels were at a level similar to those of blood Pb at day 15 of lactation, and only 10% of the milk levels found after continuous Pb exposure. Exposure to Pb via placenta and milk in offspring from dams exposed continuously resulted in more than 6 times higher blood and brain Pb levels than in offspring exposed only via the placenta. Exposure only via milk in offspring from dams exposed to Pb until parturition resulted in higher blood Pb levels than in offspring exposed to Pb only via the placenta. This indicates that the lactational transfer after current or recent exposure of Pb in dams is considerably higher than placental transfer. Offspring in all the exposed groups had decreased ALAD activity in the blood. An exponential relationship between blood Pb levels and ALAD activity was demonstrated in the offspring. Due to the exponential decrease in ALAD activity at increasing blood Pb levels, ALAD is particularly sensitive in reflecting differences in Pb exposure within the lowest range of blood Pb levels. There was a slight effect on weight gain in the offspring. However, there was no effect on milk quality, as measued by milk lipid, protein and calcium concentrations, nor on milk production assessed by the mammary gland RNA and DNA content. This indicates that the effect on weight gain was a direct effect of Pb in the offspring.

Accumulation of cadmium from wheat bran, sugar-beet fibre, carrots and cadmium chloride in the liver and kidneys of mice

The gastrointestinal absorption and organ distribution of Cd after exposure for 9 weeks to three fibre-rich foodstuffs (wheat bran, sugar-beet fibre and carrots) were determined in mice. Groups of eight mice were given a diet containing 0.05 mg Cd/kg from wheat bran, sugar-beet fibre, carrots or CdCl2 mixed in a semi-synthetic, low-Cd (< 0.007 mg/kg) feed. A control group was fed on the low-Cd semi-synthetic feed. The water consumption, food consumption and the weight of the animals were monitored throughout the study. The feed was changed once weekly and Cd was analysed in the feed at each change. myo-Inositol phosphates (hexa-, penta-, tetra- and tri-) and Zn, Cu, Fe and Ca were also analysed in the diets. After 9 weeks, the mice were killed and liver and kidneys were sampled and analysed for Cd. The group receiving the wheat-bran diet had significantly lower fractional Cd accumulation (% total Cd intake) in the liver and kidneys than the other groups, indicating a lower fractional absorption of Cd. The wheat-bran diet had markedly higher levels of inositol hexa- and pentaphosphates (phytates) and a Zn level that was twice as high as those in the other diets. The higher levels of myo-inositol hexa- and pentaphosphates in the wheat-bran diet most probably contributed more to the lower fractional absorption of Cd than the elevated Zn level, due to the formation of insoluble Cd-phytate complexes. Compared with the wheat-bran diet, the sugar-beet-fibre and carrot diets contained very low levels of myo-inositol penta- and hexaphosphates, and consequently the fractional Cd absorption from these diets was higher.

Does organic farming reduce the content of Cd and certain other trace metals in plant foods? A pilot study

The effect of organic cultivation systems on the level of Cd in wheat was studied in two consecutive harvests. Additionally, the concentrations of Cd, Pb, Cr and Zn were analysed in single harvests of rye, carrots and potatoes from different farming systems. Wheat and rye were obtained from controlled field trials using several conventional and ecological systems at two separate locations in Sweden. Potatoes and carrots were collected at private farms with conventional or ecological production. These farms were juxtapositioned and had similar soil properties. The levels of Cd in the wheat did not correlate with the cultivation system or the Cd content in the soil. Conventionally grown wheat from one field trial showed a significantly higher Cd level compared with ecologically grown wheat, while in the other field trial significantly lower Cd levels were detected in the conventionally grown wheat. No statistically significant differences in the concentrations of Cd, Pb, Cr or Zn in rye, carrots and potatoes were detected between the cultivation systems. The results indicate that organic farming, at least in the short term, does not necessarily result in reduced levels of Cd and other potentially harmful metals in foods of vegetable origin. Factors other than cultivation system may be of greater importance for the final concentration of Cd and other metals in plant foods. © 2000 Society of Chemical Industry

Aluminium in foodstuffs and diets in Sweden

ZusammenfassungDie Menge an Aluminium wurde in einer Anzahl von Lebensmittelrohstoffen, Grundnahrungsmitteln und von Duplikaten der Mahlzeiten von in Stockholm lebenden Frauen bestimmt. Die Resultate ergaben, daß die Aluminiumkonzentrationen in den meisten der Einzelprodukte sehr niedrig waren; bei Gemüse z. B. variierten diese je nach Art bis zum Faktor 10 und bei Getränken in Aluminiumdosen zeigten sich kaum Unterschiede zu jenen in Glasflaschen. Berechnet man den Aluminiumgehalt der durchschnittlichen täglichen Mahlzeit aus jenen in einzelnen Komponenten enthaltenen Mengen, aus denen sich die Mahlzeiten zusammensetzen, so kommt man auf 0,5 mg, während die experimentellen Bestimmungen einen Durchschnittswert von 13 mg ergaben. Einen wichtigen Beitrag zu dem hohen Aluminiumgehalt liefert das zur Zubereitung eines Kuchens verwendete Aluminiumphosphat enthaltende Backpulver. Tee und Aluminiumbestecke sind weitere Al-Lieferanten und erhöhen die tägliche Menge auf 24 mg. Aus dem Analysenergebnis ergibt sich die Schlußfolgerung, daß noch andere derzeit noch nicht identifizierte Quellen einen nennenswerten Beitrag zur Aluminiumzufuhr leisten müssen.SummaryThe levels of aluminium have been determined in a number of individual foodstuffs on the Swedish market and in 24 h duplicate diets collected by women living in the Stockholm area. The results show that the levels in most foods are very low and that the level in vegetables can vary by a factor 10. Beverages from aluminium cans were found to have aluminium levels not markedly different from those in glass bottles. Based on the results of the analysis of individual foods, the average Swedish daily diet was calculated to contain about 0.6 mg aluminium, whereas the mean content of the collected duplicate diets was 13 mg. A cake made from a mix containing aluminium phosphate in the baking soda was identified as the most important contributor of aluminium to the duplicate diets. Tea and aluminium utensils were estimated to increase the aluminium content of the diets by approximately 4 and 2 mg/day, respectively. The results also indicate that a considerable amount of aluminium must be introduced from other sources.