Some dietary predictors of plasma organochlorine concentrations in an elderly German population.

Associations between reported consumption of animal products and chlorinated hydrocarbon concentrations were examined in 297 elderly people who lived in Germany. Consumption of beef and lamb was correlated positively with hexachlorobenzene (HCB), beta-hexachlorocyclohexane (beta-HCH), total polychlorinated biphenyls (PCBs), and total dichloro-diphenyl-trichloroethane (DDT) (r = .13-.19, p < .05). Consumption of saltwater fish was correlated positively with alpha-HCH, dieldrin, and PCBs (r = .12-.26, p < .05). Other univariate predictors were body mass index, plasma cholesterol, pork consumption, poultry consumption, and age. Multivariate linear models of predictors of each chlorinated species were constructed, and some form of meat was used as the main predictor; the sum of all meats (exclusive of fish) was the best predictor of dieldrin and In(alpha-HCH) concentrations. Beef and lamb consumption was a positive predictor of HCB, heptachlor epoxide, total DDT, and beta-HCH. Saltwater fish was the major dietary predictor of PCBs.

[The significance of mycotoxin assimilation for the contamination of milk and milk products]. / Bedeutung einer Mykotoxin-Aufnahme für die Kontamination von Milch und Milchprodukten.

The two possible pathways contaminating milk and milk products with mycotoxins are either the secretory or post-secretory route. The latter is of only little importance due to cooling conditions in production and storage. A secretory contamination can only occur with such mycotoxins, which undergo no complete degradation through their passage into the milk. From the mycotoxins, present in cow's feed; virtually only aflatoxin B1 yields a milkborne metabolite, the aflatoxin M1. The carry over rate is low (2 +/- 1%), but can be enhanced by polyhalogenated biphenyls, also present in the forage. Under normal conditions, however, this enhancement will not be measurable due to low equimolar concentrations of both reactants. The aflatoxin M1 content in herd's bulk milk depends exclusively on the content of the precursor aflatoxin B1 in the ration of the cow and is with less than 10 ng/kg fairly low at present in the Federal Republic of Germany. A careful supervision of the imported feed ingredients for mixed feed, however, will ensure to keep those batches out of dairy cow feeding which exceed a certain level of aflatoxin. The legal threshold is 10 micrograms/kg, being even too high to ensure a milk containing less than 10 ng/kg under high energy feeding conditions. The discussed thresholds for aflatoxin M1 in milk are 50 and 10 ng/kg resp., the latter value is scheduled for milk used in infant nutrition. To keep this low concentration the intake of aflatoxin B1 must be less than 2 micrograms/kg of the daily ration.

[BSE: milk and risk potential?]. / BSE: Milch und Risikopotential?

A potential BSE risk for milk and milk products has to be evaluated by means of risk analysis, especially risk assessment. The 3rd element of risk assessment--hazard exposition--is of decisive significance. In 1997, the Scientific Steering Committee of the European Commission has categorized risk materials in 4 classes. Colostrum, milk and tissues of the mammary gland have been classified in category 4, i.e. "infectivity not detected". A secondary contamination of the milk can be excluded (living animals). However, the term "not detected" refers also to the low sensitivity of the mouse test, which has to be taken into consideration. Therefore, in 2000 investigations started in Great Britain to test milk fractions, especially the fraction of somatic cells, for the possible occurrence of prions, using newly developed and highly sensitive methods. Results can not be expected before 2003 at the earliest. In case prions would be detected, their biological activity has to be demonstrated in order to develop an appropriate risk assessment for the consumer. Investigations in Great Britain in the early nineties of the last century with suckling cows under practical conditions have shown no indications of a BSE transfer via the milk to the calves. Therefore, the statement of national and international organizations is still valid, that milk can be regarded safe according to the present state of scientific knowledge.

Detection of inhibitors in milk by microbial tests. A review.

The demands concerning microbial inhibitor tests were subjected to marked changes during the last decades: It started with the claim of being able to detect contaminated milk which might cause problems during fermentation processes ('technological safety'). Due to the present day attention drawn to toxic and allergic hazards for numerous antimicrobials Maximum Residue Limits (MRLs) or safe/tolerance levels are fixed ('toxicological safety'). This means a variety of demands underlying permanent changes with respect to the 'detection pattern' which cannot be fulfilled by a single test. Within an Integrated Detection System microbial inhibitor tests play an important role as screening methods for those antimicrobials which can be detected with satisfactory sensitivities. This paper deals with some features of microbial inhibitor tests such as detection limits, performance susceptibility for interference factors, qualitative determination and standardization.

[Residues of chlorinated hydrocarbons in milk and milk products - situation and evaluation (author's transl)]. / Rückstände chlorierter Kohlenwasserstoffe in Milch und Milchprodukten - Situation und Bewertung

Residues of the most varied chemical substances can be found in milk and in milk products. For the transfer into milk such factors as fat solubility, persistance with respect to metabolic processes and accumulation capacity in certain organic systems are of particular importance. For the description of the situation with respect to residues of chlorinated insectides the results of analyses obtained in 20 supply areas of the German Federal Republic are presented and interpreted. In 1974 the following mean values were found (fat basis): alpha-HCH 0.04, gamma-HCH 0.072, heptachloro-epoxide 0.024, dieldrin 0.021 and DDT 0.20 ppm. These mean values are far below the max. quantities legally permissible and in no way constitute a toxicological risk (referred to ADI). In the German Federal Republic the concentrations of hexachlorobenzene in some cases reach the permissible max. quantity of 0.5 ppm on a fat basis. There is reason to assume that this substance finds its way into the milk not only via its application as a fungicide but probably also via a number of other, in part unknown, sources of contamination in or on vegetable products. With PCB (polychlorinated biphenyls) average concentrations from 0.2 to 0.3 ppm must be expected to be present in milk and milk products (fat basis). At present a toxicological interpretation of the values found is hardly possible.

[Demonstration of chlorinated hydrocarbons in follicular secretions]. / Nachweis von Chlorkohlenwasserstoffen in Follikelsekreten.

To determine the concentration of HCB, HCH and PCB in human follicular fluid, 315 preovulatory follicular taken from 45 patients and aspirated by transvaginal follicular puncture were analysed with the aid of gas chromatography. We distinguished follicular fluid without oocytes and follicular fluid with oocytes. Again the latter is subdivided into follicular fluid containing secondarily fertilized oocytes and non-fertilized oocytes. There are great differences in HCB (0.08 - 1.87 ng/ml), HCH (0.05 - 1.0 ng/ml) and PCB (0.28 - 2.11 ng/ml) concentrations, varying even in the follicles of the same patient. Contrary to all our expectations we did not find any significant difference in the HCB, HCH and PCB concentration of the different follicular fluids. A direct influence of these substances on the fertilization of oocytes in IVF-ET-procedure could not be established.

[Chlorinated hydrocarbons in seminal plasma and male fertility]. / Chlorkohlenwasserstoff in Seminalplasma und männliche Fertilität.

To determine the concentration of polychlorinated biphenyls (PCB), hexachlorobenzene (HCB) and gamma hexachlorocyclohexane (gamma HCH) in human seminal plasma, 176 ejaculates taken from 156 patients consulting the Dept. of Gynecology and Obstetrics of the RWTH Aachen for sterility were analysed gas-chromatographically. 77% of the examined samples exhibited different pathological sperm findings (OAT, AT, OA, A, O, T, P, K). Contrary to all our expectations the concentration of PCB, HCB and gamma HCH in the samples with normozoospermia were higher than in the samples with pathological sperm findings. The wives of 42.5% of the patients with normozoospermia exhibited no organically or endocrinologically reasons for sterility (idiopathic sterility). In this group (normal/idiopathic) the concentrations of the toxic agents were significant higher than in that group of patients with pathological sperm findings. In the group of couples with male normozoospermia and female organic/endocrinologic reasons for sterility (normal/organic) nearly the same concentrations of PCB, HCB and gamma HCH could be shown as in samples with pathological sperm findings. The concentrations of the toxic agents in the samples with the different pathological sperm findings were similar--independent of the kind of diagnosis. A correlation between the spermiogram parameters motility, morphology and density and the concentration of PCB, HCB and gamma HCH in the seminal plasma could not be shown.

Heavy metals, chlorinated pesticides and polychlorinated biphenyls in sudden infant death syndrome (SIDS).

The concentrations of lead in blood and of cadmium and mercury in kidney tissue were determined by atomic absorption spectrometry in cases in SIDS and a control group containing cases of known causes of death. SIDS cases were split into groups from urban and rural areas and areas highly polluted with lead and zinc (sites of lead and zinc works). Neither the concentration of lead in blood (median 26.5 to 50.0 micrograms/l), nor the concentration of cadmium (median 24.0 to 44.0 micrograms/kg ww) or mercury (43.0 to 69.0 micrograms/kg ww) showed significant differences between the groups. In addition the concentrations of persistent chlorohydrocarbons (hexachlorbenzene; alpha, beta and gamma hexachlorcyclohexane; heptachlorepoxide; dieldrine; total DDT; polychlorinated biphenyls) were measured in subcutaneous fatty tissue in SIDS cases from rural and urban areas and in a control group. These substances also showed no significant concentration differences in cases of SIDS.

ICMSF Methods Studies. XV. Comparison of Four Media and Methods for Enumerating Staphylococcus aureus in Powdered Milk.

Four media were examined for their usefulness in enumerating Staphylococcus aureus inoculated (a) into milk that was then dried or (b) directly into dried milk powder. In all, seven strains of S. aureus were inoculated individually into each preparation and were enumerated after two periods of storage (18 to 19 d and 60 to 61 d). Fourteen laboratories from twelve countries participated in the comparison which found that direct plating on agar medium in 14-cm petri dishes may be as useful as enrichment followed by streaking. Plating on Baird-Parker medium or on Hauschild pork plasma fibrinogen medium and a MPN method using Giolitti and Cantoni's broth with Tween 80 were equally sensitive for enumerating S. aureus in dried milk powder. The use of Hauschild medium may eliminate the need for supplementary tests to confirm colonies as S. aureus , but in some cases was found to fail in some laboratories. Giolitti and Cantoni's broth without Tween 80 generally was less useful than the three other media for enumerating S. aureus . S. aureus inoculated into milk that was then dried survived longer than when inoculated into dried milk.