A novel method for rapid and quantitative detection of bisphenol A in urine

Bisphenol A (BPA) is classified as an endocrine disruptor (ED) and it can interact with variety of hormone receptors leading to hormonal disruption and increased risk of various adverse health effects. Reducing human exposure to BPA is one of the main challenges of public health, as it is constantly present in daily life. A low-cost and commonly applied method to enable determination of BPA in the patient's body has yet to be developed. Currently available techniques are expensive, time-consuming, and require access to highly equipped analytical chemistry laboratories. Here we describe a fast and cheap engineered lateral flow assay of our design, to detect of BPA in urine samples. The technology not only provides an opportunity to perform rapid medical diagnostics without the need for an access to the central laboratory but also a means for self-diagnosis by the patient. The addition of β-glucuronidase improves the sensitivity of detection as it releases the free BPA from glucuronide complexes in urine. This invention may become a demonstrated analytical means for lowering human exposure to BPA and probably also to other EDs and consequently, may be useful in decrease of the risk for several lifestyle diseases.

Nanomaterials in food contact materials; considerations for risk assessment

Nanotechnology applications in the food industry, including food contact materials, offer many potential benefits for consumers and manufacturers alike. The article discusses the migration of nanoparticles from food contact materials and the possible health risks associated with in the context of insufficient knowledge of the potential exposure to nanomaterial. The importance of gaps in the general knowledge on the behaviour and biological interactions of nanomaterials in biological systems becomes crucial for risk assessment. The article also discussed numerous doubts concerning the measurements of biological reactions in animal tests and the need for new approaches in the interpretation of data from nanoparticles studies in vivo. The article underlines the need to develop predictive and validated toxicological tests that can be used to screen for potential hazards, and also to develop new methodology for measuring nanoparticles in biological matrices to assess human exposure. Further studies should focus on understanding the mechanisms of action. Nanoparticles exhibit chemical and physical properties that significantly differ from those substances at a large size. Different properties of nanoparticles may lead to different toxicological properties. From that reason nanoparticles, in each case, are individually assessed by the European Food Standard Agency (EFSA) in terms of health risk before the European Commission authorizes them to be used in food contact materials.

Levels of polybrominated diphenyl ethers in house dust in Central Poland

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in numerous products, from which they are emitted to the environment, including house dust. House dust is a source of human exposure to these compounds by ingestion. The aim of this article was to determine the levels of selected PBDEs in the house dust and indicate their potential sources of origin. PBDE congeners: BDE-47, BDE-99, BDE-153 and BDE-209, were analyzed in 129 samples. The geometric mean levels (and 95% CIs) of the aforementioned congeners amounted to 3.8 (3.1-4.7) ng/g, 4.5 (3.5-5.6) ng/g, 2.2 (2.1-2.4) ng/g and 345 (269-442) ng/g respectively. BDE-209 was the dominant congener in the majority of tested samples. We found a statistically significant correlation between the concentrations of BDE-47 and the computer operating time per day (r_s - 0.18) and the living area (r_s - 0.20). Statistically significant higher levels of BDE-99 were found in homes where the floor was not replaced during the last 2 years.

Characterising the individual health risk in infants exposed to organochlorine pesticides via breast milk by applying appropriate margins of safety derived from estimated daily intakes

Milk secretion being an important way of elimination of organochlorine pesticides (OCPs) poses a concern due to potential risk for breastfed infants. This study aims to provide a tool for assessing such risks to infants exposed to OCPs (through accumulation in the mother's body), using calculated individual margins of safety (MoS). Selected OCPs included; p,p'-DDT, p,p'-DDD, p,p'-DDE, β-HCH, γ-HCH and HCB which were analysed in 28 samples of maternal milk. The highest intakes were recorded for p,p'-DDE (at 2.90 μg kg(-1)bw d(-1)) whilst the lowest was for γ-HCH, (at 0.019 μg kg(-1)bwd(-1)). For the risk characterisation purposes MoSs were calculated for the compounds for which toxicological reference values (e.g. ADI, TDI) were adopted. The MoS for average ∑DDT concentrations was found to be relatively low (2.82) somewhat similar to that for HCB at 7.08, and for γ-HCH, the MoS was substantially higher at 263.1. This, however does not take into account the extremely high individual concentrations. Thus, it was decided to calculate estimated daily intake (EDI) values based on OCP levels in individual milk samples. MoS levels of <1 (meaning unacceptable risk) were noted both for HCB in one sample as well as for ∑DDT in 3 samples indicating likely threats to infant's health. The lowest MoS noted for γ-HCH equalled to 60.6, indicating that this compound was not a threat to the health of any of the breastfed infants from the study group.

Polybrominated diphenyl ethers and polychlorinated biphenyls in cord blood from women in Poland

The purpose of this study was to assess human exposure in the prenatal period to selected PBDEs (BDE-47, BDE-99, BDE-153) and PCBs (CB-77, CB-101, CB-118, CB-126, CB-138, CB-153, CB-170, CB-180) basing on the analysis of these compounds in cord blood. The experimental material consisted of 89 cord blood samples taken from women resident in Warsaw and its vicinity. In over 90% of all tested samples the presence of congeners CB-153, CB-138, CB-180 and BDE-47 was identified. The least frequently found were CB-126 and BDE-153, which were present at relatively low concentration levels. Among all analysed PCBs, the highest average concentrations were found in the case of congeners CB-138 (11.8 ng/g of fat) and CB-153 (43.4 ng/g of fat), whereas the lowest was in the case of CB-170 (0.4 ng/g of fat) and CB-126 (0.1 ng/g of fat). In the case of PBDEs the greatest share in the total concentration was that of the congeners BDE-47 and BDE-99, whereas the smallest share was that of the higher brominated congener BDE-153. These results suggest that human exposure to the examined compounds begins already in the period of intrauterine life. The comparison of our own results with the findings of other authors indicates that the PCBs and PBDEs levels in cord blood of women living in Poland do not differ from the respective concentrations in cord blood of other female inhabitants of Europe.

Non-linear association between androgen receptor CAG and GGN repeat lengths and reproductive parameters in fertile European and Inuit men

Recently the dogma that there is an inverse linear association between androgen receptor (AR) CAG and GGN polymorphisms and receptor activity has been challenged. We analysed the pattern of association between 21 male reproductive phenotypes and AR CAG/GGN repeat lengths in 557 proven-fertile men. A linear association was only found between sperm DNA fragmentation index (DFI) and CAG length, and between inhibin B and GGN length. Men with longer CAG then the reference (22-24), had higher oestradiol levels, whereas men with shorter CAG stretches had a higher DFI and a higher proportion of Fas-positive germ cells. Subjects with either short or long CAG had increased seminal levels of prostate-specific antigen and neutral α-glucosidase activity. Compared to men with the median GGN length of 23, those with shorter GGN repeats had higher levels of inhibin B, higher proportions of normal and progressive sperm, and a higher fraction of Fas-positive sperm, while men with longer GGN had higher oestradiol levels. These data indicate that at least for some markers of male reproductive function the association with CAG or GGN repeat length is curvilinear.

Influence of chlorpyrifos on the profile of subpopulations of immunoactive cells and their phagocytic activity in an experimental in vivo model

Many environmental factors, including pesticides, cause immunological system disorders by inducing changes in humoral and cellular response. They may stimulate or trigger immunological autoaggression, hypersensitivity and allergy, as well as lead to immunosuppression, thus increasing the incidence of infectious diseases and cancers. Such activity is also attributed to organophosphorus compounds used in agriculture as insecticides, and commonly in households as biocides. The aim of the study was to define possible mechanisms of the immunotoxic activity of the chlorpyrifos (an organophosphorus compound) on experimental animals following their exposure to the compound via the oral route. The present study attempts to define the influence of chlorpyrifos on the profile of subpopulations of immunoactive cells: B, T, CD4+, CD8+, and NK, and on their phagocytic activity in an experimental in vivo model. For this purpose, the Wistar rats, were exposed orally to increasing doses of chlorpyrifos: 0.1 LD(50), 0.15 LD(50), 0.2 LD(50), 0.3 LD(50) and 0.4 LD(50) for 28 days. In the study animals, we failed to demonstrate a statistically significant decrease in the phagocytic activity of the granulocyte.

Polybrominated diphenyl ethers, polychlorinated biphenyls and organochlorine pesticides in human milk as markers of environmental exposure to these compounds

This study aimed at the generation of preliminary results allowing for the assessment of breastfed infants exposure to polybrominated diphenyl ethers (PBDEs) which constitute important contaminants in places of human habitation. The second goal was to compare the concentrations of these compounds with other contaminants which people are exposed to via food chain. 28 breast milk samples from women living in Warsaw and neighbourhood were analyzed for polybrominated diphenyl ethers (BDE-47, BDE-99, BDE-153), polychlorinated biphenyls (CB-77, CB-101, CB-118, CB-126, CB- 138, CB-153, CB170, CB-180) and organochlorine pesticides (HCB, β-HCH, γ-HCH, p,p'-DDE, p,p'-DDD, p,p'-DDT). The ΣDDT levels noted in our studies were higher than in other European countries. The concentrations of the examined polychlorinated biphenyls and polybrominated diphenyl ethers did not diverge from the levels presented by other authors and are comparable to the levels noted in other countries in Europe.

[Violations of mrls for pesticide residues in food reported for risk assessment according to RASFF procedures in Poland]

The results of risk assessment to evaluate the potential risk from food products of plant origin in cases of violations of maximum residue limits for pesticides (MRLs) have been presented. According to the rules set in the RASFF any violation of legally established limit should undergo the risk assessment to allow quantitative approach in hazard evaluation for consumers. The basis of risk assessment have been presented as tool for risk management in the official food control. In case of MRLs violations the risk was assessed for general population as well as for small children as the most vulnerable part of the population. Since beginning of the RASFF in Poland--since mid of 2003 till the end of 2007--148 notifications of MRLs violations underwent risk assessment procedures. This means 2.5% of the overall number of analyzed samples. However, as much as 0.39% of the samples taken for analysis posed a real, considerable risk for consumers health, and the small children seem to be the group at greatest risk.

Relationships between sperm DNA fragmentation, sperm apoptotic markers and serum levels of CB-153 and p,p′-DDE in European and Inuit populations

Persistent organochlorine pollutants (POPs) are suspected to interfere with hormone activity and the normal homeostasis of spermatogenesis. We investigated the relationships between sperm DNA fragmentation, apoptotic markers identified on ejaculated spermatozoa and POP levels in the blood of 652 adult males (200 Inuits from Greenland, 166 Swedish, 134 Polish and 152 Ukrainian). Serum levels of 2, 2′, 4, 4′, 5, 5′-hexachlorobiphenyl (CB-153), as a proxy of the total POP burden, and of 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p′-DDE), as a proxy of the total DDT exposure were determined. Sperm DNA fragmentation was measured by using the TUNEL assay, whereas immunofluorescence methods were utilized for detecting pro-apoptotic (Fas) and anti-apoptotic (Bcl-xL) markers. Both TUNEL assay and apoptotic markers were statistically differed across the four populations. No correlation between neither sperm DNA fragmentation nor apoptotic sperm parameters and the large variations in POPs exposure was observed for the separate study groups. However, considering the European populations taken together, we showed that both %TUNEL positivity and Bcl-xL were related to CB-153 serum levels, whereas our study failed to demonstrate any relations between DDE and %TUNEL positivity and apoptotic sperm biomarkers (Fas and Bcl-xL) in any region or overall regions. These results suggest that CB-153 and related chemicals might alter sperm DNA integrity and Bcl-xL levels in European adult males, but not in the highly exposed Inuit men. Additional issues (genetic background, lifestyle habits and characterization of total xeno-hormonal activities) need to be investigated in order to fully assess the population variations observed.

Time to pregnancy as a function of male and female serum concentrations of 2,2'4,4'5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE)

BACKGROUND

Persistent organochlorine pollutants (POP) may affect both the female and male reproductive system in animals as well as in humans.

METHODS

Blood samples were collected from pregnant women and their partners from Greenland, Warsaw and Kharkiv, and from a cohort of Swedish fishermen's wives. Blood samples were analysed for 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE). Information on the participants' fertility, measured as time to pregnancy (TTP), was collected. In total, 778 men and 1505 women were included in the analyses.

RESULTS

The data from Warsaw, Kharkiv and the Swedish fishermen's wives indicated no effect of either male or female exposure to POP on TTP. However, among men and women from Greenland, there seemed to be an association between serum concentrations of CB-153 and p,p'-DDE and prolonged TTP. Due to the strong intra-individual correlation between CB-153 and p,p'-DDE in the Greenlandic population, it was not possible to determine whether the risk was associated with CB-153 or p, p'-DDE or was an interaction between the two compounds.

CONCLUSIONS

The overall results of the present study create a somewhat ambiguous pattern, but give some support to the idea that dietary POP exposure might be harmful for couple fertility.

[High performance liquid chromatography: application in pesticide residue analysis]

Chromatographic techniques allow separation and quantitation of trace levels of organic compounds in different matrices. Chromatography is widely used in many scientific areas, including food safety. Currently, high performance liquid chromatography (HPLC) and related techniques have become the dominant analytical separation tools in such areas as pharmaceutical, chemical and food industries and environmental monitoring. Contrary to gas chromatography (GC), HPLC allows to determine low-volatile and thermolabile compounds. A variety of packings and bonded phases as well as eluents and their combinations make this technique very useful in analysis of food contaminants, including pesticide residues. Plant protection products, called commonly pesticides, contain biologically active substances having wide mode of action, used in crop protection and in many other areas. Unfortunately, besides advantages related to their use, it should be taken into account that they are also toxic for humans and environment. As general population is exposed to pesticides mainly through the food, it is necessary to monitor concentrations of these compounds using sensitive techniques for ppm or even ppb levels. This article discusses the advantages of HPLC technique for the residues analysis of some active substances of plant protection products.

[Comparative study of the effect of synthetic pyrethroids on the induction of genetic changes in mice somatic and sex cells depending on the exposure route]

Synthetic pyrethroid insecticides are widely used in the protection of fruits and vegetables as well as in the public hygiene due to their strong neurotoxic activity against insects. The induction of genetic changes in somatic and sex cells in male mice after different routes of exposure to permethrin and fenvalerate was studied. The male 8-10 weeks old mice were intraperitoneally exposed to 20 and 40 mg/kg bw of fenvalerate and 125 and 250 mg/kg bw of permethrin. Another groups of mice were exposed per os to fenvalerate and permethrin in the doses of 50, 100 and 200, 400 mg/kg bw respectively. For the sperm anomalies testing the exposure was repeated for five consecutive days followed by the 35 days waiting period after which the gonads were removed and spermatozoa prepared from the epididymis. The changed spermatozoa were counted in the smears after staining in the 0.5% eosin Y solution and the results compared with the number of normal cells. For the testing of the effect of pyrethroids on the micronuclei frequency in the bone marrow cells the tested substances were administered twice in 24 hours intervals and the bone marrow was sampled after 6 and 24 hours from the femur bone. The polychromatic erythrocytes and the presence of micronuclei were evaluated in the bone marrow smears. The results showed the difference in the action of the pyrethroids on the genetic material of the tested cells and the effect of the route of exposure. Permethrin induced the lesions in the sex cells regardless the route of exposure, however a substantial increase in the micronuclei frequency in the bone marrow was observed after oral exposure only. No signs of cytotoxicity accompanied the sperm anomalies and micronuclei induction. Fenvalerate induced changes in sperm cells after intraperitoneal exposure only. No increase in the micronuclei frequency in the polychromatic erythrocytes of the bone marrow was observed after per os or intraperitoneal exposure. The intraperitoneal exposure to this pyrethroid resulted in cytotoxicity in both bone marrow and sex cells.

Relationship between two consecutive lactations and fat level in persistent organochlorine compound concentrations in human breast milk

An attempt was made to understand how consecutive deliveries and the following lactations have an impact on the organochlorine compound levels detected in human milk. The other goal of the study was to check for a possible dependence between fat content and the levels of the studied compounds in milk samples from the same lactations. 199 milk samples were examined for the presence of p,p'-DDT, p,p'-DDE, p,p'-DDD, alpha-, beta-, gamma-HCH and sigmaPCBs. Moreover, in 87 milk samples the fat content was additionally determined. This study has indicated that, for the mother with a shorter interval between lactations, mean concentrations of the examined compounds were higher in the milk of the first lactation than that of the second. For the other donor whose second lactation began after 2 years, the mean levels of HCB, beta-HCH, p,p'-DDD, and PCBs in her milk were higher during the first lactation. At the same time, the concentrations of p,p'-DDT and p,p'-DDE after the second delivery were slightly higher. The correlation coefficients between the two data sets (fat content in milk, concentrations of the compounds studied in milk) showed no interrelationship between them.

[Selected aspects of xenoestrogens'mode of action taken from a group of persistent organochlorine compounds ]

The presence of many chemical pollutants in the environment and their potential impact to human health creates rather justified anxiety. Many of these pollutants feature such unwelcome characteristics as: persistence in different environmental media, ability to bioaccumulate and biomagnify in individual food chains, as well as ability to undergo long-range atmospheric transport. Compounds meeting these criteria include above all a large group of persistent organochlorine compounds. Recently, debate has increased concerning endocrine disrupting activity of these compounds and especially their ability to produce biologic responses comparable to those of endogenous estrogens (e.g., 17 beta-estradiol). It has been hypothesized that these compounds, among others, may be associated with increased incidence of breast cancer and other estrogen-related cancers in women due to increased proliferation of breast epithelial cells. The organochlorine xenoestrogens may produce this effect following binding to a hormone receptor (with or without metabolic activation) or by affecting the 17 beta-estradiol pathways leading to increased formation of more potent estrogenic metabolites. Numerous studies performed since early 1990s have examined the relationship between organochlorines levels in serum or adipose tissue and breast cancer, but the results are not consistent. This may be caused by various criteria of selecting the case and control groups, different compounds analyzed or different statistical approaches. None of these studies included endocrine disruptors' exposure in early and critical stages of development--from conception up to puberty age--the results of which would manifest in far future. Nevertheless the results of measurements, especially in adipose tissue are more reliable for this purpose because they reflect the whole life exposure and may be recognized as one of many environmental risk factors of cancer development.

Studies of early hepatocellular proliferation and peroxisomal proliferation in Wistar rats treated with herbicide diclofop

A study was performed to determine whether diclofop (2-(4-(2,4-dichlorophenoxy) phenoxy)propionic acid), introduced as a herbicide, exhibits the properties of peroxisome proliferators (PPs). Diclofop was administered orally at 7-56 mg/kg body weight per day to male Wistar rats for 2, 4, 7 or 14 consecutive days and some effects regarded as early hepatic markers of PPs were studied. The early changes in rat liver, produced by short-term treatment with diclofop consisted of mitogenesis and, time- and dose-related increase in liver weight. Hepatomegaly was typically associated with proliferation of smooth endoplasmic reticulum (SER) and peroxisomes. The parallel biochemical measurements showed that there was a dose-dependent increase in peroxisomal palmitoyl-CoA oxidation and catalase activity in treated rats. Markers of hepatocellular proliferation (S- and M-phase) indicated that mitogenesis was transient and declined despite continuation of diclofop treatment. The threshold exposure level for the palmitoyl-CoA oxidation (one of the peroxisome proliferation markers) was approximately the same (14 mg/kg body weightxper day) as for the stimulation of mitogenesis in Wistar rats. However, for hepatomegaly and catalase activity the threshold exposure level was 7 mg/kg body weightxper day. The results presented here demonstrate clearly that diclofop belongs to a class of rodent PPs.

[Organochlorine pesticide residues in tea]

Organochlorine pesticides still exist as environmental pollutants in many countries. In this paper, the results of monitoring of organochlorine pesticides in teas taken from the Polish market in 1998 year are presented. The monitoring included analysis of organochlorine insecticides and their metabolites (sigma DDT, sigma HCH, HCB, Heptachlor, Epoxide heptachlor, and Aldrin) in samples of black and green tea, and fruit tea. The mean concentration of the organochlorine compounds in the black tea ranged from 0.0002 to 0.003 mg/kg of product, and in the green and fruit teas from 0.0001 to 0.003 mg/kg of product depending on the pesticide. In no case the violation of the Maximum Residues Limits was observed. The results obtained in this monitoring did not differ from the results reported by the other authors.

Early hepatic changes in rats induced by permethrin in comparison with DDT

In this study permethrin [(3-phenoxyphenyl)-methyl-3-(2,2-dichloroethenyl)-2,2-dim ethylcyclopropanecarboxylate] and DDT [1,1-(2,2,2 trichloroethylidene)-bis-(4-chlorobenzene)] were compared in rats for their effects on early hepatic changes, proposed in the literature to be useful endpoints in screening for non-genotoxic hepatocarcinogenesis and/or liver tumour promotion. We compared the effects of both insecticides on the following endpoints: hepatomegaly, mitogenesis (DNA synthesis, mitotic activity, percentage of binuclear cells) and liver pathology. Male Wistar rats received permethrin (PERM) or DDT in one, three, five and 14 daily oral doses (at 24-h intervals) equivalent to 1/10 LD50. Distinct differences in early liver response between PERM and DDT were observed. DDT stimulated the early effect consisting of hepatomegaly accompanied by an increase in hepatocellular proliferation with signs of cell necrosis. Thus, it might be concluded, that the mitogenic effect of DDT was at least partly related to a regenerative liver response. Although PERM significantly affected DNA synthesis and increased binuclear hepatocytes, this compound did not increase the number of mitotic figures. These results suggest that PERM may inhibit of phase G2 in the cell cycle and consequently it may suppress the cell entering into the stage of mitosis (M-phase). In addition, the present findings provide evidence for the occurrence of abnormal mitoses in the hepatocytes of rats treated with DDT.

[Levels of organochlorine insecticides in citrus fruits in 1996-1997]

The monitoring of organochlorine insecticides (HCB, HCH, and DDT) in citrus fruits taken from the market was carried out in 9 regions in Poland in the years 1996-1997. The concentrations of the insecticides were measured in the edible part and in the peel separately. The total number of 331 samples of oranges, lemons, grapefruits and mandarins were subjected residue analysis. The mean concentrations of the organochlorine compounds in the edible parts amounted 0.0002 mg/kg for HCB, and ranged from 0.0081 to 0.0247 mg/kg for sigma HCH and from 0.0041 to 0.022 for DDT depending on the product. The highest contrentrations together with the highest violation rate (9.5%) of the Polish Maximum Residue Limit was found in case of DDT. The mean concentrations of the insecticides in the citrus peels were not markedly higher than those in the edible parts. The results obtained in this monitoring did not differ from the results reported by the other authors.

[The evaluation of urine and hair total mercury content in occupationally exposed and non-exposed people]

The study aimed at the evaluation of total mercury content in hair and urine of the workers occupationally exposed to various levels of mercury vapours. The hair and urine were taken from the workers employed in Chemical Plant Oświecim and from thermometer factory in Warsaw. The urine and hair of non-exposed Warsaw inhabitants served as a reference. Mercury levels in hair and urine were determined with atomic absorption spectrometry. The highest mercury concentration in hair (range 1.13-325.16 micrograms/g) and urine (range 15.7-800 ng/mg of creatinine) of workers employed in processing chloroalkali in Chemical Plant Oświecim. The results also suggest that the average mercury concentration in hair (0.17 and 1.0 microgram/g) and urine (0.4 and 2.36 ng/mg of creatinine) of non-occupationally exposed inhabitants from Warsaw and Oświecim does not endanger human population. Nevertheless a positive correlation between distance from chloroalkali plant in Oświecim and mercury content in the specimens from inhabitants has been observed.

Effect of changes in excretion of persistent organochlorine compounds with human breast milk on related exposure of breast-fed infants

This study was an attempt to identify if there are any trends in excretion of 1,2,3,4,5,6-hexachlorocyclohexane (HCH) isomers alpha-, beta-, and gamma-, hexachlorobenzene (HCB), [1,1,1-trichloro-2, 2-bis(4-chlorophenyl)ethane] (p,p'-DDT), [1,1-dichloro-2, 2-bis(4-chlorophenyl)ethane] (p,p'-DDD), [1,1-dichloro-2, 2-bis(4-chlorophenyl)ethylene] (p,p'-DDE), and polychlorinated biphenyls (PCBs) with human milk during lactation. The shortest lactation studied took 16 weeks, and the longest 84 weeks. Three hundred fifty-two milk samples, collected from each donor once a week, were examined. The analysis of the result showed individual differences in the excretion of the compounds. The findings from this study are not conclusive enough to claim that there are consistent trends showing a decrease or increase in the excretion of the compounds under examination. Thus, one cannot claim that the infants' exposure to those compounds decreases or increases as breast-feeding continues.

[Genetically modified organisms (GMO): toxicological aspects]

The genetically modified organisms (GMO) are one of the major public concerns partially due to the activity of the non-governmental organizations which believe that public opinion must be duly informed on what leaves the laboratories and enters the environment or is proposed as food. This article discusses some major toxicological and nutritional aspects of GMO designed as food for humans. The range of current use of GMOs, potential hazards for humans, safety assessment, allergenic concerns, and some aspects of the use of marker genes are discussed in regard to human safety. The need for relevant regulations is stressed.

[Monitoring of pesticides residues in food in Poland]

In this paper, the results of monitoring of pesticide residues in food products are reported for the 3 years period 1995-1997. The monitoring included analysis of organochlorine compounds (DDT and its metabolites--DDD and DDE, HCH isomers alpha, beta and gamma, HCB and PCBs), pyrethroids and dithiocarbamates in variety of food products such as: milk and milk products, food for infants and children, fish products, potatoes, domestic fruit and vegetables, citrus and exotic fruits, which were taken from the market. The samples were collected from 15 regions of Poland. Mean values of sigma DDT and sigma HCH in food products of animal origin, including children foods, were much lower comparing with those, reported in previous years. Only few samples analyzed had violative residues exceeding Maximum Residue Limits (MRLs) for these compounds. In none of food samples of plant origin, organochlorine compounds residues exceed Polish tolerances. The residues of synthetic pyrethroids were detected in none of tested samples of potatoes. Mean concentrations of dithiocarbamate pesticides in fruit and vegetables were higher than observed at the beginning of 1990s. In five samples of leaf and stem vegetables, the detected levels of dithiocarbamates exceed or were equal to MRLs.

[The effect of nuarimol on the mutagenic activity of n-nitrosodimethylamine and 2-acetylaminofluorene in mouse erythrocytes]

Nuarimol, the structural analogue of DDT, similarly to other polychlorinated aromatic hydrocarbons, induces monoxygenase activity. N-nitrosodimethylamine (NDMA) and 2-acetylaminofluorene (2-AAF) belong to chemical compounds exhibiting strong mutagenic and carcinogenic properties followed the metabolic activation. Genotoxic activity of promutagens, including NDMA and 2-AAF depends on the activity of monoxygenase enzymes. The study aimed at clarification of the effect of nuarimol on the mutagenic activity of NDMA and 2-AFF in in vivo micronucleus test. The experiments were performed on Swiss mice, which were exposed to nuarimol or Aroclor 1254 (as the positive control) followed by the exposure to NDMA or 2-AAF. The micronuclei were counted in the bone marrow polychromatic erythrocytes and in the erythrocytes of the peripheral blood. The results show that NDMA as well as 2-AAF induce failures in the genetic material in the bone marrow cells. Nuarimol given to the mice before the exposure to NDMA or 2-AAF did not cause changes in the micronuclei frequency. However, the prior intoxication by Aroclor 1254 resulted in the increase of the number of erythrocytes with micronuclei induced by NDMA in bone marrow and peripheral blood. This effect has not been observed in the mice intoxicated by 2-AAF prior to Aroclor 1254.

The effect of fenarimol on marker enzymes in rat liver in two-stages model of hepatocarcinogenesis

The two-stage model for the development of early markers of hepatocarcinogenesis was applied to assess the potential of fungicide fenarimol (alpha-(2-chlorophenyl)-alpha-(4-chlorophenyl)-5-pirimidinemethanol++ +) as a possible promoter in this process. In this experiment the rats were subjected to partial hepatectomy (to induce proliferation), followed by the single (50 mg/kg bw) dose of diethylnitrosamine (DEN) (initiator) and then, followed by the 26 weeks exposure to fenarimol administered in the olive oil suspension (250 mg/kg daily). The activities of gamma-glutamyltransferase (GGTase), glucose-6-phosphatase (G-6-Pase) and alkaline phosphatase (APase) regarded as markers of early stages of hepatocarcinogenesis were measured biochemically and histochemically in the livers of exposed rats as well as in the respective positive and negative controls. Rats exposed to 2-acetylaminofluorene (2-AAF), instead of fenarimol, served as positive controls. It was found that in the full initiation/promotion regimen both 2-AAF and fenarimol induced the increase of GGTase activity in the liver and formation of GGTase-positive hepatocytes. However the exposure to fenarimol alone also increased GGTase activity, although this response was not observed in rats exposed to 2-AAF alone. The possible mechanisms and explanation for such types of responses were discussed, and conclusion has been drawn that fenarimol did not affect the rat hepatocarcinogenesis induced by PH and DEN.

[Induction of micronuclei in erythrocytes of bone marrow and peripheral blood in laboratory mice following acute and subchronic exposure to DDT(fenarimol and nuarimol)]

The frequency of micronuclei was assessed in polychromatic erythrocytes of bone marrow and normochromatic erythrocytes in peripheral blood of mice following exposure to fenarimol (50, 100, 200 mg/kg b.w.) and nuarimol (100, 200, 400 mg/kg b.w.) for 21 days. Mitomycin C (2 mg/kg b.w.), cyclophosphamide (25 mg/kg b.w.) and colchicyne (2 mg/kg b.w.) were administered to the positive control mice for 5 days. These results obtained in this experiment were compared with the incidence of micronuclei in bone marrow and peripheral blood in mice exposed twice (two consecutive injections, 24 hours interval) to fenarimol and nuarimol and mitomycin C, cyclophosphamide and colchicine. The results show that fenarimol and nuarimol did not cause micronuclei induction in the bone marrow and peripheral blood of mice under the conditions of these experiments. However, mitomycin C, cyclophosphamide and colchicine induced of micronuclei in the investigated tissues. Moreover, the positive relationship between frequencies of micronuclei in normochromatic erythrocytes in peripheral blood and time of exposure was observed.

The effect of organic chlorine compounds and their metabolites present in human milk on newborn mice

The effect of pesticides and their metabolites (DDE, DDT, DDD, alpha, beta and gamma-HCH and PCBs) isolated from human milk on the blood and liver morphology of the mouse were studied. Mouse neonates were fed an extract of the organochlorine compounds in linseed oil for a period of 6 weeks. The lowest dose used in the experiment equalled that which a human infant can receive with its mother's milk, calculated per gram of body weight. Doses 10 and 100 times higher were also used. At the end of the experiment, tissue samples for electron microscopy and blood samples for haemotological examination were taken. Haematological examinations, in mice receiving pesticides, revealed a significant rise in the number of Heinz bodies in erythrocytes and an increased number of lymphocytes. These changes were related to the concentrations of the organic chlorine compounds that the animals were given. Electronmicroscopy demonstrated that organochlorine pesticides at doses equal to that might be received by infants caused proliferation of the smooth endoplasmic reticulum in hepatocytes without any clear damage to other subcellular structures. Doses 10 and 100 times higher resulted in more extensive proliferation of the smooth endoplasmic reticulum, reduction of the rough elements of the endoplasmic reticulum and damage to mitochondria. The latest changes were associated with an increased number of prominent Kupffer cells and the appearance of immigratory cells with traits characteristic of lymphocytes and monocytes.