Associations between congenital cryptorchidism in newborn boys and levels of dioxins and PCBs in placenta.

In animal studies, exposure to dioxins has been associated with disrupted development of the male reproductive system, including testicular maldescent. Some polychlorinated biphenyls (PCBs) have also dioxin-like effects. In addition, one previous case-control study has reported an association between congenital cryptorchidism and colostrum PCB levels. We performed a case-control study to evaluate whether congenital cryptorchidism in boys was associated with increased levels of dioxins or PCBs in placenta reflecting foetal exposure. In addition, associations between placenta levels of these chemicals and reproductive hormone levels in boys at 3 months were studied. Placentas were collected in a Danish-Finnish joint prospective cohort study on cryptorchidism (1997-2001). The boys were examined for cryptorchidism at birth and at 3 months. Altogether, 280 placentas [112 Finnish (56 cases, 56 controls) and 168 Danish (39 cases, 129 controls)] were analysed for 17 toxic polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 37 PCBs (including 12 dioxin-like PCBs). Infant serum samples taken at 3 months were analysed for reproductive hormones. No significant differences between cases and controls were observed in either country in dioxin WHO-TEq levels (median 9.78 vs. 8.47 pg/g fat, respectively, in Finland, and 11.75 vs. 10.88 pg/g fat in Denmark) or PCB WHO-TEq levels (median 2.12 vs. 2.15 pg/g fat in Finland, 2.34 vs. 2.10 pg/g fat in Denmark) or total-TEq levels (median 11.66 vs. 10.58 pg/g fat in Finland, 13.94 vs. 13.00 pg/g fat in Denmark). Placenta WHO-TEq levels of dioxins were not associated with infant reproductive hormone levels at 3 months. In Finland, PCB WHO-TEq levels in placenta associated positively with infant LH levels. WHO-TEq levels of dioxins and PCBs and total-TEq levels were higher in Danish than Finnish samples. In conclusion, no association between placenta levels of dioxins or PCBs and congenital cryptorchidism was found. Significant country differences in chemical levels were observed.

Association between chemical pattern in breast milk and congenital cryptorchidism: modelling of complex human exposures.

During the past four decades, there has been an increase in the incidence rate of male reproductive disorders in some, but not all, Western countries. The observed increase in the prevalence of male reproductive disorders is suspected to be ascribable to environmental factors as the increase has been too rapid to be explained by genetics alone. To study the association between complex chemical exposures of humans and congenital cryptorchidism, the most common malformation of the male genitalia, we measured 121 environmental chemicals with suspected or known endocrine disrupting properties in 130 breast milk samples from Danish and Finnish mothers. Half the newborns were healthy controls, whereas the other half was boys with congenital cryptorchidism. The measured chemicals included polychlorinated biphenyls (PCBs), polybrominated diphenyl-ethers, dioxins (OCDD/PCDFs), phthalates, polybrominated biphenyls and organochlorine pesticides. Computational analysis of the data was performed using logistic regression and three multivariate machine learning classifiers. Furthermore, we performed systems biology analysis to explore the chemical influence on a molecular level. After correction for multiple testing, exposure to nine chemicals was significantly different between the cases and controls in the Danish cohort, but not in the Finnish cohort. The multivariate analysis indicated that Danish samples exhibited a stronger correlation between chemical exposure patterns in breast milk and cryptorchidism than Finnish samples. Moreover, PCBs were indicated as having a protective effect within the Danish cohort, which was supported by molecular data recovered through systems biology. Our results lend further support to the hypothesis that the mixture of environmental chemicals may contribute to observed adverse trends in male reproductive health.

Country-specific chemical signatures of persistent environmental compounds in breast milk.

Recent reports have confirmed a worldwide increasing trend of testicular cancer incidence, and a conspicuously high prevalence of this disease and other male reproductive disorders, including cryptorchidism and hypospadias, in Denmark. In contrast, Finland, a similarly industrialized Nordic country, exhibits much lower incidences of these disorders. The reasons behind the observed trends are unexplained, but environmental endocrine disrupting chemicals (EDCs) that affect foetal testis development are probably involved. Levels of persistent chemicals in breast milk can be considered a proxy for exposure of the foetus to such agents. Therefore, we undertook a comprehensive ecological study of 121 EDCs, including the persistent compounds dioxins, polychlorinated biphenyls (PCBs), pesticides and flame retardants, and non-persistent phthalates, in 68 breast milk samples from Denmark and Finland to compare exposure of mothers to this environmental mixture of EDCs. Using sophisticated, bioinformatic tools in our analysis, we reveal, for the first time, distinct country-specific chemical signatures of EDCs with Danes having generally higher exposure than Finns to persistent bioaccumulative chemicals, whereas there was no country-specific pattern with regard to the non-persistent phthalates. Importantly, EDC levels, including some dioxins, PCBs and some pesticides (hexachlorobenzene and dieldrin) were significantly higher in Denmark than in Finland. As these classes of EDCs have been implicated in testicular cancer or in adversely affecting development of the foetal testis in humans and animals, our findings reinforce the view that environmental exposure to EDCs may explain some of the temporal and between-country differences in incidence of male reproductive disorders.

Polychlorinated biphenyls (PCBs) and hydroxy-PCBs in adipose tissue of women in Southeast Spain.

Polychlorinated biphenyls (PCBs) and hydroxylated PCBs (OH-PCBs) were investigated in human adipose tissue samples collected from 20 women undergoing surgery. Mean sum of PCB and sum of OH-PCB levels were 737ng/g of lipid and 8pg/g of lipid, respectively. Among PCBs, congeners 180, 153, 138 and 170 were the most frequent and abundant, and together constituted 72% of the total amount of PCBs in adipose tissue. The PCB congener pattern and the frequencies and concentrations of non-dioxin-like and non-hydroxylated congeners observed in adipose tissue were similar in distribution and order of magnitude to the profile previously published in Spain but lower than that found in other European countries. Among OH-PCB congeners studied, 4-OH-PCB 107/118 was found at the highest concentrations followed by 3'-OH-PCB 180 and 3-OH-PCB 138. To date, no information on levels of PCB metabolites in the Spanish population is available for comparison. These three predominant OH-PCBs contributed 97% of all OH-PCBs. Twelve dioxin-like PCBs contributed around 8% of the total PCB exposure, and all were present in all study subjects. Further research is required to determine trends in human exposure to PCBs and OH-PCBs and how existing banning measures affect exposure.

Dioxins in adipose tissue of women in Southern Spain.

Seventeen polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were quantified in adipose tissue samples of non-occupationally exposed women living in Southern Spain. Geometric mean levels of sum of congeners and WHO(PCDD/F)-TEQ(2005) were 410 and 17.9pgg(-1) fat, respectively. Among PCDDs, octachlorodibenzo-p-dioxin (OCDD) showed the highest concentration with a mean value of 265pgg(-1) fat, followed by 1,2,3,6,7,8-HxCDD (49.3pgg(-1) fat) and 1,2,3,4,6,7,8-HpCDD (45.2pgg(-1) fat). These three congeners were responsible for around 90% of the sum of all PCDD/F congeners in adipose tissue. The geometric mean 2,3,7,8-TCDD value was 1.87pgg(-1) fat. 2,3,4,7,8-PeCDF (8.43pgg(-1) fat) showed the highest concentration among the PCDFs, followed by 1,2,3,4,7,8-HxCDF (4.17pgg(-1) fat) and 1,2,3,6,7,8-HxCDF (3.28pgg(-1) fat), and these three congeners were responsible for 4% of the sum of all studied PCDD/F congeners in adipose tissue and 76% of the sum of ten PCDFs. 1,2,3,7,8,9-HxCDF was the only congener not quantified in any sample, while 1,2,3,4,7,8,9-HpCDF, 1,2,3,7,8-PeCDF, OCDF and 2,3,7,8-TCDF were found in 5, 16, 16 and 19 samples, respectively. All other congeners were quantifiable in all 20 samples. Congeners contributing most to the WHO(PCDD/F)-TEQ(2005) were 1,2,3,7,8-PeCDD (31.6%), 1,2,3,6,7,8-HxCDD (28.3%) and 2,3,4,7,8-PeCDF (14.6%). The body burden of log-transformed WHO(PCDD/F)-TEQ(2005) levels increased with age (B=0.02; 95% CI=0.01, 0.03; p=0.02). Although these adipose tissue PCDD/F levels are similar to previously published findings in Spain and other European countries, further research is needed to determine trends in the exposure of women to these chemical residues.

Concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in milk of women from Catalonia, Spain.

In this study, the concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in milk from women living in the vicinity of a new hazardous waste incinerator (HWI) in Catalonia, Spain, were determined. The study was performed after 4 years of regular operations in the facility and the present PCB levels were compared with baseline concentrations obtained in a pre-operational program. PCBs and PBDEs levels were determined by HRGC/HRMS in 15 samples. In the present study planar PCBs ranged from 1.3 to 6.3 pg WHO-TEQ/g fat with a mean value of 3.8 pg WHO-TEQ/g fat. After adding dioxin-like mono-ortho-PCBs the total PCB-TEQ concentrations ranged from 3.8 to 13.3 pg WHO-TEQ/g fat (mean value: 8.7 pg WHO-TEQ/g fat). A comparison of the current data with those obtained in the baseline study showed significant decreases for both planar and total WHO-TEQ of PCBs: 47.9% and 44.6%, respectively. PCB concentrations in milk of women living in urban zones were higher than those living near industrial areas (10.1 and 7.4 pg WHO-TEQ/g fat, respectively). Mean PBDE concentrations were 2.2 and 2.5 ng/g fat for women living in urban and industrial zones, respectively. Dietary intake of PCBs and PBDEs for a standard adult woman samples were 898 and 843 ng/day for PCBs, and 72 and 63 ng/day for PBDEs, for residents in urban and industrials areas, respectively. This study suggests that dietary intake is more relevant for human exposure to PCBs and PBDEs than living near the HWI.

PBDEs and PBBs in the adipose tissue of women from Spain.

Polybromodiphenyl ethers (PBDEs) and polybromobiphenyls (PBBs) were investigated in adipose tissue of women living in Southeastern Spain. Mean Sigma PBDE (BDE 28, 75, 71, 47, 66, 77, 100, 119, 99, 85, 154, 153, 138, and 183) and Sigma PBB (PBB 18, 29, 31, 22, 38, 37, 53, 52, 49, 75, 80, 56, 77, 103, 101, 155, 154, 153, and 169) levels were 3.85 and 0.36 ng/g of lipid, respectively. Among PBDEs, congeners 153, 47, 183, 99, and 100 were the most frequent and abundant and together constituted 96% of the total amount of PBDEs in adipose tissue. Concentrations of PBDEs in this population were similar to those reported in other parts of Spain and in Swedish and Belgium populations but lower than those found in other Western countries. Among PBB congeners studied, PBB 153 presented the highest concentrations and contributed 79% of all PBBs. There are no published data on PBB congeners in adipose tissues of the Spanish population for comparison, but the levels found were similar to those described in other European countries. Further research is needed to determine trends in human exposure to PBDEs and PBBs and to explore putative effects on human health.

Carcinogenicity of the drinking water mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone in the rat.

BACKGROUND: Several epidemiologic studies have suggested that the consumption of chlorinated drinking water may be associated with the development of certain cancers in humans. 3-Chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a byproduct of the chemical reactions that occur in chlorinated drinking water, has been found to be mutagenic in bacteria and mammalian cells; however, its potential to cause tumors in animals has not been tested previously. PURPOSE: The objective of this study was to evaluate the carcinogenicity of MX in rats given MX in their drinking water. METHODS: MX was administered to male and female Wistar rats (50 rats per dose group) in drinking water for 104 weeks at concentrations yielding the average daily doses of MX of 0.4 mg/kg of animal weight (low dose), 1.3 mg/kg (mid dose), and 5.0 mg/kg (high dose) for males and 0.6 mg/kg, 1.9 mg/kg, and 6.6 mg/kg for females, respectively. Control rats received water from the same source used for preparation of the MX dose formulations (after its adjustment to the same pH range). Body weight, clinical signs, and food and water consumption were recorded regularly. At the end of the treatment period, the animals were killed and full histopathologic analysis was performed on 47 tissues and all lesions. RESULTS: Dose-dependent increases in tumor incidence were observed in rats given MX-containing drinking water; the same MX doses had no obvious toxic effects on animals. MX consumption increased most drastically the prevalence of follicular adenoma (up to 43% and 72% in high-dose males and females, a test [one-sided] for positive trend in all dose groups P = .0045 and P = .0000, respectively) and carcinoma (55% [P = .0000] and 44% [P = .0000], respectively) in thyroid glands and cholangioma in the liver (8% [P = .0009] and 66% [P = .0000] in the high-dose males and females, respectively). Among rats given the higher doses of MX in their drinking water, cortical adenomas of the adrenal glands were increased in both sexes, alveolar and bronchiolar adenomas of the lungs and Langerhans' cell adenomas of the pancreas were increased in males, and lymphomas, leukemias, and adenocarcinomas and fibroadenomas of the mammary glands were increased in females. Even the lowest MX dose studied was carcinogenic. CONCLUSION: MX is a potent carcinogen in both male and female rats, and it causes tumors at doses that are not overtly toxic to rats. IMPLICATIONS: Although these findings cannot be extrapolated to humans, MX should be studied as a candidate risk factor in the possible association between consumption of chlorinated drinking water and cancer in humans.

Liver tumor-promoting activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in TCDD-sensitive and TCDD-resistant rat strains.

Risk assessment of dioxins is currently based on induction of liver tumors in rats. The toxicity of dioxins is characterized by large sensitivity differences among animal species and even strains of the same species, which complicates the risk assessment. The significance of these differences in dioxin-induced carcinogenicity is not known. We therefore studied the liver tumor-promoting activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the sensitive Long-Evans (L-E) and the resistant Han/Wistar (H/W) rats differing >1000-fold in their sensitivity to the acute lethaity of TCDD. Female rats were partially hepatectomized, initiated with nitrosodiethylamine, and treated with TCDD for 20 weeks. Altered hepatic foci (AHF) were stereologically quantitated using glutathione S-transferase P as a marker. AHF were significantly (P < 0.001) and dose dependently increased in L-E rats at 10 and 100 ng/kg/day, but in H/W rats only at 1000 ng/kg/day and above, indicating a remarkable (approximately 100-fold) sensitivity difference between L-E and H/W rats. The same sensitivity difference but 10-fold less foci were observed between nonhepatectomized/noninitiated L-E and H/W rats. Induction of AHF was related to hepatotoxicity but not to cytochrome P4501A1 activity in the liver. Liver TCDD concentrations were similar in both strains. H/W rats are exceptionally resistant to induction of AHF by TCDD, and the resistance is associated with an altered transactivation domain of the aryl hydrocarbon receptor. Genetic differences may account for significant interindividual/intraspecies sensitivity differences in dioxin-induced carcinogenesis. Understanding the role of transactivation domain of the aryl hydrocarbon receptor in carcinogenesis is therefore likely to improve dioxin risk assessment.

A new sensitive bioassay for determination of microbially available phosphorus in water

The content of assimilable organic carbon has been proposed to control the growth of microbes in drinking water. However, recent results have shown that there are regions where it is predominantly phosphorus which determines the extent of microbial growth in drinking waters. Even a very low concentration of phosphorus (below 1 &mgr;g of P liter-1) can promote extensive microbial growth. We present here a new sensitive method to determine microbially available phosphorus concentrations in water down to 0.08 &mgr;g of P liter-1. The method is a bioassay in which the analysis of phosphorus in a water sample is based on maximum growth of Pseudomonas fluorescens P17 when the energy supply and inorganic nutrients, with the exception of phosphorus, do not limit bacterial growth. Maximum growth (CFU) in the water sample is related to the concentration of phosphorus with the factor 373,200 +/- 9,400 CFU/&mgr;g of PO4-P. A linear relationship was found between cell growth and phosphorus concentration between 0.05 to 10 &mgr;g of PO4-P liter-1. The content of microbially available phosphorus in Finnish drinking waters varied from 0.1 to 10.2 &mgr;g of P liter-1 (median, 0.60 &mgr;g of P liter-1).

Environmental chemicals and changes in sex ratio: analysis over 250 years in finland.

It has been proposed that environmental chemicalization is responsible for the recent decline in male ratio, but these speculations are based on statistics going back only a few decades. The objective of this study was to evaluate whether Finnish long-term data are compatible with the hypothesis that the decrease in the ratio of male to female births in industrial countries is caused by environmental factors. We analyzed the sex ratio of births from the files of Statistics Finland and all live births in Finland from 1751 to 1997. Running averages of 9 years (1751-1904) or 5 years (1905-1997) were analyzed for sex ratios. Additionally, to identify potential explanations for the findings, births from 1990 to 1997 were correlated with various family parameters. We found an increase in the proportion of males from 1751 to 1920; this was followed by a decrease and interrupted by peaks in births of males during and after World War I and World War II. None of the family parameters (paternal age, maternal age, age difference of parents, birth order) could explain the time trends. The turning point of male proportion precedes the period of industrialization or the introduction of pesticides or hormonal drugs, rendering a causal association unlikely. Moreover the trends are similar to those observed in other countries with worse pollution and much greater pesticide use.

Birth weight and sex of children and the correlation to the body burden of PCDDs/PCDFs and PCBs of the mother.

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) were analyzed in 167 random human milk samples from urban and rural areas in Finland. Dietary habits and background information on each mother and child were gathered by questionnaire. Body mass indexes (BMI) before pregnancy and delivery in the rural area were 5-10% higher than in the urban area, but fat content of mother's milk was about 10% higher in the urban area. The mean weights of children (+/- standard deviation) were similar in the rural and urban areas among primiparae, 3,500 +/- 597 g and 3,505 +/- 454 g, respectively, although dioxin international toxic equivalents (I-TEQs) were significantly higher in the urban area. The mother's level of education did not affect the weight of the child, but concentrations of PCDDs/PCDFs (I-TEQ, 2,3,4,7,8-Cl5 dibenzofuran,1,2, 3,7,8-Cl5 dibenzodioxin) and PCBs [sum of PCBs (sumPCB), PCB-TEQ, and most PCB congeners] increased with advanced education. This is considered to be due to differences in the mother's consumption of fish. The birth weight, especially of boys, slightly decreased with increasing concentrations of I-TEQ, 2,3,4,7,8-Cl5 dibenzofuran, 1,2,3, 7,8-Cl5 dibenzodioxin, and 2,3,7,8-Cl4 dibenzodioxin; however, when the analysis was restricted to primiparae, there was no statistically significant correlation between birth weight and the concentrations of PCDDs/PCDFs. No correlation was found between the weight of the child and PCBs, PCB-TEQs, or individual PCB congeners in the whole material or among primiparae, or among boys or girls. The concentrations of PCDDs/PCDFs and PCBs inhuman milk were modeled for primiparae by weighing fish consumption, age of mother, milk fat content, and BMI before pregnancy. The linear regression resulted in values of R = 0.67 and 0.30 for the modeled dioxin I-TEQs in the urban and rural areas, respectively, and the corresponding values for sumPCBs of R = 0.60 and 0.11. The increase of PCDD/PCDF body burden was calculated to be on average 0.58 pg I-TEQ/g milk fat/year in the urban area and 0.39 pg I-TEQ/g milk fat/year in the rural area.

Modulation of TCDD-induced wasting syndrome by portocaval anastomosis and vagotomy in Long-Evans and Han/Wistar rats.

Portocaval anastomosis and vagotomy operations were performed in Long-Evans (L-E) and Han/Wistar (H/W) rats to elucidate the mechanism of anorexia induced by TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin). TCDD-sensitive L-E rats were given a sublethal (5 micrograms/kg) or a lethal dose (20 micrograms/kg) by gavage 5-8 weeks after portocaval anastomosis. TCDD-resistant H/W rats were given a nonlethal dose (500 or 7200 micrograms/kg). The shunt operation did not reduce lethality from TCDD. The effect on wasting of the marginally toxic dose of 5 micrograms/kg in L-E rats was potentiated by the portocaval operation, and the lethal dose was effective in both shunted and sham-operated L-E rats. TCDD failed to decrease food intake and body weight in shunted rats of H/W strain at either dose level though it did so in sham-operated controls. The lack of effect may be due to the already reduced weight of shunted rats at the time of TCDD dosing. TCDD anorexia was not explained by changes in histamine or serotonin (5-HT) turnover in the brain. Vagotomy did not influence lethality after TCDD, although reduction in food intake was somewhat blunted in H/W rats. The results seem to indicate that the anorectic effect of TCDD is modified when portal blood bypasses the liver. The mechanisms remain to be elucidated in detail, but the results do not favor the role of liver as the only or the major initiator of TCDD anorexia. Little evidence was found to support a crucial role of vagal afferent input.

Effects of human placental S9 and induced rat liver S9 on the mutagenicity of drinking waters processed from humus-rich surface waters.

The mutagenicity of chlorinated drinking waters processed from humus-rich surface waters has been shown to be very high. The effect of placental S9 on the mutagenicity of drinking waters has not been studied previously. The purpose of this study was to compare the effects of human placental and rat liver microsomal fractions on the mutagenicity of drinking waters processed from humus-rich surface waters. The samples of 34 drinking and two raw waters from 26 localities in Finland were tested for mutagenicity in Ames Salmonella typhimurium tester strain TA100 with and without metabolic activations. Between the drinking water samples, clear differences were recorded in the presence of placental and rat liver S9, suggesting different mutagens in the drinking waters. Rat liver S9 decreased the mutagenicities of drinking water concentrates, but placental S9 increased, decreased, or had no effect. It is not known if placental mutagenicity enhancing system might cause any health hazard to a developing fetus.

Altered enzyme activities of xenobiotic biotransformation in kidneys after subchronic administration of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) to rats.

Activities of the xenobiotic metabolizing enzymes were measured in the liver, kidney, duodenum and lung microsomes and cytosol fractions of Wistar rats after subchronic administration of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a potent bacterial mutagen in chlorinated drinking water. MX was administered by gavage at the dose level of 30 mg/kg for 18 weeks (low dose), or at the dose level which was raised gradually from 45 mg/kg for 7 weeks via 60 mg/kg for 2 weeks to a clearly toxic dose of 75 mg/kg for 5 weeks (high dose). Microsomal and cytosolic preparations were made and the activities of 7-ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-dealkylase (PROD), NADPH-cytochrome-c-reductase, UDP-glucuronosyltransferase (UDPGT) and glutathione-S-transferase (GST) were measured. Kidneys were affected most. A dose-dependent decrease was observed in EROD (90% in males, 80% in females at the high dose) and in PROD (58% in females at the high dose) in kidneys. An increase was, however, detected in kidney NADPH-cytochrome-c-reductase (66% in females at high dose), UDPGT (89% in males and 97% in females at high dose) and GST activities (56% in males and 50% in females at high dose). MX caused only a few changes in the enzyme activities of the liver. The EROD activity was decreased 25% to 37%, both in the livers of males and females, but the total content of P450s was not altered. Hepatic GST activity was elevated in females in a dose-dependent manner (31% and 44%). GST activity was elevated in duodenum in females (59%) at the high dose. There were no marked changes in the enzyme activities in the lungs. MX was a weak inhibitor of EROD activity both in the liver and kidney microsomes in vitro, decreasing the EROD activity by 53% and 43%, respectively at the concentration of 0.9 mM. The results indicate that MX decreases the activity of phase I metabolism enzymes, but induces phase II conjugation enzyme activities, particularly in kidneys in vivo. It is possible that these changes contribute to metabolism of MX in kidneys and renders them susceptible to MX in the course of repeated exposure.

Chlorinated drinking water is mutagenic and causes 3-methylcholanthrene type induction of hepatic monooxygenase.

Acid/neutral fractions of 4 chlorinated drinking water samples were tested for mutagenicity in the Ames' test and injected intraperitoneally to 10- and 20-day-old Wistar rats at doses of 200 and 100 liters of water/kg body weight. Cytochrome P-450 mediated enzyme activities of ethylmorphine-N-demethylase (EMND), 7-ethoxycoumarin-O-deethylase (ECOD), 7-ethoxyresorufin-O-deethylase (EROD) and 7-pentoxyresorufin-O-dealkylase (PEROD) were determined in the 9000 g supernatant fraction of liver homogenate. EROD was introduced by the concentrates. The induction was related to the mutagenic activity. About 4-fold increase in activity was observed with the most mutagenic sample. PEROD was also slightly enhanced. EMND and ECOD activities were not affected by the lower dose, but the higher dose caused inhibition of 30-40%. Although the extracts were not toxic to bacteria, they were unexpectedly toxic to rats. It is concluded that the samples contained 3-methylcholanthrene (3-MC) type inducer(s).

Determination of bromide ion in raw and drinking waters by capillary zone electrophoresis.

A new capillary zone electrophoretic method was developed for the determination of bromide ion in raw and drinking waters. An NaCl-based low-pH buffer caused a reduction of electroosmotic flow (EOF) in the buffer zone, whereas injected water sample resulted in higher EOF in the sample zone thus pumping out the neutral water plug. Sample stacking was used for the preconcentration. The method was applicable for waters from low to intermediate ionic strengths, i.e., the concentration of chloride should preferably be less than 40 mg/l. The method had a limit of detection of 15 micrograms/l at a signal-to-noise ratio of three (S/N = 3) and a limit of quantitation of 20 micrograms/l. CZE results obtained with real samples were compared with ion chromatography--inductively coupled mass spectrometric results.

Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry.

Extractable tannins were analysed by liquid chromatography-electrospray ionisation mass spectrometry in two oak species, North American white oak (Quercus alba) and European red oak (Quercus robur). They mainly included various glucose gallic and ellagic acid esters. The structures were partially determined, and they included grandinin/roburin E, castalagin/vescalagin, gallic acid, valoneic acid bilactone, monogalloyl glucose, digalloyl glucose, trigalloyl glucose, ellagic acid rhamnose, quercitrin and ellagic acid.

Gas chromatographic-mass spectrometric detection of 2- and 3-hydroxy fatty acids as methyl esters from soil, sediment and biofilm.

Hydroxy fatty acids (OH-FAs) can be used in the characterization of microbial communities, especially Gram-negative bacteria. We prepared methyl esters of 2- and 3-OH-FAs from the lipid extraction residue of soil, sediment, and biofilm samples without further purification or derivatization of hydroxyl groups. OH-FA methyl esters were analyzed using a gas chromatograph equipped with a mass selective detector (GC-MS). The ions followed in MS were m/z 103 for 3-OH-FAs and m/z 90 and M-59 for 2-OH-FAs. The rapid determination of 3- and 2-OH-FAs concomitantly with phospholipid fatty acids provided more detailed information on the microbial communities present in soil, sediment, and drinking water biofilm.

Formation of methemoglobin by 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone, MX, in rat erythrocytes in vitro.

Oxidative effects of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), the principal bacterial mutagen in chlorinated drinking water were studied in rat erythrocytes. Upon incubation of rat blood with 14C-labelled MX (2 micrograms/ml), 42% of the radioactivity was found in plasma, 26% in erythrocyte cell membranes and 32% bound in hemoglobin. Although it was bound to hemoglobin, MX (1 mM) did not immediately affect the oxygen binding capacity of hemoglobin. MX (0.5 to 5 mM) decreased the portion of oxyhemoglobin and increased that of methemoglobin in erythrocytes suspended in buffer in a time- and concentration-dependent fashion. In the same concentration range MX did not stimulate proteolysis nor did it cause hemolysis in erythrocytes. The results indicate that MX binds to hemoglobin and stimulates oxidation of hemoglobin in erythrocytes but MX does not cause overt oxidative damage to erythrocytes.