Preliminary screening for the potential of drinking water disinfection byproducts to alter male reproduction

There is increasing epidemiologic interest in the role drinking water disinfection byproducts (DBPs) may play in adverse reproductive outcomes such as inability to conceive, spontaneous abortion, and low birth weight. Although dozens of DBPs already have been identified, only a few studies have attempted to determine whether DBPs alter male reproductive parameters such as testicular and epididymal histology, testicular and epididymal sperm numbers, and epididymal sperm morphology and motility in laboratory animals. In these studies, alterations in epididymal sperm motility seemed to be predictive of more generalized toxicity of the male reproductive system. Because there is a need to prioritize DBPs for thorough reproductive and developmental toxicity testing, preliminary screening for the potential of DBPs to alter reproductive function seems warranted. Here, we elected to examine only cauda epididymal sperm motion parameters and testicular and epididymal histopathology. The effects of exposure to two commonly occurring DBPs, bromodichloromethane (BDCM) and chloral hydrate (CH), via drinking water were evaluated in F344 rats at an interim (52 week) necropsy during cancer bioassay studies. Exposure to 22 and 39 mg/kg BDCM and 55 and 188 mg/kg CH did not produce any systemic toxicity. Histopathologic evaluation revealed no gross lesions in the reproductive organs, and no tumors were detected in any tissues. In contrast, exposure to 39 mg/kg BDCM significantly decreased the mean straight-line, average path, and curvilinear velocities of sperm recovered from the cauda epididymidis. This BDCM exposure shifted the average path velocity distribution to a lower modal velocity range. Exposure to 188 mg/kg CH significantly decreased both the percentage of motile and progressively motile sperm. This CH exposure shifted the straight-line velocity distribution to a lower modal velocity range. These are the first reproductive toxicity data from exposure to BDCM and CH. The observed effects on sperm motion occurred in the absence of carcinogenesis. Because the effects of BDCM on sperm motility occurred at a lower exposure than that of other DBPs that compromise sperm motility, a thorough reproductive evaluation now is underway.     

Irritating effects of disinfection by-products in swimming pools

Compounds which can occur as disinfection by-products (DBP's) in swimming pool water were examined for their mucous membrane irritating potential. Previous studies using the rabbit eye test (Draizé test) have shown that the irritating potential of typical concentrations of free and combined chlorine are insufficient to explain the degree of eye irritation that can result from exposure to swimming pool water. Other DBP's which may be responsible for eye irritation include halogenated carboxyl compounds (HCC's) which act as precursors during the formation of chloroform. In this study, a modified HET-CAM Test (Hens Egg Test at the Chorion Allantois Membrane) has been used to investigate the mucous membrane irritating effects of HCC's. Some of the compounds tested were found to have a significantly increased irritating effect when compared to a chlorine/chloramine mixture of the same concentration, several mixtures of HCC's where even more active at lower concentrations than single compounds. However, the irritating effects of individual compounds as well as of mixtures of HCC's were not sufficiently intense to allow the identification of those compounds specifically responsible for the overall observed increase in irritation. HCC's were therefore tested in the presence of aqueous chlorine solution. When combined with aqueous chlorine, a number of compounds exhibited significantly enhanced effects. Our results show that the eye irritating effects of low concentrations of DBP's can be investigated using a modified HET-CAM assay. Moreover, results obtained using this assay suggest that the mucous membrane irritating potential of swimming pool water is a consequence of the effects and synergistic action of a number of DBP's in the presence of chlorine. Further work should be carried out in order to establish an indicator for eye irritating effects of swimming pool water.     

Effect of monochloramine disinfection of municipal drinking water on risk of nosocomial Legionnaires' disease

BACKGROUND: Many Legionella infections are acquired through inhalation or aspiration of drinking water. Although about 25% of municipalities in the USA use monochloramine for disinfection of drinking water, the effect of monochloramine on the occurrence of Legionnaires' disease has never been studied. METHODS: We used a case-control study to compare disinfection methods for drinking water supplied to 32 hospitals that had had outbreaks of Legionnaires' disease with the disinfection method for water supplied to 48 control-hospitals, with control for selected hospital characteristics and water treatment factors. FINDINGS: Hospitals supplied with drinking water containing free chlorine as a residual disinfectant were more likely to have a reported outbreak of Legionnaires' disease than those that used water with monochloramine as a residual disinfectant (odds ratio 10.2 [95% CI 1.4-460]). This result suggests that 90% of outbreaks associated with drinking water might not have occurred if monochloramine had been used instead of free chlorine for residual disinfection (attributable proportion 0.90 [0.29-1.00]). INTERPRETATION: The protective effect of monochloramine against legionella should be confirmed by other studies. Chloramination of drinking water may be a cost-effective method for control of Legionnaires' disease at the municipal level or in individual hospitals, and widespread implementation could prevent thousands of cases.     

Workshop report. Health risks of drinking water chlorination by-products: report of an expert working group

Studies of water chlorination by-products have suggested a possible increased risk of bladder and colon cancers, as well as adverse reproductive and developmental effects such as increased spontaneous abortion rates and fetal anomalies. A workshop for an expert working group was convened to advise Health Canada on the need for further action. Participants were given background papers and a set of key questions to review prior to the meeting. At the workshop, experts presented an overview of what was known to date on water chlorination by-products from toxicologic studies, epidemiologic studies of cancer and adverse reproductive/developmental effects, and risk assessment. This paper summarizes the information provided in the background papers and presentations, describes the consensus arrived at regarding assessment of evidence for level of risk and presents a number of suggestions for future research.     

Solar disinfection of drinking water contained in transparent plastic bottles: characterizing the bacterial inactivation process

A series of experiments is reported to identify and characterize the inactivation process in operation when drinking water, heavily contaminated with a Kenyan isolate of Escherichia coli, is stored in transparent plastic bottles that are then exposed to sunlight. The roles of optical and thermal inactivation mechanisms are studied in detail by simulating conditions of optical irradiance, water turbidity and temperature, which were recorded during a series of solar disinfection measurements carried out in the Kenyan Rift Valley. Optical inactivation effects are observed even in highly turbid water (200 ntu) and at low irradiances of only 10 mW cm-2. Thermal inactivation is found to be important only at water temperatures above 45 degrees C, at which point strong synergy between optical and thermal inactivation processes is observed. The results confirm that, where strong sunshine is available, solar disinfection of drinking water is an effective, low cost method for improving water quality and may be of particular use to refugee camps in disaster areas. Strategies for improving bacterial inactivation are discussed.     

Hepatotoxicity of diisopropyl ester of malonic acid and chloromalonic acids, disinfection by-products of the fungicide isoprothiolane

The fungicide isoprothiolane (diisopropyl 1,3-dithiolane-2-ylidenemalonate) decomposes to the diisopropyl esters of malonic acid (DM), chloromalonic acid (DCM) and dichloromalonic acid (DDCM) upon aqueous chlorination. In this study, the cytotoxicity of these compounds was examined using rat hepatocytes cultured on Matrigel. DCM and DDCM caused hepatocellular death at concentrations > 0.5 mM, while DM had no effect on the cell viability even at the maximum concentration examined (4 mM). Significant lipid peroxidation, measured as 2-thiobarbituric acid reactive substances, was observed in both DCM- and DDCM-treated hepatocyte cultures, and was significantly enhanced by pretreatment with 0.1 mM bis(p-nitrophenyl)phosphate (BNPP), a carboxylesterase inhibitor. When both BNPP and SKF-525A, a cytochrome P450 inhibitor, were present in the medium, DCM-induced cytotoxicity and lipid peroxidation were significantly suppressed compared to cultures with BNPP-treatment alone. By contrast, the DDCM-induced cytotoxicity was not affected by the combined pretreatment of SKF-525A and BNPP. These results indicate that DCM is metabolically activated by cytochrome P450 in an ester form, while DDCM is activated by a mechanism other than one involving cytochrome P450. To further elucidate the cytochrome P450 isozyme involved in the metabolic activation of DCM, microsomal lipid peroxidation was studied in vitro using microsomes from rats treated with beta-naphthoflavone, musk xylene, phenobarbital, pyrazole, or dexamethasone. Among these preparations, the microsomes from dexamethasone-treated rats showed the most extensive lipid peroxidation in the presence of DCM, and the lipid peroxidation was enhanced by BNPP as observed in hepatocyte cultures. These findings suggest the possible involvement of cytochrome P450 3A in the metabolic activation of DCM.     

Minerals in Tunisia's drinking water

We have made the physico-chemical analysis of drinking waters sampled from different Tunisian areas. The results obtained show that those waters are rich in mineral elements particularly those of the south of the country. Calcium and magnesium level in south drinking water is about three times higher than the maximum admitted concentration by WHO an EEC. The sodium, chloride and sulfate level is twice higher. The nitrate contents slightly exceeds the EEC guide level. The high mineralization observed needs a chemical quality improvement of those waters.     

Lithium therapy and drinking water

ain causes of failure and giving up in psychotropic lithiotherapics because of instable lithiemy to the same patient or functional acute renal insufficiency, are principaly mistaken diets, those mistaken concerning the amount, the quality and the way of taking drinking water and other beverages. Lithium salt, taken either in two times, morning and evening, or in one, must be absorbed at the end of a solid meal with at least 25 cl. of water. The patient must absorb at least 1.5 l. of water per day, and up to 3 l. in case of physical efforts or heat. The pH of this water and it ionic compound should be stable, as close as possible to the plasma's, without additives that could change its taste. This includes cooking water and infusions. Physicopharmacological explanations.     

Calcium supplementation of hen drinking water

Two experiments with White Leghorn hens (42 and 56 wk old, respectively) examined the effects of calcium supplementation through drinking water in the presence of adequate and inadequate dietary calcium. Each experiment was of 28 d duration with six replicate pens of five individually caged hens in each treatment. Treatments were a combination of either 2.25 or 3.5% dietary calcium coupled with tap water or water supplemented with .2% calcium from calcium lactate. In both studies, specific gravity of eggs was significantly improved when low dietary calcium was supplemented with .2% calcium in the drinking water. Egg production and egg weight were not influenced by waterborne calcium. Daily water intake was reduced by calcium lactate in all cases. Feed consumption was also depressed by waterborne calcium in both studies when 3.5% dietary calcium was given, and in Experiment 1 when 2.25% was fed. Waterborne calcium as calcium lactate was found to be effectively utilized for eggshell quality improvement when dietary sources were inadequate.     

Full-scale studies of factors related to coliform regrowth in drinking water

An 18-month survey of 31 water systems in North America was conducted to determine the factors that contribute to the occurrence of coliform bacteria in drinking water. The survey included analysis of assimilable organic carbon (AOC), coliforms, disinfectant residuals, and operational parameters. Coliform bacteria were detected in 27.8% of the 2-week sampling periods and were associated with the following factors: filtration, temperature, disinfectant type and disinfectant level, AOC level, corrosion control, and operational characteristics. Four systems in the study that used unfiltered surface water accounted for 26.6% of the total number of bacterial samples collected but 64.3% (1,013 of 1,576) of the positive coliform samples. The occurrence of coliform bacteria was significantly higher when water temperatures were > 15 degrees C. For filtered systems that used free chlorine, 0.97% of 33,196 samples contained coliform bacteria, while 0.51% of 35,159 samples from chloraminated systems contained coliform bacteria. The average density of coliform bacteria was 35 times higher in free-chlorinated systems than in chloraminated water (0.60 CFU/100 ml for free-chlorinated water compared with 0.017 CFU/100 ml for chloraminated water). Systems that maintained dead-end free chlorine levels of < 0.2 mg/liter or monochloramine levels of < 0.5 mg/liter had substantially more coliform occurrences than systems that maintained higher disinfectant residuals. Free-chlorinated systems with AOC levels greater than 100 micrograms/liter had 82% more coliform-positive samples and 19 times higher coliform levels than free-chlorinated systems with average AOC levels less than 99 micrograms/liter. Systems that maintained a phosphate-based corrosion inhibitor and limited the amount of unlined cast iron pipe had fewer coliform bacteria. Several operational characteristics of the treatment process or the distribution system were also associated with increased rates of coliform occurrence. The study concludes that the occurrence of coliform bacteria within a distribution system is dependent upon a complex interaction of chemical, physical, operational, and engineering parameters. No one factor could account for all of the coliform occurrences, and one must consider all of the parameters described above in devising a solution to the regrowth problem.     

Actual standards for drinking water quality

In freshly isolated rat CCD segments, the effects of arginine vasopressin (AVP), oxytocin (OT), adrenaline (Ad), and their specific receptor agonists and antagonists on the intracellular Ca2+ activity ([Ca2+]i) were measured using the Ca2+ sensitive dye Fura-2 as fluorescence indicator. We observed that AVP, the V1-receptor agonist [Phe2Orn8] vasotocin ([Phe2]OVT), and OT increased [Ca2+]i biphasically. AVP (n = 9) and OT (n = 8) induced increases in [Ca2+]i were completely blocked by the V1A-receptor antagonist d(CH2)5Tyr(Me)2AVP. However, neither the V2-receptor agonist [Val4-D-Arg8]AVP (100 nM, n = 5), nor the OT-receptor agonist [Thr4,Gly7]OT (100 nM, n = 5) nor forskolin (1 microM, n = 4 and 10 microM, n = 5) did significantly change [Ca2+]i. Ad and the beta-adrenoceptor agonist isoproterenol (ISO) increased [Ca2+]i, which was not mimicked by the alpha 2-adrenoceptor agonist clonidine (1 microM, n = 10) or the alpha 1-adrenoceptor agonist phenylephrine (1 microM, n = 5). The beta-adrenoceptor antagonist propranolol (1 microM) completely blocked this Ad (1 microM, n = 4) induced [Ca2+]i increase. Insulin (INS 10 nM, n = 8), endothelin (ET 1 microM, n = 6), and angiotensin II (Ang II 1 pM to 10 nM; each n = 4) had no significant effect on [Ca2+]i. Considering the present results we propose a V1A-receptor and beta-adrenoceptor dependent modulation of [Ca2+]i in rat CCD.     

Detection of psychotrophic aeromonads in drinking water

In the context of evaluating their pathogenic relevance, culture on solid media is the only approach presently suitable for culture of psychotrophic aeromonads from drinking water. In this respect, a check must be effected to ensure that the culture medium cannot engender selective culture losses for individual species. For this reason, media to which e.g. ampicillin has been added are unsuitable.     

Cardiac teratogenesis of halogenated hydrocarbon-contaminated drinking water

OBJECTIVES: The purpose of this study was to test the hypothesis that administration of trichloroethylene and dichloroethylene to pregnant rats during organogenesis would produce a significant fetal cardiac teratogenic effect. It was also hypothesized that administration of these compounds only before pregnancy would not be associated with fetal cardiac teratogenesis. BACKGROUND: Epidemiologic observations demonstrated an increased number of congenital cardiac defects in children whose mother resided in an area with drinking water contaminated by trichloroethylene and dichloroethylene. A prior provocative intrauterine exposure study in rats established a positive link between these contaminants and an increased number of fetal hearts with congenital cardiac defects. METHODS: Sprague-Dawley rats were given pure tap drinking water (control subjects) or water contaminated with high or low dose of trichloroethylene or dichloroethylene (experimental groups) during prepregnancy only, prepregnancy and pregnancy or during pregnancy alone. RESULTS: A total of 2,045 fetuses were examined. Trichloroethylene or dichloroethylene delivered exclusively in the period before pregnancy caused no increase in congenital cardiac malformations over the control level. Compared with the control group, rats exposed to these agents both before and during pregnancy, had a significantly greater number of fetuses with cogenital cardiac malformations. Trichloroethylene (high dose only) administered only during pregnancy produced a significant increase in cardiac defects. Other fetal variables, including noncardiac congenital abnormalities, showed no significant difference between control and treated groups. CONCLUSIONS: Trichloroethylene and dichloroethylene administered during organogenesis are cardiac, but not general, teratogens. The data indicate that these agents administered in drinking water to pregnant rats caused an increased number of congenital cardiac defects in rat fetuses.     

Reproductive and neurobehavioral effects of amaranth administered to mice in drinking water

The color additive amaranth was given in the drinking water at levels of 0 (control), 0.025, 0.075, and 0.225% from 5 weeks of age in F0 generation until F1 generation mice were weaned, with selected reproductive, developmental and behavioral parameters being measured. Amaranth had little adverse effect upon litter size, litter weight and sex ratio. Average body weight in both sexes of the F1 mice was significantly increased in the 0.025% group in both sexes. Survival index at postnatal day (PND) 21 was reduced in the 0.025% amaranth group. For the neurobehavioral parameters, surface righting at PND 4 in female offspring and olfactory orientation in both sexes were significantly affected by treatment. Several parameters of movement activity of male offspring at 3 weeks of age were affected in amaranth 0.075% group, but those of female offspring were similar in all groups. The dose levels of amaranth in this study produced a little adverse effect on behavioral development in mice.