Comparative genotoxicity of halogenated acetic acids found in drinking water

20 years after the introduction of the hepatitis-B vaccine the question still remains unsolved as to how the 2 to 5 per cent of the vaccinees who, after basic immunisation, respond with no anti-HBs levels (0-10 IU/l nonresponder, NR) or low levels (11-99 IU/l low-responder, LR) should be boostered to acquire sufficient and long-lasting protective anti-HBs levels. In a retrospective analysis of booster results we found in 75 NR and LR that the probability for long-lasting protection is very low for NR, but better for LR (60%). In a second part of this publication, the efficacy of intradermal and intramuscular hepatitis-B boosters was examined by retrospective analysis of booster results among 26 NR and LR. A slight advantage of the intradermal application was found concerning post-booster anti-HBs increase and the maximal HBs values reached. Long-lasting protective anti-HBs values could not be established for either way of application. Finally, a survey of the literature summing up true results of intradermal hepatitis-B basic immunisations with reduced doses (mostly 2 micrograms), shows that whereas the seroconversion rates achieved by this method are almost compatible with those after regular basic vaccination, the GMT values were far lower than those after regular basic vaccination. Prospective and randomised studies are needed to show which kind of booster is most efficient for nonresponders and low-responders.     

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.     

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.     

The effect of water pipelines on the quality of drinking water

Examined whether marital discord over childrearing contributes to child behavior problems after taking into account general marital adjustment, and if child age moderates associations between child behavior problems and either general marital adjustment or marital discord over childrearing. Participants were 146 two-parent families seeking services for their child's (4 to 9 years of age) conduct problems. Data on marital functioning and child behavior problems were collected from both parents. Mothers' and fathers' reports of marital discord over childrearing related positively to child externalizing problems after accounting for general marital adjustment. Child age moderated associations between fathers' reports of general marital adjustment and both internalizing and externalizing child problems, with associations being stronger in families with younger children. The discussion highlights the role that developmental factors may play in understanding the link between marital and child behavior problems in clinic-referred families.     

Phosphorus and bacterial growth in drinking water

The availability of organic carbon is considered the key factor to regulate microbial regrowth in drinking water network. However, boreal regions (northern Europe, Russia, and North America) contain a large amount of organic carbon in forests and peatlands. Therefore, natural waters (lakes, rivers, and groundwater) in the northern hemisphere generally have a high content of organic carbon. We found that microbial growth in drinking water in Finland is highly regulated not only by organic carbon but also by the availability of phosphorus. Microbial growth increased up to a phosphate concentration of 10 micrograms of PO4-P liter-1. Inorganic elements other than phosphorus did not affect microbial growth in drinking water. This observation offers novel possibilities to restrict microbial growth in water distribution systems by developing technologies to remove phosphorus efficiently from drinking water.     

Intragastric water and the acquisition of schedule-induced drinking

A case of multiple neonatal haemangiomatosis is described. A short course of steroid therapy produced rapid and marked improvement of cutaneous lesions, without any effect on testicular involvement. The authors emphasize the value of an early treatment with steroids.     

Atropine poisoning after drinking Indian tonic water

After 13.5 years in vivo a 2-0 Terylene frontalis loop was excised because of an insufficiency. Histology showed a persisting giant cell reaction while lymphocytes were almost totally absent. The fibrils of the suture seemed to be intact. However, they were separated by ingrowing connective tissue which, on theoretical grounds, should improve the function of the frontal muscle on the upper eyelid. Therefore, insufficiency of the loop was probably caused by the (subclinical) foreign body reaction or the long-lasting mechanical stress leading to tissue damage.     

Phenobarbital drinking curves after varied water deprivation

The phenobarbital dose-drinking response curves were obtained for 11 1/2 and 23 1/2 hr of water deprivation in rats. The results indicated that the same quadratic curve was found in both cases displaced as a function of degree of deprivation. These results are explicable by regarding phenobarbital as an adequate stimulus for drinking or by disinhibiting drinking if level of inhibition is not directly concerned with regulation of water ingestion per se. The response to phenobarbital upon the days following injection is similar for both degrees of deprivation investigated.     

饮用水中砷处理技术的研究进展

简单介绍了饮用水中砷的来源及危害,重点阐述了发展较为成熟的饮用水除砷技术,包括：混凝／沉淀法、吸附法、离子交换法、膜技术以及生物技术,通过分析比较可知,各种技术各具优缺点,混凝沉淀法和吸附法已被广泛应用;对环境条件要求较高的离子交换法和膜技术发展受到限制;生物技术具有良好的环境效益,应用前景广阔．最后对我国饮用水除砷技术的发展方向进行了展望,指出从我国基本国情考虑,混凝吸附为主的小型除砷装置占优势;从长远角度考虑,离子交换法和膜技术最具应用前景;从环境保护的角度看,生物技术高效廉价,必将引来更多的关注和研究．     

Behavioral effects of chemicals in drinking water.

In Exp I, 42 Ss (mean age 30.4 yrs) tracked a moving target and monitored lights after receiving sublingual drops that contained either water, sodium nitrate (4.5, 45, 450, or 4,500 ppm), or sodium fluoride (.1, 1, 10, or 100 ppm). Dosage levels equaled, exceeded, or fell below those of municipal waters. In Exp II, 20 females performed this task after receiving sublingual drops of the same test substances in a repeated measures design; dosage levels equaled or exceeded levels found in municipal waters by 100 or 500 times. Neither type nor amount of chemical affected primary task performance; however, after receiving sublingual drops in Exp I, Ss paid less attention to lights on their right. In Exp II, Ss made more errors and had longer response latencies after they received moderate and very high concentrations of test substances. It is concluded that challenge testing is a safe but effective technique for provoking and studying reactions to chemicals when combined with a sensitive measure of sensorimotor performance. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exposure estimates to disinfection by-products of chlorinated drinking water

Exposure to disinfection by-products (DBPs) of drinking water is multiroute and occurs in households serviced by municipal water treatment facilities that disinfect the water as a necessary step to halt the spread of waterborne infectious diseases. Biomarkers of the two most abundant groups of DBPs of chlorination, exhaled breath levels of trihalomethanes (THMs) and urinary levels of two haloacetic acids, were compared to exposure estimates calculated from in-home tap water concentrations and responses to a questionnaire related to water usage. Background THM breath concentrations were uniformly low. Strong relationships were identified between the THM breath concentrations collected after a shower and both the THM water concentration and the THM exposure from a shower, after adjusting for the postshower delay time in collecting the breath sample. Urinary haloacetic acid excretion rates were not correlated to water concentrations. Urinary trichloroacetic acid excretion rates were correlated with ingestion exposure, and that correlation was stronger in a subset of individuals who consumed beverages primarily within their home where the concentration measurements were made. No correlation was observed between an average 48-hr exposure estimate and the urinary dichloroacetic acid excretion rate, presumably because of its short biological half-life. Valid biomarkers were identified for DBP exposures, but the time between the exposure and sample collection should be considered to account for different metabolic rates among the DBPs. Further, using water concentration as an exposure estimate can introduce misclassification of exposure for DBPs whose primary route is ingestion due to the great variability in the amount of water ingested across a population.     

浅谈白云鄂博生活饮用水除氟

本文介绍了水除氟的方法和白云地区采用定时、定质供水的可行性及定时、定质供水的方案。