Avilian

With thanks to DailyIndia.com 13.1.08

Traces of cancer and psychiatric drugs have been found in Britain’s tap water, a report reveals. The report, commissioned by the drinking water watchdog in the country, the Drinking Water Inspectorate (DWI), reveals that pharmaceuticals are finding their way into the water supply despite extensive purification treatments used by water companies.
During the tests on drinking water, trace levels of bleomycin, a cancer chemotherapy drug, and diazepam, a sedative have been found.

While the levels are considered too low to pose a direct risk to health, doctors have expressed concern about exposing pregnant women to drugs that could harm an unborn child.

The report, compiled for the DWI by the consultants Watts and Crane Associates, recommends that drinking water should be monitored for hazardous drugs.

“The observed concentrations of pharmaceuticals in raw waste water indicate that the major source of pharmaceuticals to the environment is via sewage treatment works effluent,” the Telegraph quoted the report, as stating.

“Drinking water treatment works use a wider and technically more advanced range of processes, but again these are not specifically designed to remove pharmaceuticals and several compounds have been reported in drinking water.

“Even in the worst-case situation, there is no significant risk to health from the intake of pharmaceuticals via drinking water,” the report added.

Sue Pennison, from the DWI, said: “The recommendations are now being considered and this may include conducting testing on drinking water.”

Cytotoxic and genotoxic potential of drinking water: A comparison between two different concentration methods Buschini A, Giordani F, Pellacani C, Rossi C, Poli P. Dipartimento di Genetica, Biologia dei Microrganismi, Antropologia, Evoluzione, Università di Parma, Via Usberti, 11/A, 43100 Parma, Italy Water Res. 2007 Dec 15

The level of exposure to hazardous compounds through drinking water is low but it is maintained throughout life, therefore representing a risk factor for human health.

The use of techniques averaging the consumer’s exposure over time could be more useful than relying on intermittent grab samples that may misrepresent average tap water concentrations due to short-term temporal variability.

In this study, we compared the induction of in vitro cytotoxic and genotoxic effects (DNA damage by the comet assay) in relation to different sampling methods, i.e. exposure over time (semipermeable membrane devices, SPMDs, exposed for 30 days) or intermittent grab samples (5 weekly water sampling, C18 concentration).

Waters with different chemical characteristics were sampled to test the sensitivity of the two methods. We did not found any positive correlation between the biological findings and water chemical parameters. SPMD extracts induced a significantly greater DNA damage than C18.

The different behaviour was specially found for the water samples with a low level of organic compounds and when C18 extracts were highly cytotoxic.

Our findings suggest that SPMD could be of a great interest in assessing genotoxic contaminants in both raw and drinking water, with great suitability for continuous monitoring.

Furthermore, the results of this study have confirmed the great importance of the biological assays in evaluating the effects of a complex mixture such as water in addition to the conventional chemical examination of water quality.

Total fluid and water consumption and the joint effect of exposure to disinfection by-products on risk of bladder cancer Michaud DS, Kogevinas M, Cantor KP, Villanueva CM, Garcia-Closas M, Rothman N, Malats N, Real FX, Serra C, Garcia-Closas R, Tardon A, Carrato A, Dosemeci M, Silverman DT. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts 02115, USA. dmichaud@hsph.harvard.edu Environ Health Perspect. 2007 Nov;115(11):A551.

BACKGROUND: Findings on water and total fluid intake and bladder cancer are inconsistent; this may, in part, be due to different levels of carcinogens in drinking water.

High levels of arsenic and chlorinated by-products in drinking water have been associated with elevated bladder cancer risk in most studies.

A pooled analysis based on six case-control studies observed a positive association between tap water and bladder cancer but none for nontap fluid intake, suggesting that contaminants in tap water may be responsible for the excess risk.

OBJECTIVES: We examined the association between total fluid and water consumption and bladder cancer risk, as well as the interaction between water intake and trihalomethane (THM) exposure, in a large case-control study in Spain.

METHODS: A total of 397 bladder cancer cases and 664 matched controls were available for this analysis. Odds ratios (OR) were estimated using unconditional logistic regression, controlling for potential confounders.

RESULTS: Total fluid intake was associated with a decrease in bladder cancer risk [OR = 0.62; 95% confidence interval (CI), 0.40-0.95 for highest vs. lowest quintile comparison]. A significant inverse association was observed for water intake (for > 1,399 vs. < 400 mL/day, OR = 0.47; 95% CI, 0.33-0.66; p for trend < 0.0001), but not for other individual beverages. The inverse association between water intake and bladder cancer persisted within each level of THM exposure; we found no statistical interaction (p for interaction = 0.13).

CONCLUSION: Findings from this study suggest that water intake is inversely associated with bladder cancer risk, regardless of THM exposure level.

Impact of intensive agricultural practices on drinking water quality in the EVROS Region (NE GREECE) by GIS analysis Nikolaidis C, Mandalos P, Vantarakis A. Laboratory of Hygiene and Environmental Protection, Medical School, Democritus University of Thrace, 68100, Alexandroupolis, Greece, avantar@med.duth.gr. Environ Monit Assess. 2007 Sep 16

Chemical fertilizers are used extensively in modern agriculture, in order to improve yield and productivity of agricultural products. However, nutrient leaching from agricultural soil into groundwater resources poses a major environmental and public health concern.

The Evros region is one of the largest agricultural areas in Northern Greece, extending over 1.5 million acres of cultivated land. Many of its drinking water resources are of groundwater origin and lie within agricultural areas.

In order to assess the impact of agricultural fertilizers on drinking water quality in this region, tap-water samples from 64 different locations were collected and analyzed for the presence of nitrates, nitrites, ammonium, sulfate and phosphate.

These chemicals were selected based on the information that ammonium nitrate, ammonium sulfate and inorganic phosphate were the primary fertilizers used in local crop production.  Levels exceeding accepted values were recorded in 6.25, 4.70 and 9.38% of all sampling points, respectively. Concentrations, on the other hand, were inside the permitted range.

The data generated were introduced into a geographic information system (GIS) program for computer analysis and projection maps representing afflicted areas were created.

Our results indicate a profound geographic correlation in the surface distribution of primary contaminants in areas of intensified agricultural production.

Thus, drinking water pollution in these areas can be attributed to excessive fertilizer use from agricultural sources.

Development of physiologically based toxicokinetic models for improving the human indoor exposure assessment to water contaminants: trichloroethylene and trihalomethanes Haddad S, Tardif GC, Tardif R. Département des sciences biologiques, TOXEN, Université du Québec à Montréal, Montréal, Qc, Canada. haddad.sami@uqam.ca J Toxicol Environ Health A. 2006 Dec;69(23):2095-136

Generally, ingestion is the only route of exposure that is considered in the risk assessment of drinking water contaminants. However, it is well known that a number of these contaminants are volatile and lipophilic and therefore highly susceptible to being absorbed through other routes, mainly inhalation and dermal.

The objective of this study was to develop physiologically based human toxicokinetic (PBTK) models for trihalomethanes (THM) and trichloroethylene (TCE) that will facilitate (1) the estimation of internal exposure to these chemicals for various multimedia indoor exposure scenarios, and (2) consideration of the impact of biological variability in the estimation of internal doses.

Five PBTK models describing absorption through ingestion, inhalation and skin were developed for these contaminants. Their concentrations in ambient air were estimated from their respective tap water concentrations and their physicochemical characteristics.

Algebraic descriptions of the physiological parameters, varying as a function of age, gender and diverse anthropometric parameters, allow the prediction of the influence of interindividual variations on absorbed dose and internal dosimetry.

Simulations for various scenarios were done for a typical human (i.e., 70 kg, 1.7 m) as well as for humans of both genders varying in age from 1 to 90 years.

Simulations show that ingestion contributes to less than 50% of the total absorbed dose or metabolized dose for all chemicals.

This contribution to internal dosimetry, such as maximal venous blood concentrations (Cmax) and the area under the venous blood concentration time curve (AUC), decreases markedly (e.g., as low as 0.9% of Cmax for bromodichloromethane).

The importance of this contribution varies mainly as a function of shower duration.

Moreover, model simulations indicate that multimedia exposure is more elevated in children than adults (i.e., up to 200% of the adult internal dose).

The models developed in this study allow characterization of the influence of the different routes of exposure and an improved estimation of the realistic multimedia exposure to volatile organic chemicals present in drinking water.

Hence, such models will greatly improve health risk assessment for these chemicals.