Spyros K. Golfinopoulos

Organochlorine pesticides in the surface waters of Northern Greece

A survey undertaken in Northern Greece has shown that organochlorine pesticides are present in the surface waters. Surface water samples have been collected seasonally from four rivers and five lakes for a period of two years. Solid-phase extraction followed by gas chromatographic techniques with electron capture detection was used for the determination of the compounds. The most commonly encountered organochlorine pesticides in surface waters were the isomers of hexachlorocyclohexane, aldrin, dieldrin and endosulfan sulfate. In some cases the concentrations detected were higher than the qualitative target levels set by the European Union, especially for hexachlorocyclohexane and aldrin. The occurrence of these compounds in Greek surface waters can be attributed to intense agricultural activity as well as to transboundary pollution.

Comparison of methods for determination of volatile organic compounds in drinking water

Comparison of four methods including liquid-liquid extraction (LLE), direct aqueous injection (DAI), purge and trap (PAT) and head space (HS) were carried out in this work for determination of volatile organic compounds (VOCs) including trihalomethanes (THMs) in drinking water. This comparison is made especially to show the advantages and disadvantages and specifically the different detection limits (DL) that can be obtained for a given type of analysis. LLE is applicable only for determination of the THMs concentrations, while DAI, PAT, HS methods with different DL each of them are applicable for all VOCs, with PAT to be the most sensitive. Sampling apparatus and procedure for all these methods except of PAT are very simple and easy, but possible disadvantages for LLE and DAI are the low sensitivity and especially the detection only of THMs with LLE.

Application of different analytical methods for determination of volatile chlorination by-products in drinking water.

Four analytical methods have been applied for the determination of volatile chlorination by-products in drinking water, based on the following techniques: liquid-liquid extraction-gas chromatography-electron capture detection (LLE-GC-ECD); liquid-liquid extraction-gas chromatography-mass spectrometry (LLE-GC-MS); purge and trap-gas chromatography-mass spectrometry (purge and trap-GC-MS); and headspace-gas chromatography-mass spectrometry (headspace-GC-MS). The compounds studied were trihalomethanes, haloacetonitriles, haloketones, chloral hydrate and chloropicrin. LLE-GC-ECD method proved to be the most sensitive for determination of all compounds studied, followed by LLE-GC-MS. Purge and trap-GC-MS method gave good results in the case of trihalomethanes, but had high detection limits for the other volatile chlorination by-products. Headspace-GC-MS method had acceptable recoveries for trihalomethanes, but the detection limits were higher.

Determination of volatile organic compounds in surface waters and treated wastewater in Greece

The occurrence of volatile organic compounds (VOCs) was studied in river water, lake water, seawater and treated wastewater in Greece from October 1998 to September 1999. The determination of 41 VOCs was performed with a Purge and Trap-Gas Chromatography-Mass Spectrometry method. Samples were collected seasonally from 10 rivers, seven lakes, three gulfs and four wastewater treatment plants. In surface water samples, 15 VOCs were detected. In wastewater samples, occurrence of 31 VOCs was observed. The results suggest that not only agricultural and industrial activity within the Greek territory, but also transboundary pollution deriving from neighbouring countries consist important sources of VOCs in surface waters of Greece. However, the measured concentrations did not in any case exceed the guideline values proposed by the EC.

Multiple regression models: A methodology for evaluating trihalomethane concentrations in drinking water from raw water characteristics

The presence of trihalomethanes (THMs) in drinking water has attracted the attention of both researchers and professionals, because of the harmful effects of these substances on human health. A multiple regression model was developed to estimate THM concentrations in finished drinking water, using data from the Menidi Treatment Plant of Athens. A number of routinely measured characteristics--including chlorine dose, chlorophyll a, temperature, pH and bromide--of raw water, were used to generate a reliable methodology for predicting both total THM and individual species concentrations. Seasonality effects were also considered during the analysis. In general, these models were found to give acceptable fits, estimating accurately lows and highs over the annual cycle.

Health impacts of long-term exposure to disinfection by-products in drinking water in Europe: HIWATE

There appears to be very good epidemiological evidence for a relationship between chlorination by-products, as measured by trihalomethanes (THMs), in drinking water and bladder cancer, but the evidence for other cancers, including colorectal cancer appears to be inconclusive and inconsistent. There appears to be some evidence for a relationship between chlorination by-products, as measured by THMs, and small for gestational age (SGA)/intrauterine growth retardation (IUGR) and preterm delivery, but evidence for other outcomes such as low birth weight (LBW), stillbirth, congenital anomalies and semen quality appears to be inconclusive and inconsistent.The overall aim of the HIWATE study is to investigate potential human health risks (e.g. bladder and colorectal cancer, premature births, SGA, semen quality, stillbirth, congenital anomalies) associated with long-term exposure to low levels of disinfectants (such as chlorine) and DBPs occurring in water for human consumption and use in the food industry. The study will comprise risk-benefit analyses including quantitative assessments of risk associated with microbial contamination of drinking water versus chemical risk and will compare alternative treatment options. The outcome will be improved risk assessment and better information for risk management. The work is divided into different topics (exposure assessment, epidemiology, risk assessment and management) and studies.

DBP levels in chlorinated drinking water: effect of humic substances.

Chlorination is the most widely used technique for disinfection of drinking water. A consequence of chlorination is the formation of Disinfection By-Products (DBPs). The formation of DBPs in drinking water results from the reaction of chlorine with naturally occurring organic materials, principally humic and fulvic acids. This paper focuses on the effect of humic substances on the formation of twenty-four compounds belonging to different categories of DBPs. This investigation was conducted in two water treatment plants in Greece, Menidi and Galatsi, from July 1999 to April 2000. Humic substances were determined by the diethylaminoethyl (DEAE) method with subsequent UV measurement. The techniques used for the determination of DBPs were liquid-liquid extraction, gas chromatography and mass spectrometry. The concentrations of DBPs were generally low. Total trihalomethanes (TTHMs) ranged from 5.1 to 24.6 μg L-1, and total haloacetic acids (HAAs) concentration ranged from 8.6 to 28.4 μg L-1, while haloaketones (HKs) and chloral hydrate (CH) occurred below 1 μg L-1. The content of humic substances was found to influence the formation of DBPs and especially TTHMs, trichloroacetic acid (TCA), dibromoacetic acid (DBA), CH, 1,1-dichloropropanone (1,1-DCP) and 1,1,1-trichloropropanone (1,1,1-TCP). Seasonal variation of TTHMs and HAAs generally followed that of humic substances content with peaks occurring in autumn and spring. The trends of 1,1-DCP, 1,1,1-TCP and CH formation seemed to be in contrast to TTHMs and HAAs. Trends of formation of individual compounds varied in some cases, probably due to influence of parameters other than humic substances content. Statistical analysis of the results showed that the concentrations of TTHMs, CH, 1,1-DCP, 1,1,1-TCP, TCA and DBA are strongly affected from humic substances content (at 0.01 confidence level). The opposite is true for dichloroacetic acid (DCA) concentration. Humic substances also vary to a statistically significant degree during different months, as well as the concentrations of TTHMs, CH, 1,1-DCP, 1,1,1-TCP, TCA and DCA. The variance of DBA was not statistically significant. Regarding the effect of sampling station, humic substances content showed no statistically significant difference between the two raw water sources studied.

The occurrence of trihalomethanes in the drinking water in Greece

This paper summarizes and completes an investigation into the occurrence of trihalomethanes (THMs) in public water supplies in Greece. The investigation was conducted in three cities of Greece, Athens, Mytilene and Chalkida, from 1993 to 1998. Samples were collected from three treatment plants of Athens (Galatsi Treatment Plant--GTP, Menidi Treatment Plant--MTP, Kiourka Treatment Plant--KTP) and from the distribution systems of Athens, Mytilene and Chalkida. The sources for these systems are lakes, boreholes and wells. The concentrations of THMs ranged from 5 to 106 microg/l, from 4 to 27 microg/l and from 5 to 96 microg/l, in the distribution systems of Athens, Mytilene, Chalkida, respectively. The wide ranges of concentrations in three cities should be attributed to the organics concentration of raw water. In all the cases the THMs concentrations were higher during the summer and fall than in spring and winter. In GTP and in the distribution system receives water by GTP, from April 1993 to January 1995, Mytilene and Chalkida, brominated THMs dominated and existed at the highest concentration levels, whereas chloroform was the least prevalent compound, while in all the other cases the opposite was observed. In all samples the concentrations were lower than the maximum level of 100 microg/l for total trihalomethanes (TTHMs) set by European Community (EC).

Determination of haloacetic acids in water by acidic methanol esterification–GC–ECD method

Acidic methanol esterification followed by gas chromatography (GC) with electron capture detection (ECD) was applied for the determination of the nine haloacetic acids in water. The main advantage of this method is the use of acidic methanol as the derivatization agent instead of the hazardous diazomethane. The recoveries, estimated at concentrations ranging from 0.5 to 30 microg/l, are high for eight of the nine haloacetic acids, with the only exception being monochloroacetic acid. However, problems with this compound have been reported with diazomethane derivatization methods as well. The detection limits of the method range from 0.01 to 0.2 microg/l.

Use of a multiple regression model for predicting trihalomethane formation

For many years the water supply system of Athens in Greece has been disinfected mainly by chlorination. A consequence of chlorination is the formation of trihalomethanes (THMs). A survey was conducted to determine their levels in the Athens water supply system over a period of time. A multiple regression model for THM formation was generated for predicting THMs in the finished water leaving the plant using the field sampling of the Galatsi Treatment Plant (GTP) of Athens with respect to temperature, pH, chlorine dose, bromide and chlorophyll a. In general, this model was found to give acceptable fits. Overall 82% of the predicted values were within ±20% of the measured values.