The occurrence of THMs and AOX in drinking water of Shandong Province, China.

Trihalomethanes (THMs) and adsorbable organic halides (AOX) were generated in chlorinated water. The purpose of the study was to provide a comprehensive picture of concentration distribution, the seasonal and different water source variability of THMs and AOX. Data for THMs, AOX, and other physico-chemical parameters were from 538 samples of 16 drinking water work through a 3-year sampling program which was conducted in Shandong province with typical temperate and monsoonal climate. Selected samples were considered with the influence of factors such as season, water source, and disinfectant. The THMs and AOX concentration of the samples disinfected with chlorine ranged from 2.1-105 µg/L and 11-238 µg/L, respectively. The THMs and AOX concentration of the samples disinfected chlorine dioxide ranged from N.D.-47.6 µg/L and N.D.-102 µg/L, respectively. The median concentration of THMs and AOX of samples disinfected with chlorine were 35 µg/L and 61 µg/L, much higher than chlorine dioxide, respectively. Ninety-two percent of the samples disinfected with chlorine and all samples disinfected with chlorine dioxide met Chinese drinking water standard for THMs. The ratio of tribromethane (TBM) to THMs of samples disinfected with chlorine was 19%, lower than chlorine dioxide 42%. Bromine substitution factor (BSF) of THMs and initial concentration of bromide showed weak correlation, and the Spearman correlation coefficient was 0.38. THMs and AOX concentrations showed noticeable seasonal variations with the highest median concentrations in spring. The levels of THMs and AOX in drinking water varied with different water sources and followed the order local reservoir > Yellow River reservoir > ground water. The survey results complement the database of THMs and AOX occurrence in drinking water in China, and offer a significant reference data for setting disinfections by-products occurrence in countries or regions with similar climate around the world.

Trihalomethane concentrations in tap water as determinant of bottled water use in the city of Barcelona.

Bottled water consumption is increasing worldwide, despite its huge economic and environmental cost. We aim to describe personal and tap water quality determinants of bottled water use in the city of Barcelona. This cross-sectional study used data from the Health Survey of Barcelona in 2006 (N=5417 adults). The use of bottled water to drink and to cook was evaluated in relation to age, gender, educational level, district and levels of trihalomethanes (THMs), free chlorine, conductivity, chloride, sodium, pH, nitrate and aluminium in municipal tap water using Robust Poisson Regression. The prevalence of bottled water use to drink and cook was 53.9% and 6.7%, respectively. Chemical parameters in water had a large variability (interquartile range of THMs concentrations: 83.2-200.8µg/L) and were correlated between them, except aluminium. Drinking bottled water increased with educational level, while cooking with bottled water was higher among men than among women and decreased with age. After adjusting by these personal determinants, a dose-response relationship was found between concentrations of all chemicals except aluminium in tap water and bottled water use. The highest association was found for THMs, with a Prevalence Ratio of 2.00 (95%CI=1.86, 2.15) for drinking bottled water and 2.80 (95%CI=1.72, 4.58) for cooking with bottled water, among those with >150µg/L vs. <100µg/L THMs in tap water. CONCLUSION: More than half of Barcelona residents regularly drank bottled water, and the main determinant was the chemical composition of tap water, particularly THM level.

Baseline blood trihalomethanes, semen parameters and serum total testosterone: a cross-sectional study in China.

Toxicological studies showed that trihalomethanes (THMs), the most abundant classes of disinfection by-products (DBPs) in drinking water, impaired male reproductive health, but epidemiological evidence is limited and inconsistent. This study aimed to examine the associations of baseline blood THMs with semen parameters and serum total testosterone in a Chinese population. We recruited 401 men seeking semen examination from the Reproductive Center of Tongji Hospital in Wuhan, China between April 2011 and May 2012. Baseline blood concentrations of THMs, including chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM) were measured using SPME-GC/ECD method. Semen quality and serum total testosterone were analyzed. Multivariable linear regressions were used to assess the associations of baseline blood THM concentrations with semen parameters and serum total testosterone levels. We found that baseline blood THM concentrations were not associated with decrements in sperm motility, sperm straight-line and curvilinear velocity. However, moderate levels of BDCM (ß=-0.13 million; 95% CI: -0.22, -0.03) and DBCM (ß=-4.74%; 95% CI: -8.07, -1.42) were associated with decreased sperm count and declined sperm linearity compared with low levels, respectively. Suggestive dose-response relationships were also observed between elevated blood TCM or ∑ THMs (sum of TCM, BDCM, DBCM and TBM) concentration and decreased sperm concentration (both p for trend=0.07), and between elevated blood DBCM concentration and decreased serum total testosterone (p for trend=0.07). Our results indicate that elevated THM exposure may lead to decreased sperm concentration and serum total testosterone. However, the effects of THM exposure on male reproductive health still warrant further studies in humans.

[Substantiation of both safety indices for control over the use of chemicals for water disinfection and need to harmonize them with international requirements].

The domestic and also foreign indices applied for control over the safety of chemical disinfecting of water are considered. The data confirming need of extension of the list of legislatively approved indices are provided of water, efficiency and safety indicators, harmful impurity, transformation products. On the basis of the performed analysis of literature data and own investigations the following indices for inclusion in the processed. Sanitary standards and rules on drinking water are suggested: the total content of THM, the total content of haloacetic acids, the total maintenance of up to AHC index (adsorbed halogen-containing organic compounds) in water chlorination; chlorite- and chlorate ions in application of dioxide of chlorine; control over efficiency of water disinfection up to the steadiest microorganisms depending on an applied method. Introduction of settlement about necessity of control over the content of dangerous monomers and impurities in a commodity products in application of polymeric reagents and means of water disinfection is proved.

Factorial analysis of the trihalomethanes formation in water disinfection using chlorine.

The factors that affect trihalomethane (THM) (chloroform, bromodichloromethane, chlorodibromomethane and bromoform) formation from the chlorination of aqueous solutions of hydrophobic fulvic acids (FA) were investigated in a prototype laboratorial simulation using factorial analysis. This strategy involved a fractional factorial design (16 plus 5 center experiments) of five factors (fulvic acids concentration, chlorine dose, temperature, pH and bromide concentration) and a Box Behnken design (12 plus 3 center experiments) for the detailed analysis of three factors (FA concentration, chlorine dose and temperature). The concentration of THM was determined by headspace analysis by GC-ECD. The most significant factors that affect the four THM productions were the following: chloroform-FA concentration and temperature; bromodichloromethane-FA concentration and chlorine dose; chlorodibromomethane-chlorine dose; and, bromoform-chlorine dose and bromide concentration. Moreover, linear models were obtained for the four THM concentrations in the disinfection solution as function of the FA concentration, chlorine dose and temperature, and it was observed that the complexity of the models (number of significant factors and interactions) increased with increasing bromine atoms in the THM. Also, this study shows that reducing the FA concentration the relative amount of bromated THM increases.