Trihalomethanes Levels Research Articles

Gene expression changes in blood RNA after swimming in a chlorinated pool

Exposure to disinfection by-products (DBP) such as trihalomethanes (THM) in swimming pools has been linked to adverse health effects in humans, but their biological mechanisms are unclear. We evaluated short-term changes in blood gene expression of adult recreational swimmers after swimming in a chlorinated pool. Volunteers swam 40min in an indoor chlorinated pool. Blood samples were drawn and four THM (chloroform, bromodichloromethane, dibromochloromethane and bromoform) were measured in exhaled breath before and after swimming. Intensity of physical activity was measured as metabolic equivalents (METs). Gene expression in whole blood mRNA was evaluated using IlluminaHumanHT-12v3 Expression-BeadChip. Linear mixed models were used to evaluate the relationship between gene expression changes and THM exposure. Thirty-seven before-after pairs were analyzed. The median increase from baseline to after swimming were: 0.7 to 2.3 for MET, and 1.4 to 7.1μg/m3 for exhaled total THM (sum of the four THM). Exhaled THM increased on average 0.94μg/m3 per 1 MET. While 1643 probes were differentially expressed post-exposure. Of them, 189 were also associated with exhaled levels of individual/total THM or MET after False Discovery Rate. The observed associations with the exhaled THM were low to moderate (Log-fold change range: −0.17 to 0.15). In conclusion, we identified short-term gene expression changes associated with swimming in a pool that were minor in magnitude and their biological meaning was unspecific. The high collinearity between exhaled THM levels and intensity of physical activity precluded mutually adjusted models with both covariates. These exploratory results should be validated in future studies.

TIC-Tox: A preliminary discussion on identifying the forcing agents of DBP-mediated toxicity of disinfected water

The disinfection of drinking water is a major public health achievement; however, an unintended consequence of disinfection is the generation of disinfection by-products (DBPs). Many of the identified DBPs exhibit in vitro and in vivo toxicity, generate a diversity of adverse biological effects, and may be hazards to the public health and the environment. Only a few DBPs are regulated by several national and international agencies and it is not clear if these regulated DBPs are the forcing agents that drive the observed toxicity and their associated health effects. In this study, we combine analytical chemical and biological data to resolve the forcing agents associated with mammalian cell cytotoxicity of drinking water samples from three cities. These data suggest that the trihalomethanes (THMs) and haloacetic acids may be a small component of the overall cytotoxicity of the organic material isolated from disinfected drinking water. Chemical classes of nitrogen-containing DBPs, such as the haloacetonitriles and haloacetamides, appear to be the major forcing agents of toxicity in these samples. These findings may have important implications for the design of epidemiological studies that primarily rely on the levels of THMs to define DBP exposure among populations. The TIC-Tox approach constitutes a beginning step in the process of identifying the forcing agents of toxicity in disinfected water.

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.

Evaluation of Drinking Water Disinfectant Byproducts Compliance Data as an Indirect Measure for Short-Term Exposure in Humans.

In the absence of shorter term disinfectant byproducts (DBPs) data on regulated Trihalomethanes (THMs) and Haloacetic acids (HAAs), epidemiologists and risk assessors have used long-term annual compliance (LRAA) or quarterly (QA) data to evaluate the association between DBP exposure and adverse birth outcomes, which resulted in inconclusive findings. Therefore, we evaluated the reliability of using long-term LRAA and QA data as an indirect measure for short-term exposure. Short-term residential tap water samples were collected in peak DBP months (May–August) in a community water system with five separate treatment stations and were sourced from surface or groundwater. Samples were analyzed for THMs and HAAs per the EPA (U.S. Environmental Protection Agency) standard methods (524.2 and 552.2). The measured levels of total THMs and HAAs were compared temporally and spatially with LRAA and QA data, which showed significant differences (p < 0.05). Most samples from surface water stations showed higher levels than LRAA or QA. Significant numbers of samples in surface water stations exceeded regulatory permissible limits: 27% had excessive THMs and 35% had excessive HAAs. Trichloromethane, trichloroacetic acid, and dichloroacetic acid were the major drivers of variability. This study suggests that LRAA and QA data are not good proxies of short-term exposure. Further investigation is needed to determine if other drinking water systems show consistent findings for improved regulation.

Case study approach to modeling historical disinfection by-product exposure in Iowa drinking waters

In the 1980s, a case–control epidemiologic study was conducted in Iowa (USA) to analyze the association between exposure to disinfection by-products (DBPs) and bladder cancer risk. Trihalomethanes (THMs), the most commonly measured and dominant class of DBPs in drinking water, served as a primary metric and surrogate for the full DBP mixture. Average THM exposure was calculated, based on rough estimates of past levels in Iowa. To reduce misclassification, a follow-up study was undertaken to improve estimates of past THM levels and to re-evaluate their association with cancer risk. In addition, the risk associated with haloacetic acids, another class of DBPs, was examined. In the original analysis, surface water treatment plants were assigned one of two possible THM levels depending on the point of chlorination. The re-assessment considered each utility treating surface or groundwater on a case-by-case basis. Multiple treatment/disinfection scenarios and water quality parameters were considered with actual DBP measurements to develop estimates of past levels. The highest annual average THM level in the re-analysis was 156μg/L compared to 74μg/L for the original analysis. This allowed the analysis of subjects exposed at higher levels (>96μg/L). The re-analysis established a new approach, based on case studies and an understanding of the water quality and operational parameters that impact DBP formation, for determining historical exposure.

Online Monitors Detect Low‐Level THMs in Treated Wastewater

The city of Paso Robles, Calif., used an online water quality instrument to identify and monitor low trihalomethane (THM) levels in its treated wastewater used for groundwater recharge. The high frequency of reliable and accurate THM data proved essential to the city's efforts to achieve regulatory compliance.

Trihalomethanes formation in marine environment in front of Nuweibaa desalination plant as a result of effluents loaded by chlorine residual

Trihalomethanes have been identified as the most important disinfection byproducts resulted from using chlorine in desalination plants. Nuweibaa desalination plant was chosen to study their effluents impacts on the marine environment in front of the plant in the coastal area of Gulf of Aqaba. Surface and bottom Water Samples were collected from nine locations in the outfall area of this desalination plant during spring and autumn 2014, and analyzed for water temperature, pH value, Salinity, Dissolved Oxygen, Biological oxygen demand, Oxidizible organic matter, Total, fixed and volatile suspended matter, residual chlorine (free and combined) and trihalomethanes. High total chlorine dosage discharged from the desalination plant achieved high levels of trihalomethanes in the receiving seawater of the outfall area. It has been estimated that about 14524.65671kg of BOD, 74123.4kg of OOM, 166896.4375kg of total suspended solids, 623.634kg of free chlorine, 469.21kg of combined chlorine, 206.64kg of chloroform and 76.48kg of bromoform are discharged annually from this plant into the Gulf of Aqaba affecting the marine ecosystems. The results of THMs showed that the two main forms of THMs formed in the receiving seawater were chloroform and bromoform and ranged between (5.09–156.59), (2.82–566.06)μg/L respectively. High pH and High combined chlorine concentrations favored the formation of high concentrations of chloroform.

Composition profiles, levels, distributions and ecological risk assessments of trihalomethanes in surface water from a typical estuary of Bohai Bay, China

To characterize the spatiotemporal distribution and potential ecological risk for trihalomethanes (THMs) in the surface water of a river estuary, surface water samples were collected over five consecutive months (from March to July 2016) from four sites in the Haihe River estuary of Bohai Bay. The potential ecological risks of THMs were evaluated quantitatively based on a species sensitivity distribution (SSD) model. The results demonstrate that trichloromethane (TCM) was the predominant THM in surface water of the Haihe River estuary (2.93±1.98μg/L) followed by tribromomethane (TBM) (0.42±0.33μg/L), bromodichloromethane (BDCM) (0.14±0.06μg/L) and dibromochloromethane (DBCM) (0.09±0.10μg/L). The concentration of TCM was higher in summer than that in spring, while TBM displayed the opposite trend. The TCM concentration decreased from the estuary to the adjacent sea. However, the levels of TBM and DBCM in the adjacent sea were higher than those in the estuary. The ecological risks of THMs in surface water of Haihe River were notably low, and the ecological risks of THMs in freshwater were generally higher than those in seawater. Compared with other contaminants in water and surface sediment from rivers and coastal areas, the ecological risk levels of THMs in surface water can be considered low. This study is a contribution to the progress of ecological risk assessment of THMs.

Disinfection Byproducts in Drinking Water and Evaluation of Potential Health Risks of Long-Term Exposure in Nigeria.

Levels of trihalomethanes (THMs) in drinking water from water treatment plants (WTPs) in Nigeria were studied using a gas chromatograph (GC Agilent 7890A with autosampler Agilent 7683B) equipped with electron capture detector (ECD). The mean concentrations of the trihalomethanes ranged from zero in raw water samples to 950 μg/L in treated water samples. Average concentration values of THMs in primary and secondary disinfection samples exceeded the standard maximum contaminant levels. Results for the average THMs concentrations followed the order TCM > BDCM > DBCM > TBM. EPA-developed models were adopted for the estimation of chronic daily intakes (CDI) and excess cancer incidence through ingestion pathway. Higher average intake was observed in adults (4.52 × 10−2 mg/kg-day), while the ingestion in children (3.99 × 10−2 mg/kg-day) showed comparable values. The total lifetime cancer incidence rate was relatively higher in adults than children with median values 244 and 199 times the negligible risk level.

Evaluating trihalomethanes in tap water and swimming pool water at Ho Chi Minh city

Trihalomethanes (THMs) are byproducts of the process of disinfecting water with chlorine, in which, 4 compounds are most interested such as chloroform (CF), bromodichloromethane (BDCM), dibromochloromethane (DBCM) and bromoform (BF). These DBPs even at very low concentrations pose harmful health effects. These health risks may include cancers, reproductive disorders, birth defects and miscarriage. This study evaluates the 4 THMs in water supplied at 6 districts of Ho Chi Minh City and in swimming pool water at Tan Binh district. All samples were extracted by using liquid- liquid extraction method with n-hexane: diisopropylether (1:1) before analyzing by GC-ECD. The results showed that 4/4 THMs were found in water samples and 2/4 THMs (chloroform and bromodichloromethane) were found in swimming pool water samples. The results showed that there are differences in the THMs levels between sampling site. The average concentration of THMs in supplied water was 31.40 ±29.23 μg.L-1 (20 – 110 μg.L-1), in swimming pool water was 109.78 ± 15.21 μg.L-1 (90 – 140 μg.L-1). The sampling site which has the highest average concentration is Tan Phu district (102.45 ± 16.0 μg.L-1) and the lowest is district 1 (23.74 ± 1.92 μg.L-1). The results showed that the concentration of THMs in the supplied water and swimming pool water does not exceed the limit of national technical regulation on drinking water quality (QCVN 01: 2009/BYT), however, the chloroform concentration of some sampling sites exceeds the limit given by the Environmental Protection Agency (EPA).

Vigilância na qualidade da água: um trabalho multidisciplinar do PET - Vigilância em Saúde/UFPR

O artigo tem como objetivo descrever a experiência de implantação do PET-Saúde/Vigilância em Saúde no Programa de Vigilância da Qualidade da Água para o Consumo Humano (VIGIAGUA) em Colombo-PR. Foram estabelecidos pelo grupo de trabalho seis momentos pedagógicos: 1) Conceitual / Teórico / Operacional; 2) Vivência de campo nas ações municipais do VIGIAGUA; 3) Avaliação das amostras coletadas no VIGIAGUA; 4) Implantação do heterocontrole de fluoretos e vigilância do trihalometanos; 5) Avaliação dos resultados do heterocontrole dos fluoretos e do trihalometanos; 6) Publicidade e divulgação das ações na comunidade. Essa proposta metodológica tem proporcionado uma reflexão sobre as práticas em serviço com os integrantes do PET-Saúde/VS, possibilitando uma avaliação de recursos e tecnologias desenvolvidas, além da divulgação no meio científico e comunitário das ações realizadas na vigilância em saúde.

Drinking Water Disinfection By-products, Genetic Polymorphisms, and Birth Outcomes in a European Mother-Child Cohort Study.

We examined the association between exposure during pregnancy to trihalomethanes, the most common water disinfection by-products, and birth outcomes in a European cohort study (Health Impacts of Long-Term Exposure to Disinfection By-Products in Drinking Water). We took into account exposure through different water uses, measures of water toxicity, and genetic susceptibility. We enrolled 14,005 mothers (2002-2010) and their children from France, Greece, Lithuania, Spain, and the UK. Information on lifestyle- and water-related activities was recorded. We ascertained residential concentrations of trihalomethanes through regulatory records and ad hoc sampling campaigns and estimated route-specific trihalomethane uptake by trimester and for whole pregnancy. We examined single nucleotide polymorphisms and copy number variants in disinfection by-product metabolizing genes in nested case-control studies. Average levels of trihalomethanes ranged from around 10 μg/L to above the regulatory limits in the EU of 100 μg/L between centers. There was no association between birth weight and total trihalomethane exposure during pregnancy (β = 2.2 g in birth weight per 10 μg/L of trihalomethane, 95% confidence interval = 3.3, 7.6). Birth weight was not associated with exposure through different routes or with specific trihalomethane species. Exposure to trihalomethanes was not associated with low birth weight (odds ratio [OR] per 10 μg/L = 1.02, 95% confidence interval = 0.95, 1.10), small-for-gestational age (OR = 0.99, 0.94, 1.03) and preterm births (OR = 0.98, 0.9, 1.05). We found no gene-environment interactions for mother or child polymorphisms in relation to preterm birth or small-for-gestational age. In this large European study, we found no association between birth outcomes and trihalomethane exposures during pregnancy in the total population or in potentially genetically susceptible subgroups. (See video abstract at http://links.lww.com/EDE/B104.).

Climatic, Geographic and Operational Determinants of Trihalomethanes (THMs) in Drinking Water Systems.

Trihalomethanes (THMs) are conditionally carcinogenic compounds formed during chlorine disinfection in water treatment processes around the world. THMs occur especially when source waters are subject to marine influences, high and-or regular precipitation, and elevated levels of organic matter. THMs formation is then rooted in geographic, operational and climatic factors, the relative importance of which can only be derived from large datasets and may change in the future. Ninety three full-scale Scottish water treatment plants (WTPs) were assessed from Jan 2011 to Jan 2013 to identify factors that promote THMs formation. Correlation analysis showed that ambient temperature was the primary THMs formation predictor in potable water (r2 = 0.66, p < 0.05) and water distribution systems (r2 = 0.43, p = 0.04), while dissolved organic carbon (r2 = 0.55, p < 0.001) and chloride (indicating marine influence; r2 = 0.41, p < 0.001) also affected THMs formation. GIS mapping of median THMs levels indicated brominated THMs were most prevalent in coastal areas and on islands. This real-world dataset confirms both geographic and climatic factors are key to THMs formation. If ambient temperatures increase, THMs control will become more challenging, substantiating concerns about the impact of global warming on water quality.

Occurrence of DBPs in Drinking Water of European Regions for Epidemiology Studies

A three‐year study was conducted on the occurrence of disinfection by‐products (DBPs)—trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetonitriles—in drinking water of regions of Europe where epidemiology studies were being carried out. Thirteen systems in six countries (i.e., Italy, France, Greece, Lithuania, Spain, United Kingdom) were sampled. Typically chlorinated DBPs dominated. However, in most of Catalonia (Spain) and in Heraklion (Greece), brominated DBPs dominated. The degree of bromine incorporation into the DBP classes was in general similar among them. This is important, as brominated DBPs are a greater health concern. In parts of Catalonia, the reported levels of tribromoacetic acid were higher than in other parts of the world. In some regions, the levels of HAAs tended to be peaked in concentration in a different time period than when the levels of THMs peaked. In most epidemiology studies, THMs are used as a surrogate for other halogenated DBPs. This study provides exposure assessment information for epidemiology studies.

A novel electrochemical device as a disinfection system to maintain water quality during washing of ready to eat fresh produce

Electrolyzed water (EW) is known by its bactericidal efficacy and capability to oxidize organic matter. The present research evaluated the efficacy of recently developed electrolytic cells able to generate higher concentration of reactive oxygen species using lower power and salt concentration than conventional cells. This study tested the inactivation of Escherichia coli O157:H7, the organic matter depletion and trihalomethane (THM) generation by EW in process wash water under dynamic conditions. To achieve this, clean tap water was continuously added up to 60 min with artificial process water with high chemical oxygen demand (COD) inoculated with E. coli O157:H7, in experiments performed in a pilot plant that recirculated water through one electrolytic cell. Plate counts of E. coli O157:H7, COD, THMs, free, combined and total chlorine, pH, temperature and oxidation-reduction potential were determined. Results indicate that the novel electrolysis system combined with minimal addition of NaCl (0.05%) was able to suppress E. coli O157:H7 population build-up and decreased the COD accumulation in the process wash water. THM levels in the water were relatively high but its concentration in the washed product was marginal. Highly effective electrolysis has been proven to reduce the occurrence of foodborne diseases associated to cross-contamination in produce washers without having an accumulation of THMs in the washed product.

Atrazine in public water supplies and risk of ovarian cancer among postmenopausal women in the Iowa Women's Health Study

BackgroundFew studies have evaluated environmental chemical exposures in relation to ovarian cancer. We previously found an increased risk of ovarian cancer among postmenopausal women in Iowa associated with higher nitrate...

Blood Lead Levels Among Children Aged

During April 25, 2014-October 15, 2015, approximately 99,000 residents of Flint, Michigan, wereaffected by changes in drinking water quality aftertheir water source was switched from the Detroit Water Authority (DWA), sourced from Lake Huron, tothe Flint Water System (FWS), sourced from the Flint River.* Because corrosion control was not used at the FWS water treatment plant, the levels of lead in Flint tap water increased over time. Adverse health effects are associated with lead exposure (1). On January 2, 2015, a water advisory was issued because of detection of high levels of trihalomethanes, byproducts of disinfectants.(†)(,)(§) Studies conducted by local and national investigators detected an increase in the prevalence of blood lead levels (BLLs) ≥5 µg/dL (the CDC reference level) among children aged <5 years living in Flint (2) and an increase in water lead levels after the water source switch (3). On October 16, 2015, the Flint water source was switched back to DWA, and residents were instructed to use filtered tap water for cooking and drinking. During that time, pregnant and breastfeeding women and children aged <6 years were advised to consume bottled water.(¶) To assess the impact on BLLs of consuming contaminated drinking water, CDC examined the distribution of BLLs ≥5 µg/dL among children aged <6 years before, during, and after the switch in water source. This analysis enabled determination of whether the odds of having BLLs ≥5 µg/dL before the switch differed from the odds during the switch to FWS (before and after the January 2, 2015, water advisory was issued), and after the switch back to DWA. Overall, among 9,422 blood lead tests in children aged <6 years, 284 (3.0%) BLLs were ≥5 µg/dL during April 25, 2013-March 16, 2016. The adjusted probability of having BLLs ≥5 µg/dL was 46% higher during the period after the switch from DWA to FWS (and before the January 2, 2015, water advisory) than during the period before the water switch to FWS. Although unrelated to lead in the water, the water advisory likely reduced tap water consumption and increased consumption of bottled water. Characterizing exposure to lead contaminated drinking water among children aged <6 years living in Flint can help guide appropriate interventions.

ESTIMATION OF THE TOTAL TRIHALOMETHANES CONCENTRATION IN DRINKING WATER IN SOME AREA OF BAGHDAD, IRAQ

In Iraq the surface water is one of the important sources of potable water. Water chlorination is the disinfection method most widely used, having however the disadvantage of producing Trihalomethanes (THMs) as secondary compounds. THMs formation is influenced by the raw water composition and chlorine from the disinfection process.This research estimated the THMs concentration and the changes in Purification Water Plants and surrounding Feeding Stations. The duration of these monitoring tasks was three months (February, April and August) in 2014. There were forty eight water samples were collected from four Water Purification Water Plants (Qadisiyah, Karama, Al-Wethba and Al-Wehda) and from four Feeding Stations (Karrada, Bab-Almuadam, Utaifiyya and Qadisiyah). The total concentration of THMs ranged between (64 – 84.5 ppb), (68 – 92.6 ppb) and (74.3 –105.9 ppb) at Water Purification Water Plants in February, April and August, respectively. While the total concentration of THMs ranged between (60 – 67.1 ppb), (65 – 75.9 ppb) and (72 – 86 ppb) at the Feeding Stations, respectively. The highest values were recorded in August compared with remaining months (February and April). All the water samples within minimum limits according to WHO, IQS (0.15ppm) for drinking water. Generally, THMs levels increased during Summer and decreased in Winter regardless of disinfection method.

Nitrate from Drinking Water and Diet and Bladder Cancer Among Postmenopausal Women in Iowa.

Background:Nitrate is a drinking water contaminant arising from agricultural sources, and it is a precursor in the endogenous formation of N-nitroso compounds (NOC), which are possible bladder carcinogens.Objectives:We investigated the ingestion of nitrate and nitrite from drinking water and diet and bladder cancer risk in women.Methods:We identified incident bladder cancers among a cohort of 34,708 postmenopausal women in Iowa (1986–2010). Dietary nitrate and nitrite intakes were estimated from a baseline food frequency questionnaire. Drinking water source and duration were assessed in a 1989 follow-up. For women using public water supplies (PWS) > 10 years (n = 15,577), we estimated average nitrate (NO3-N) and total trihalomethane (TTHM) levels and the number of years exceeding one-half the maximum contaminant level (NO3-N: 5 mg/L, TTHM: 40 μg/mL) from historical monitoring data. We computed hazard ratios (HRs) and 95% confidence intervals (CIs), and assessed nitrate interactions with TTHM and with modifiers of NOC formation (smoking, vitamin C).Results:We identified 258 bladder cancer cases, including 130 among women > 10 years at their PWS. In multivariable-adjusted models, we observed nonsignificant associations among women in the highest versus lowest quartile of average drinking water nitrate concentration (HR = 1.48; 95% CI: 0.92, 2.40; ptrend = 0.11), and we found significant associations among those exposed ≥ 4 years to drinking water with > 5 mg/L NO3-N (HR = 1.62; 95% CI: 1.06, 2.47; ptrend = 0.03) compared with women having 0 years of comparable exposure. TTHM adjustment had little influence on associations, and we observed no modification by vitamin C intake. Relative to a common reference group of never smokers with the lowest nitrate exposures, associations were strongest for current smokers with the highest nitrate exposures (HR = 3.67; 95% CI: 1.43, 9.38 for average water NO3-N and HR = 3.48; 95% CI: 1.20, 10.06 and ≥ 4 years > 5 mg/L, respectively). Dietary nitrate and nitrite intakes were not associated with bladder cancer.Conclusions:Long-term ingestion of elevated nitrate in drinking water was associated with an increased risk of bladder cancer among postmenopausal women.Citation:Jones RR, Weyer PJ, DellaValle CT, Inoue-Choi M, Anderson KE, Cantor KP, Krasner S, Robien K, Beane Freeman LE, Silverman DT, Ward MH. 2016. Nitrate from drinking water and diet and bladder cancer among postmenopausal women in Iowa. Environ Health Perspect 124:1751–1758; http://dx.doi.org/10.1289/EHP191

Impacts of Typhoon Soudelor (2015) on the water quality of Taipei, Taiwan.

Typhoon Soudelor was one of the strongest storms in the world in 2015. The category 5 hurricane made landfall in Taiwan on August 8, causing extensive damage and severe impacts on the environment. This paper describes the changes of trihalomethane (THM) concentrations in tap and drinking fountain water in selected typhoon-affected areas in Taipei before and after the typhoon. Samples were taken from water transmission mains at various distances from the local water treatment plant. The results showed that organic matter increased between pre- and post-typhoon periods with a greater proportion of aromatic compounds. Although drinking fountains showed moderately less total trihalomethane (TTHM) levels than that of tap water, the intake of high turbidity water considerably diminished the efficiency of their purification systems after the typhoon. The percentage distribution of THM species increased throughout the distribution network, probably due to a longer contact time between chlorine and the organic matter in the pipelines. After 2 to 5 min of boiling, THM reduction was considerable in all cases with the greater extent in post-typhoon samples. It is evident that extreme weather conditions may have a severe impact on water quality, and thus more cautious strategies should be adopted in such cases.