Exposure assessment for swimmers in bathing waters and swimming pools

Bathing water compliant with bathing water legislation may nevertheless contain pathogens to such a level that they pose unacceptable health risks for swimmers. Quantitative Microbiological Risk Assessment (QMRA) can provide a proper basis for protective measures, but the required data on swimmer exposure are currently limited or lacking. The objective of this study was to collect exposure data for swimmers in fresh water, seawater and swimming pools, i.e. volume of water swallowed and frequency and duration of swimming events.The study related to swimming in 2007, but since the summer of 2007 was wet and this might have biased the results regarding surface water exposure, the study was repeated relating to swimming in 2009, which had a dry and sunny summer. Exposure data were collected through questionnaires administered to approximately 19 000 persons representing the general Dutch population.Questionnaires were completed by 8000 adults of whom 1924 additionally answered the questions for their eldest child (<15 years). The collected data did not differ significantly between 2007 and 2009. The frequency of swimming and the duration of swimming were different for men, women and children and between water types. Differences between men and women were small, but children behaved differently: they swam more often, stayed in the water longer, submerged their heads more often and swallowed more water.Swimming pools were visited most frequently (on average 13-24 times/year) with longest duration of swimming (on average 67-81 min). On average, fresh and seawater sites were visited 6-8 times/year and visits lasted 41-79 min. Dependent on the water type, men swallowed on average 27-34 ml per swimming event, women 18-23 ml, and children 31-51 ml.Data on exposure of swimmers to recreational waters could be obtained by using a questionnaire approach in combination with a test to measure mouthfuls of water for transformation of categorical data to numerical data of swallowed volumes of water. Previous assumptions on swimmer exposure were replaced with estimates of exposure parameters, thus reducing uncertainty in assessing the risk of infection with waterborne pathogens and enabling identification of risk groups. QMRA for Cryptosporidium and Giardia was demonstrated based on data from previous studies on the occurrence of these pathogens in recreational lakes and a swimming pool.     

Detection,occurrence, and removal of selected pharmaceuticals in Missouri source and finished drinking waters

A simple, sensitive, and selective solid phase extraction – ultra-fast liquid chromatography – tandem mass spectrometry (SPE-UFLC-MS/MS) method was developed and applied for the analysis of selected important pharmaceutical compounds in source and finished drinking waters. The method detected the following six pharmaceuticals, cotinine, cephapirin, ciprofloxacin, enrofloxacein, azithromycin, and diphenhydramine, at sub-μg/L level in multiple water matrices after pre-concentration by SPE. Cotinine-d₃ and ¹³C₃¹⁵ N-Ciprofloxacin were used as internal standards for accurate quantitation. This method was validated through spike recoveries (67–129%), reproducibility (RSD: 2.3–15.7%), and method detection limits (MDLs: 2–5 ng/L). The method was used to test for occurrence of these pharmaceuticals in source and drinking waters from 13 Missouri water treatment facilities in four different seasons. In general, higher detection frequency and concentrations of pharmaceuticals were observed in colder months due presumably to less dilution (at lower flows) and slower degradation. The PPCP removals by different activated carbons were also evaluated. The occurrence and removal results in this study provide valuable information to help water treatment facilities taking appropriate strategies for better control of trace pharmaceuticals in drinking water.     

An analytical method for the analysis of trihalomethanes in ambient air using solid‐phase microextraction gas chromatography‐mass spectrometry: An application to indoor swimming pool complexes

A simple method for the collection and analysis of the four brominated and chlorinated trihalomethanes (THMs) in air samples is described. Ambient air samples were collected in pre‐prepared glass vials, with THM analysis performed using solid‐phase microextraction gas chromatography‐mass spectrometry, where the need for chemical reagents is minimized. Analytical parameters, including oven temperature program, solvent volume, incubation time, vial agitation, extraction time and temperature, as well as desorption time and temperature, were evaluated to ensure optimal method performance. The developed method allows for point‐in‐time quantification (compared to an average concentration measured over extended periods of time), with detection limits between 0.7 to 2.6 µg/m³. Excellent linearity (r² > 0.99), repeatability (3% to 11% RSD), and reproducibility (3% to 16% RSD) were demonstrated over a concentration range from 2 to 5000 µg/m³. The method was validated for the analysis of THMs in indoor swimming pool air and was used to investigate the occurrence of THMs in the air above 15 indoor swimming pools. This is the first study to report the occurrence of THMs in swimming pool air in Australia, and concentrations higher than those previously reported in other countries were measured.     

Occurrence, oral exposure and risk assessment of volatile organic compounds in drinking water for Izmir

Concentrations of volatile organic compounds (VOCs) were measured in the drinking water in Province of Izmir, Turkey, and associated health risks due to ingestion of these compounds were investigated using population weighted random samples. A total of 100 houses were visited in different districts of Izmir and drinking water samples were collected from consumers' drinking water source. Questionnaires were administered to one participant in each house to determine demographics and drinking water consumption rates. Oral exposure and risks were estimated for each participant and Izmir population by deterministic and probabilistic approaches, respectively. The four trihalomethane (THM) species (i.e., chloroform, bromodichloromethane, dibromochloromethane, and bromoform), benzene, toluene, p-xylene, and naphthalene were the most frequently detected VOCs with concentrations ranging from below detection limit to 35 microg/l. The risk estimates were found to be less than the values reported in the literature with few exceptions. Noncarcinogenic risks attributable to ingestion of VOCs for Izmir population were negligible, whereas the mean carcinogenic risk estimates for bromodichloromethane and dibromochloromethane were above the de minimis level of one in a million (10(-6)). For all VOCs, the concentrations measured in metropolitan area were greater than those in other districts. All THM species were detected in higher concentrations in tap water, whereas nontap water contained more benzene, toluene, p-xylene, and naphthalene. Therefore, the concentrations of the latter four compounds and associated risks increased with increasing income and education level since bottled water was used in larger proportions within these subgroups. The results of this study showed that oral exposure to drinking water contaminants and associated risks may be higher than the acceptable levels even if the concentrations fall below the standards.     

Natural radioactivity in various surface waters in stanbul, Turkey

Gross-α and gross-β, activities of eight well and five tap water samples taken in stanbul were determined. Ra²²⁶, Rn²²², Pb²¹⁴, Bi²¹⁴, K⁴⁰, Cs¹³⁷ activity concentrations in four lake, four sea water, one snow and one rain water samples were also analyzed in order to determine their radioactivity. The results obtained showed that, in general, natural activities in drinking water samples did not exceed WHO and ITS guidelines. In sea and lake water, four samples were over WHO and TSI guidelines. Concentrations ranging from 0.007 to 0.04 Bq l⁻¹ and from 0.02 to 0.1 Bq l⁻¹ were observed for drinking water and the gross-α and gross-β activities, respectively. For all samples the gross-β activities were higher than the corresponding gross-α activities. In order to evaluate the annual effective dose equilavent of ingestion of these waters, a conservative dosimetric calculation was carried out using dose conversion factor suggested by the ICRP. An average annual effective dose equivalent of 0.84 μSv y⁻¹ for Ra²²⁶ was calculated.     

Impact of source waters,disinfectants, seasons and treatment approaches on trihalomethanes in drinking water: a comparison based on the size of municipal systems

This study compares concentrations of trihalomethanes (THMs) in municipal water for 2001–2007 from the small and large systems in two provinces in Canada (Newfoundland and Quebec) based on source waters, disinfectants, seasons and treatment approaches. Approximately 71 and 94%, respectively, of the municipal systems in Quebec and Newfoundland are small systems (serving fewer than 3000 people). The small systems serve approximately 8.6% (0.57 million) and 44.1% (0.18 million) of the populations in Quebec and Newfoundland, respectively. Concentrations of THMs and its variability are much higher in the small systems (Quebec: 0–941 μg/L; Newfoundland: 0–875 μg/L) than in the systems with populations 10 000 or more (Quebec: 0–364 μg/L; Newfoundland: 2.3–205 μg/L). The study reveals that the differences in THMs between the small and medium/large systems are because of different types of source waters, treatments, disinfection strategies and seasons. The results emphasize that regulatory agencies must focus more on the occurrence of DBPs in small systems and identify strategies to reduce their levels in drinking water.     

Occurrence and removal of pharmaceuticals and endocrine disruptors in South Korean surface, drinking, and waste waters

Liquid chromatography/tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) was used to measure the concentrations of 14 pharmaceuticals, 6 hormones, 2 antibiotics, 3 personal care products (PCPs), and 1 flame retardant in surface waters and wastewater treatment plant effluents in South Korea. Tris (2-chloroethyl) phosphate (TCEP), iopromide, naproxen, carbamazepine, and caffeine were quite frequently observed (>80%) in both surface waters and effluents. The analytes of greatest concentration were iopromide, TCEP, sulfamethoxazole, and carbamazepine. However, the primary estrogen hormones, 17alpha-ethynylestradiol and 17beta-estradiol, were rarely detected, while estrone was detected in both surface water and wastewater effluent. The elimination of these chemicals during drinking water and wastewater treatment processes at full- and pilot-scale also was investigated. Conventional drinking water treatment methods were relatively inefficient for contaminant removal, while efficient removal (approximately equal to 99%) was achieved by granular activated carbon (GAC). In wastewater treatment processes, membrane bioreactors (MBR) showed limited target compound removal, but were effective at eliminating hormones and some pharmaceuticals (e.g., acetaminophen, ibuprofen, and caffeine). Membrane filtration processes using reverse osmosis (RO) and nanofiltration (NF) showed excellent removal (>95%) for all target analytes.     

Reducing the concentration of assimilable organic carbon (AOC) in treated drinking water

This study focuses on reducing the concentration of assimilable organic carbon (AOC) in treated drinking water. Experiments were conducted to evaluate the efficiency of AOC removal by biological activated carbon filters (BACF) in a pilot-scale system. The measured values of AOC in treated drinking water were approximately 59.0 ± 8.6 μg acetate-C/L. The results show that BACFs reduce the total concentration of AOC. The concentration of AOC primarily indicates microbial growth in a water supply network, and the amount of AOC in the water is significantly reduced after BACF treatment. After BACF treatment, the removal of AOC was approximately 58% after 40 min of empty-bed contact time. An AOC empirical equation was established by determining the relationship between water quality parameters, such as total organic carbon, dissolved organic carbon, UV₂₅₄, ammonia nitrogen, and total phosphorous.     

Evaluation of the occurrence and biodegradation of parabens and halogenated by-products in wastewater by accurate-mass liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-QTOF-MS)

An assessment of the sewage occurrence and biodegradability of seven parabens and three halogenated derivatives of methyl paraben (MeP) is presented. Several wastewater samples were collected at three different wastewater treatment plants (WWTPs) during April and May 2010, concentrated by solid-phase extraction (SPE) and analysed by liquid chromatography-electrospray-quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS). The performance of the QTOF system proved to be comparable to triple-quadrupole instruments in terms of quantitative capabilities, with good linearity (R² > 0.99 in the 5-500 ng mL⁻¹ range), repeatability (RSD < 5.6%) and LODs (0.3-4.0 ng L⁻¹ after SPE). MeP and n-propyl paraben (n-PrP) were the most frequently detected and the most abundant analytes in raw wastewater (0.3-10 μg L⁻¹), in accordance with the data displayed in the bibliography and reflecting their wider use in cosmetic formulations. Samples were also evaluated in search for potential halogenated by-products of parabens, formed as a result of their reaction with residual chlorine contained in tap water. Monochloro- and dichloro-methyl paraben (ClMeP and Cl₂MeP) were found and quantified in raw wastewater at levels between 0.01 and 0.1 μg L⁻¹. Halogenated derivatives of n-PrP could not be quantified due to the lack of standards; nevertheless, the monochlorinated species (ClPrP) was identified in several samples from its accurate precursor and product ions mass/charge ratios (m/z). Removal efficiencies of parabens and MeP chlorinated by-products in WWTPs exceeded 90%, with the lowest percentages corresponding to the latter species. This trend was confirmed by an activated sludge biodegradation batch test, where non-halogenated parabens had half-lives lower than 4 days, whereas halogenated derivatives of MeP turned out to be more persistent, with up to 10 days of half-life in the case of dihalogenated derivatives. A further stability test performed with raw wastewater also showed that parabens degrade rapidly in real sewage, with half-lives lower than 10 h for n-butyl-paraben, while dihalogenated species again turned out to be more stable, with half-lives longer than a week.     

The control of organics in drinking water in Canada and the United States (standards,legislation and practice)

Both the United States and Canada have a federal form of government, but approaches used in the two countries to ensure the safety of drinking water supplies differ. The Environmental Protection Agency currently enforces regulations for 10 organic chemicals (including 6 pesticides) under the Safe Drinking Water Act and provides advice on others through its health advisory program. Canada, however, does not have similar legislation, but rather provides health-related guidelines for 21 organic chemicals (including 16 pesticides) which are used by the provincial agencies responsible for drinking water supplies. Both countries are in the process of revising their standards and will include a variety of additional synthetic organic chemicals.Where possible, standards are set using a calculated acceptable daily intake usually derived from animal feeding experiments. Procedures for setting standards for carcinogens involve a blend of risk estimation coupled with consideration of the feasibility of reducing the risk in light of socio-economic factors. Most drinking water treatment plans in North America utilize ‘conventional’ treatment. Some now employ modifications in order to minimize trihalomethane formation. A few use aeration or granular activated carbon to remove synthetic organic chemicals.     

自由氯、氯胺和顺序氯化对饮用水消毒效果的试验研究

研究了自由氯、氯胺和顺序氯化三种消毒方式对大肠埃希氏菌和粪肠球菌的灭活效果.结果表明,自由氯浓度越高,对细菌的灭活速率和最终灭活率越大;氯胺浓度越高,对细菌的灭活速率和最终灭活率越大;顺序氯化消毒效果优于单独使用自由氯或氯胺时的消毒效果.同时,还探讨了pH和温度对三种消毒方式的影响.     

Determination of cyanuric acid levels in swimming pool waters by u.v. absorbance, HPLC and melamine cyanurate precipitation

A u.v. method, recommended for use in surveys of the operation of swimming pools, depends on measuring the difference in absorbance at 225 nm between basified and acidified aliquots of sample and comparing with values obtained for standard solutions of cyanuric acid similarly treated. Also described is a High Performance Liquid Chromatography (HPLC) method which would be advantageous for large numbers of samples and for other analytical applications where cyanuric acid must be separated before quantitation by measuring the u.v. absorbance. Turbidimetric methods based on the precipitation of melamine cyanurate are less precise but still useful for pool-side monitoring of cyanuric acid levels. The performance of commercial test kits based on this principle should be checked by a controlling laboratory.     

Estimating elasticities of demand and willingness to pay for clean drinking water: empirical evidence from a household level survey in northern Pakistan

This study estimates income and price elasticities of demand for improved drinking water quality in Peshawar, Pakistan. The estimates indicate that improved water can be described as a necessity but normal and an ordinary and price elastic service. Confidence intervals show however that the classification as a necessity is statistically significant. Income elasticities of willingness to pay for drinking water are estimated. The study finds that income and willingness to pay vary directly and significantly. The elasticity estimates, in general, are greater than zero, but less than unity. The study concludes that improvements in drinking water are more beneficial to low‐income groups than for high‐income groups.     

Pharmaceuticals, personal care products and endocrine-disrupting chemicals in U.S. surface and finished drinking waters: A proposed ranking system

This study developed a comprehensive ranking system, for the first time as per authors' knowledge, for prioritizing the monitoring of pharmaceuticals and personal care products and endocrine-disrupting chemicals (together termed as EOCs, hereafter; a total of 100 EOCs considered) in U.S. stream water/source water and finished drinking water (termed as “EOCRank,” hereafter). The EOCRank system was developed using a total of 4 criteria: (1) occurrence, (2) treatment in drinking water treatment plants, (3) ecological effects, and (4) health effects and characterized using 7 attributes: prevalence, frequency of detection, removal, bioaccumulation, ecotoxicity (for fish, daphnid, and algae aquatic indicator species), pregnancy effects, and health effects. The health effects attribute was characterized using 7 sub-attributes: carcinogenicity, mutagenicity, impairment of fertility, central nervous system acting, endocrine effects, immunotoxicity, and developmental effects. Rank scores of EOCs were calculated as summations of multiplications of importance weights and utility functions of multiple criteria and were arranged to highlight EOCs needing immediate attention. Two different ranking lists of EOCs were developed for U.S. finished drinking water and stream water/source water and observed to differ with each other, indicating the effect of water type on ranking of EOCs. A ranking list of priority EOCs, developed using a particular criterion, was observed to differ with that, developed using multiple criteria. Health effects and treatment criteria were observed to be important criteria influencing overall data gap rank scores and need further data collection. The generalized nature of the system could be customized for specific geographical locations (occurrence information and importance weights of different components). The developed database of the EOCRank system is available on: http://www.egr.msu.edu/~xagorara/research.html).     

Toxicological and chemical characterization of organic micropollutants in river po waters (Italy)

River Po waters were collected at the end of the drainage basin, extracted by means of XAD-2 resins and tested for toxicity on aquatic organisms (Daphnia magna and Selenastrum capricornutum) and for mutagenicity with a modified Ames test. The extracts were analyzed by HRGC/FID and selective detectors for the determination of the most common classes of toxic compounds. The relationships between toxicological responses and analytical results are discussed.     

Distributions of polycyclic aromatic hydrocarbons in surface waters, sediments and soils of Hangzhou City, China

Ten polycyclic aromatic hydrocarbons (PAHs) were simultaneously measured in 17 surface water samples and 11 sediments of four water bodies, and 3 soils near the water-body bank in Hangzhou, China in December 2002. It was observed that the sum of PAHs concentrations ranged from 0.989 to 9.663 microg/L in surface waters, from 132.7 to 7343 ng/g dry weight in sediments, and from 59.71 to 615.8 ng/g dry weight in soils. The composition pattern of PAHs by ring size in water, sediment and soil were surveyed. Three-ring PAHs were dominated in surface waters and soils, meanwhile sediments were mostly dominated by four-ring PAHs. Furthermore, PAHs apparent distribution coefficients (K(d)) and solid f(oc)-normalized K(d) (e.g. K(oc)= K(d) / f(oc)) were calculated. The relationship between logK(oc) and logK(ow) of PAHs for field data on sediments and predicted values were compared. The sources of PAHs in different water bodies were evaluated by comparison of K (oc) values in sediments of the river downstream with that in soils. Hangzhou section of the Great Canal was heavily polluted by PAHs released from industrial wastewater in the past and now PAHs in sediment may serve as sources of PAHs in surface water. PAHs in Qiantang River were contributed from soil runoff. Municipal road runoff was mostly contributed to West Lake PAHs.     

Investigation of volatile organic compounds in office buildings in Bangkok,Thailand: Concentrations,sources, and occupant symptoms

To conserve energy, office buildings with air-conditioning systems in Thailand are operated with a tight thermal envelope. This leads to low fresh-air ventilation rates and is thought to be partly responsible for the sick building syndrome symptoms reported by occupants. The objectives of this study are to measure concentrations and to determine sources of 13 volatile organic compounds (VOCs) in office buildings with air-conditioning systems in the business area of Bangkok. Indoor and outdoor air samples from 17 buildings were collected on Tenax-TA^™ sorbent tubes and analyzed for individual VOCs by thermal desorption-gas chromatography/mass spectrometry (TD–GC/MS). Building ventilation was measured with a constant injection technique using hexafluorobenzene as a tracer gas. The results show that the VOC concentrations varied significantly among the studied buildings. The two most dominant VOCs were toluene and limonene with average concentrations of 110 and 60.5 μg m⁻³, respectively. A Wilcoxon sum rank test indicated that the indoor concentrations of aromatic compounds and limonene were statistically higher than outdoor concentrations at the 0.05 level, while the indoor concentrations of chlorinated compounds were not. Indoor emission factors of toluene and limonene were found to be highest with the average values of 80.9 and 18.9 μg m⁻² h⁻¹, respectively. Principal component analysis was applied to the emission factors of 13 VOCs, producing three components based on source similarities. Furthermore, a questionnaire survey investigation and field measurements of building air exchange pointed to indoor air complaints related to inadequate ventilation.     

On the presence of iron(II) in oxygenated surface waters: analytical implications

Iron(II) analyses using bathophenanthroline are shown to be characterized by an inherent, small positive interference when the pH of analysis is below 6.5 and iron(III) is present. The interference, which is due to a colored complex formed in the presence of FeOH²⁺ and bathophenanthroline, varies in magnitude according to the presence or generation of FeOH²⁺ during analysis. This interference necessitates reconsideration of published claims that low levels of stable iron(II) exist in oxygenated natural waters, particularly the surface layers of lakes.     

Contamination by chlorinated hydrocarbons (DDT,PCBs) in surface sediment and macrobenthos of the river Adige (Italy)

Surface sediments and macrobenthos communities have been employed as contamination indicators for halogenated hydrocarbons (DDT and PCBs) in the river Adige and its tributaries Fibbio and Alpone in the province of Verona. Two sampling campaigns were carried out, before and after the spring-summer floods, to determine the effects of this event on the contamination of the river. The halocarbons in the sediment were found to be associated with the fine fraction (< 53 μm) and organic carbon. From the relative concentrations of contaminants determined at various sampling stations, some information has been obtained on the sources.     

Evaluation of Po River water quality in Torino (Italy): Effects of diffuse and local point loads

The aim of this paper is to examine the Po River water quality in a small stretch in Piedmont (northern Italy). In this stretch a large pollution load, derived from the wastewater treatment plant of Torino area (more than 2 million inhabitants), is discharged and diluted in the water. In this study this load has been quantified and modeled in order to understand the sources, destinations and effects of the emitted pollutants. The objective was to determine the impact produced by the Torino Wastewater Treatment Plant on the quality of the water, based on various hydrological conditions and the possible intervention on the point and diffuse loads.