Abstract  The volume of water ingested by swimmers while swimming is of great interest to individuals who develop risk assessments using quantitative microbial risk assessment or epidemiological approaches. We have used chloroisocyanurate disinfected swimming pool waters to determine the amount of water swallowed by swimmers during swimming activity. The chloroisocyanurate, which is in equilibrium with chlorine and cyanuric acid in the pool water, provides a biomarker, cyanuric acid, that once swallowed passes through the body into the urine unchanged. The concentration of cyanuric acid in a 24 hour urine specimen and the concentration in pool water can be used to calculate the amount of water swallowed. Our study population of 549 participants, which was about evenly divided by gender, and young and adult swimmers, indicated that swimmers ingest about 32 mL per hour (arithmetic mean) and that children swallowed about four times as much water as adults during swimming activities. It was also observed that males had a tendency to swallow more water than females during swimming activity and that children spent about twice as much time in the water than adults.

Abstract  BACKGROUND: There is a surprising paucity of studies that have systematically examined the correlates of water intake in the US population.

OBJECTIVE: The objective was to examine the association of contributors of water intake with dietary characteristics, meal consumption, and body weight in the US population.

DESIGN: We used 24-h dietary recall data from the National Health and Nutrition Examination Survey (NHANES) 1999-2004 (n = 12,283) and the NHANES 2005-2006 (n = 4112) to examine the independent association of intakes of plain water, beverage moisture, food moisture, and total water with sociodemographic factors, dietary characteristics (energy, nutrients, diet quality, and energy density), and meal patterns (number of eating episodes, mention of breakfast or snack) by using multiple regression methods.

RESULTS: In 2005-2006, American adults reported consuming 3.18 L of total water within the previous 24 h (in 1999-2004, estimated total water intake was 3.35 L), with plain water and beverages contributing 33% and 48% of the total, respectively. Plain water intake was unrelated to the intake of energy and body mass index but was positively related to dietary fiber and inversely related to beverages, sugars, and the energy density of foods; these associations were in the opposite direction for beverage moisture intake. Total water intake was inversely related to energy from fat and energy density but positively related to dietary fiber, caffeine, alcohol, and diet quality. The number of eating episodes predicted higher beverage and food moisture and total water intakes. A higher body mass index predicted higher intakes of beverage moisture and total water.

CONCLUSION: Various contributors of total water intake differed in their association with dietary characteristics and body weight in the adult US population.

Abstract  Key Findings: Data from the National Health and Nutrition Examination Survey, 2009-2012 - Among U.S. adults, men consumed an average of 3.46 liters (117 ounces) of water per day, and women consumed 2.75 liters (93 ounces) per day. - Men aged 60 and over consumed less water (2.92 liters) than men aged 20-39 (3.61 liters) and 40-59 (3.63 liters). Similarly, women aged 60 and over consumed less water (2.51 liters) than women aged 20-39 (2.78 liters) and 40-59 (2.9 liters). - Non-Hispanic white men and women consumed more water daily than non-Hispanic black and Hispanic men and women. - Water intake increased with physical activity level for both men and women. - Among men, 30% of total water consumed was plain water (with the remainder from other foods and liquids) compared with 34% for women.

Abstract  This report presents current estimates of per capita water ingestion. The basis for these estimates is dietary and demographic data collected during a 1994 through 1996 survey conducted by the United States Department of Agriculture (USDA). In this survey, known as the Continuing Survey of Food Intakes by Individuals (SCFII), two non-consecutive days of food ingestion data were collected from a sample of more than 15,000 individuals in the 50 United States and the District of Columbia. Respondent information, in conjunction with food code, recipe, and nutrient data from USDA, forms the means of estimating per capita ingestion of plain drinking water (direct water) and water ingested indirectly. Water used in the final preparation of foods and beverages at home, or by food service establishments such as school cafeterias and restaurants is defined as indirect water. Quantities of ingested water reported in the USDA 1994 through 1996 CSFII are averaged by participant to generate a two-day average. These daily average ingestion amounts comprise the empirical distributions from which mean and upper percentile per capita ingestion estimates are produced. The CSFII survey, and consequently estimates reported in this document extend to the population of the United States. We augment population per capita ingestion estimates with estimates of per capita ingestion by various population subsets. These population subsets include (1) gender and age categories and (2) pregnant, lactating, and childbearing-age women. Subpopulation ingestion estimates support assessments of 'at risk' populations.

Abstract  This two-disk CD-ROM contains microdata on food and nutrient intakes from The Supplemental Children's Survey (CSFII 1998) to the 1994-96 Continuing Survey of Food Intakes by Individuals (CSFII 1994-96). CSFII 1998 was conducted in response to the Food Quality Protection Act of 1996, which required the U. S. Department of Agriculture to provide data from a larger sample of children for use by the Environmental Protection Agency in estimating exposure to pesticide residues in the diets of children. The CSFII 1998 adds intake data from 5,559 children birth through age 9 years to the intake data collected from 4,253 children of the same ages participating in the CSFII 1994-96. The CSFII 1994-96 included the collection of data from persons of all ages (1-day dietary intake data for 16,103 individuals). The 1998 survey was designed so that the data could be combined with those from the 1994-96 survey, thus the approaches to sample selection, data collection, data file preparation, and weighting in CSFII 1998 were consistent with those used in the CSFII 1994-96. The survey data files on these disks contain data from both the CSFII 1994-96 and CSFII 1998; all 4 years of data are nationally representative surveys conducted by the Agricultural Research Service of the U.S. Department of Agriculture. The data set may be analyzed in a variety of ways: the combined 1994-96, 1998 data; the 1998 data separately; the 3-year CSFII 1994-96 data; or any of the 3 years of the CSFII 1994-96 separately. The seven data files include: household, household member, sample person, food line item, daily intake (food group amounts), daily intake (nutrients), and Diet and Health Knowledge Survey (from the 1994-96 survey only).

Abstract  A Nationwide Food Consumption Survey was conducted by the U.S. Department of Agriculture (USDA) in 1977-78 to investigate the food intake of various selected segments of the U.S. food intake patterns. In this report data was used from the USDA survey to determine food intake patterns by age and sex in the general population and to establish food utilization factors that can be used in assessing radionuclide intake through food consumption by individuals in the U.S. population.

Abstract  The mission of National Center for Environmental Assessment (NCEA) of EPA's Office of Research and Development is to provide guidance and risk assessments aimed at protecting human health and the environment. To accomplish this mission, NCEA works to develop and improve the models, databases, tools, assumptions, and extrapolations used in risk assessments. This handbook is a tool developed by NCEA aimed at refining the assumptions used in exposure assessments and reducing uncertainty. This handbook was first published in 1989 and later updated in 1997 to provide statistical data on the various human factors used in assessing exposure. This revised edition of the handbook provides the most up-to-date data on these exposure factors. The recommended values are based solely on our interpretations of the available data. In many situations different values may be appropriate to use in consideration of policy, precedent or other factors. The Exposure Factors Handbook provides a summary of the available statistical data on various factors used in assessing human exposure. This Handbook is addressed to exposure assessors inside the Agency as well as outside, who need to obtain data on standard factors to calculate human exposure to environmental agents. These factors include: drinking water consumption, soil ingestion, inhalation rates, dermal factors including skin area and soil adherence factors, consumption of fruits and vegetables, fish, meats, dairy products, homegrown foods, human milk intake, human activity factors, consumer product use, and building characteristics. Recommended values are for the general population and also for various segments of the population who may have characteristics different from the general population. NCEA has strived to include full discussions of the issues that assessors should consider in deciding how to use these data and recommendations.

Abstract  The first edition of Recommended Dietary Allowances, published in 1943 with the objective of "providing standards to serve as a goal for good nutrition," defined "in accordance with newer information the recommended daily allowances for the various dietary essentials for people of different ages" (FNB, 1943). A major objective of the Food and Nutrition Board of the National Research Council continues to be to encourage the development of food use practices by the population of the United States that will allow for maximum dividends in the maintenance and promotion of health (FNB, 1968). Health is defined, according to the World Health Organization, as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity" (Anon., 1970).

Abstract  Contaminated tap water can become a health risk, e.g. by metals or environmental pollution particularly for sensitive population groups such as infants and young children. There is a lack of data on exactly measured water intake. In the DONALD Study, individual food and fluid intakes were measured by use of 3-day weighed diet records. Here we report on the distribution of individual intakes of tap water in 504 healthy normally nourished subjects aged 3-36 months (1962 diet records) between 1990 and 1998. We calculate scenarios for potential tap water contamination. Tap water intake per kg body weight was significantly higher in formula-fed (FF) infants than in breast-fed (BF) infants. The estimated median intake of lead and nitrate per kg body weight from tap water was higher in FF infants than in BF infants or mixed fed (MF) young children. The scenarios based on intakes at the median, P95 or maximums show that higher risks for exceeding the presently existing maximums could be expected in FF infants. Our data could also be used for estimations of potential risks from other contaminants of tap water.

Abstract  In infants, the majority of total ingested fluoride is obtained from water, formula and beverages prepared with water, baby foods, and dietary fluoride supplements. Few studies have investigated the distribution of fluoride intake from these sources among young children at risk for dental fluorosis. The purpose of this study was to assess estimated water fluoride intake from different sources of water among a birth cohort studied longitudinally from birth until age 9 months. Parental reports were collected at 6 weeks, 3 months, 6 months, and 9 months of age for water, formula, beverage, and other dietary intake during the preceding week. Fluoride levels of home and child-care tap and bottled water sources were determined. This report estimates daily quantities of fluoride ingested only from water--both by itself and used to reconstitute formula, beverages, and food. Daily fluoride intake from water by itself ranged to 0.43 mg, with mean intakes < 0.05 mg. Water fluoride intake from reconstitution of concentrated infant formula ranged to 1.57 mg, with mean intakes by age from 0.18 to 0.31 mg. Fluoride intake from water added to juices and other beverages ranged to 0.67 mg, with means < 0.05 mg. Estimated total daily water fluoride intake ranged to 1.73 mg fluoride, with means from 0.29 to 0.38 mg.

Abstract  BACKGROUND: Despite theoretically higher requirements for water due to physiologic demands of pregnancy and lactation, little is known of actual ranges of intake in pregnant and lactating women.

METHODS: Population-based estimates of total water and tapwater intake in women of reproductive age were derived using data from the 1977-78 USDA Nationwide Food Consumption Survey. Three-day average intakes were calculated for 188 pregnant women, 77 lactating women, and 6,201 non-pregnant, non-lactating control women.

RESULTS: Total water intake (mean +/- SD) was 1,940 +/- 686 g/day (median 1,835) for control women, 2,076 +/- 743 g/day (median 1,928) for pregnant women and 2,242 +/- 658 g/day (median 2,164) for lactating women. Tapwater intake was 1,157 +/- 635 g/day (median 1,065) for control women, 1,189 +/- 699 g/day (median 1,063) for pregnant women, and 1,310 +/- 591 g/day (median 1,330) for lactating women. Total water intake was equal to or greater than 3,000 g/day among 7 percent of control women, 11 percent of pregnant women, and 13 percent of lactating women. Tapwater intake was equal to or greater than 2,000 g/day among 10 percent of control women, 15 percent of pregnant women, and 8 percent of lactating women.

CONCLUSIONS: These results should be useful in estimating amounts of nutrients and toxic substances that women of reproductive age obtain through the water supply.

Abstract  Divers may run a higher risk of infection with waterborne pathogens than bathers because of more frequent and intense contact with water that may not comply with microbiologic water quality standards for bathing water. In this study we aimed to estimate the volume of water swallowed during diving as a key factor for infection risk assessment associated with diving. Using questionnaires, occupational and sport divers in the Netherlands were asked about number of dives, volume of swallowed water, and health complaints (nausea, vomiting, diarrhea, and ear, skin, eye, and respiratory complaints). Occupational divers, on average, swallowed 9.8 mL marine water and 5.7 mL fresh surface water per dive. Sport divers swallowed, on average, 9.0 mL marine water; 13 mL fresh recreational water; 3.2 mL river, canal, or city canal water; and 20 mL water in circulation pools. Divers swallowed less water when wearing a full face mask instead of an ordinary diving mask and even less when wearing a diving helmet. A full face mask or a diving helmet is recommended when diving in fecally contaminated water. From the volumes of swallowed water and concentrations of pathogens in fecally contaminated water, we estimated the infection risks per dive and per year to be as high as a few to up to tens of percents. This may explain why only 20% of the divers reported having none of the inquired health complaints within a period of 1 year. It is highly recommended that divers be informed about fecal contamination of the diving water.

Abstract  Chloroisocyanurates are commonly added to outdoor swimming pools to stabilize chlorine disinfectants. The chloroisocyanurates decompose slowly to release chlorine and cyanuric acid. Studies conducted to determine if the chloroisocyanurates might be toxic to swimmers showed that they were not and that ingested cyanuric acid passed through the body unmetabolized. This fact was used to determine the amount of water swallowed during swimming activity. Fifty-three recreational swimmers, using a community swimming pool disinfected with cyanuric acid stabilized chlorine, participated in the study. The participants did not swim on the day before or after the test swim. The swimmers were asked to actively swim for at least 45 minutes and to collect their urine for the next 24 hours. Cyanuric acid was measured in pool water using high performance liquid chromatography and porous graphitic carbon columns with UV detection. The urine sample assay required a clean-up procedure to remove urinary proteins and interfering substances. Results of the study indicate that non-adults ingest about twice as much water as adults during swimming activity. The average amount of water swallowed by non-adults and adults was 37 ml and 16 ml, respectively. The design for this study and the analytical methodology used to assay cyanuric acid in swimming pool water and human urine were effective for measuring the volume of water swallowed during swimming activity.

Abstract  Below is a summary of the recommendations reached by the Methodological Subcommittee of the HNIS/NCHS Analytic Working Group on the issues of variance estimation and statistical reporting standards. Specific recommendations are underlined, whereas suggested practices are italicized. The implementation of these recommendations and suggestions will vary from survey to survey and, perhaps, from estimate to estimate. Nevertheless, official agency publications should contain a "statistical notes" section describing the variance estimation and statistical reporting standards used therein. The design-based approach to the estimation and analysis of survey data is assumed here. Unlike model-dependent alternatives, the design-based approach makes few assumptions about the nature of the data being summarized and/or analyzed. Two aspects of the sampling design must be taken into account when using this approach: the sample weights and the complex sample design (stratified, multi-stage sampling). Weights are used in the this approach when estimating mean, medians, and other descriptive statistics as well as analytical statistics like regression coefficients. Both weights and indicators of stratum and primary sampling unit (PSU) membership are used when estimating variances and testing for statistical significance. In general, using statistical weights that reflect the probability of selection and propensity of response for sampled individuals will affect parameter estimates, while incorporating the attributes of the complex sample design (i.e., clustering and stratification) will affect estimated standard errors and thereby test statistics and confidence intervals. The recommendations for presentation of statistical data that follow arise from the issue of sampling variability, and reflect the random way (in the rigorous statistical sense) in which the sample was selected. Although beyond the scope of this report, a consideration of nonsampling issues such as measurement error, nonresponse bias, and other methodological biases are necessary for any thorough interpretation and evaluation of the validity of survey findings.

Abstract  Characterisation of exposure levels is an essential requirement of health risk assessment; however for water exposures other than drinking, few quantitative exposure data exist. Thus, regulatory agencies must use estimates to formulate policy on treatment requirements for non-potable recycled water. We adapted the use of the swimming pool chemical cyanuric acid as a tracer of recreational water ingestion to permit detection of small water volumes inadvertently ingested from spray exposures. By using solutions of 700-1000 mg/L cyanuric acid in an experimental spray exposure scenario, we were able to quantify inadvertent water ingestion in almost 70% of participants undertaking a 10 min car wash activity using a high pressure spray device. Skin absorption was demonstrated to be negligible under the experimental conditions, and the measured ingestion volumes ranged from 0.06 to 3.79 mL. This method could be applied to a range of non-potable water use activities to generate exposure data for risk assessment processes. The availability of such empirical measurements will provide greater assurance to regulatory agencies and industry that potential health risks from exposure to non-potable water supplies are well understood and adequately managed to protect public health.

Abstract  The goals of this study were to describe plain drinking water intake patterns of the U.S. population and determine whether total, tap, and bottled water intakes differ by gender, race/ethnicity, income, and activity level. Twenty-four-hour dietary recall data from 16,566 individuals age 2 years and over participating in What We Eat In America (WWEIA), the dietary intake component of the National Health and Nutrition Examination Survey (NHANES), in 2005-2008 were analyzed. Appropriate sample weights were applied to produce nationally representative estimates. T-tests were used to identify differences in intakes of total plain, tap, and bottled water intake by gender, race/ethnicity, activity level, and income. Regression procedures were used to adjust estimated means for confounding variables when testing for differences in daily plain water intake by race/ethnicity, activity level, and income. On any given day, 76 percent of individuals age 2 years and over report plain drinking water, and the mean intake per person (including both reporters and nonreporters) is 3.9 cups. Total plain drinking water intakes do not differ by gender within age group, but tap water intakes are higher for males 12-19 years than for females the same age and for females 60+ years than for males the same age (p<.001). The majority of plain drinking water is consumed at home. Nearly three-quarters of plain drinking water (both tap and bottled) is consumed at snacks, and over one-half is consumed at eating occasions for which no other food or beverage is reported. There are some differences in intakes by race/ethnicity, income, and activity level. In some age groups, including adults 20+ years, tap water intake is higher for non-Hispanic whites than for non-Hispanic blacks and Hispanics. Among adults 20+ years, there is a positive association between bottled water intake and income, though intakes of total plain and tap water do not differ by income. Adults who are physically active drink more plain water than sedentary adults do. The information furnished by this study is useful to anyone who is interested in plain drinking water in the U.S., including legislators, program planners, nutritionists, media, educators, and consumers.

Abstract  Cyanuric acid (CYA) excretion in urine has been used to estimate the volume of water ingested during swimming and other recreational activities in outdoor pools containing this chemical. These estimates of water ingestion are based on the assumption of 100% excretion within 24 hours, but the supporting evidence for this is scant. While adapting this methodology to investigate other water ingestion scenarios, we observed a high degree of variability in cyanuric acid excretion among experimental subjects, with over 25% of individuals excreting less than 80% of an ingested dose. Use of cyanuric acid to measure inadvertent water ingestion may be a valuable tool to generate data for health risk assessment of non-potable water sources, but our observations indicate that this technique carries an inherent degree of underestimation that should be taken into account when calculating water exposure.

Abstract  Epidemiological studies examining the association between exposure to tap water contaminants (such as chlorination by-products) and disease outcomes (such as cancer and adverse reproductive outcomes) have been limited by inaccurate exposure assessment. Failure to take into account the variation in beverage and tap water consumption and exposure to volatile contaminants through inhalation and dermal absorption can introduce misclassification in assessing the association between exposure to tap water contaminants and health. To refine exposure assessment of tap water contaminants, we describe in detail the tap water consumption, showering, and bathing habits of pregnant women and their male partners as assessed by a questionnaire and a 3-day water diary. We found good agreement between questionnaire and 3-day water diary values for drinking water intake (Pearson's r = 0.78) and for time spent showering(r = 0.68) and bathing (r = 0.78). Half of the participants consumed tap water on a regular basis with an overall mean +/- 1 standard deviation (SD) of 0. 78 +/- 0.51 l/day. Our results further suggest that full-time employees, compared to women working part-time or less, have more heterogeneous consumption patterns over time. Seventy-nine percent of women and 94% of men took showers for an average of 11.6 +/-4.0 min and 10.4 +/- 4.8 min, respectively. Baths were taken more frequently by women than men (21% vs. 3%) for an average of 22.9 +/-10.1 min and 21.3 +/- 12.4 min, respectively. Thus, these patterns of tap water use should be considered in the design and interpretation of environmental epidemiology studies.

Abstract  The assumption that people using the same water supply have similar intakes of minerals from drinking water is examined. Duplicate samples of all water drunk during a 24 hour period, including that boiled for beverage preparation, were collected by 109 adult subjects. The results showed that there may be more than a tenfold variation in the amount of water people drink daily. In addition it was found that the mineral concentrations in the 24 hour samples can vary markedly from those in water collected from the source or supply or from household taps which are the usual sampling points for epidemiological studies. The convention of using total hardness as an indicator of mineral intakes from hard and soft water is questioned.