Maternal ingestion of radon-222 in drinking water and the absorbed radiation dose to the embryo

Maternal ingestion of high concentrations of radon-222 (Rn-222) in drinking during pregnancy may pose a significant radiation hazard to the developing embryo. The effects of ionizing radiation to the embryo and fetus have been the subject of research, analyses, and the development of a number of radiation dosimetric models for a variety of radionuclides. Currently, essentially all of the biokinetic and dosimetric models that have been developed by national and international radiation protection agencies and organizations recommend calculating the dose to the mother's uterus as a surrogate for estimating the dose to the embryo. Heretofore, the traditional radiation dosimetry models have neither considered the embryo a distinct and rapidly developing entity, the fact that it is implanted in the endometrial layer of the uterus, nor the physiological interchanges that take place between maternal and embryonic cells following the implantation of the blastocyst in the endometrium. The purpose of this research was to propose a new approach and mathematical model for calculating the absorbed radiation dose to the embryo by utilizing a semiclassical treatment of alpha particle decay and subsequent scattering of energy deposition in uterine and embryonic tissue. The new approach and model were compared and contrasted with the currently recommended biokinetic and dosimetric models for estimating the radiation dose to the embryo. The results obtained in this research demonstrate that the estimated absorbed dose for an embryo implanted in the endometrial layer of the uterus during the fifth week of embryonic development is greater than the estimated absorbed dose for an embryo implanted in the uterine muscle on the last day of the eighth week of gestation. This research provides compelling evidence that the recommended methodologies and dosimetric models of the Nuclear Regulatory Commission and International Commission on Radiological Protection employed for calculating the radiation dose to the embryo from maternal intakes of radionuclides, including maternal ingestion of Rn-222 in drinking water would result in an underestimation of dose. ^

Drinking water quality perception along the U.S.-Mexico border

Drinking water-related exposures within populations living in the United States-Mexico border region, particularly among Hispanics, is an area that is largely unknown. Specifically, perceptions that may affect water source selection is an issue that has not been fully addressed. This study evaluates drinking water quality perceptions in a mostly Hispanic community living along the United States-Mexico border, a community also facing water scarcity issues. Using a survey that was administered during two seasons (winter and summer), data were collected from a total of 608 participants, of which 303 were living in the United States and 305 in Mexico. A (random) convenience sampling technique was used to select households and those interviewed were over 18 years of age. Statistically significant differences were observed involving country of residence (p=0.002). Specifically, those living in Mexico reported a higher use of bottled water than those living in the United States. Perception factors, especially taste, were cited as main reasons for not selecting unfiltered tap water as a primary drinking water source. Understanding what influences drinking water source preference can aid in the development of risk communication strategies regarding water quality. ^

The relationship between alcohol consumption and HDL cholesterol: A study of Hispanic drinking patterns

There has been very little research that has studied the effects of alcohol on biochemical markers in ethnic populations. This particular study is designed to identify the association, if any, between drinking patterns and high density lipoprotein cholesterol (HDL-C) levels in a Hispanic population. Most of what we know about the association between alcohol and HDL-C deals specifically with volume of alcohol consumed on a daily basis. Frequency, or how often alcohol consumption occurs within a given time period, is a variable that has rarely been studied. The results of this study showed how both volume and frequency of alcohol consumption affect HDL-C levels in a predominantly middle-aged Hispanic population. Ultimately, we will be able to apply these findings to future studies concerning risk of CHD in Hispanics. ^

The effects of binge drinking on military readiness: The inability to deploy

The negative outcomes from alcohol misuse have been chronicled for decades in epidemiological studies. Recent research has focused on patterns of drinking. Binge and heavy drinking have been associated with multiple negative outcomes, to include surrogate outcomes designed to measure decrements to military readiness. This study is perhaps the first to examine whether binge or heavy drinking patterns are associated with the U.S. military’s overall inability to deploy rate or the individual reasons unable to deploy. ^ The prevalence of binge and heavy drinking and the inability to deploy rates were assessed from responses to the 2005 Department of Defense Survey of Health Related Behaviors Among Military Personnel. A secondary analysis of extant data resulted in a final sample size of 13,619 respondents who represented 847,253 active-duty military personnel. Multivariate models were fitted to examine the association between patterns of drinking and individual reasons for the inability to deploy. ^ Logistic regression showed no association of binge or heavy drinking to greater inability to deploy. Interestingly, individual reasons for the inability to deploy did show an association to include: Training, Dental Issue, No HIV Test, and Family Situation. There was no association noted for the individual reasons: Injury, Illness, Leave/Temporary Duty, or Other. Binge and heavy drinkers appear to be more susceptible to the psychosocial determinants than physical determinants as reasons for the inability to deploy. ^

Health significance of chlorination byproducts in drinking water: The Houston experience: A continuation study

Background. Houston, Texas, once obtained all its drinking water from underground sources. However, in 1853, the city began supplementing its water from the surface source Lake Houston. This created differences in the exposure to disinfection byproducts (DBPs) in different parts of Houston. Trihalomethanes (THMs) are the most common DBP and are useful indicators of DBPs in treated drinking water. This study examines the relationship between THMs in chlorinated drinking water and the incidence of bladder cancer in Houston. ^ Methods. Individual bladder cancer deaths, from 1975 to 2004, were assigned to four surface water exposure areas in Houston utilizing census tracts—area A used groundwater the longest, area B used treated lake water the longest, area C used treated lake water the second longest, and area D used a combination of groundwater and treated lake water. Within each surface water exposure area mortality rates were calculated in 5 year intervals by four race-gender categories. Linear regression models were fitted to the bladder cancer mortality rates over the entire period of available data (1990–2004). ^ Results. A decrease in bladder cancer mortality was observed amongst white males in area B (p = 0.030), white females in area A (p = 0.008), non-white males in area D (p = 0.003), and non-white females in areas A and B (p = 0.002 & 0.001). Bladder cancer mortality differed by race-gender and time (p ≤ 0.001 & p ≤ 0.001), but not by surface water exposure area (p = 0.876). ^ Conclusion. The relationship between bladder cancer mortality and the four surface water exposure areas (signifying THM exposure) was insignificant. This result could be attributable to Houston controlling for THMs starting in the early 1980’s by using chloramine as a secondary disinfectant in the drinking water purification process.^

AN ASSESSMENT OF THE RELATION OF CANCER MORTALITY RATES AND SOURCES OF DRINKING WATER IN TEXAS

The geographic distribution of average annual age-adjusted mortality rates (1964-1976) for four types of cancer (all cancer sites combined, gastrointestinal, urinary, and lung cancer) were compared by sources of drinking water for 254 Texas counties and county rural areas and 301 Texas cities. Exposure variables considered were surface versus ground water, public water supplies versus individuals wells, and trihalomethane levels in municipal water supplies. Each general source of "surface" and "ground" water was further divided by aggregating ground water using areas by aquifers and surface water using study areas by river basins. Potential confounding variables taken into account included median education, employment in cancer risk industries, population mobility, ethnicity, and urbanicity. A pattern of higher and lower cancer mortality rates was found for populations using some aquifers and river basins. Further study is required to determine whether the differences in cancer mortality rates that were observed are related to drinking water content or are coincidental with differences in personal characteristics which could not be taken into account in this ecologic study design. ^

Objective metrics for functional evaluation of upper limb during the ADL of drinking: application in SCI

Three-dimensional kinematic analysis provides quantitative assessment of upper limb motion and is used as an outcome measure to evaluate movement disorders. The aim of the present study is to present a set of kinematic metrics for quantifying characteristics of movement performance and the functional status of the subject during the execution of the activity of daily living (ADL) of drinking from a glass. Then, the objective is to apply these metrics in healthy people and a population with cervical spinal cord injury (SCI), and to analyze the metrics ability to discriminate between healthy and pathologic people. 19 people participated in the study: 7 subjects with metameric level C6 tetraplegia, 4 subjects with metameric level C7 tetraplegia and 8 healthy subjects. The movement was recorded with a photogrammetry system. The ADL of drinking was divided into a series of clearly identifiable phases to facilitate analysis. Metrics describing the time of the reaching phase, the range of motion of the joints analyzed, and characteristics of movement performance such as the efficiency, accuracy and smoothness of the distal segment and inter-joint coordination were obtained. The performance of the drinking task was more variable in people with SCI compared to the control group in relation to the metrics measured. Reaching time was longer in SCI groups. The proposed metrics showed capability to discriminate between healthy and pathologic people. Relative deficits in efficiency were larger in SCI people than in controls. These metrics can provide useful information in a clinical setting about the quality of the movement performed by healthy and SCI people during functional activities.

Case-based reasoning to support decision making for managing drinking water quality events in distribution systems

Peer reviewed

Management of Trihalomethanes in Finished Drinking Water Through Source Water Precursor Monitoring

Trihalomethanes are organic compounds formed in drinking water distribution systems as a result of disinfection. This capstone project researched and evaluated the statistical correlation of trihalomethanes in finished drinking water and total organic carbon in source water using data generated by Denver area utilities. Results of the study conclude that some drinking water supply systems show a slight correlation between source water total organic carbon levels and trihalomethane levels in finished water. Results of the study also verify the assertion that changes to treatment for the reduction of trihalomethanes, for the protection of human health under the Safe Drinking Water Act should be determined by each utility, using information from gathered data, seasonal trends, and small scale batch testing.

The Effects of Climate Change on Algae in the Denver Metro Area's Drinking Water Reservoirs

Six Denver metro water reservoirs were sampled to see what types of algae were found, and what impact the algae would have on drinking water reservoirs in the event of a bloom caused by warming water temperatures. Each sample contained algae. Toxic cyanobacteria, filamentous green algae, and different species of diatoms were found in the samples. Current climate change models show the temperature along the Front Range is rising and will continue to rise. With an increase in climate change and an increase in population, humans and animals will be at a greater risk of ingesting or coming into contact with toxic algae.

Review of Desalination and Concentrate Management Issues for Increasing Drinking Water Supplies

Water quantity and quality issues worldwide are causing nations to consider alternate sources for drinking water. Desalination and other membrane processes for treatment of seawater and brackish inland waters have been in use for the past quarter century and are growing in use worldwide. These treatment processes create a highly concentrated waste stream in which the principal constituents are dissolved solids. This report provides an overview of desalination methods and the methods available to dispose of this waste stream. Innovative technologies being studied for possible future use are also discussed.