Changes in Breath Trihalomethane Levels Resulting from Household Water-Use Activities

Common household water-use activities such as showering, bathing, drinking, and washing clothes or dishes are potentially important contributors to individual exposure to trihalomethanes (THMs), the major class of disinfection by-products of water treated with chlorine. Previous studies have focused on showering or bathing activities. In this study, we selected 12 common water-use activities and determined which may lead to the greatest THM exposures and result in the greatest increase in the internal dose. Seven subjects performed the various water-use activities in two residences served by water utilities with relatively high and moderate total THM levels. To maintain a consistent exposure environment, the activities, exposure times, air exchange rates, water flows, water temperatures, and extraneous THM emissions to the indoor air were carefully controlled. Water, indoor air, blood, and exhaled-breath samples were collected during each exposure session for each activity, in accordance with a strict, well-defined protocol. Although showering (for 10 min) and bathing (for 14 min), as well as machine washing of clothes and opening mechanical dishwashers at the end of the cycle, resulted in substantial increases in indoor air chloroform concentrations, only showering and bathing caused significant increases in the breath chloroform levels. In the case of bromodichloromethane (BDCM), only bathing yielded a significantly higher air level in relation to the preexposure concentration. For chloroform from showering, strong correlations were observed for indoor air and exhaled breath, blood and exhaled breath, indoor air and blood, and tap water and blood. Only water and breath, and blood and breath were significantly associated for chloroform from bathing. For BDCM, significant correlations were obtained for blood and air, and blood and water from showering. Neither dibromochloromethane nor bromoform gave measurable breath concentrations for any of the activities investigated because of their much lower tap-water concentrations. Future studies will address the effects that changes in these common water-use activities may have on exposure

Influence of Tap Water Quality and Household Water Use Activities on Indoor Air and Internal Dose Levels of Trihalomethanes

Individual exposure to trihalomethanes (THMs) in tap water can occur through ingestion, inhalation, or dermal exposure. Studies indicate that activities associated with inhaled or dermal exposure routes result in a greater increase in blood THM concentration than does ingestion. We measured blood and exhaled air concentrations of THM as biomarkers of exposure to participants conducting 14 common household water use activities, including ingestion of hot and cold tap water beverages, showering, clothes washing, hand washing, bathing, dish washing, and indirect shower exposure. We conducted our study at a single residence in each of two water utility service areas, one with relatively high and the other low total THM in the residence tap water. To maintain a consistent exposure environment for seven participants, we controlled water use activities, exposure time, air exchange, water flow and temperature, and nonstudy THM sources to the indoor air. We collected reference samples for water supply and air (pre–water use activity), as well as tap water and ambient air samples. We collected blood samples before and after each activity and exhaled breath samples at baseline and postactivity. All hot water use activities yielded a 2-fold increase in blood or breath THM concentrations for at least one individual. The greatest observed increase in blood and exhaled breath THM concentration in any participant was due to showering (direct and indirect), bathing, and hand dishwashing. Average increase in blood THM concentration ranged from 57 to 358 pg/mL due to these activities. More research is needed to determine whether acute and frequent exposures to THM at these concentrations have public health implications. Further research is also needed in designing epidemiologic studies that minimize data collection burden yet maximize accuracy in classification of dermal and inhalation THM exposure during hot water use activities

Rotation of planet-harbouring stars

The rotation rate of a star has important implications for the detectability, characterisation and stability of any planets that may be orbiting it. This chapter gives a brief overview of stellar rotation before describing the methods used to measure the rotation periods of planet host stars, the factors affecting the evolution of a star's rotation rate, stellar age estimates based on rotation, and an overview of the observed trends in the rotation properties of stars with planets.Comment: 16 pages, 4 figures: Invited review to appear in 'Handbook of Exoplanets', Springer Reference Works, edited by Hans J. Deeg and Juan Antonio Belmont

Ipsilesional trajectory control is related to contralesional arm paralysis after left hemisphere damage

We have recently shown ipsilateral dynamic deficits in trajectory control are present in left hemisphere damaged (LHD) patients with paresis, as evidenced by impaired modulation of torque amplitude as response amplitude increases. The purpose of the current study is to determine if these ipsilateral deficits are more common with contralateral hemiparesis and greater damage to the motor system, as evidenced by structural imaging. Three groups of right-handed subjects (healthy controls, LHD stroke patients with and without upper extremity paresis) performed single-joint elbow movements of varying amplitudes with their left arm in the left hemispace. Only the paretic group demonstrated dynamic deficits characterized by decreased modulation of peak torque (reflected by peak acceleration changes) as response amplitude increased. These results could not be attributed to lesion volume or peak velocity as neither variable differed across the groups. However, the paretic group had damage to a larger number of areas within the motor system than the non-paretic group suggesting that such damage increases the probability of ipsilesional deficits in dynamic control for modulating torque amplitude after left hemisphere damage

A somato-cognitive action network alternates with effector regions in motor cortex

Motor cortex (M1) has been thought to form a continuous somatotopic homunculus extending down the precentral gyrus from foot to face representation

Jowett’s Thucydides: A corpus-based analysis of translation as political intervention

Thucydides’ History of the Peloponnesian War is a key text in the classical Greek canon and an important source of insights into the structures and tensions at the heart of ancient Athenian democracy. Consequently, modern interpretations of his analysis have repeatedly played a major role in shaping debates on the viability and desirability of democratic rule. This paper aims to build on previous discussion of Benjamin Jowett's 1881 translation of Thucydides by applying a comparative corpus-based methodology to explore how this translator's own personal politics shaped his re-presentation of this text. The analysis reveals a striking emphasis on the position and activity of democratic leaders throughout Jowett’s version, strongly consistent with the ideology of leadership that he developed during his career as Master of Balliol College, Oxford

Temporal changes in clinical and radiographic variables in dogs with preclinical myxomatous mitral valve disease: The EPIC study

The Evaluation of pimobendan in dogs with cardiomegaly caused by preclinical myxomatous mitral valve disease (EPIC) study monitored dogs with myxomatous mitral valve disease (MMVD) as they developed congestive heart failure (CHF)