The NTP Examines DBPs
This month's NIEHS News (p. A64) describes work being done by the National Toxicology Program to understand the chemistry and health effects of disinfection by-products, or DBPs, which result from adding chlorine and other chemicals to public drinking water supplies.
The State of the World's Drinking Water
Potable water is one of the most basic human needs and--in some areas--one of the most elusive public health achievements. The Focus (p. A68) examines the quality and availability of drinking water around the world today.
Livestock Farming after Floyd
The Spheres of Influence (p. A74) asks some tough questions in the wake of last September's flooding in eastern North Carolina: what will it take to make livestock operations less likely to contribute to environmental devastation, and how will state livestock regulations be improved to lessen the public health effects of future floods?
Sea Change in Desalination
As increasing scarcity drives the push to find new sources of water, scientists are looking to the earth's oceans as a possible solution to the shortage. The Innovations (p. A78) investigates current research into methods of desalination, turning saltwater into fresh water.
Assessing Particulate Pollution and Mortality
Bates (p. 91) comments that associations between particulate pollution and various outcomes should be frequently reevaluated for causality because of the volume of new experimental information. He suggests that there is now stronger associative evidence for causality and that there are demonstrable biologic reasons for a number of the adverse effects attributed to particulate pollution exposure.
Epidemiology and Risk Estimates for Radiation
A Commentary by Stewart (p. 93) suggests a modification for the role of epidemiology in the detection of harmful effects of radiation and for the setting of safety standards. She urges radiation protection committees to recognize that levels of radiosensitivity are much higher at the beginning and end of the life span than during the intervening period, and suggests that the risk of childhood leukemia from low-level in utero radiation exposure may be greater than currently believed.
Xenoestrogen Activation of the Estrogen Receptor
The estrogen-like activities of octylphenol, bisphenol A, DDT, and DDE to induce human estrogen receptor dimerization and transcriptional activation were investigated by Sheeler et al. (p. 97) using three yeast genetic systems. The authors report that these xenoestrogens act through the estrogen receptor and that the coactivator RIP140 markedly potentiates the activity.
Passive Smoking and Plasma Vitamin C
The effects of tobacco smoke exposure on plasma vitamin C levels in humans were examined by Ayaori et al. (p. 105). The authors report changes in the oxidative state of vitamin C in active and passive smokers and suggest that exposure may increase oxidative stress and contribute to the pathogenesis of passive smoke exposure.
A Meta-Analysis of PM10 Mortality
Levy et al. (p. 109) examined the variability in data from 19 U.S. studies of particulate matter and mortality, and estimated that mortality rates increased on average by 0.7% per 10 µg/m3 increase in PM10 concentrations. The authors recommend further analyses to determine which specific factors influence the relationship between PM10 and mortality.
Climate and Tick Distribution
Climate moderation in the 1990s may have been the determinate factor for a change in the density and distribution of ticks in Sweden. Lindgren at al. (p. 119) show that there was a northern shift in the disease-transmitting tick Ixodes ricinus between the early 1980s and mid-1990s, thus providing another example of the effects of climate change on human health.
Acidic Particulate Matter and Mortality
A variety of air pollutants contribute to adverse health effects, including aerosol acidity, PM10, coefficient of haze, O3, CO, SO2, and NO2. When Gwynn et al. (p. 125) examined these components, acidic aerosols showed the strongest association with respiratory hospital admissions and mortality, even after adjusting for O3.
Magnetic Fields and Intracellular Calcium
Wey et al. (p. 135) investigated the effects of a 1.5-G 50-Hz magnetic field on intracellular calcium using the Jurkat lymphocyte T-cell line. In contrast to previous reports, cells exposed for 8 min to a magnetic field, a sham field, or no field exhibited no differences in transients, as measured by changes in intracellular calcium using microscopic imaging of fura-2 loaded cells.
Effects of Drug Abuse on the Human Placenta
Paaki et al. (p. 141) demonstrated that maternal drug abuse affected human placental xenobiotic and steroid metabolizing activities. The responses raise the possibility of increased metabolism-related chemical and oxidative stress in fetal tissues resulting from maternal drug use.
Serum Polybrominated Biphenyl Decay in Women
Blanck et al. (p. 147) conducted pharmacokinetic studies of archived data from the Michigan cohort exposed to food contaminated by PBBs in 1973. The authors calculated subject-specific decay rates for PBBs to enable better estimates for body burden at times other than the time of serum collection, and to gain more information from studies that relate PBB exposure to health outcomes.
Asbestos Affects Human Cell Membranes
The effects of exposure of crocidolite asbestos on the cell membrane of human mesothelial cells were examined by Dopp et al. (p. 153). Changes in dielectric properties and morphologic and biochemical changes were measured using electrorotation, electron microscopy, and flow cytometry. The authors report changes in the surface properties of the cell membranes and interior dielectric changes related to loss of microvilli, reduced cell size, increased granularity, and apoptotic changes.
Perinatal Mortality in Germany from 1980 to 1993
Scherb et al. (p. 159) conducted numerous statistical analyses of time trends in perinatal mortality in Germany and Bavaria and report that increased mortality may be associated with cesium deposition from the Chernobyl radiation accident. The authors acknowledge weaknesses of such ecologic studies for proving causal interpretation and recommend further studies.
Lake Michigan Fish and PCB Congeners
Humphrey et al. (p. 167) examined the PCB congener profile in serum of humans exposed to PCBs by consumption of recreationally caught fish from Lake Michigan. The authors report that the congener profile accurately identified exposure to PCBs in individuals with lower and higher PCB levels and that this analytical approach is cost-effective without compromising scientific information.
Effects of Air Pollution on Czech Birth Weight
Bobak (p. 173) measured maternal exposures to sulfur dioxide, total suspended particles, and oxides of nitrogen during each trimester of pregnancy in the birth district of infants. There were approximately 108,173 births in the 67 districts where at least one pollutant was monitored in 1990-1991. Low birth weight and prematurity were associated with sulfur dioxide and total suspended particles. Low gestational age accounts for the association between pollutants and low birth weight.
Seasonality of Children's Lead Exposure
Yiin et al. (p. 177) examined seasonal changes in residential dust lead content and its relationship to blood lead in preschool children in New Jersey between 1992 and 1995. Blood lead in children was increased in the summer months because of increases in outdoor activity and increases in dust lead in the home.
Last Updated: February 1, 2000