Environmental Signals
Populations of wildlife species exhibit anomalies in development, behavior, and reproduction shown to be caused by endocrine-disrupting chemicals in the environment.
LeBlanc
comments that scientists, regulators and legislators alike must not relax environmental regulations and should continue to catalogue cases of ecotoxicity, lest potential threats to human health signaled by indicator species be overlooked.
Cleaning up Down Under
Because of their small population and geographic isolation, Australia and New Zealand have so far been spared many of the environmental health problems that plague other industrialized countries. However, these two nations recognize that problems such as ozone depletion, toxic waste disposal, and declining air and water quality are beginning to affect the environment, and they are working to halt the degradation and reverse the effects on human health. The first Focus article discusses the emerging environmental health problems in these countries and the programs they are implementing to ensure "a cleaner Australia" and a "clean and green" New Zealand.
Canada Comes Clean
The second largest nation in the world, Canada has also been home to some very large environmental health problems, particularly those associated with chemical exposures to wildlife and humans from paper manufacturing, hydroelectric plants, and fossil fuel combustion. In recent years, however, Canadians have mounted a number of campaigns to clean up polluted air, water, and soil, and have succeeded in drastically reducing exposures to some chemicals. Programs such as Great Lakes 2000, Lawrence Vision 2000, and the recently enacted Toxic Substances Management Plan, discussed in the second Focus article, will provide a plan of action for protecting Canada's environment and health into the next century.
Pulling Answers out of Thin Air
Traditional air sampling by chemical and other manufacturers using hand-held "sniffers" provides only snapshot data on the type and amount of pollutants in the air. A new system, described in
Innovations, uses a technique called Remote Sensing Computed Tomography (RSCT) to give industrial hygienists the bigger picture. RSCT, developed by a team at the University of North Carolina at Chapel Hill led by Lori Todd, provides real-time measurements of multiple chemicals over large distances. The team hopes the more sophisticated technology will eventually help manufacturers ensure compliance with environmental health regulations and make better decisions regarding the safety of their employees.
Exposure to Nuclear Fuels
Lang et al. reviews the toxicological effects of insoluble nuclear fuel compounds released into the environment by nuclear power plants, nuclear weapons tests, or nuclear accidents. The dosimetry, biological effects, and biokinetic properties of insoluble nuclear fuel compounds are discussed in relation to the various toxic reponses exhibited in the gastrointestinal tracts, lungs, and skin of animal models and in humans exposed during the Chernobyl accident.
Chernobyl Radiation Affects Israeli Immigrants
About 1500 Russian immigrants to Israel were divided into groups based on levels of exposure to radiation from the Chernobyl nuclear power plant explosion. Kordysh et al. used questionnaires and physical examinations to document acute radiation exposure. They found that bronchial asthma and health complaints from children and hypertension in adults were among the nonmalignant effects from prolonged radiation exposure. These toxic responses were associated with the extent of radiation encountered by individuals as measured by body burdens of radioactive cesium-137.
Use of Transgenic Mice to Identify Carcinogens and Risk
Tennant et al. used two transgenic mouse lines to accelerate testing of chemicals, prioritize chemicals for standard 2-year carcinogen tests, and to examine low-level dose responses for improved estimation of risk assessment. The p53+/- transgenic mouse and the TG.AC transgenic mouse carrying a v-Ha-ras
construct were used in 20-week dosed-feed or skin paint assays, and results were compared with those from 2-year assays. The authors report a high degree of concordance between the short-term and long-term assays and suggest that that transgenic assays could be used to improve the extrapolation of data from rodents to humans.
Lead Affects Children's Growth
Kim et al. report on a cohort of children exposed to lead that was examined at about 7 years of age for tooth lead and was reexamined at about 20 years of age for weight, height, and bone lead. The study revealed a positive association between childhood tooth lead and body mass index in cross-sectional and longitudinal analyses: tooth lead in 7 year old children compared to original body mass index or compared to change in body mass index between 7 and 20 years old. The data suggested that chronic lead exposure in childhood may result in obesity that persists into adulthood.
Last update: October 26, 1995
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