Classifying Carbon Disulfide
Carbon disulfide is a chemical commonly used in the production of rubber, rayon, and cellophane, and it's discharged into U.S. skies at the rate of approximately 76 million pounds per year. An award-winning series of studies led by a team of NIEHS scientists, described in the NIEHS News (p. A428), establishes the mechanism of neurotoxicity of this chemical.
Problems with Plant-Pesticides
The thought of eating food that has been genetically engineered to contain pesticides may seem, well, unsavory. Nevertheless, scientists are exploring the possibilities of using genetically introduced Bacillus thuringiensis to protect potato, corn, and cotton crops and, while questions remain, the results, described in the Focus article (p. A432), seem promising.
Thirsty Trees
Trichloroethylene, a probable human carcinogen, is showing up in unsafe amounts in over one-third of the U.S. cities that depend on groundwater for their municipal water supplies. But help may be on the way: the Innovations article (p. A438) describes a new environmentally friendly method for removing the toxin from soil and groundwater using hybrid poplar trees, which not only absorb the chemical through their roots, but fully metabolize it as well.
Residual Risk and the Clean Air Act
Charnley and Goldstein (p. 519) present a commentary on new pollution control technology requirements for industrial sources of air pollution. The authors describe the public health approach and how it applies to evaluating residual risks under the Clean Air Act mandated by Congress.
Environmental Risks for Breast Cancer
Breast cancer has become the most common cancer in women throughout the world. A commentary by Davis et al. (p. 523) reviews epidemiologic and toxicologic evidence on breast cancer risks and presents a comprehensive construct intended to focus on the identification of risk factors that can be controlled or modified.
Association between Fine Particulate Matter and Mortality
The association between air pollution and mortality was reviewed by Gamble (p. 535), who reports that the weight of the evidence suggests no substantive basis for a cause and effect relationship between long-term PM2.5 exposure and increased mortality.
Screening Chemicals for Endocrine Disruptors
A novel fluorescence polarization method to screen chemicals for endocrine disruptor activity was developed by Bolger et al. (p. 551) to measure the capacity of a chemical to displace a high affinity fluorescent ligand from human estrogen receptors. The estrogenicity data for 16 compounds shows concordance with that from traditional receptor binding assays while using a nonradioactive receptor binding principle.
Toxicity of Methylmercury in Seychelles Children
Axtell et al. (p. 559) examined children from the Seychelles Child Development Study and reported no demonstrable association between children's age at walking and talking and mothers who ate seafood contaminated with low levels of methylmercury.
Lead Dusts in Smelting Operations
Spear et al. (p. 565) examined lead dust components from different plant areas of an industrial lead smelter. The authors report that the mineralogy of the dusts changes in response to smelting operations, such that potential health hazards may be greater in blast and dross furnace areas because of the greater concentrations of exchangeable lead and finer particle size fractions.
Breath Analysis of Trichloroethene in Humans
Human subjects exposed 4 hours to trichlorethylene were sampled for blood and breath measurements to develop a noninvasive method for measuring human exposure to volatile organic compounds. Pleil et al. (p. 573) report that blood levels for trichlorethylene can be accurately predicted from breath measurements.
Estrogenicity of Plant Hormones
A rat endometrial adenocarcinoma cell model was developed by Hopert et al. (p. 581) to investigate the molecular mechanism of action of phytoestrogens. The authors report an increase of complement C3 mediated by increases in steady state mRNA levels, indicating the utility of the model for elucidating the potency and functionality of environmental phytoestrogens.
Metallothionein Induction in Human Kidney Cells
In a study utilizing human proximal tubule cells, Garret et al. (p. 587) report that MT-2A mRNA, a product of an isoform of the human metallothionein gene family, was not induced by exposure to certain metals, as occurs in animal models. The data provide initial evidence that gene regulation underlying metallothionein protein expression may be divergent between species.
Carbon Tetrachloride and Rat Liver Toxicity
Dalu et al. (p. 597) examined the hepatotoxicity of carbon tetrachloride in rats and report that toxicant-stimulated cell division and tissue repair mechanisms play a critical role in the resiliency of rats during early postnatal development, suggesting a need for considering age factors in risk assessment for such environmental chemicals.
Asthma and Climate in New Zealand
In a study of the relationship between climate and asthma prevalence in New Zealand, Hales et al. (p. 607) sampled 31,470 people 20-44 years of age in a one-page questionnaire, with an overall response of 82%. The authors report that on day-to-day time scales, low temperatures may directly result in acute exacerbations of asthma symptoms, while warmer average temperatures are associated with increased asthma prevalence.
Mortality from Chronic Carbon Disulfide Exposure
A Grand Rounds article by Frumkin (p. 611) reports on central nervous system toxicity exhibited in a patient that had been exposed to carbon disulfide in a viscose rayon manufacturing plant for over 30 years. Progressive deterioration resulted in severe ataxia when clinical diagnosis of olivopontocerebellar atrophy was confirmed by CT and MRI scans; death occurred about 9 years later from multiple medical complications.
Last Updated: August 19, 1998
