Women's Health Research
As part of its Under the Scope series, the NIEHS News (p. A18) looks at studies performed by Barbara J. Davis and colleagues at the NIEHS to determine causes and effects of ovarian toxicity.
Oldie Moldies
Mycotoxins--the toxic secondary metabolites of fungi, especially molds--have been acknowledged as a human health concern for thousands of years. The Focus (p. A20) describes the occurrence and effects of various mycotoxins and outlines efforts to control them.
Exposure Marks the Spot
Somewhere between epidemiology and environmental science lies the field of human exposure assessment, which seeks to explain how environmental exposures affect public health. The Spheres of Influence (p. A24) explores some of the pressing questions and concerns in this evolving field of study.
Better Asthma Meds
In research described in the Innovations (p. A28), scientists have begun coating glucocorticoids with nanometer-thin layers of a biodegradable polymer, possibly yielding improved versions of these widely used asthma drug formulations.
DDE Exposure and Cancer Mortality
Cocco et al. (p. 1) examined the role of DDE in cancer etiology by analyzing the association between 1975-1994 age-adjusted mortality rates for cancers and the 1968 adipose DDE levels of population samples from 22 states in the United States. Many results for cancers were negative, but the authors suggest that the association between liver cancer and DDE warrants further investigation.
High-Tech Identification of Agricultural Pesticide Exposure
The role agricultural pesticide exposure plays in cancer risk is difficult to assess. Ward et al. (p. 5) used satellite imagery data and historical farm records in a feasibility study for the investigation of any potential associations between non-Hodgkin lymphoma, pesticide use, and farmers' residences in Nebraska.
PCDDs and PCDFs in Food Products
Goldman et al. (p. 13) examined polychlorinated dibenzo-p-dioxins and dibenzofurans in residents who consumed contaminated chicken and beef products. Serum elevations of contaminants showed that tainted food was the source. Pentachlorophenol use and incineration were identified as sources of contaminants. The authors suggest that site-specific risk assessments should include estimates of exposure to contaminated food products.
Bisphenol A Released from Sealants
HPLC, gas chromatography, and mass spectrometry were used by Pulgar et al. (p. 21) to determine the effects of pH on leaching of dental composites and sealants made from bisphenol A diglycidylether methacrylate. The authors report that leaching of estrogenic monomers occurred in concentrations at which biologic effects have been demonstrated in in vivo experimental models.
Biologic Monitoring for Methylmercury
The neurotoxicity of methylmercury in the rat brain was investigated by Coccini et al. (p. 29). Prolonged low-level ingestion of methylmercury stimulated muscarinic cholinergic receptors in the hippocampus and cerebellum of the rat brain, which was preceded by measurable effects in splenic lymphocytes. These effects in peripheral lymphocytes may be predictive indicators of adaptive responses to brain toxicity.
Sources for Indoor Air Particle Pollution
Homes in Boston were monitored for air particles (PM0.02-10) by Abt et al. (p. 35) for one or two 6-day periods. Cooking, cleaning, and the movement of people were identified as the most important indoor particle sources in the homes. Increased air exchange rates > 1 exchange/hr reduced the impact of indoor particle sources.
Heavy Metals and Semen Quality in Males
Telisman et al. (p. 45) report highly significant correlations between lead and cadmium concentrations in blood and seminal fluid, as well as sperm abnormalities, in individuals with only moderate exposure. The authors show that blood lead and cadmium can significantly reduce human semen quality without causing demonstrable male reproductive endocrine dysfunction.
Cadmium and Stress Protein in Human Lung Cells
Cadmium induces development of emphysema and lung cancer and is an inducer of stress proteins. Croute et al. (p. 55) measured the hsp72 stress protein and metallothioneins as indicators of damaged protein and as biomarkers of cadmium exposure in vitro using the A549 pulmonary lung cell line. The authors postulate that cell adaptation occurs in vivo throughout chronic exposure to cadmium and that hsp induction fades out. The persistence of the expression of metallothioneins may provide a more reliable biomarker of cadmium exposure.
p53 Knockout Mouse as Cancer Model
A model for vascular tumor carcinogenesis by Carmichael et al. (p. 61) employed the heterozygous p53 knockout mouse. Mice were exposed to the vascular carcinogen urethane for 6 months; dose-related mortality and tumors occurred at doses of 10 and 100 mg/kg, whereas there was no toxicity or neoplasia at 1 mg/kg, indicating that it was a useful model for investigating vascular tumorigenesis.
Selenium and Thyrotoxicity in Children
Zagrodzki et al. (p. 67) investigated the interaction between selenium and iodine metabolism in Polish children living in areas with iodine deficiency and sulfur industries. The authors report that selenium deficiency was associated with higher levels of free thyroxine in plasma in female but not in male children.
Cancer and Passive Smoke Exposure in Children
Boffetta et al. (p. 73) conducted a meta-analysis of more than 30 studies of the association between parental tobacco smoke exposure and cancer in children. The authors report a weak risk factor between paternal tobacco smoke exposure and some cancers in children, but state that increased sample numbers were required before confirmation was possible.
Malformed Frogs Provide Environmental Sentinals
A multidisciplinary group of scientific experts convened to discuss possible causes and highlight recent findings related to frog deformities. In a Workshop Summary, Burkhart et al. (p. 83) provide insight for strategies to continue investigations at the federal and state level, and report that there is no indication whether a human health factor may be associated with the phenomenon.
Last Updated: January 4, 2000
