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T M Schnorr

Publications and source records attributed to T M Schnorr.

26 records · Page 2Linked to original sources
PubMed1991

Video display terminals and the risk of spontaneous abortion.

BACKGROUND: The relation between spontaneous abortion and the use of video display terminals (VDTs) is of great public health concern. Previous investigators of this issue have reported inconsistent findings. METHODS: To determine whether electromagnetic fields emitted by VDTs are associated with an increased risk of spontaneous abortion, a cohort of female telephone operators who used VDTs at work was compared with a cohort of operators who did not use VDTs. To obtain reliable estimates of exposure, we determined the number of hours of VDT use per week from company records and measured electromagnetic fields at VDT workstations and, for purposes of comparison, at workstations without VDTs. Operators who used VDTs had higher abdominal exposure to very-low-frequency (15 kHz) electromagnetic fields (workstations without VDTs did not emit very-low-frequency energy). Abdominal exposure to extremely-low-frequency fields (45 to 60 Hz) was similar for both operators who used VDTs and those who did not. Among 2430 women interviewed, there were 882 pregnancies that met our criteria for inclusion in the study. RESULTS: We found no excess risk of spontaneous abortion among women who used VDTs during the first trimester of pregnancy (odds ratio = 0.93; 95 percent confidence interval, 0.63 to 1.38), and no dose-response relation was apparent when we examined the women's hours of VDT use per week (odds ratio for 1 to 25 hours per week = 1.04; 95 percent confidence interval, 0.61 to 1.79; odds ratio for greater than 25 hours per week = 1.00; 95 percent confidence interval, 0.61 to 1.64). There continued to be no risk associated with the use of VDTs when we accounted for multiple pregnancies, conducted separate analyses of early abortion, late abortion, and all fetal losses, or limited our analyses to spontaneous abortions for which a physician was consulted. CONCLUSIONS: The use of VDTs and exposure to the accompanying electromagnetic fields were not associated with an increased risk of spontaneous abortion in this study.

Abortion, Spontaneous↗
PubMed1988

NIOSH selection of chemicals and study publications: setting priorities for reproductive research.

The National Institute for Occupational Safety and Health (NIOSH) prioritizes topics for reproductive research in order to allocate limited resources to the most important issues. In the past, we have relied on an informal network including our own project officers, toxicologists, and the public to nominate chemicals to study. Setting priorities has consisted of the evaluation of research ideas by criteria such as the chemical's probable toxicity and the extent of exposure to the chemical in the workplace. NIOSH researchers are developing a system for evaluating large databases of toxicologic and occupational exposure information to identify potential reproductive toxins. When this system is operational it will provide a systematic way to nominate chemicals for study.

Government Publications as Topic↗
PubMed1988

NIOSH epidemiologic studies of pregnancy outcomes.

The conduct of pregnancy outcome studies among occupationally exposed populations is a relatively new research area with many methodologic and pragmatic difficulties. This paper reviews the experience of conducting reproductive epidemiologic research at the National Institute for Occupational Safety and Health (NIOSH). The advantages and disadvantages of the three epidemiologic study types most often conducted at NIOSH are discussed: 1) surveillance studies, 2) descriptive studies, and 3) industrywide studies. Some of the problems inherent in the conduct of industrywide investigations are illustrated in a discussion of a reproductive outcome study of video display operators currently underway. These problems include sample size, referent availability, exposure and outcome validation, tracing, analytic methods, and cost.

Cluster Analysis↗
PubMed1985

Mortality among a cohort of U.S. cadmium production workers--an update.

A previous retrospective mortality study of 292 U.S. cadmium production workers employed for a minimum of 2 years showed increased mortality from respiratory and prostate cancer and from nonmalignant lung disease. To examine further the mortality experience of these workers, investigators from the National Institute for Occupational Safety and Health extended the study to include 602 white males with at least 6 months of production work in the same plant between 1940 and 1969. Vital status was determined through 1978, which included the addition of 5 years to the original follow-up. Cause-specific mortality rates for seven causes of death potentially related to cadmium exposure were compared between the overall cohort and U.S. white males and between subgroups. Mortality from respiratory cancer and from nonmalignant gastrointestinal disease was significantly greater among the cadmium workers than would have been expected from U.S. rates. All deaths from lung cancer occurred among workers employed for 2 or more years. A statistically significant dose-response relationship was observed between lung cancer mortality and cumulative exposure to cadmium. A 50% increase in lung cancer mortality, which was not statistically significant, was observed even among workers whose cumulative exposure to cadmium was between 41 and 200 micrograms/m3 over 40 years. Since the previous investigation, no new deaths from prostate cancer and no excess of deaths from nonmalignant respiratory disease have been observed.

Arsenic↗
PubMedDate not supplied

Prioritization of NTP reproductive toxicants for field studies.

Population studies that evaluate human reproductive impairment are time consuming, expensive, logistically difficult, and with limited resources must be prioritized to effectively prevent the adverse health effects in humans. Interactions among health scientists, unions, and industry can serve to identify populations exposed to potential hazards and develop strategies to evaluate and apply appropriate controls. This report describes a systematic method for prioritizing chemicals that may need human reproductive health field studies. Rodent reproductive toxicants identified from the National Toxicology Program (NTP) Reproductive Assessment by Continuous Breeding (RACB) protocol were prioritized on the basis of potency of toxic effect and population at risk. This model for prioritization links NTP findings with data from the National Occupational Exposure Survey (NOES) and the Hazardous Substance Data Base (HSDB) or the High Production Volume Chemical Database (HPVC) to prioritize chemicals for their potential impact on worker populations. The chemicals with the highest priority for field study were: dibutyl phthalate, boric acid, tricresyl phosphate, and N, N-dimethylformamide.

Animals↗