Biomedical subjects

A B Dindal

Publications and source records attributed to A B Dindal.

5 recordsLinked to original sources

PubMed2001

Meeting data quality objectives with interval information.

Immunoassay test kits are promising technologies for measuring analytes under field conditions. Frequently, these field-test kits report the analyte concentrations as falling in an interval between minimum and maximum values. Many project managers use field-test kits only for screening purposes when characterizing waste sites because the results are presented as semiquantitative intervals. However, field-test kits that report results as intervals can also be used to make project-related decisions in compliance with false-rejection and false-acceptance decision error rates established during a quantitative data quality objective process. Sampling and analysis plans can be developed that rely on field-test kits to meet certain data needs of site remediation projects.

Data Collection↗

PubMed2000

Determination of cocaine and heroin vapor pressures using commercial and illicit samples.

The establishment of drug vapor pressure reference values provides valuable information in the development of vapor sensing devices for drug detection. The purpose of this work was to determine equilibrium headspace vapor pressures for commercial and illicit drug samples for use in such applications. Samples of cocaine, both free base and hydrochloride forms, and heroin hydrochloride were evaluated. The procedure used to measure the vapor pressures was a modification of a previously published method. Vapor pressure values at 20 degrees C previously reported for cocaine free base range from 0.37 x 10(-7) to 1.20 x 10(-7) Torr. The vapor pressure value determined in this study was 2.96 x 10(-7) Torr. It is likely that the discrepancies are due to differences in experimental conditions, varying sources of samples, and uncertainty in the methodologies. When the values were compared for commercial (99% purity) and illicit (unknown purity) sources of cocaine free base, there were no statistical differences in the projected room temperature (20 degrees C) vapor pressure values. However, the commercial and illicit samples of cocaine hydrochloride did show statistical differences. Although no comparison was made with the vapor pressure values for a pure, commercial sample, the vapor pressures of heroin hydrochloride (81% purity) at various temperatures were determined using the method developed for cocaine and are reported in this paper.

Cocaine-Related Disorders↗

PubMed1996

Determination of personal exposure of non-smokers to environmental tobacco smoke in the United States.

The potential health effects of exposure to environmental tobacco smoke (ETS) is a controversial subject, especially in the United States. Most studies on this subject have relied on reports of exposure from interviews or from questionnaires administered to the subjects. Other studies have derived data from actual measurements of markers of ETS in areas where tobacco products, especially cigarettes, are "being smoked" and the exposure of the subjects have been extrapolated from the values obtained. In this study, measurements of airborne ETS markers were made in approximately 1000 non-smokers in the US, who wore personal air sampling systems "at work" and "away from work". Participants in this study stated that they had not used tobacco products, nicotine patches, or nicotine gum for at least 6 months. It was found that the largest concentrations of ETS markers were encountered "away from work" and that, in general, the amount of ETS to which the subjects were exposed was markedly lower than those estimated in previous studies. Additionally, it appears that there is an important difference between the exposure to ETS perceived by participants and the actual exposures measured in this study.

Adult↗

PubMedDate not supplied

Determination of exposure to environmental tobacco smoke in restaurant and tavern workers in one US city.

Approximately 173 subjects employed as waiters, waitresses, or bartenders in the Knoxville, TN, Standard Metropolitan Statistical Area collected a sample of air from their breathing zone while at their workplace for one shift. In addition, area samples were placed near the work spaces of many of the subjects. Collected samples were analyzed for respirable suspended particulate matter (RSPM), ultraviolet-absorbing and fluorescing particulate matter, solanesol, 3-ethenyl pyridine (3-EP), and nicotine. Saliva samples were collected from the subjects prior to and within 24 h following their work shift, to confirm their non-smoking status. The range of concentrations of environmental tobacco smoke (ETS) constituents encountered was considerable, e.g., for nicotine, from undetectable to more than 100 microg/m3. However, the highest RSP levels observed were considerably lower than OSHA workplace standards. Distributions of ETS concentrations suggest that there are two "ETS exposure" types of bartenders: those that work in single room bars and those that work in larger, multiroom restaurant/bars. Personal exposure to ETS of the former group was ca. 10x greater than those of the latter group, who were exposed to ETS levels more comparable to those encountered by wait staff. Exposure (concentration x duration) differences between wait staff and workers in other types of unrestricted smoking environments reported in other studies suggest that exposures in the restaurant environment may be more difficult to assess than originally considered. Salivary cotinine levels indicated that for those subjects living in smoking homes, ETS exposures outside the workplace are at least as important as those in the workplace.

Adolescent↗

PubMedDate not supplied

Exposure to environmental tobacco smoke in sixteen cities in the United States as determined by personal breathing zone air sampling.

Approximately one hundred nonsmoking individuals in each of 16 metropolitan areas of the United States collected a sample of air from their breathing zone while in their workplace and a sample while away from work during their 24-hour days. Individuals were selected for the study in an attempt to equally represent those working and living in smoking and nonsmoking environments. Collected samples were analyzed for respirable particulate matter (RSP) (3.5 microns diameter), ultraviolet absorbing particulate matter, fluorescing particulate matter, solanesol, scopoletin, nicotine, 3-ethenyl pyridine, and myosmine. Individuals living and/or working in environments where smoking occurs were confirmed to be the most highly exposed to environmental tobacco smoke (ETS). Residential RSP levels ranged from 50 to 113% of those which have been reported by other investigators. For the majority of subjects who either lived or worked in smoking environments, the home was found to be the greater source of ETS exposure. Exposures of subjects whose spouses smoked unrestrictedly within the home were a factor of two to four higher than those of subjects who worked in locations where smoking occurred and was not restricted. Exposures of typical subjects to nicotine in the workplace were 30-60% of those estimated by the Occupational Safety and Health Administration (OSHA) and 15-20% of those estimated by the OSHA for the most highly exposed workers.

Adult↗