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Biomedical subjects

D Shusterman

Publications and source records attributed to D Shusterman.

At least 19 recordsLinked to original sources

Usefulness of computed tomographic scan in the evaluation of sensorineural hearing loss in children.

A retrospective chart study was conducted to determine the diagnostic yield of temporal bone imaging for children with sensorineural hearing loss of unknown cause. Seventy consecutive cases, spanning 4.5 years, were identified and individual computed tomography films reviewed. Cases were analyzed with respect to patients' age, duration of hearing loss, sudden onset vs progressive loss, unilateral vs bilateral, and other symptoms. Of the 70 computed tomographic scans, nine showed temporal bone or other intracranial abnormalities. The majority of these findings were localized to structures in the posterior and middle cranial fossae. No eight nerve tumors were identified. Congenital hearing loss and hearing loss secondary to viral infections are the most common cause of sensorineural hearing loss when discovered in early childhood and, often, have no radiographic abnormality. The decision to explore an ear for a presumed perilymph fistula is based almost exclusively on the history and physical examination, and not on the demonstration of any radiographic findings. For the children presenting with stable hearing impairment in the absence of other findings, computed tomographic scans were either negative or did not contribute to diagnosis. Since tumors of the eighth nerve are rare in children under 16 years of age (without neurofibromatosis), and radiologic studies have a low yield in identifying perilymph fistulas, the routine use of computed tomographic imaging in such children may be unjustified.

Adolescent

Exposure to organic solvents and adverse pregnancy outcome.

In a large case-control study (n = 1,926) of spontaneous abortion (SAB), exposure to solvents was ascertained by a telephone interview that asked about occupational use of 18 specific solvents or products, as well as an open-ended "other" solvent category. The adjusted odds ratio for use of any solvent was 1.1 (0.8, 1.5). Solvents for which at least a doubled crude risk of SAB was found included perchlorethylene (OR = 4.7, 95% CI = 1.1, 21.1), trichloroethylene (OR = 3.1, CI = 0.9, 10.4), and paint thinners (OR = 2.3, CI = 1.0, 5.1). Comparing exposure greater than 10 hours per week versus less did not show consistent dose-response effects. By solvent class, an association was seen with aliphatic solvents (adjusted OR = 1.8, 95% CI = 1.1, 3.0), but there was no dose-response effect by hours of use. Household use of solvent-containing products was generally not strongly associated with SAB, nor did it appear to confound the association seen with occupational use. From this and other studies, occupational exposure to at least some solvents appears associated with SAB. The associations of solvent exposure and fetal growth among liveborn offspring of controls was also examined.

Abortion, Spontaneous

Health effects of indoor odorants.

People assess the quality of the air indoors primarily on the basis of its odors and on their perception of associated health risk. The major current contributors to indoor odorants are human occupant odors (body odor), environmental tobacco smoke, volatile building materials, bio-odorants (particularly mold and animal-derived materials), air fresheners, deodorants, and perfumes. These are most often present as complex mixtures, making measurement of the total odorant problem difficult. There is no current method of measuring human body odor, other than by human panel studies of expert judges of air quality. Human body odors have been quantitated in terms of the "olf" which is the amount of air pollution produced by the average person. Another quantitative unit of odorants is the "decipol," which is the perceived level of pollution produced by the average human ventilated by 10 L/sec of unpolluted air or its equivalent level of dissatisfaction from nonhuman air pollutants. The standard regulatory approach, focusing on individual constituents or chemicals, is not likely to be successful in adequately controlling odorants in indoor air. Besides the current approach of setting minimum ventilation standards to prevent health effects due to indoor air pollution, a standard based on the olf or decipol unit might be more efficacious as well as simpler to measure.

Air Pollution, Indoor

Symptom prevalence and odor-worry interaction near hazardous waste sites.

Retrospective symptom prevalence data, collected from over 2000 adult respondents living near three different hazardous waste sites, were analyzed with respect to both self-reported "environmental worry" and frequency of perceiving environmental (particularly petrochemical) odors. Significant positive relationships were observed between the prevalence of several symptoms (headache, nausea, eye and throat irritation) and both frequency of odor perception and degree of worry. Headaches, for example, showed a prevalence odds ratio of 5.0 comparing respondents who reported noticing environmental odors frequently versus those noticing no such odors and 10.8 comparing those who described themselves as "very worried" versus "not worried" about environmental conditions in their neighborhood. Elimination of respondents who ascribed their environmental worry to illness in themselves or in family members did not materially affect the strength of the observed associations. In addition to their independent effects, odor perception and environmental worry exhibited positive interaction as determinants of symptom prevalence, as evidenced by a prevalence odds ratio of 38.1 comparing headaches among the high worry/frequent-odor group and the no-worry/no-odor group. In comparison neighborhoods with no nearby waste sites, environmental worry has been found to be associated with symptom occurrence as well. Potential explanations for these observations are presented, including the possibility that odors serve as a sensory cue for the manifestation of stress-related illness (or heightened awareness of underlying symptoms) among individuals concerned about the quality of their neighborhood environment.

Adult

Hypotheses to explain the higher symptom rates observed around hazardous waste sites.

Five studies were carried out around hazardous waste sites in California in which the main route of exposure was to low-level parts per billion concentrations of either gaseous emissions or airborne dust particles. Although there was no evidence suggesting excesses in cancer or birth defects, the total number and the prevalence of many of subjective symptoms were higher in areas near the site than in control neighborhoods. We discuss a number of causal processes that could explain these results. We conclude that a classical toxicological response and mass psychogenic illness are not valid explanations. Recall bias may explain part of the pattern. We present data from situations where stress alone from environmental anxiety has produced a similar magnitude of excess symptoms in populations. The fact that excess symptoms in waste site neighbors is found primarily in those who complain of odors or who are worried about environmental chemicals suggests the possibility that autonomic, stress-mediated mechanisms or behavioral sensitization are active in the genesis of these symptoms. A variety of confounders were controlled for. The hypothesis that chemically "acquired immune deficiency" can cause subtle symptomatology as a prodrome to subsequent serious disease has been raised in testimony at several toxic tort trials about waste sites. Although this hypothesis seems unlikely, particularly at sites such as the ones we studied with low airborne exposures, if true it would have profound regulatory implications.

Anxiety

Pregnancy outcomes in women potentially exposed to occupational solvents and women working in the electronics industry.

Associations of occupational solvent exposure and/or work in electronics production with adverse pregnancy outcomes were examined in a large cross-sectional community-based reproductive health study of 1038 California women pregnant between 1980 and 1985. Occupational solvent exposure was determined by two different methods: Bureau of Census codes judged by experts to probably include solvent exposure and self-reported exposure. First trimester solvent exposure classified by either method (n = 52) was significantly associated with spontaneous abortion, adjusted odds ratio 3.34 (95% confidence interval 1.42, 7.81). Among 29 women reporting regular and daily solvent exposure, the adjusted odds ratio increased to 4.44 (95% confidence interval 1.86, 10.58). Work in electronics assembly was significantly associated with delivering a low birth weight infant (adjusted odds ratio 5.38; 95% confidence interval 1.42, 20.46) but was not associated with spontaneous abortions. Further research using biologic monitoring and/or other objective measures of exposure is needed to validate these findings.

Abortion, Spontaneous

Pregnancy outcomes in women potentially exposed to solvent-contaminated drinking water in San Jose, California.

During 1980-1981, solvents leaked from an underground storage tank of a semiconductor firm in southern Santa Clara County, California, contaminating local drinking water. The contaminated well was closed in December 1981. An epidemiologic study conducted in 1983 confirmed statistically significant excesses of adverse pregnancy outcomes in an exposed community compared with an unexposed community, but could not establish a causal connection between the leak and the adverse outcomes. This study expanded the first study; adverse pregnancy outcomes occurring in 1980-1985 were studied in two communities exposed to the contaminated drinking water and in two demographically comparable but unexposed communities. The period 1980-1981 was the time period in which the well was considered to have been contaminated and 1982-1985 was considered the postcontamination time period. Both exposed and unexposed communities were considered unexposed during the latter period (1982-1985). Out of 10,055 households surveyed, interviews were conducted with 1,105 women who reported one or more eligible pregnancies. Miscarriages and birth defects were validated by medical record review or physician reports. Although the authors again observed statistically significant excesses of spontaneous abortions and birth defects in the originally studied exposed area in 1980-1981, they observed deficits of these outcomes in the second exposed study area. Adjustment for potential confounders did not alter these findings. Analyses of pregnancy outcomes during 1981 in relation to exposure estimates based on hydrogeologic modeling of water and contaminant distribution within the exposed areas also indicated that the leak was not likely to have caused the observed excesses of adverse pregnancy outcomes in the originally studied area.

Abnormalities, Drug-Induced

Methylene chloride intoxication in a furniture refinisher. A comparison of exposure estimates utilizing workplace air sampling and blood carboxyhemoglobin measurements.

A 35-year-old furniture refinisher came to the occupational medicine clinic with complaints of upper respiratory irritation, fatigue, and lightheadedness occurring on a daily basis after using a methylene chloride-containing paint stripper. Determinations of blood carboxyhemoglobin (COHb) on three occasions showed an apparently linear elevation of COHb as a function of hours worked on the day of sampling. COHb levels predicted from spot industrial hygiene measurements were in close concordance with those observed in the patient, indicating the potential usefulness of COHb monitoring in estimating airborne exposure levels. Methylene chloride (or dichloromethane) is an organic solvent that has found wide use as a degreaser, paint remover, aerosol propellant, and a blowing agent for polyurethane foams, and as a solvent in food processing, photographic film production, and plastics manufacturing. Discovery of its unusual metabolic fate--conversion to carbon monoxide in vivo--has earned the compound a special place in the solvent toxicology literature. Demonstration of oncogenicity in experimental animals has occasioned a reconsideration of exposure limits, with emphasis upon stricter controls. In some workplaces, conditions prevail in which controls are inadequate to prevent even acute toxicity, much less long-term exposure risks.

Adult

Prolonged fever associated with inhalation of multiple pyrolysis products.

A case of smoke inhalation with a self-limited but prolonged febrile course, including headaches and chills, is reported. A final diagnosis of polymer fume fever was made, although the duration of fever was longer than generally has been reported with this syndrome. Pyrolysis products involved included those of polyurethane, methylene chloride, and polytetrafluoroethylene ("Teflon"). The results of toxicological testing are reported and discussed.

Adult

Problem-solving techniques in occupational medicine.

The diagnosis of occupational illnesses may be considerably more difficult than is the case with occupational injuries because of a variety of factors: an intervening latency period, uncertainty in identifying the most significant chemical or physical exposures, determination of exposure levels retrospectively, and coordination of the physician with regulatory and workers' compensation bureaucracies. Such problem-solving techniques as retrospective industrial hygiene and attention to in-situ chemistry can act as means of reducing the uncertainty in making the diagnosis of occupational illness. Advance familiarity with workers' compensation and state or federal regulatory agencies can further facilitate diagnosis and patient advocacy.

Adult

Kinetics of bilirubin oxidation with peroxidase, as applied to studies of bilirubin-albumin binding.

In the determination of unbound bilirubin by rate of oxidation with peroxidase, errors may be caused by (1) phenol, propylparaben, and phenothiazines (free radical acceleration), (2) haemoglobin (peroxidase effect), and (3) ascorbate (inhibition). Such errors may be diminished by dilution 1:40, or with an anti-oxidant, tert-butyl-p-hydroxyanisole, and ascorbate oxidase.

Ascorbate Oxidase

Critical review: the health significance of environmental odor pollution.

Environmental odor pollution problems generate a significant fraction of the publicly initiated complaints received by air pollution control districts. Such complaints can trigger a variety of enforcement activities under existing state and local statutes. However, because of the frequently transient timing of exposures, odor sources often elude successful abatement. Furthermore, because of the predominantly subjective nature of associated health complaints, air pollution control authorities may predicate their enforcement activities upon a judgment of the public health impact of the odor source. Noxious environmental odors may trigger symptoms by a variety of physiologic mechanisms, including exacerbation of underlying medical conditions, innate odor aversions, aversive conditioning phenomena, stress-induced illness, and possible pheromonal reactions. Whereas relatively consistent patterns of subjective symptoms have been reported among individuals who live near environmental odor sources, documentation of objective correlates to such symptoms would require as-yet unproven research tools. Therefore, given our current state of knowledge, any differential regulatory response to environmental odor pollution, which is based upon the distinction between community "annoyance reactions" and "health effects," is a matter of legal--not scientific--interpretation.

Air Pollution