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Biomedical subjects

D Shusterman

Publications and source records attributed to D Shusterman.

At least 19 recordsLinked to original sources

Medical causation analysis heuristics.

Medical causation analysis determines whether or not a specific patient's illness is the result of a work site or an environmental exposure. In the past, this has been conducted implicitly with little analysis of the process per se. Our review suggests that there are several distinct heuristics that may be utilized; these include probability-based models, application of group-based data (epidemiology) to individuals, Bayesian analysis, a priori assumptions about which conclusions are better, and others. Some methods consider only work causes, whereas others explicitly consider alternative explanations. There are considerable differences among the methods in process, outcome, and fundamental assumptions. Formal assessment of the medical causation analysis process can provide insight and may ultimately lead to its standardization and improvement.

Causality

Predictors of carbon monoxide and hydrogen cyanide exposure in smoke inhalation patients.

OBJECTIVE: A prospective study of civilian (nonfirefighter) smoke inhalation patients was carried out to test the hypotheses that: 1) absorption of carbon monoxide and hydrogen cyanide from smoke can be predicted by clinical examination and historical data; and, more specifically 2) a history of exposure to burning synthetic polymers is an important predictor of systemic cyanide levels. METHODS: The study was conducted over a three-year period at six urban hospitals. Patients with or without burns who were exposed to smoke within five hours of hospital arrival were sampled for carboxyhemoglobin, whole blood cyanide, urine cotinine and urine creatinine. Controls consisted of a smaller group of smoking status-matched, nonsmoke-exposed burn patients. ANALYSIS: Historical information was obtained on SMOKING status, FIRETYPE (structural vs other), MATERIAL burned (natural vs synthetic) and LAGTIME (from exposure to sampling). A smoke inhalation SCORE (0-10) was assigned to each case, based on physical examination findings and changes on chest X ray, and carboxyhemoglobin and cyanide levels were entered into various multivariate linear regression models. RESULTS: A total of 40 cases and 9 controls were recruited, ranging in age from 15 to 92 years. Thirty-four cases were discharged alive and six expired in-hospital. Observed carboxyhemoglobin levels ranged from 1.2% to 41.6% in cases (mean 8.6%), and from 0.5 to 7.3% in controls (mean 2.9%). Observed cyanide levels ranged from nondetectable (< 0.05 micrograms/mL) to 2.79 micrograms/mL in cases (mean 0.25 micrograms/mL), and from nondetectable to 0.11 micrograms/mL in controls (mean 0.03 micrograms/mL). Among cases, linear regression models explained up to 35% of the observed variance in carboxyhemoglobin levels (p < 0.001) and up to 48% of the variance in cyanide levels (p = 0.0001). CONCLUSIONS: SCORE was the strongest predictor of both carboxyhemoglobin and cyanide levels; LAGTIME also explained significant variance for [log-transformed] carboxyhemoglobin. Historical factors, such as FIRETYPE, MATERIAL, and SMOKING status, did not explain significant variance in most of the statistical models employed.

Adolescent

Latex allergy.

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Dermatitis, Allergic Contact

Persistent respiratory health effects after a metam sodium pesticide spill.

STUDY OBJECTIVE: To report the occurrence of persistent respiratory disorders, including irritant-induced asthma, among adults living and working near an environmental spill of the pesticide, metam sodium, after the derailment of a tank car. DESIGN: Retrospective clinical case series. SETTING: California communities situated within one-half mile of the Sacramento River, from Mt. Shasta City to Shasta Lake. PATIENTS: 197 adults referred to a university occupational/environmental health clinic or to a private occupational/environmental health practitioner for evaluation of health problems potentially related to the spill. MEASUREMENTS AND RESULTS: History, physical examination, review of medical records, spirometry, and methacholine challenge testing revealed 20 cases of persistent irritant-induced asthma and 10 cases of persistent exacerbation of asthma. CONCLUSIONS: This is the first reported series of cases of persistent irritant-induced asthma involving both community residents and occupationally exposed individuals.

Adult

The respiratory health impact of a large urban fire.

OBJECTIVES: In July 1988, a fire destroyed a huge supermarket warehouse in Richmond, Calif, sending smoke into residential neighborhoods for nearly a week. There was no organized public health response. To evaluate the respiratory health impact on the general population, a survey of emergency room visits and hospital admissions to the two acute-care hospitals serving the population downwind was conducted. METHODS: Medical records of 489 patients meeting specified diagnostic criteria during the week of the fire and several reference periods were abstracted. Ratios of proportions for respiratory diagnoses (i.e., emergency room visits for a given diagnosis/total emergency room visits) were calculated, comparing the fire week with the reference periods, and 1988 mortality data for the area were reviewed. RESULTS: Ratios of proportions for emergency room visits for asthma and all lower respiratory conditions increased significantly during the fire. Respiratory-related hospitalizations also increased. However, there was no observable increase in respiratory mortality. CONCLUSIONS: This fire was found to have had a moderate impact on the respiratory health of local residents. Public health intervention is indicated to prevent respiratory morbidity when extended exposure to structural fire smoke is predictable.

Asthma

Immediate health effects of an urban wildfire.

To document the immediate health effects of the urban wildfire that swept through parts of Alameda County, California, on October 20 and 21, 1991, we conducted a retrospective review of emergency department and coroner's records. Nine hospitals (6 local and 3 outlying) were surveyed for the week beginning October 20, 1991. Coroner's reports were reviewed for 25 identified fire-related deaths. A total of 241 fire-related emergency encounters, including 44 inpatient admissions, were recorded for 227 persons. Nearly a fourth of emergency department patients were seen for work-related injuries, more than half of which occurred among professional firefighters. Smoke-related disorders constituted more than half of all emergency department cases; of these, 61% had documented bronchospasm. Major trauma and burns contributed 1% and 4% of principal diagnoses, respectively; these were exceeded in number by corneal abrasions (13%), other medical problems (8%), and minor trauma (7%), among other diagnoses. All coroner's cases involved extensive burns, many with documented smoke inhalation injury. While the Oakland-Berkeley fire storm resulted in a high case-fatality ratio among major burn cases (25/31), those who survived the initial fire storm did well clinically. Among emergency department patients, medical (particularly smoke-related) disorders outnumbered traumatic presentations by a ratio of more than 2 to 1.

Adolescent

Employment in electronics manufacturing and risk of spontaneous abortion.

A large case-control study of environmental risk factors for spontaneous abortion was conducted among women living in Santa Clara County, California. Because of the prevalence of electronics production work within this population, a specialized questionnaire was administered to women who self-identified as electronics production workers. Spontaneous abortions were identified from pathology records, and controls were identified from birth certificates. The odds ratio for spontaneous abortion and any electronics production work was 0.94 (95% confidence interval = 0.58, 1.5). Odds ratios for the three main branches of electronics production (semiconductor fabrication, printed circuit board manufacturing, and assembly) were likewise near or below unity. Specific production activities with elevated odds ratios included semiconductor diffusion, parts encapsulation, soldering, and flux removal, although the numbers were small and none of the confidence intervals excluded unity. Limitations of this study included modest statistical power and a potential for nondifferential misclassification of exposures, both of which could bias findings toward the null.

Abortion, Spontaneous

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