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Biomedical subjects

E L Baker

Publications and source records attributed to E L Baker.

At least 19 recordsLinked to original sources

Lead exposure from conventional and cottage lead smelting in Jamaica.

A survey was conducted to determine the distribution and determinants of environmental and blood lead levels near a conventional and several cottage lead smelters and to assess the relationship between environmental and blood lead levels in a tropical, developing-country setting. Fifty-eight households were studied in the Red Pond community, the site of the established smelter and several backyard smelters, and 21 households were studied in the adjacent, upwind Ebony Vale community in Saint Catherine Parish, Jamaica. Households were investigated, using questionnaires, soil and housedust lead measurements, and blood lead (PbB) measurements from 372 residents. Soil lead levels in Red Pond exceeded 500 parts per million (ppm) at 24% of households (maximum--18,600 ppm), compared to 0% in Ebony Vale (maximum 150 ppm). Geometric mean PbB in Red Pond, where 44% of children less than 6 years of age had PbB levels greater than or equal to 25 micrograms per deciliter (micrograms/dL), was more than twice that Ebony Vale in all age groups (p less than 0.0005). Within Red Pond, proximity to backyard smelters and to the conventional smelter were independent predictors of soil lead (p less than 0.05). Soil lead was the strongest predictor of PbB among Red Pond subjects under 12 years of age. The blood lead--soil lead relationship in children differed from that reported in developed countries; blood lead levels were higher than expected for the household-specific soil lead levels that were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Child

Environmentally related disorders of the nervous system.

Specific physical and chemical agents found in the workplace and in the general environment are responsible for characteristic pathologic processes within the nervous system. It has been shown that many neurotoxic agents produce a dose-related spectrum of impairment ranging from mild slowing of nerve conducting velocity or prolongation in reaction time to neuropathy and frank encephalopathy. Clinical manifestations are determined by the agent involved, by the dose of exposure, the vulnerability of the cellular target, the ability of the organism to metabolize and excrete the agent, and the ability to repair damage. An occupational history, including evaluation of evidence of specific agents and job history, is a critical component in the clinical management of individuals with suspect neurotoxic disease. Environmentally-induced disorders can be prevented by appropriate environmental controls. Prevention of neurotoxic disease is a complex process requiring continuous involvement of public health agencies and strong scientific research.

Central Nervous System Diseases

Some conditions of compliance and resistance among hypnotic subjects.

Five experimental approaches to the resolution of the century-old Bernheim/Janet dispute and the issue of involuntariness or coercion (the classical suggestion effect) are presented. Four experiments are reported that follow one of the approaches: attempts to induce hypnotic subjects to resist suggestions made in trance. The design is one in which a "resistance instructor" proposes a reward for the resisting subject. Tentative inferences from the results are that the classical suggestion effect is found with a small number of subjects; for a larger number of subjects there is no classical suggestion effect, and for many subjects the outcome is equivocal. Relational factors in the hypnotic dyad influence responsiveness in the subject, the effect being least for those whose susceptibility is high.

Adult

Attitudes and practices regarding clinical hypnosis with psychotic patients--a survey: a brief communication.

Attitudes toward and actual use of hypnotherapeutic techniques with psychotic patients were assessed. Results are discussed in light of historical and current attitudes toward the use of hypnosis with psychotics. Respondents were selected from the 1980 membership directory of the Society for Clinical and Experimental Hypnosis (SCEH). 80 respondents completed and returned the survey. Results indicate that the perceived usefulness of hypnosis with psychotics is currently quite high and negative attitudes toward its use quite low. The growth of the use of hypnotherapeutic techniques and the need for further research are discussed.

Adult

Role of medical screening in the prevention of occupational disease.

Some occupational medical screening programs are designed to detect adverse health effects of workplace hazards and to complement environmental control programs. Often, programs are developed using the approach of clinical practice, and procedures are not adequately standardized. The logic that guides this decision making is not well developed, thus limiting the ability of occupational health practitioners to make defensible decisions regarding the management of individual workers at risk. Although the programs are, in theory, constructed to benefit the worker, little thought has been given to standardization of data collection and to using the medical information that is obtained. Currently, the National Institute for Occupational Safety and Health (NIOSH) is developing recommendations to present to the Occupational Safety and Health Administration to be used in the development of a "generic approach" to screening. These recommendations will include guidelines for threshold exposure levels for screening, rosters of screenable health effects to be targeted, algorithms linking exposure and effects, criteria for test result evaluation, plans for courses of action after testing, and procedures to ensure confidentiality. NIOSH's comprehensive approach to developing occupational screening programs should benefit employees, employers, the scientific community, and the community at large.

Humans

Lead-induced anemia: dose-response relationships and evidence for a threshold.

We conducted a cross-sectional epidemiologic study to assess the association between blood lead level and hematocrit in 579 one to five year-old children living near a primary lead smelter in 1974. Blood lead levels ranged from 0.53 to 7.91 mumol/L (11 to 164 micrograms/dl). To predict hematocrit as a function of blood lead level and age, we derived non-linear regression models and fit percentile curves. We used logistic regression to predict the probability of hematocrit values less than 35 per cent. We found a strong non-linear, dose-response relationship between blood lead level and hematocrit. This relationship was influenced by age, but (in this age group) not by sex; the effect was strongest in youngest children. In one year-olds, the age group most severely affected, the risk of an hematocrit value below 35 percent was 2 percent above background at blood lead levels between 0.97 and 1.88 mumol/L (20 and 39 micrograms/dl), 18 percent above background at lead levels of 1.93 to 2.85 mumol/L (40 to 59 micrograms/dl), and 40 percent above background at lead levels of 2.9 mumol/L (60 micrograms/dl) and greater; background was defined as a blood lead level below 1.88 mumol/L (20 micrograms/dl). This effect appeared independent of iron deficiency. These findings suggest that blood lead levels close to the currently recommended limit value of 1.21 mumol/L (25 micrograms/dl) are associated with dose-related depression of hematocrit in young children.

Air Pollutants, Occupational

Visceral and nodal calcification in patients with AIDS-related Pneumocystis carinii infection.

Clinical and radiologic findings in nine patients with AIDS and disseminated Pneumocystis carinii infection were analyzed retrospectively. The diagnosis was confirmed by autopsy (five patients) and by biopsy (two patients). All nine had a history of P. carinii pneumonia. CT showed parenchymal calcifications in the spleen (seven patients), liver (six patients), kidneys (six patients), abdominal lymph nodes (three patients), adrenal glands (two patients), and mediastinal lymph nodes (one patient). Multiple punctate calcifications in the liver, spleen, kidneys, and/or adrenal glands were visible on plain films in three patients. Sonography showed diffuse tiny echogenic foci without shadowing in the liver, spleen, and kidneys. In one patient, CT showed multiple hypodense lesions in the spleen. P. carinii infection should be included in the differential diagnosis when calcifications or focal lesions are detected at one or more extrapulmonary sites in an immunodeficient patient, even if there is no history or evidence of P. carinii pneumonia.

Acquired Immunodeficiency Syndrome

Lead exposure among lead-acid battery workers in Jamaica.

To assess lead exposure in the Jamaican lead-acid battery industry, we surveyed three battery manufacturers (including 46 production workers) and 10 battery repair shops (including 23 battery repair workers). Engineering controls and respiratory protection were judged to be inadequate at battery manufacturers and battery repair shops. At manufacturers, 38 of 42 air samples for lead exceeded a work-shift time-weighted average concentration of 0.050 mg/m3 (range 0.030-5.3 mg/m3), and nine samples exceeded 0.50 mg/m3. Only one of seven air samples at repair shops exceeded 0.050 mg/m3 (range 0.003-0.066 mg/m3). Repair shop workers, however, had higher blood lead levels than manufacturing workers (65% vs. 28% with blood lead levels above 60 micrograms/dl, respectively). Manufacturing workers had a higher prevalence of safe hygienic practices and a recent interval of minimal production had occurred at one of the battery manufacturers. Workers with blood lead levels above 60 micrograms/dl tended to have higher prevalences of most symptoms of lead toxicity than did workers with lower blood lead levels, but this finding was not consistent or statistically significant. The relationship between zinc protoporphyrin concentrations and increasing blood lead concentrations was consistent with that described among workers in developed countries. The high risk of lead toxicity among Jamaican battery workers is consistent with studies of battery workers in other developing countries.

Adult

Sister chromatid exchange in painters recently exposed to solvents.

Epidemiologic studies have suggested that exposure to solvent-based materials in the painting trades is associated with an increased cancer risk. In order to determine if the solvent exposures of current union members of the International Brotherhood of Painters and Allied Tradesman (IBPAT) are associated with a genotoxic risk, we have measured the sister chromatid exchange (SCE) frequency in their peripheral blood lymphocytes. Previous reports have shown that chronic solvent exposure of these workers does not elevate SCE frequencies. We now report that acute exposure, estimated by the number of days worked over the month prior to venipuncture, is associated with elevated SCE levels in currently smoking workers. No elevation in SCE was associated with similar recent exposure in nonsmoking, solvent-exposed painters.

Adult

The hypnotic relationship: an investigation of compliance and resistance.

The purpose of this investigation was to assess the ability of hypnotic Ss to voluntarily resist a neutral suggestion when a monetary reward is offered for resistance. 19 of 40 Ss (47.5%) successfully resisted after money was offered by the "resistance instructor." The correlation between resistance/compliance and hypnotizability was -.44 (high hypnotizables were more likely to comply). Ss' impressions of the hypnotist tended to be positive; impressions of the resistance instructor tended to be neutral. There was a tendency for nonresistors to have a more positive view of the hypnotist but it is not as marked as was found in an earlier study (Levitt & Baker, 1983).

Adult

Lead poisoning among household members exposed to lead-acid battery repair shops in Kingston, Jamaica.

To investigate the risk of lead poisoning among household members exposed to 'backyard' battery repair shops (BBRS) in Kingston, Jamaica, environmental and blood lead (PbB) were measured at 24 households (112 individuals) with a BBRS worker or located at a BBRS premises and at 18 neighbourhood control households (74 individuals). Elevated PbB (greater than or equal to 25 micrograms per decilitre [micrograms/dl]) was common among subjects of all ages living at BBRS premises, especially among children less than age 12, 43% of whom had PbB greater than 70 micrograms/dl. Potentially hazardous soil and house dust lead levels were also common at BBRS premises, where 84% of yards had soil lead levels above 500 parts per million (geometric mean 3388 parts per million [ppm] at BBRS premises households with a BBRS worker). Geometric mean blood and environmental lead levels were significantly lower at control households, where less than 10% of subjects in all age groups had elevated PbB (maximum 33 micrograms/dl). Sharing a premises with a BBRS was a stronger determinant of household blood lead and environmental contamination than was the presence of a BBRS worker in a household. Blood lead levels were associated with soil and house dust lead levels in all age groups. We conclude that small battery repair shops, which have also been described in other developing countries, create a high lead poisoning risk for nearby residents.

Adolescent

Sentinel Event Notification System for Occupational Risks (SENSOR): the concept.

Although many states have laws that require health providers to report cases of occupational illness and injury, most states do not maintain a comprehensive system that actively identifies and targets potential sources of case reports and then responds to such reports. NIOSH has developed a Sentinel Event Notification System for Occupational Risks (SENSOR) that uses targeted sources of sentinel providers to recognize and report selected occupational disorders to a state surveillance center. SENSOR is a cooperative state-federal effort designed to develop local capability for preventing selected occupational disorders. To demonstrate the feasibility of this approach, NIOSH initially funded seven SENSOR projects in 1987 and three additional projects in early 1988 (Table 1). Currently, these projects are in the preliminary stages of organization and start-up, with some having begun to receive case reports. As funds become available, NIOSH intends to gradually expand the scope of the program to include additional states over the next several years.

Humans

The selection and definition of targeted work-related conditions for surveillance under SENSOR.

Lists of reportable conditions and case definitions are important tools for epidemiologic surveillance. As part of an initiative to encourage occupational disease surveillance systems linked to intervention at the state level, we have proposed a list of target conditions and are developing a set of standard epidemiologic case definitions. Experience gained from state health department pilot projects using SENSOR and other surveillance approaches will be used to promote effective condition-specific surveillance strategies on a wider scale.

Carpal Tunnel Syndrome