Biomedical subjects

M E Baser

Publications and source records attributed to M E Baser.

12 recordsLinked to original sources

PubMed1992

The development of registries for surveillance of adult lead exposure, 1981 to 1992.

OBJECTIVES: Since 1981, 15 states have established registries for surveillance of adult lead absorption, primarily based on reports of elevated blood lead levels from clinical laboratories. I review the status of the registries and recommend steps for further development. METHODS: Companies reported to the New York registry are compared with those cited by the Occupational Safety and Health Administration (OSHA). I present data on US workers and plants with potential lead exposures and blood tests, as well as review registries' reporting requirements. RESULTS: Registries identify many companies not cited by the Occupational Safety and Health Administration, but underreporting occurs because (1) reporting is usually not required from laboratories outside the state, (2) most registries use a blood lead reporting level of 1.21 mumol/L, which excludes many exposed workers, and (3) many companies with potential exposures do not have routine monitoring programs. CONCLUSIONS: Registries' reporting requirements and procedures should be standardized, including a blood lead reporting level of 0.72 mumol/L. Elevated blood lead levels should be a reportable condition nationwide, and a comprehensive national surveillance system should be established: clinical laboratories should be required to report cases to those states with lead registries or directly to the national adult lead registry.

Adult↗

PubMed1991

Pulmonary function and respiratory symptoms in wildland firefighters.

We studied cross-seasonal changes in pulmonary function and respiratory symptoms in 52 wildland firefighters in Northern California. The mean cross-seasonal change in forced expiratory volume in 1 second (FEV1) was -1.2% (95% confidence interval [CI] -0.5%, -2.0%) with a corresponding mean change in forced expiratory volume (FVC) of -0.3% (95% CI 0.4%, -1.0%). Decreases in FEV1 and FVC were most strongly associated with hours of recent fire-fighting activity (P = .002 and .01, respectively). When the study group was divided into three categories based on recent fire-fighting activity, firefighters in the high activity category (mean +/- SE, 73 +/- 7 hours of fire-fighting in previous week) had a -2.9% (130 mL) change in FEV1 and a -1.9% (102 mL) change in forced vital capacity (FVC). There was a significant cross-seasonal increase in most respiratory symptoms evaluated. Several symptoms (eye irritation, nose irritation, and wheezing) were associated with recent fire-fighting. These findings suggest that wildland firefighters experience a small cross-seasonal decline in pulmonary function and an increase in several respiratory symptoms. Research is under way to identify the fire conditions and specific components of exposure that produce pulmonary irritants, and to examine the potential reversibility of acute pulmonary change.

Adolescent↗

PubMed1990

Hydroxyl radical generating activity of hydrous but not calcined kaolin is prevented by surface modification with dipalmitoyl lecithin.

The catalytic activity of kaolin, an aluminum silicate, for generating hydroxyl radicals (.OH) from hydrogen peroxide (H2O2) was studied in a chemical system that measured .OH as evolution of methane (CH4) from dimethyl sulfoxide. In the presence of a reducing agent and 10 mM H2O2, hydrous and calcined kaolin generated mean +/- SE CH4 concentrations of 1634 +/- 328 and 1395 +/- 29 ppm, respectively. Surface modification with dipalmitoyl lecithin, the lipid of pulmonary surfactant, blocked generation of .OH in hydrous kaolin (38 +/- 38 ppm CH4) but not in calcined kaolin (875 +/- 262 ppm CH4). The catalytic activity of kaolin for producing .OH from H2O2 may be important in the pathogenesis of kaolin toxicity, and calcined kaolin may be more toxic than hydrous kaolin because the calcined form is resistant to surface modification by lipids of pulmonary surfactant.

Humans↗

PubMed1990

Formation of polycyclic aromatic hydrocarbon-DNA adducts in peripheral white blood cells during consumption of charcoal-broiled beef.

The effect of ingesting charcoal-broiled (CB) beef on polycyclic aromatic hydrocarbon (PAH)-DNA adduct levels in nucleated peripheral white blood cells (WBCs) was examined in four healthy, non-smoking males who consumed an average of 280 g CB beef daily for 7 days. PAH-DNA adducts were quantitated by enzyme-linked immunosorbent assay. During the week of CB beef consumption, two individuals exhibited a 3- to 6-fold increase in PAH-DNA adducts above baseline levels observed during the month prior to CB beef consumption. In contrast, PAH-DNA adduct levels in the two other subjects did not increase. Thus, dietary sources of PAH can contribute to the PAH-DNA adduct load in peripheral WBCs in some individuals.

Adult↗

PubMed1990

A statewide case registry for surveillance of occupational heavy metals absorption.

The New York State Heavy Metals Registry is a legislatively mandated program through which clinical laboratories, physicians, and health facilities report state residents 18 years of age and older with elevated levels of lead, mercury, arsenic, or cadmium in blood or urine. From 1982-86, the current employer was determined for 95.9 percent of 3,309 cases. Occupational exposures in 328 companies accounted for 82.8 percent of cases. The majority of companies were reported for lead (247 companies, 75.3 percent of total) or mercury (47 companies, 14.3 percent of total). Of the 247 companies reported to the Registry for lead, the Occupational Safety and Health Administration (OSHA) inspected 18 of 98 companies (18.4 percent) in the manufacturing sector, but only one of 149 companies (0.6 percent) outside the manufacturing sector. We conclude that the Registry effectively detects companies with heavy metals exposures, and is an especially useful adjunct to OSHA inspections outside the manufacturing sector.

Adolescent↗

PubMed1989

Differences in lung function and prevalence of pneumoconiosis between two kaolin plants.

To investigate the origin of differences in previously published pulmonary function studies of workers in kaolin plants in Georgia, spirometric and radiographic data collected in a cross sectional survey of two large plants were analysed. As compared with workers in plant 2, workers in plant 1 had a 2.7-fold greater prevalence of pneumoconiosis and a mean 0.361 decrement in adjusted forced vital capacity. Our previous finding that exposure to kaolin was not associated with a decrement in lung function may have resulted from failure to consider differences between the plants.

Adolescent↗

PubMed1988

Eosinophilia, respiratory symptoms and pulmonary infiltrates in rubber workers.

This report describes a spectrum of respiratory illnesses associated with eosinophilia which occurred in a group of workers exposed to fumes from a synthetic rubber-based curing operation. Respiratory syndromes induced by this exposure included an acute sensitizing illness with dyspnea and wheezing in some workers and pulmonary infiltrates with eosinophilia in others. Another worker developed chronic obstruction of the airways with recurrent bronchitic illnesses. Mild to marked peripheral eosinophilia, up to 3,000/cu mm, was usually present in the symptomatic workers and in 11 of 30 asymptomatic workers. These cases illustrate the diversity of respiratory illnesses which may result from a common workplace exposure and reinforce the importance of considering occupational exposures in the differential diagnosis of peripheral eosinophilia.

Acute Disease↗

PubMed1986

Peripheral eosinophilia and respiratory symptoms in rubber injection press operators: a case-control study.

To evaluate a suspected association between an outbreak of acute respiratory illness and eosinophilia and employment as a rubber worker, we performed a retrospective review of medical records of rubber workers employed from September 1983 to July 1984 in a plant housing a thermoinjection process. Twenty-five workers met the case definition of a respiratory illness requiring a physician visit. The predominant respiratory illness was acute in onset with cough, chest tightness, and dyspnea. Peripheral eosinophilia, up to 40% of white blood cells in a peripheral smear, was seen in 10 of 18 (56%) cases. Twenty-one of 25 white males with respiratory symptoms were employed in the thermoinjection process (odds ratio = 22, p less than .001). Smoking and employment in this process contributed independently to an increased risk of being a case as determined by a logistic regression analysis. Return to the plant building caused recurrence of symptoms in most cases, and these workers have been transferred or left the company. We conclude that a strong previously unrecognized association exists between employment in this neoprene rubber thermoinjection process and the development of an acute respiratory illness.

Adult↗

PubMed1985

Pulmonary function and respiratory symptoms in polyvinylchloride fabrication workers.

We performed preshift and postshift spirometry and administered a standardized respiratory symptoms questionnaire to 174 white males currently employed in polyvinylchloride (PVC) fabrication to examine the acute and chronic respiratory effects of work exposure. Although there were no significant differences between the in-plant comparison group and any department with potential exposures, there was evidence for respiratory effects in the combined group of comparison and exposed workers. In the combined group, duration of employment was significantly associated with decrements in adjusted cross-shift ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC), preshift FEV1/FVC, and prevalence of chronic cough and chronic phlegm. In nonsmokers, the prevalences of chronic wheeze and chest tightness were high (36.0 and 50.5%, respectively). The age-adjusted prevalence of chronic wheeze in nonsmokers was also elevated 3.54-fold when compared with that in a community study in the literature. We conclude that the cross-sectional design and in-plant comparison group may mask the effects of exposures on the entire plant population, and that employment in this plant is associated with patterns of obstructive air-flow limitation and respiratory symptoms consistent with exposure to pulmonary irritants. These results suggest that possible agents of pulmonary effects in PVC fabrication are not limited to vinyl chloride monomer, PVC dust, and PVC thermal degradation products.

Adult↗

PubMedDate not supplied

Sperm count suppression without endocrine dysfunction in lead-exposed men.

To determine if increased lead absorption was associated with sperm count suppression or perterbation of the hypothalamopituitary system, we compared battery workers (N = 18), who were exposed to high airborne lead levels, with cement workers (N = 18), who were exposed to ambient lead levels. Blood lead, urinary lead, semen lead, and zinc protoporphyrin concentrations were markedly elevated (p less than .001) in battery workers. Battery workers had a significantly shifted (p less than .025) frequency distribution of sperm count (median count, 45 vs. 73 X 10(6) cells/cc, respectively). There were no significant differences between the two groups in mean follicle-stimulating hormone, testosterone, prolactin, luteinizing hormone, or total neutral 17-ketosteroid levels. Potential confounding factors (alcohol, cigarette, and coffee consumption, frequency of intercourse, and days of abstinence prior to semen donation) were not significantly different between the two groups. These results suggest a direct toxic effect of increased lead absorption on sperm production or transport in man.

Alcohol Drinking↗

PubMedDate not supplied

Sperm count suppression without endocrine dysfunction in lead-exposed men.

Adult↗

PubMedDate not supplied

Elevated serum IgE, eosinophilia, and lung function in rubber workers.

We previously reported an outbreak of acute respiratory illness associated with eosinophilia in a group of rubber workers who performed a thermoinjection process in which synthetic rubber was heated and then injected onto metal molds. This study was conducted to determine if persistent respiratory health effects were associated with this work area and to explore the possible allergic etiology of this syndrome. A survey was performed 1 mo after a major improvement in area ventilation and consisted of baseline, cross-shift, and cross-week spirometry; diffusing capacity; serum immunoglobulin E (IgE), total eosinophil count; and skin patch testing. Baseline lung function, cross-shift, and cross-week spirometry were not significantly worse in the exposed group as compared to the control group. However, either eosinophilia (greater than 450/mm3) or elevated serum IgE (greater than 470 ng/ml) were present in 44% of exposed workers vs. 11% of the control group (p = .003). Nine months later, neither eosinophilia nor elevated IgE were associated with employment in this work area. We conclude that employment in the thermoinjection process was associated with eosinophilia and elevated IgE, which suggests sensitization to one of the components of the rubber, although no effect on pulmonary function could be demonstrated.

Adult↗