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Biomedical subjects

R Lilis

Publications and source records attributed to R Lilis.

At least 55 records · Page 3Linked to original sources
PubMed1982

Body burden of polychlorinated biphenyls among persons employed in capacitor manufacturing.

In an effort to assess exposure among workers engaged in capacitors manufacture, PCB concentration was determined in plasma (290) and adipose tissue (61). In general, males had higher concentrations of PCBs than females. The correlation of plasma concentration (1-546 ppb) of the more highly chlorinated PCBs, which had been used in past, with total duration of employment suggested accumulation over time. The gc-ec pattern of these PCB peaks was, in most cases, characteristic of exposure to a PCB mixture with 54% chlorine. The less highly chlorinated PCBs, di-, tri-, and tetrachlorobiphenyls, were the source of current exposure, and were observed in concentrations of 6-2530 ppb in plasma. Higher exposure occurred among persons with direct contact with PCBs in jobs such as capacitor filling. Adipose tissue concentrations, for both the more highly chlorinated PCBs (1-165 ppm) and lower chlorinated PCBs (0.6-414 ppm), were proportional to those in plasma.

Adipose Tissue↗
PubMed1982

A composite index of lead effects. Comparative study of four occupational groups with different levels of lead absorption.

Biological indicators of lead effects on the central nervous system (CNS), hematogenous bone marrow, and kidney function as measured by performance tests, hemoglobin (Hgb) and BUN levels respectively were combined in an integrative index (INDEX). Such an index was calculated by removing age effects in measures of performance and kidney function and then transforming all the variables to Z (standard) units. The relationships between INDEX and biological indicators of lead exposure and absorption (Pb-B and ZPP) were studied in four groups: 191 non-lead exposed males (control group), 169 copper smelter workers, 133 autobody shop workers and 87 secondary lead smelter workers. We found that: 1) the magnitude of the correlation coefficient between INDEX and ZPP was much higher than were the correlations between the various single indicators of lead effects (performance test scores, Hgb, and BUN); and 2) the magnitude of the correlation coefficients was related to the degree of lead exposure and absorption (as reflected in distribution patterns of Pb-B and ZPP) in each group. The concept of an integrative index of biological effects of lead is important for the evaluation of early manifestations of lead toxicity and also for the correct assessment of adverse health effects of lesser intensity than those characteristic for the classic picture of overt lead poisoning.

Adult↗
PubMed1981

An integrative index of biological effects of lead.

Biological indicators of lead effects on the central nervous system (as measured by performance tests), hematogenous bone marrow (hemoglobin levels) and kidney function (BUN Levels) can be combined in an integrative index (INDEX). This integrative index can be in turn related to indicators of lead exposure and absorption. Such an index was calculated by removing age effects in measures of performance and kidney function and then transforming all the variables to Z (standard) units. Secondary lead smelter workers and a control group were studied. In secondary lead smelter workers this INDEX was found to be significantly correlated with ZPP, blood lead levels, and duration of lead exposure. In this population the magnitude of the correlation coefficients with ZPP levels was much higher than than for blood lead levels. INDEX had a higher correlation with ZPP than with each of its components: performance test scores, hemoglobin, and BUN levels. Although performance test scores, hemoglobin, and BUN levels were shown to discriminate between the control, non-lead-exposed population, and the lead-exposed group, INDEX (and particularly one pair of its components, CNS and hemoglobin levels) achieved the best discrimination between groups. The concept of an integrative index of biological effects of lead may be especially useful in defining populations at high risk for developing chronic, potentially irreversible neurologic and kidney dysfunction, and in assessing the severity of lead effects in individual cases.

Analysis of Variance↗
PubMed1981

Long-term occupational lead exposure, chronic nephropathy, and renal cancer: a case report.

The case of a 61-year-old male with repeated episodes of overt clinical lead poisoning and courses of chelation therapy during his 34 years of employment in a secondary lead smelter is presented. Renal function impairment with elevated serum creatinine and blood urea nitrogen and with markedly reduced glomerular filtration rate was detected several years before the discovery of a clear cell adenocarcinoma of the right kidney. After successful surgical removal of the tumor, the patient's renal function continued its previous trend of slow deterioration.

Adenocarcinoma↗
PubMed1981

Review of pulmonary effects of poly(vinyl chloride) and vinyl chloride exposure.

The contributions of several recent reports to the definition of pulmonary effects of PVC dust inhalation are reviewed. Granulomatous reaction, with inclusion of PVC particles in macrophages and histocytes, and associated interstitial pulmonary fibrosis have been found to lead to exertional dyspnoea, diffuse micronodular chest radiographic opacities and restrictive pulmonary dysfunction. The effects of vinyl chloride (VC) monomer (gas) on proteins and the immunologic mechanisms triggered by the altered protein are possible mechanisms for the development in some cases of interstitial pulmonary fibrosis secondary to VC exposure. Vinyl chloride, a confirmed carcinogen, has been associated with, among other malignant tumors, a significant increase in the incidence of lung cancer. The magnitude of this effect has not yet been completely evaluated.

Dust↗
PubMed1980

Radiological evidence of asbestos disease among ship repair workers.

Asbestos materials are now infrequently used in new ship construction. However, significant amounts were used in vessels constructed before 1975. As a consequence, for the next 30 or more years, the potential for asbestos exposure in the repair of such vessels will remain. We studied 286 workers who were 30 or more years from onset of employment in ship repair work. Eighty-six percent had radiological evidence of asbestosis, and five instances of previously undiagnosed lung cancer were found. This suggests that unless industrial hygiene precautions are taken in the future repair of vessels that have been built with asbestos, we will add additional decades to the legacy we already face as the result of uncontrolled shipyard exposures of the past.

Adult↗
PubMed1980

Lung cancer prevalence among shipyard workers.

The prevalence of lung cancer has been ascertained during a survey of 286 shipyard workers all 20 to 45 years from onset of asbestos exposure in shipyard work. Two men had had previous thoracic surgery for lung cancer. In addition, bronchogenic carcinoma was found in five men. One was among the 35 men less than 30 years in the yard; three were in the 191 who had begun work 30 to 39 years before, and one was in the group of 60 men who were 40+ years from onset. The potential usefulness of large-scale surveillance programs for the early detection of lung cancer among current and former shipyard workers is discussed.

Aged↗
PubMed1980

Zinc protoporphyrin, blood lead and clinical symptoms in two occupational groups with low-level exposure to lead.

The results of cross-sectional clinical field surveys of 45 cable manufacturing workers and 90 telephone cable splicers are presented. Despite the rare occurrence of clinically overt lead poisoning among these occupational groups, high prevalence of lead-associated central nervous system symptoms and gastrointestinal symptoms was found. Hierarchical log-linear models for multidimensional contingency tables were fitted to those data and indicate that there is a partial correlation between reported symptoms and zinc protoporphyrin: individuals with high zinc protoporphyrin levels were more likely to report symptoms than those with low levels. No significant partial association was found between symptoms and blood lead. Because of the intermittent lead exposure encountered in one of the populations, individuals were identified with "normal" blood lead levels associated with "elevated" zinc protoporphyrin concentrations, thus indicating the difference in the biological significance between indicators of lead absorption (blood lead) and of biological response tests (ZPP). Suggestion is made that both types of diagnostic tests be utilized in the medical surveillance of lead-exposed workers.

Adult↗
PubMed1980

Kidney function and lead: relationships in several occupational groups with different levels of exposure.

Potential kidney function decrement with long term lead exposure is important in the overall assessment of adverse health effects of lead in industrial workers or other exposed groups. Two clinical field studies of secondary lead smelter workers have shown that a significant proportion of workers had slightly to moderately elevated blood urea nitrogen (BUN) and creatinine levels; the prevalence was higher in those with longer lead exposure. Since a decrement of kidney function with age has been documented, and since duration of lead exposure may also be strongly related to age, it was necessary to assess the age dependent renal function decrement in control (non-lead-exposed) populations. BUN and creatinine levels in the lead exposed workers showed a much more significant correlation with age than that which was found in the non-exposed populations; the correlation remained statistically significant after correcting for the age-dependent decrement derived from the control populations. Moreover, highly significant correlations between BUN and creatinine and the biological indicator of lead absorption, zinc protoporphyrin, were found. The results indicate a sizeable and significant decrement in kidney function in the secondary lead smelter workers studied; by removing its age-dependency, this effect was found to be lead-induced. In other occupational groups, with lesser and/or shorter lead exposure, a significant effect on renal function as reflected in BUN and creatinine levels could not be detected.

Adult↗
PubMed1980

Lead exposure and behavioral changes: comparisons of four occupational groups with different levels of lead absorption.

The association between lead absorption and objective psychological performance tests in five groups with different levels of lead absorption was studied in the following groups: (1) a control, non-lead-exposed group; (2) cable splicers, (3) cable manufactures, and (4) secondary lead smelter workers. The following performance tests were used: Block Design, Digit Symbol, and Embedded Figures. Age-corrected performance test scores and the average of three test scores (INDEX) were used throughout. A significant association between performance tests scores and increased lead absorption was found. Zinc protoporphyrin level was a more "powerful" (in the statistical sense) indicator of lead-induced CNS effects than blood lead levels. This study provides additional evidence that neurotoxic effects associated with occupational exposure to lead can be demonstrated by means of performance tests. It has been known and widely accepted that increased lead absorption is associated with "non-specific" subjective symptoms: tiredness, sleep disturbance, irritability, etc. Psychometric techniques (including an appropriate statistical analysis strategy) are highly sensitive for the early detection of CNS neurotoxicity, such as metal toxicity. Moreover, even in lead-exposed but asymptomatic individuals, a significant correlation (negative) between test scores and levels of lead absorption could be detected. It is concluded that workers exposed to lead at levels considered "safe" might be at risk of developing brain dysfunction with long term exposure.

Humans↗