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Biomedical subjects

J M Peters

Publications and source records attributed to J M Peters.

At least 199 records · Page 11Linked to original sources
PubMed1986

Contribution of metals to respiratory cancer.

This paper reviews studies on the adverse health effects of exposure to metals, using arsenic and cadmium as examples. The carcinogenic potential of arsenic has been studied in various settings. Inhalation is clearly related to the development of lung cancer in (copper) smelting and arsenical pesticide manufacturing, and also in heavily exposed wine merchants who had an additional source of exposure by ingestion. Animal studies have shown cadmium to be a lung carcinogen, while a study by Thun et al. provides the best evidence to date that cadmium inhaled as CdO particles may be a human lung carcinogen. On the basis of this latter study, EPA estimates the risk due to cadmium at 1.8 X 10(-3) cases/micrograms/m3, which results in more than 100,000 excess lung cancers (lifetime). For arsenic, the risk estimate of 4.29 cases/1,000 micrograms/m3, based on epidemiologic data also results in more than 100,000 lung cancers (lifetime). This paper reviews the bases for these estimates and presents recommendations for further research. Lung cancer risks also exist for other metals such as nickel, chromium, and beryllium. Further study is required before a definitive conclusion can be reached about the significance and magnitude of environmental exposures to metals as a cause of lung cancer.

Air Pollutants↗
PubMed1986

Regional cerebral blood flow and metabolic rates in human focal epilepsy and status epilepticus.

Positron emission tomography with the oxygen-15 steady state or bolus inhalation technique was used to provide quantitative values of regional cerebral blood flow (CBF), oxygen extraction ratio (OER) and oxygen consumption (CMRO2) in 25 patients with partial complex seizures during the interictal state and in 5 patients during status epilepticus. Glucose utilization (CMRglu) was also studied in one case of status epilepticus with the 18F-fluorodeoxyglucose technique (18FDG). Interictal scans showed zone(s) of hypoperfusion and hypometabolism without significant variation of the OER in approximately 80% of patients. In 62%, there was a strong correlation between the overall EEG localization and the area(s) of hypoperfusion and hypometabolism. In all cases, ictal scans revealed a focal or multifocal increase in CBF and CMRO2. The localization of the most affected regions correlated well with the spatial distribution of the electroencephalograph (EEG) abnormalities. Comparison of the different values of CBF, CMRO2, and OER showed that the increase in perfusion always exceeded that of oxygen consumption and hence was accompanied by a significant decrease of OER; the latter was always the most prominent in the region of the epilepticus focus determined by serial EEG recordings. These results showed that the supply of oxygen by blood flow is large enough to meet metabolic demand. When comparing these values with CMRglu, it appeared that the relative changes in CMRglu and CBF were very similar, indicating that the increase in blood flow correlated with the enhancement in glucose utilization. The observed imbalance between blood flow, glucose utilization, and oxygen consumption could suggest that an impairment of oxygen utilization by the mitochondria could occur in the epileptic focus during prolonged status epilepticus.

Cerebrovascular Circulation↗
PubMed1986

Investigation of lung cancer among female cosmetologists.

Using a population-based cancer registry to identify subjects, a case-control study of female cosmetologists in Los Angeles County was conducted to investigate possible occupational and environmental causes for the elevated lung cancer risk found in this group. A standardized questionnaire was administered to proxy informants for decreased lung cancer patients and decreased nonpulmonary cancer control patients. No associations between lung cancer and specific beauty shop tasks, beauty product use, or environmental exposures were observed in the crude analysis or after controlling for smoking status. Case subjects had held more jobs outside of cosmetology than control subjects, but these jobs did not appear to be associated with any known hazardous exposures. Despite the elevated risk of lung cancer among female cosmetologists, researchers were unable to relate this excess to any specific occupational tasks or exposures. The excess of lung cancer in cosmetologists is most likely accounted for by a higher frequency of smoking in this occupational group.

Aged↗
PubMed1985

Pancreas cancer is unrelated to the workplace in Los Angeles.

From 1975 to 1981, 490 cases of exocrine adenocarcinoma of the pancreas, representative of those occurring in the working-age population of Los Angeles County, were compared to matched neighborhood controls. Among the items of information obtained from each subject was a lifetime job history and a history of specific workplace exposures; this came directly from both case and control in 124 pairs. Although the matched cases and controls were generally comparable, they were not matched with respect to job history. While other strong risk factors for pancreas cancer were found in the same study, no significant or suggestive differences in the jobs or perceived chemical or process exposures between cases and controls were found. Those minor differences which were found did not suggest credible mechanisms of carcinogenesis when examined in detail. Our study does not point to the workplace as an important determinant of pancreas cancer in the economically diversified urban area of Los Angeles.

Adenocarcinoma↗
PubMed1985

Respiratory effects of borax dust.

The relation of respiratory symptoms, pulmonary function, and abnormalities of chest radiographs to estimated exposures of borax dust has been investigated in a cross sectional study of 629 actively employed borax workers. Ninety three per cent of the eligible workers participated in the study and exposures ranged from 1.1 mg/m3 to 14.6 mg/m3. Symptoms of acute respiratory irritation such as dryness of the mouth, nose, or throat, dry cough, nose bleeds, sore throat, productive cough, shortness of breath, and chest tightness were related to exposures of 4.0 mg/m3 or more, and were infrequent at exposures of 1.1 mg/m3. Symptoms of persistent respiratory irritation meeting the definition of chronic simple bronchitis were related to exposure among non-smokers. Decrements in the FEV1 as a percentage of predicted were seen among smokers who had heavy cumulative borax exposures (greater than or equal to 80 mg/m3 years) but were not seen among less exposed smokers or among non-smokers. Radiographic abnormalities were uncommon and were not related to dust exposure. Borax dust appears to act as a simple respiratory irritant and perhaps causes small changes in the FEV1 among smokers who are heavily exposed.

Acute Disease↗
PubMed1985

Absence of respiratory effects in subjects exposed to low concentrations of TDI and MDI: a reevaluation.

Because of criticisms of the authors' previously reported study showing absence of respiratory effects in subjects exposed to low concentrations of toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), the data have been reanalyzed. This reanalysis confirms the accuracy of the results and the conclusions based on them. Subjects exposed to 0.0010 to 0.0015 ppm of TDI and around 0.0003 to 0.0006 ppm of MDI demonstrated a normal age- and smoking-related rate of decline in forced expiratory volume in 1 s and no evidence that it was related to isocyanate exposures. Control of isocyanate exposure sufficient to protect industrial workers against measurable deterioration in lung function appears feasible.

Cyanates↗
PubMed1985

Uses of a cancer registry in the assessment of occupational cancer risks.

Five approaches for the evaluation of occupational factors in cancer etiology are described. These approaches, based on one's having access to cancer registry data, are for examining cancer profiles for industry and occupation, evaluating information on occupation and industry to infer exposure, observing time trends in incidence to evaluate tumors of occupational interest, using cases of interest to form the basis for case-control studies, and linking cohorts with known exposure to the tumor registry to ascertain cancer incidence in that cohort.

Adult↗
PubMed1984

Job activity and colon cancer risk.

The authors studied 2,950 population-based colon cancer cases in males in Los Angeles County, California, that were diagnosed between 1972 and 1981. To determine if colon cancer risk is reduced by physical activity on the job in males aged 20-64 years, the authors first rated each occupation by judging the activity level as high, moderate, or sedentary. Men with sedentary jobs had a colon cancer risk at least 1.6 times that of men whose jobs required a high level of activity. Risk increased in a stepwise manner as activity level decreased. This gradient was consistently seen within each socioeconomic stratum, among whites, blacks, immigrant and native Hispanics, and for each subsection of the colon from the hepatic flexure to the sigmoid. The protective effect of physical activity was very strong in the descending colon and diminished in a gradient both proximally and distally. There was no such relationship between physical activity and risk for rectal cancer. Physical activity may play a major, previously unrecognized role in colon cancer etiology. Such a role is consistent with the known pattern of colon cancer occurrence and with our understanding of colon physiology and colon cancer pathogenesis. In addition to the implications for prevention, understanding the effects of physical activity on colon cancer risk may allow future studies to evaluate more accurately the role played by diet.

Adult↗
PubMed1984

Respiratory and eye irritation from boron oxide and boric acid dusts.

Boron oxide has been shown in animals to irritate the respiratory mucosa and conjunctiva. The present study was undertaken to determine whether exposures to boron oxide and its hydration product, boric acid, cause respiratory and eye irritation in humans. One hundred thirteen workers exposed to these materials and 214 unexposed workers were interviewed regarding symptoms. Statistically significant associations were found between eye irritation, dryness of the mouth, nose, or throat, sore throat, and productive cough and mean exposures of 4.1 mg/m3 (which probably did not exceed 8.5 mg/m3).

Adult↗
PubMed1984

Pulmonary effects of exposures in silicon carbide manufacturing.

Chest x rays, smoking histories, and pulmonary function tests were obtained for 171 men employed in the manufacturing of silicon carbide. A lifetime exposure to respirable particulates (organic and inorganic fractions) and sulphur dioxide was estimated for each worker. Chest x ray abnormalities were related to respirable particulates (round opacities) and to age and smoking (linear opacities). Pulmonary function was affected by respirable particulates (FVC) and by sulphur dioxide and smoking (FEV1). Pleural thickening was related to age. No exposures exceeded the relevant standards; we therefore conclude that the current standards do not provide protection against injurious pulmonary effects, at least in this industry.

Adult↗
PubMed1984

Pulmonary regional ventilation. C15O2 single breath method. New technical improvements.

After a single inhalation of C15O2 labelled air, from residual volume to total lung capacity, followed by a few seconds apnea, it is possible to record in four or six lung zones the regional activity changes on a time basis. A first fast rise in activity is seen during the inhalation phase, corresponding to the ventilation in the region of interest (ROI). During the apnea, a slower decreasing component is observed in the different ROI, proportional to the regional blood flow, as almost instantaneously C15O2 is converted to labelled water. After the pioneer work of West & Dollery (1962) very few papers appeared on the subject despite technical improvements as, for instance, coincidence counting of radioactive events. We thus decided to improve the reproducibility and accuracy of the method which were of such a poor quality that no individual measurements were possible in the past. Were of critical importance: a careful positioning of the patients between the counters, a faster electronics improving true coincidence counting. In six healthy volunteers (age 22-35) the values obtained for regional ventilation with the C15O2 single breath were compared to the values given by the inhalation of a poorly soluble gas (Nitrogen13). The correlation between the two sets of measurements is high (r = 0.975). The slope of the regression line is 0.859, ordinate at origin is 2.35. This reveals a systematic error. A mathematical model was therefore developed to take into account the "washout" occurring during the constitution of the ventilation peak, and to correct its value.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Organic chemicals and malignant melanoma.

Chemists with cancer were interviewed to generate hypotheses that might explain an apparent excess of malignant melanoma in chemists in Los Angeles County (LAC). The chemists were identified by the LAC Cancer Surveillance Program, a population-based cancer registry. Interviews that included information on work history and exposure to specific chemicals were conducted by telephone. Chemists with melanoma were found to be better educated than chemists with other cancers and they reported more work with organic chemicals. They also cited more exposure to multiple chemicals, solvents, plastics, pesticides, benzoyl peroxide, and ionizing radiation. Although differences in educational level may account for the differences in exposure reported by cases and controls, the hypotheses that specific chemical exposures are related to melanoma occurrence are plausible and deserve further study. We also suggest that this method of generating hypotheses about cancer causes using cases identified from registries could be used more extensively.

Adult↗
PubMed1982

Pulmonary function in firefighters: a six-year follow-up in the Boston Fire Department.

Tests of ventilatory capacity, objective cough, and standardized respiratory questionnaires were used in a prospective study to measure the effect of firefighting on pulmonary function in a cohort of 951 white Boston firefighters between 1970-1976. During the six years of follow-up, the mean annual decrements in forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were 36 and 29 ml per year, respectively. At the end of the study in 1976, the mean FEV1 for this group was 98.3% of the level predicted for healthy nonsmoking adults, while the FVC was 97.8%. Current cigarette smoking was associated with an increased prevalence of bronchitis, a loose cough, reduced levels of FEV1 and FVC, and increased longitudinal changes in FEV1 and FVC. The longitudinal changes and current levels of FEV1 and FVC were not correlated with any index of firefighting exposure in active firefighters. Increased use of protective respiratory apparatus and previously described selection effects within the Boston Fire Department appear to be protecting this group of firefighters from long-term effects of smoke exposure as measured by these techniques.

Adult↗
PubMed1982

Multiple myeloma in cosmetologists.

In an hypothesis-generating activity, data in a population-based cancer registry were analyzed according to occupation and industry. The number of cases of multiple myeloma was found to be excessive for females in the occupation "cosmetologists, hairdressers and manicurists." Race did not explain the excess. People in this occupation have potential exposure to a number of chemicals that produce mutations in bacteria. Studies should be done to investigate the hypothesis that these chemicals cause multiple myeloma in cosmetologists.

Beauty Culture↗