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Biomedical subjects

C W Heath

Publications and source records attributed to C W Heath.

At least 91 records · Page 5Linked to original sources
PubMed1980

Clinical epidemiology of occupational neurotoxic disease.

Occupational exposures to neurotoxic chemicals have produced large outbreaks of illness in chemical and pesticide workers worldwide. Outbreaks of occupational neurologic disease in the United States have included (1) the Kepone episode in Hopewell, Virginia, in which 76 workers at a pesticide plant producing the chlorinated hydrocarbon insecticide, Kepone, developed a previously unrecognized syndrome of nervousness, tremor, ataxia, weight loss, opsoclonus, pleuritic and joint pain, and oligospermia; (2) an outbreak of 104 cases of autonomic neuropathy in polyurethane foam workers in Marblehead, Massachusetts, manifest principally by urinary bladder dysfunction, which followed exposure to a new catalyst, dimethylaminopropionitrile (DMAPN); and (3) an outbreak of acute mixed motor and sensory neuropathy in 48 plastic fabric workers in Columbus, Ohio, exposed to the solvent methyl butyl ketone (MBK). These outbreaks underscore the vulnerability of chemical workers to neurotoxins. In addition, occurrence of these large, easily detectable epidemics suggests that many more smaller clusters and single cases of neurologic disease of undetermined origin, particularly in younger adults, may be caused by exposure to occupational or to other toxic chemicals. Detection of the etiology of chemically induced neurologic illness requires a high index of suspicion and careful ascertainment of occupational history.

Adult↗
PubMed1979

Cohort study of Michigan residents exposed to polybrominated biphenyls: epidemiologic and immunologic findings.

Polybrominated biphenyls (PBB) were dispersed widely in Michigan by a 1973 shipping accident in which PBB was introduced into cattle feed. Human exposure resulted principally from ingestion of contaminated dairy food products. To determine whether PBB exposure has or will cause acute or chronic illness, a prospective cohort study of 4545 persons has been undertaken. Three exposure groups were sought; all persons living on PBB-quarantined farms; persons who had received food directly from such farms; workers (and their families) engaged in PBB manufacture. Enrollment rates were 95.6, 95.1 and 78.0%. Also enrolled were 725 persons with low-level PBB exposure. All were queried concerning 17 symptoms and conditions related possibly to PBB. Venous blood was drawn on 3639 and analyzed for PBB by gas chromatography. Mean serum PBB levels were 26.9 ppb in quarantined farm families, 17.1 in recipients, 43.0 ppb in workers, and 3.4 ppb in the low exposure groups. No associations were found between serum PBB levels and symptom prevalence rates. To evaluate peripheral lymphocyte function, T and B cell quantitation and in vitro responses to 3 nonspecific mitogens were studied in 34 persons with highest PBB levels (mean, 787 ppb), and in 56 with low values (mean, 2.8 ppb). No statistically significant differences in lymphocyte number or function were noted.

Adolescent↗
PubMed1978

Lung cancer after employment in shipyards during World War II.

A case-control study, undertaken to identify reasons for the exceptionally high rate of lung cancer among male residents of coastal Georgia, revealed a significantly increased risk associated with employment in area shipyards during World War II. The summary relative-risk estimate, adjusted for smoking, other occupations, age, race and county of residence was 1.6 (95 per cent confidence limits = 1.1 to 2.3). A synergistic relation was found between shipyard employment and cigarette smoking. These findings suggest that asbestos and possible other shipyard exposures during wartime employment account for part of the excess mortality from lung cancer in certain coastal areas of the United States.

Aged↗
PubMed1978

Lung cancer in coastal Georgia: a death certificate analysis of occupation: brief communication.

A comparison of death certificate statements on occupation for 858 white males who lived in coastal Georgia counties and who died of lung cancer during 1961--74, and for 858 controls who were of the same age and county of residence revealed a twofold excess risk of lung cancer associated with the construction industry. No elevated risk of lung cancer was found for workers in the wood and paper industries in the urban areas of Savannah, Brunswick, or Waycross, but a threefold increase was uncovered for the remaining coastal counties where the wood and paper industry was the largest employer.

Aged↗
PubMed1978

Environmental pollutants and the epidemiology of cancer.

Cancer etiology involves the interplay of genetic and environmental factors. Striking geographic differences and changes in cancer incidence over time have led epidemiologists to infer that probably the major etiologic component is environmental. Recent experiences with vinyl chloride, kepone, and polybrominated biphenyl illustrate the problems involved in epidemiologic studies of proven or suspected environmental carcinogens. While epidemiologic studies will continue to be an essential means for monitoring potential human risks, the long latent periods involved in human carcinogenesis severely limit the usefulness of such approaches for disease prevention. While in vitro and animal test systems can never fully supplant human studies, they represent our only means for detecting potential carcinogenicity before human exposure has become widespread or long established.

Animals↗
PubMed1977

High school contact among persons with leukemia and lymphoma.

We studied frequency of contact among Connecticut high school students and teachers with leukemia and lymphoma diagnosed during or after high school from 1960 through 1971. Risk of having attended the same grade at the same school during the same year was greater among students with Hodgkin's disease (HD) than among simulated controls drawn in proportion to school enrollment (relative risk = 1.44; approximate 95% lower confidence limit = 1.05). Risk of developing HD was also greater among students enrolled simultaneously at the same school as students already diagnosed with HD than among students not so enrolled (relative risk = 2.05; 95% lower confidence limit = 1.39). However, fewer HD cases (16) were diagnosed from 1965 through 1970 at schools that formerly had patients enrolled (1959-64) than at matched schools without such patients (24). We found no evidence of increased contact among persons with non-HD lymphomas or leukemias, except between HD and non-HD lymphomas (relative risk = 1.41; approximate 95% lower confidence limit = 1.11).

Adolescent↗
PubMed1977

Cancer incidence following infectious mononucleosis.

By means of a mailed questionnaire, the investigators examined the incidence of cancer among 2282 former college students in whom heterophile-positive infectious mononucleosis (IM) was diagnosed between 1949 and 1969 at five U.S. universities. Cancer incidence among these IM cases was compared both with national incidence rates and with an age and sex-matched group of 2779 non-IM students. No significant increase in cancer incidence was found. Three cases of Hodgkin's disease (HD) had occurred in the IM group (1.3 cases expected) and one case in the control group. All three post-IM cases of HD were in males. Intervals between diagnoses of IM and HD were three, four, and seven years, respectively. Only two other cases of lymphoma or leukemia were observed, and both were in the control group.

Adolescent↗
PubMed1976

Nasopharyngeal cancer in Bermuda.

Six cases of nasopharyngeal carcinoma (NPC) were diagnosed in residents of Bermuda in the 7-year period 1966-1972. While epidemiologic study revealed no history of common environmental exposures, two of the six cases occurred in adult sibs from a family in which a third adult sib developed NPC in 1963. These three cases were from a large, possibly in-bred Portuguese family with origins in the Azores Islands. The remaining four cases were all in black children ages 10-15; two of these were first cousins. These observations suggest the possibility that genetic influence may contribute to the etiology of NPC.

Adolescent↗
PubMed1976

Case clustering in cancer.

There is little evidence that time-space clustering is important in the epidemiology of leukemia, lymphoma, Burkitt's tumor, and myeloma. Clustering by interpersonal contact, particularly in Hodgkin's disease, does appear to occur, but more study is needed to warrant the conclusion that such contact is necessary for subsequent illness to develop. Future epidemiologic studies should include the use of laboratory analysis to evaluate the role of viruses, genetics, and environmental factors in cluster studies.

Acute Disease↗
PubMed1975

Characteristics of cases of angiosarcoma of the liver among vinyl chloride workers in the United States.

A total of 13 cases of ASL have been documented to date among VC workers in four different plants in the United States. In this particular industrial population, this number of cases represents at least a 400-fold increase over expected incidence for this extremely rare tumor. The first case occurred in 1961. Average age at diagnosis is 48.2 years. Average length of time between initial VC work and diagnosis has been 20.3 years. A detailed review of 7 cases associated with one plant revealed that clinical features varied from little or no overt illness prior to diagnosis to advanced liver disease with portal hypertension and marked splenomegaly. Portal fibrosis was present in all 7 of these ASL cases as well as in 4 additional cases with non-malignant liver disease among VC workers at the same plant. These findings suggest that exposure to VCM in industrial settings can produce hepatic fibrosis with angiosarcoma as a late manifestation. Conventional liver function tests may not be sensitive indicators of such liver impairment, at least in its early stages.

Adult↗