摘要:

AbstractThe person‐years approach to analyzing mortality data from occupational cohorts was introduced in the midtwentieth century. It cross‐classifies all observed deaths and observation times into cells, computes the number of expected deaths for each cell based on referenced mortality rates, and then examines the ratio of total number of observed deaths to total number of expected deaths (the standardized mortality ratio). The maximum likelihood method of statistical inference was developed in the early twentieth century. However, only recently has it been applied to the analysis of occupational cohort data. When so applied, it provides estimates of measures of association between exposures and disease by maximizing the probability of the observed data. This paper shows how recent developments in the use of this tool justify and extend the person‐years approach. In particular, problems with the standardized mortality ratio cited in the literature are shown to result from reliance on assumptions that are inappropriate for the data at hand. Methods for testing these assumptions are described. The discussion is illustrated with examples from occupational cohort studies of lung c

ISSN:0271-3586    

DOI:10.1002/ajim.4700120302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractExposure evaluation for epidemiology has special requirements, which can be derived from the pharmacological processes that determine the exposure‐effect relationship. Since environmental concentrations of toxic agents typically are highly variable over time, the tissue concentrations they produce will vary over time, and consequently the level of effects will also vary over time. A general, six‐step approach is proposed for developing an exposure assessment for an epidemiologic study. This approach uses pharmacologic models to guide the choice of exposure measurement parameters and to guide the epidemiologic data analysis. The approach is illustrated for evaluations of reversible airway effects of ozone and irreversible pulmonary effects of a mixed silica dust. Effect indices are introduced as a means of quantifying the temporal interrelationships of the exposure profiles and the pharmacologic models. These indices have advantages over both dose indices and simple dose‐outcome m

ISSN:0271-3586    

DOI:10.1002/ajim.4700120303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractAcute poisoning among pesticide applicators is still a prominent health hazard in rural areas in developing countries, but published reports are very rare. Registration analysis and descriptive study are helpful in giving guidance for orientation and evaluation of preventive strategies and measures. Data and material from China show that, in circumstances with a well organized grass‐roots‐level network of primary health care services, poisoning episodes can be prevented through dissemination of information of hazards and provision of prevention training courses. Among pesticide manufacturing workers, especially manual packers of organophosphorus insecticides, there is suggestive evidence of subacute posioning resulting from continuous low‐level exposure. Chronic delayed neuropathy has, rarely, been reported. Further study of the cause of subacute poisoning now requires analytical rather than descriptive investigations. There is still no solid documentation of an association of excess human cancer and the use of chlorinated hydrocarbon insecticides. Phenoxyacetic and chlorophenol herbicides recently have been widely studied for causation of soft tissue sarcoma, non‐Hodgkin's leukemia, and lymphoma. Although the evidence at present indicates a positive association, discrepancies in findings and resultant controversy require further study. Epidemiological surveys on the harmful effect of DBCP are quite instructive. Investigations in exposed populations verified and extended the observation in animals as infertility and gender ratio change in the next generation. Adverse reproductive effects of a number of pesticides, particularly birth defects resulting from pesticides (other than those already documented for organomercurials), require furthe

ISSN:0271-3586    

DOI:10.1002/ajim.4700120304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractByssinosis, other respiratory symptoms, and ventilatory capacity were investigated in 186 male spinners in two Sudanese textile mills located in Khartoum and Hassaheisa. The prevalence of byssinosis was 37% among Khartoum spinners where coarse cotton was processed, significantly higher (p<0.01) than the 1% found among Hassaheisa spinners, where fine cotton was used. The prevalence of chronic bronchitis was 29% in Khartoum and 2% in Hassaheisa spinners. A significant reduction in forced expiratory volumes (FEV1after a shift) was observed in spinners of both factories. Our findings provide evidence that very low rates or absence of byssinosis, related respiratory symptoms, and significant functional abnormalities (FEV1) in the late stages of cotton yarn processing all depend on the quality of cotton used and low levels of cotton dust concentration.

ISSN:0271-3586    

DOI:10.1002/ajim.4700120305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractAlmost immediately after the discovery of the Roentgen ray, in 1895, radiation injuries of various kinds began to be encountered in early X‐ray workers, radium handlers, radiologists, and exposed patients. The injuries, which were predominantly acute reactions resulting from the killing of cells in affected tissues, were found to be preventable merely by keeping exposures below relevant threshold levels. By the middle of the twentieth century, however, it was realized that thresholds might not exist for certain effects of ionizing radiation, such as mutagenic, carcinogenic, and teratogenic effects. The risks of such effects in workers and other populations exposed to low‐level radiation have thus been of increasing concern in recent years. The scientific basis for assessing such risks and the principles that have evolved for their control have important implications for occupational and environmental health in gene

ISSN:0271-3586    

DOI:10.1002/ajim.4700120306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractSeveral studies of styrene‐butadiene rubber (SBR) workers have reported excess cancers at various sites; however, little could be concluded concerning specific etiologic agents because of the multiple exposures encountered by these groups. The current study examined cause‐specific mortality in a cohort of 2,586 male workers employed for at least 6 months between 1943 and 1979 in a butadiene manufacturing plant that supplied butadiene to two SBR plants. Standardized mortality ratios were calculated using national (NSMR) and local (LSMR) comparison populations. The all‐cause NSMR was 80 (p<0.05) and the all‐cancer NSMR was 84; the corresponding LSMRs were 96 and 76 (p<0.05). No significant excesses were observed for any cause of death except lymphosarcoma and reticulum cell sarcoma (NSMR = 235). When the cohort was subdivided into routine, nonroutine, and low‐exposure groups, the SMRs were consistently elevated for this cause of death in all three groups. However, direct comparisons between each of the two exposure groups and the low‐exposure group were inconsistent. This suggests butadiene may not be responsible for the excess, but the association deserves close attention in fut

ISSN:0271-3586    

DOI:10.1002/ajim.4700120307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractIgE‐mediated acute and late phase reactions associated with occupational metal fume exposure are rare compared with the more common metal fume fever. The latter is a common acute industrial disease caused by inhalation of oxides of metals, especially zinc. It is a flu‐like illness and is thought to be self‐limited. This article describes the first case, to my knowledge, of an immediate and a late phase reaction (urticaria and angioedema) to zinc fumes, associated with a metal fume fever‐like reaction. Hives and angioedema developed immediately and in a delayed fashion in a 34‐year‐old man after he had welded zinc at his job. There also was an associated metal fume fever‐like reaction. The relationship was proved by a challenge test done at home. The patient has been asymptomatic since using complete protective measures while welding zinc. Possible immunologic mechanisms

ISSN:0271-3586    

DOI:10.1002/ajim.4700120308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

ISSN:0271-3586    

DOI:10.1002/ajim.4700120309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

ISSN:0271-3586    

DOI:10.1002/ajim.4700120301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY