The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform

Jingxian Chen - One of the best experts on this subject based on the ideXlab platform.

  • Filtering, Smoothing, and Extrapolations in Dose-Response Experiments: Application to Data on Respiratory Tumors in Rats
    Bayesian Analysis in Statistics and Econometrics, 1992
    Co-Authors: Nozer D. Singpurwalla, Jingxian Chen
    Abstract:

    A method for inference and extrapolations in certain dose-response, damage-assessment s and accelerated life-testing studies as been proposed by Meinhold and Singpurwalla in 1986. The method is based on a use of the Kalman-filter algorithm and involves the double lognormal as the distributional assumption. In this paper, we discuss issues pertaining to a practical implementation of this methodology. This involves some insights based on a simulation study about the specification of prior parameters and an application of the proposed methodology to some published data on doses of Bischloromethyl Ether administered to rats.

E Ward - One of the best experts on this subject based on the ideXlab platform.

  • Overview of preventable industrial causes of occupational cancer. Environ Health Perspect 1995;103 Suppl 8:197–203
    2013
    Co-Authors: E Ward
    Abstract:

    This paper summarizes what is known about preventable causes of occupational cancer, including single agents, complex mixtures, and broad occupational associations. Epidemiologic methods have been very successful in documenting cancer risks associated with single agents. Epidemiologic data are most conclusive when an exposure-response relationship can be demonstrated. Examples of agents for which epidemiologic studies provide evidence of an exposure-response relationship include benzene and (concurrent exposure to) ortho-toluidine and aniline. Vinyl chloride and Bischloromethyl Ether are examples of associations between single agents and rare histologic types of cancer. It is more difficult to conduct epidemiologic studies to identify cancer risks associated with complex mixtures. Studies of diesel exhaust and lung cancer and metal machining oils are cited as having employed advanced industrial hygiene and epidemiologic methods for studies of complex mixtures. Elevated cancer risks have also been identified in broad occupational groups, including painters and dry cleaners. Epidemiologic case-control studies are often used to detect such associations but are limited in their abilities to detect the causal agents. Major gaps exist in knowledge of occupational cancer risks.among women workers and workers of color. Because epidemiologic research measures illness and mortality that have already occurred, a positive study can be interpreted to represent a failure in prevention. The challenge we face in the next decade is to identify interventions earlier in the causal pathway (toxicologic testing, biomarkers of exposure or precancerous changes, institution of engineering and good industrial hygiene practices to reduce occupational exposure levels) so that occupational cancer can be prevented.- Environ Health Perspect 103(Suppl 8):197-203 (1995) Key words: carcinogen, standards, occupational health, epidemiolog

  • Overview of preventable industrial causes of occupational cancer.
    Environmental health perspectives, 1995
    Co-Authors: E Ward
    Abstract:

    This paper summarizes what is known about preventable causes of occupational cancer, including single agents, complex mixtures, and broad occupational associations. Epidemiologic methods have been very successful in documenting cancer risks associated with single agents. Epidemiologic data are most conclusive when an exposure-response relationship can be demonstrated. Examples of agents for which epidemiologic studies provide evidence of an exposure-response relationship include benzene and (concurrent exposure to) ortho-toluidine and aniline. Vinyl chloride and Bischloromethyl Ether are examples of associations between single agents and rare histologic types of cancer. It is more difficult to conduct epidemiologic studies to identify cancer risks associated with complex mixtures. Studies of diesel exhaust and lung cancer and metal machining oils are cited as having employed advanced industrial hygiene and epidemiologic methods for studies of complex mixtures. Elevated cancer risks have also been identified in broad occupational groups, including painters and dry cleaners. Epidemiologic case-control studies are often used to detect such associations but are limited in their abilities to detect the causal agents. Major gaps exist in knowledge of occupational cancer risks among women workers and workers of color. Because epidemiologic research measures illness and mortality that have already occurred, a positive study can be interpreted to represent a failure in prevention. The challenge we face in the next decade is to identify interventions earlier in the causal pathway (toxicologic testing, biomarkers of exposure or precancerous changes, institution of engineering and good industrial hygiene practices to reduce occupational exposure levels) so that occupational cancer can be prevented.

Nozer D. Singpurwalla - One of the best experts on this subject based on the ideXlab platform.

  • Filtering, Smoothing, and Extrapolations in Dose-Response Experiments: Application to Data on Respiratory Tumors in Rats
    Bayesian Analysis in Statistics and Econometrics, 1992
    Co-Authors: Nozer D. Singpurwalla, Jingxian Chen
    Abstract:

    A method for inference and extrapolations in certain dose-response, damage-assessment s and accelerated life-testing studies as been proposed by Meinhold and Singpurwalla in 1986. The method is based on a use of the Kalman-filter algorithm and involves the double lognormal as the distributional assumption. In this paper, we discuss issues pertaining to a practical implementation of this methodology. This involves some insights based on a simulation study about the specification of prior parameters and an application of the proposed methodology to some published data on doses of Bischloromethyl Ether administered to rats.

Kenzaburo Tsuchiya - One of the best experts on this subject based on the ideXlab platform.

  • Development of occupational health in Japan.
    Journal of UOEH, 1991
    Co-Authors: Kenzaburo Tsuchiya
    Abstract:

    This paper was presented as a Lucas Lecture 1990 before the Faculty of Occupational Medicine, Royal College of Physicians, United Kingdom. It describes the development of occupational health in Japan including primitive industrialization (mining, smelting and others) back as far as the 8th century. The modern industrialization of Japan began slightly over one hundred years ago, i.e. from the beginning to the middle of the Meiji era. Before World War II, Japanese workers in industry suffered terrible working conditions, represented by a booklet published in 1925 entitled "The Tragic History of Female Workers" by Wakizo Hosoi. At that time a pioneer named Dr. Gito Teruoka was hard at work. He literally became the "Father of Occupational Health" in Japan. He established the Kurashiki Institute of Science of Labour in 1921 in Kurashiki City located in western Honshu, which is the main island of Japan. At the beginning of the Showa era, from 1930 to 1950, various types of occupational diseases were reported and the situation was overviewed by Dr. Juko Kubota. The rapid industrialization immediately after World War II during which workers were exposed to chromium, benzidine, beta 2-naphthylamine, arsenic, vinyl chloride monomer, asbestos, Bischloromethyl Ether and other chemicals gave rise to occupational cancer. The Ministry of Labour (MOL) was established in 1947 and the Labour Standard Law enacted. As a result, the incidence of tuberculosis decreased rapidly and occupational health emphasized the early detection of tuberculosis. After tuberculosis was nearly eradicated, more complicated working conditions developed in various industries. MOL enacted the Industrial Safety and Health Law in 1972 and occupational health practices improved greatly. Furthermore, in 1988 MOL amended the Law and announced guidelines on maintenance and promotion of health for the work population. However, there is a great disparity in occupational health services between large establishments and small factories. The University of Occupational and Environmental Health, Japan, (UOEH) was established in 1978 to promote occupational health sciences as well as to train and foster occupational health personnel to meet the short supply of occupational health physicians. However, there is no authority that establishes standards for occupational health physicians and nurses. The urgent necessity of establishing an authorized institution for the qualification of occupational health personnel is emphasized. Language: en

Roger O. Mcclellan - One of the best experts on this subject based on the ideXlab platform.

  • Reducing uncertainty in risk assessment by using specific knowledge to replace default options
    Drug Metabolism Reviews, 1996
    Co-Authors: Roger O. Mcclellan
    Abstract:

    This paper has advocated the development of specific scientific information, especially information on the mechanisms of action of chemicals, to use in place of default options in assessing human cancer risks. Four examples have been discussed that build largely on information from the CIIT research program. These four examples are worthy of consideration as a group, with a view to developing insights for increasing the effectiveness and efficiency of obtaining such data in the future and, most of all, to increase their acceptance for use instead of default options. In my view, key features of all four examples are that the data are framed within an exposure-dose-response paradigm and that there is a clear linkage to the end point of concern-cancer. As the number of techniques available for making observations at the cellular and molecular levels continues to increase at a rapid pace, linking these observations to the health end points of concern such as cancer is going to be increasingly important, especially in enhancing the value of the observations for risk assessment purposes. Equally as important, the mechanistic observations must be linked to realistic exposures and associated tissue dose that can be related to realistic human exposure scenarios. In my opinion, the likelihood of obtaining information of value for risk assessment purposes using the most sophisticated of molecular and cellular techniques will be of limited value if the exposures or doses are not realistically linked to those likely to be encountered by humans. The mechanism of alpha 2u-globulin nephropathy and its association with kidney tumors in male rats and the conclusion that the male rat kidney tumor findings are not applicable to assessing human cancer risk is an example of a qualitative decision. I suspect this may be a somewhat unusual case. As one looks across the various mammalian species used for experimentation and makes comparisons with humans, a unifying theme is the relative abundance of similarities. Indeed, this is a major argument for the use of laboratory animals to obtain information relevant to humans. Nonetheless, vigilance to differences among species is important. When differences are observed, we must capitalize on them to better understand the underlying biological mechanisms that mediate the differences. If, as I have suggested, laboratory animal species are more like than different from humans in their basic biological characteristics, there is a rationale for continuing to use laboratory animals as sources of data to help assess human risks of exposure to chemicals. It follows from this that quantitative differences among species such as observed with both formaldehyde and 1,3-butadiene assume major importance for assessing human risks. In my opinion, quantitation of the likely human carcinogenic potency of chemicals is of major importance. It is not sufficient to simply classify chemicals with regard to the likelihood of their being human carcinogens, as done by IARC (1994) and U.S. EPA (1986). IARC has placed more than 60 chemicals or processes (such as coke production) in group 1, carcinogenic to humans; more than 50 in group 2a, probably carcinogenic to humans; and 250 in group 2b, possibly carcinogenic to humans. This rank order implies differing levels of concern for three categories. However, even this rough three-bin system does not convey a very clear picture as to the degree of concern that should be accorded a given chemical for producing cancer. For example, the chemicals categorized as group 1, human carcinogens, using potency estimates developed by the U.S. EPA differ in potency by roughly 4 orders of magnitude. For example, a lifetime cancer risk is 6.2 x 10(-2) per micrograms/m3 for Bischloromethyl Ether and 8.3 x 10(-6) for benzene (NRC, 1994). Differences such as this offer strong arguments for complementing simplistic hazard identification schemes such as the IARC and EPA carcinogen classification systems w