Estimation of Health Condition of Chemical Tanker Crews Exposed to Cargo Vapors : Risk Levels of Tanker Crew

Abstract

IMO (International Maritime Organization) recognized that chronic exposure to benzene vapor in air may cause leukemia even if the concentration is very low, such as a few parts per million. Chemical tankers in Japan, however, transport various kinds of chemicals over 15 (MT/year). Not only benzene but also another chemical transported by marine vessels have adverse effects to the human health condition. In the previous paper, we analyzed the risk levels for tanker crews caused from transporting carcinogens (benzene and acrylonitrile) and non-carcinogen (xylene), with LLE (Loss of Life Expectancy). The advantage using LLE is that we can compare the degree of the adverse effects induced from exposure to carcinogens and non-carcinogens. This paper targets seven chemical substances that are major cargo transported by chemical tankers in Japan. The risk levels of each substance are calculated with tanking into account transportation quantity, toxicological data, occupational exposure concentration and so on. The result of computed risk levels is summarized as a form of risk ranking.