a. Geo-Resources and Environment Institute, AIST, Tsukuba 305-8569, Japan
b. School of Engineering, Department of Geosystem Engineering, The University of Tokyo

In Japan, surface mines mainly consist of limestone and crushed stone quarries. This paper summarizes a current situation of fatalities and injuries occurred in these surface quarries in Japan. At first, based on the annual reports of mining safety issued by MITI, severity rate (lost days per 1000 employee-hours) and frequency rate (number of incidents per million employee-hours) of limestone mines in 1954-1999 is discussed. Both rates had decreased rapidly within these years. Especially, the frequency rate has decreased logarithmically between the years of 1954 and 1990 A half-time period of the frequency rate was 7 years Therefore, should be realized that fatalities and injuries in surface mines have been decreasing dramatically in Japan. But if we compare these numbers with other industries in Japan, the level might be regarded as not so low, For example the number of industrial accidents resulted in death was 1,884 in a calendar year of 1998. Among these, 26 people were died in surface mines. This fact resulted in higher primary rate of incidents compared with other industries.
In order to investigate these surface mine incidents in detail, a. total number of 312 cases concerned about fatal and non-fatal accidents were collected from reports by LSJ (Limestone Association of Japan) and JCSA (Japan Cnished Stone Association). These incidents were grouped by place, month, day, time, age, and experience. Main results derived from this analysis are; incidents are concentrated on Mondays, and time between 9:00-10:00/14:00-15:00. An age group of 35-60 has more number of fatal and injury number compared to age group 18-35, and 60 over. As for experience year, almost 50 % of fatal incidents are caused by who has a mining experience less than 7 years