Increasing the number of federal coal mine inspections by one quarter would save the lives of up to 13 miners a year and prevent up to 1,300 disabling injuries, a new study suggests.

"By increasing the cost of unsafe behavior" through inspections and resultant fines, "enforcement should lead to safer production methods and thereby to lower accident rates," Leslie I. Boden writes in the current American Journal of Public Health.

Boden's study analyzes records of 535 underground mines from the Mine Safety and Health Administration to determine the effect of federal inspections on safety.

His analysis showed a direct correlation between the number of fines and penalties and a decrease in injuries.

In 1973, when the average mine was fined $6,860 and closed for 3.3 days, there were 0.56 deaths and 54.6 disabling injuries per million work hours.

In 1975, with average fines of $9,700 and 5.6 days closed, there were 0.41 deaths and 36.2 disabling injuries per million hours.

In addition to the potential benefits of more inspections, Boden, who teaches economics at the Harvard School of Public Health, reports that:

* Large mines are safer than small mines. "This suggests that there are economies of scale in the provision of safety among these mines."

* Unionized mines have fewer deaths but more disabling injuries than other mines. This may be because union mines report injuries more consistently.