OSAKA -- One of Japan's largest air pollution lawsuits ended Wednesday when about 100 plaintiffs settled four court cases with the state and Hanshin Express Public Corp.

The settlement will not bring payments from the state and the public corporation or an apology recognizing their responsibility for causing health problems. But it does call for specific measures to improve air quality, effectively showing the state's partial responsibility for the pollution, observers said.

The agreement ended a 20-year legal battle in which the plaintiffs sought damages for health problems caused by the exhaust fumes from vehicles and smokestacks here in Nishi-Yodogawa Ward.