1.   Even air pollution regulators, not normally the ones to criticize permit rules, say Title V requirements are more daunting than necessary.

2.   It also needs flexibility from state and federal air pollution regulators.

3.   Pollution regulators should also pay more attention to off-road sources of emissions, the report said.

4.   The documents are under investigation by state pollution regulators.

5.   While diesel engines are far cleaner than ever, only now are air pollution regulators catching up in earnest with their belching exhausts.