This analysis warns that some diesel engine makers are starting to certify new diesel offroad engines for sale WITHOUT USING ADD-ON POLLUTION CONTROLS and that this could lead to increased particle soot emissions compared to new engines that have been sold in recent years. (Using particle filters leads to emission reductions well beyond the actual standards. These “bonus” reductions could be lost.)
These emission control makers also call on EPA to set a tougher particle soot standard for gasoline engines as part of its Tier 3 plan to dovetail with the standards set by California. (Clean Air Watch and Sierra Club made similar recommendations in our Tier 3 comments to EPA.) This report quantifies additional health benefits that would take place with tougher particle soot standards.
This report is a real warning that we need to take particle soot emissions more seriously and set standards that limit not only the aggregate “mass” of emissions, but the actual number of particles emitted.