Diesel fumes are bad for people. But diesel power is good for a lot of heavy-duty work. So, for now, one answer to threading the needle of that little conundrum is to make diesel engines as clean as possible. To that end, the US Environmental Protection Agency (EPA) has announced $9 million worth of grant funds from the DERA National Funding Assistance Program. If the EPA's numbers are correct, that money could be worth something like $117 million in public health benefits.