The US has provided $1.5 million (£1m) to tackle air pollution in the state of Oregon.
The Oregon Department of Environmental Quality (DEQ) will use the funding to reduce emissions from diesel-fuelled activities around its Port in Portland.
It will replace 23 heavy-duty diesel trucks – which travel more than 1.3 million miles a year – and add diesel filters to cargo equipment, two tractors and an aerial lift.
The project is expected to reduce carbon dioxide by 6,000 tons among many other greenhouse gas emissions.
Gina McCarthy, Administrator at the Environmental Protection Agency (EPA) said: “Every dollar we invest in clean diesel generates between $7 (£4.60) and $18 (£11.90) in public health benefits. By promoting clean diesel technologies, we can help save lives locally and play a leadership role on climate change globally.”