Yes, it absolutely is. Unfortunately, Boeing has had problems with pollution in the past. In addition to the fact that plane engines pollute the air in general, Boeing has pollution problems due to older factories, like the company's Plant 2. Specifically, the Duwamish River riverbed has been polluted in the past.
Boeing has a number of efforts to clean up the Duwamish. One of the biggest is the dredging of the riverbottom. In the third and final season of dredging, Boeing removed and then replaced enough sand to fill approximately 3,000 railcars, installing a water filter to help decontaminate the dredge water. In addition, Boeing is undertaking a large habitat restoration effort. The company is doing this in partnership with the U.S. Environmental Protection Agency and the Washington State Department of Ecology.
Unfortunately, you can't exactly help to dredge the bottom of the river. Therefore, the most important thing you can do is be aware. Be aware that the river is polluted, and that environmental problems in general do exist. And even if it doesn't directly benefit the Duwamish river, do your part to recycle and compost. We all share the same planet, and we're all in this together.
To learn more about this issue, you can visit Boeing's official site.