What environmental consequence of Parkesine was noted by early observers, linking its legacy to current challenges?

It was noted for being difficult to dispose of due to its persistence in the environment.

Although the early inventors focused intensely on the material creation aspects, the issue of end-of-life management for synthetic materials was recognized, albeit dimly, even at the earliest stages. Specific observers noted that Alexander Parkes' original creation, Parkesine, was persistent and difficult to dispose of effectively. This early observation foreshadowed the defining challenge of the entire plastic age—environmental impact and long-term persistence. While Parkesine's instability led to cracking, its overall persistence presented a disposal problem that mirrored the massive environmental accountability issues faced centuries later regarding modern, highly durable polymers, creating a cyclical connection between the first invention and current global efforts toward chemical accountability.