Thank you for your environmentally sensitive question. It is all right to put disposable adult diapers in the trash that goes to the landfill. Although, most brands are made from mostly biodegradable material, there is still some plastic covering as well as the fumes of human waste. Recent studies have shown that adult disposable diapers are more environmentally safe than the cloth ones due the energy required for frequent laundering.
Also, environmentally it helps to understand the deep ecology. Today older adults are more within the mainstream of life. Elders are working, volunteering, traveling, dancing and generally living more active lifestyles,no longer hindered by incontinence problems. Our society has gone from diapers to pull ups, which are like regular panties,to briefs,and special incontinence pads.
We have the support of disposable incontinence products to live life with more dignity even with infirmities.
Also, the absorbent material that goes into disposable products keeps the skin drier. disposables need to be changed less often. Also, they do more to prevent diaper rash.