Thank you for your response. The textbook is to be printed and presented as an ebook. The print version is not a problem nor is the ebook version when viewed in a pdf viewer other than Adobe Reader, or in Adobe Reader in the non-default state with the Thin Line Enhancement feature disabled.
I attempted to resolve the Adobe Reader Thin Line Enhancement problem by increasing line widths and ensuring that interrupted lines segments were aligned. Sadly, the overall size of the illustrations limits the the maximum width of the thinnest lines and Thin Line Enhancement problem persisted.
The reason I ask if there is anything which can be done within InDesign to counter the distortion of Reader's Thin Line Enhancement is the following observation. An MS Word document with the same illustrations embedded as png graphics and saved as a pdf does not suffer the Thin Line Enhancement distortion when viewed in Adobe Reader. I am hoping that whatever is done when MS Word saves a document as a pdf can be replicated when InDesign exports a pdf. Unfortunately, I am constrained by my publisher to link rather than embed the graphics. I have experimented linking eps, Illustrator, and pdf graphics files but they pdfs exported from InDesign were distorted when viewed in the default configuration of Adobe Reader.
I must disagree with your assertion that the only correct way to view the pdf is in Adobe Reader. Adobe Reader distorts the images unless the user has disabled the Thin Line Enhancement. I believe that I am a typical user of Adobe Reader in that I was unaware that the feature existed until recently. I mistakenly presumed that what may have been distorted graphics were simply poor quality graphics. Given my choice, I would hope that none of the future readers of the text use Adobe Reader, but, unfortunately, I know that many will. That is why I am attempting to resolve this problem.