Entitlement to service connection for a lung condition claimed as due to environmental hazards is remanded.

Board reasoning

The Board found that there has not been substantial compliance with prior remand directives and thus remanded again to obtain a medical opinion clarifying diagnosed lung conditions, if any, and their etiology related to service. It noted conflicting PFT results and speculative language about asthma, which cannot support the claim, and emphasized that the Board cannot substitute medical judgment, requiring a thorough rationale from a new examiner to resolve the diagnosis and link to service, including exposure to explosions and IEDs in Afghanistan and presumptive toxic exposure.