With unemployment rising, more people with high-risk health problems are expected to turn to state-subsidized insurance that takes effect Thursday. But so far only 500 of the 180,000 North Carolinians estimated to qualify have applied. State legislators established the N.C. Health Insurance Risk Pool more than a year ago to provide an option for people whose illnesses push them out of the market for private health insurance. The pool's benefits are limited, and its costs are high. But for people with chronic diseases, enrollment can reduce out-of-pocket expenses by half—especially after they've lost their jobs and exhausted their health insurance benefits under provisions of the Consolidated Omnibus Budget Reconciliation Act, or COBRA.