After June 30, 1990, any hospital, hospital authority, county, municipality, or other person or entity is authorized to contribute to the trust fund. The contribution of public funds to the trust fund shall be a valid public purpose for which those funds may be expended. Contributions to the trust fund shall be irrevocable and shall not include any limitation upon the use of such contributions except as permitted in this article or by the department.
OCGA § 31-8-153