If the Copyright Office has no confirmation that a composer or song-writer is still living and it has been 75 years since the first copyright protection order was granted, or 100 years since the recognized creation date of the piece, it becomes public domain.
Exposure to blue-green algae can cause rashes, skin and eye irritation, allergic reactions, gastrointestinal upset, and other effects. At high levels, exposure can result in serious illness or death.
The natural color of these algae can give bodies of water a dark-green appearance. The altitude, temperature, and sun exposure where the blue-green algae are grown dramatically influence the types and mix of blue-green algae in the water. Some blue-green algae products are grown under controlled conditions.