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.
They also have the potential to form harmful (toxic) blue-green algal blooms, although the factors that cause blue-green algae to produce toxins are not well understood. Harmful blue-green algae blooms can cause health effects when people and animals come in contact with them.