Mutagen is an agent that causes DNA mutations. UVA radiation penetrates deep into the skin and acts as a mutagen. UV light is the most common source of radiation that affects DNA, but it is a weak radiation and it penetrates only the surface cells of your skin.
Elevated carbon dioxide levels may mitigate losses of biodiversity from nitrogen pollution. ... Rising levels of carbon dioxide may overheat the planet and cause other environmental problems, but fears that rising carbon dioxide levels could directly reduce plant biodiversity can be allayed, according to a new study.