…the presence in or introduction into the environment of a substance which has harmful or poisonous effects…
…the presence in or introduction into the environment of a substance which has harmful or poisonous effects…
…brightening of the night sky that inhibits the observation of stars and planets, caused by street lights and other man-made sources…
…the spread of altered genes from genetically engineered organisms to other, non-engineered organisms, especially by cross-pollination…
…the controversial problem of pollution…
