Bronze is best known as an alloy of copper and tin, but copper alloyed with aluminum, arsenic, manganese, phosphorous, silicon, etc., can also referred to as bronzes.
Yes, it is, see this 2010 paper Eating artificially ripened fruits is harmful. Calcium carbide is extremely hazardous to the human body as it contains traces of arsenic and phosphorus. It is banned in many countries of the world, but it is freely used in India, Pakistan, Bangladesh, Nepal and other countries. Thus we are at risk of short-term and long-term health effects simply by eating fruits that are induced to ripen. Calcium carbide CaC2 is used to easily generate low levels of ethylene gas which can hasten the (outside at least) ripening of fruits like bananas, mangoes etc.
1 As the small brown spots grow on the peel, the fruit inside ripens even further. 2  When the peel shows more brown or black than yellow, the fruit is over-ripe. 3  Avoid bananas that have a gray tint and look dull in color. 4  This is a sign that the bananas were refrigerated, which interferes with proper ripening. Put green bananas into a brown paper bag to speed up the ripening process. 2  Add an apple or a tomato to the bag to ripen the bananas in less than 1 day. 3  Another way to speed up the ripening process is to place the bananas near other ripe fruit in a bowl, such as other ripe bananas.