The evidence of major air pollution disasters indicates adverse symptoms in animals of a character similar to those suffered by man. Animals then suffered from acute respiratory distress, bronchitis, emphysema and heart failure. Fluorides, arsenic and lead are highly toxic pollutants that may cause diseases in animals by accumulation in the forage and other crops that constitute the principal diet of cattle and other farm animals. Many other pollutants derived from the incomplete combustion of fuels and from specific industrial processes possess toxic properties.