In 1945, government researchers realized that nitrates and nitrites, commonly used to preserve color in meats, and other food additives, caused cancer.

• 1945年,政府部门的科研工作者了解到,被广泛用于肉类以保持肉类色泽的硝酸盐、亚硝酸盐和其他的添加剂可诱发癌症。