Battery cage chinchilla and foxes in fur farming, and most recently for the Asian palm civet for kopi luwak production of coffee. An early reference to battery cages appears in Milton Arndt's 1931 book, "Battery Brooding", where he reports that his cage flock was healthier and had higher egg production than his conventional flock. At this early date, battery cages already had the sloped floor that allowed eggs to roll to the front of the cage, where they were easily collected by the farmer and out of the hens' reach. Arndt also mentions the use of conveyor belts under the cages to
Electronic waste in the United States of which has been documented to cause significant health problems in the surrounding area. Open burnings are the most common means of 'disposing of' e-waste and occur primarily in rural areas with low incomes of developing countries. Communities use open burning for a variety of functions: For direct disposal, it takes the least amount of man-power and is the cheapest option. For precious metal extraction, it can be an effective method to extract certain valuable metals, such as gold. The combustion of burning e-waste results in ash that contains fine particulate matter; a measure of pollutants that has been linked