but not when it comes to environmental protection. 24-year-old cileine fernandes has a long hot day aheadf her. >> good morning. i've come for the plastic bottles. it's exchange day today. so how's it going? is everything ready? >> a lot of bottles have piled up in her grandmother's back yard. every couple of months it's time to get rid of them. >> aren't there any more lying around? we've got to collect the whole lot. >> the bottles are valuable because they can be exchanged. >> everybody wants the biosphere bottles. it really motivates the kids more than anything. they collect as many as they can, so you hardly see any lying in the streets now. >> everyone wants to trade in their bottles. the lucky ones can hop onboard for a ride, the most popular means of getting around here anyway. it's busy at the collection site and stays that way the whole day long. the locals settle in for an extended, patient wait. fernandes works for the biosphere reserve and helps with the counting. the main cause of the glut of plastic bottles is the palm oil used for cooking here. there's a collection every c