Singapore has very limited landspace, with only 0.1 square kilometres per 1000 people, and hence has an extremely high population density. Due to this, Singaporeans are entrusted with the important responsibility and duty of keeping their work and living areas clean and green. Even so, Singapore has had a few land issues, namely that of littering, a lack of waste dumping areas, deforestation, and the many recent outbreaks of dengue fever.