A disease is any condition which results in the disorder of a structure or function in a living organism that is not due to any external injury. The study of disease is called pathology, which includes the study of cause. Disease is often construed as a medical condition associated with specific symptoms and signs. It may be caused by external factors such as pathogens or by internal dysfunctions, particularly of the immune system, such as an immunodeficiency, or by a hypersensitivity, including allergies and autoimmunity.
European small and medium-sized enterprises (SMEs) are developing a more environment-friendly and energy-efficient way of treating sewage sludge. This will help solve the challenge of how to deal with growing levels of sewage sludge in the face of increasingly stringent environmental legislation.