Nanotoxicology is a discipline of toxicology that studies the toxicity of nanomaterials originating from combustion processes (such as diesel soot), manufacturing processes (such as spray drying or grinding), and naturally occurs. It is an understanding the extent to which nanomaterials (materials with at least one dimension of less than 100 nanometers) constitute a risk to human health and the environment. Nanoscale materials may have biological effects that differ from those generated by their bigger counterparts due to their small size, huge surface area-to-volume ratio, and quantum size effects.