hospital ventilation systems, it could detect and therefore prevent contamination of other patients or equipment by many highly contagious pathogens. The detection of lung cancer or other medical conditions by detecting the VOC's (volatile organic compounds) that indicate the medical condition. The detection of viral and bacterial infections in COPD Exacerbations. The quality control of food products as it could be conveniently placed in food packaging to clearly indicate when food has started to rot or used in the field to detect bacterial or insect contamination. Nasal implants could warn of the presence of natural gas, for those who had anosmia or a weak sense of smell. The Brain Mapping Foundation used the electronic nose to detect brain cancer cells. Possible and future applications in the field of crime prevention and security The ability of the electronic nose to detect odorless smells makes it ideal for use in the police force, such as the ability to detect bomb odors despite other airborne odors capable of confusing police dogs. It may also be used as a drug detection method in airports. Through careful placement of several or more electronic noses and effective computer systems, one could triangulate the location of drugs to within a few metres of their location in less than a few seconds. Demonstration systems that detect the vapours given off by explosives exist, but are currently some way behind a well trained sniffer dog. In environmental monitoring For identification of volatile organic compounds in air, water and soil samples. For environmental protection. Various application notes describe analysis in areas such as flavor and fragrance, food and beverage, packaging, pharmaceutical, cosmetic and perfumes, and chemical companies. More recently they can also address public concerns in terms of olfactive nuisance monitoring with networks of on-field devices. Since emission rates on a site can be extremely variable for some sources, the electronic nose can provide a tool to track fluctuations and trends and assess the situation in real time. It improves understanding of critical sources, leading to pro-active odor management. Real time modeling will present the current situation, allowing the operator to understand which periods and conditions are putting the facility at risk. Also, existing commercial systems can be programmed to have active alerts based on set points (odor concentration modeled at receptors/alert points or odor concentration at a nose/source) to initiate appropriate actions. See also Chemical field-effect transistor Chemiresistor Electronic