smoking one or two cigarettes in terms of particulate inhalation by weight. The analysis is complicated, however, by the fact that the organic compounds present in various ambient particulates may have a higher carcinogenicity than the compounds in cigarette smoke particulates. Secondhand tobacco smoke is the combination of both sidestream and mainstream smoke emissions from a burning tobacco product. These emissions contain more than 50 carcinogenic chemicals. According to the United States Surgeon General's 2006 report on the subject, "Short exposures to secondhand [tobacco] smoke can cause blood platelets to become stickier, damage the lining of blood vessels, decrease coronary flow velocity reserves, and reduce heart variability, potentially increasing the risk of a heart attack". The American Cancer Society lists "heart disease, lung infections, increased asthma attacks, middle ear infections, and low birth weight" as ramifications of smoker's emission. Smoke can obscure visibility, impeding occupant exiting from fire areas. In fact, the poor visibility due to the smoke that was in the Worcester Cold Storage Warehouse fire in Worcester, Massachusetts was the reason why the trapped rescue firefighters could not evacuate the building in time. Because of the striking similarity that each floor shared, the dense smoke caused the firefighters to become disoriented. Corrosion Smoke can contain a wide variety of chemicals, many of them aggressive in nature. Examples are hydrochloric acid and hydrobromic acid, produced from halogen-containing plastics and fire retardants, hydrofluoric acid released by pyrolysis of fluorocarbon fire suppression agents, sulfuric acid from burning of sulfur-containing materials, nitric acid from high-temperature fires where nitrous oxide gets formed, phosphoric acid and antimony compounds from P and Sb based fire retardants, and many others. Such corrosion is not significant for structural materials, but delicate structures, especially microelectronics, are strongly affected. Corrosion of circuit board traces, penetration of aggressive chemicals through the casings of parts, and other effects can cause an immediate or gradual deterioration of parameters or even premature (and often delayed, as the corrosion can progress over long time) failure of equipment subjected to smoke. Many smoke components are also electrically conductive; deposition of a conductive layer on the circuits can cause crosstalks and other deteriorations of the operating parameters or even cause short circuits and total failures. Electrical contacts can be affected by corrosion of surfaces, and by deposition of soot and other conductive particles or nonconductive layers on or across the contacts. Deposited particles may adversely affect