Inhalation secondary processing

Industrial processes primary organic aerosols from, 48 secondary organk aerosols from, 101 Infmed spectra of aerosols, 68 Inhalation. See also Respiratory tystem of ozone, 165... 

Determining anticipated route and magnitude of exposure is an important component in the overall assessment of safety and must be done on a nanomaterial-by-nanomaterial basis, with secondary exposures taken into consideration when necessary. The estimated exposure levels for a nanomaterial may then be compared with the calculated safe dose derived from the hazard identification evaluation. The procedures and factors considered in the exposure assessment process are not expected to be any different for nanomaterials than for larger particles or chemicals. The degree of hazard associated with exposure to any chemical or substance, regardless of its physicochemical characteristics, depends on several factors, including its toxicity, dose-response curve, concentration, route of exposure, duration and/or frequency of exposure. However, depending on the route of anticipated exposure (dermal, inhalation, oral) and types of associated toxicities (local or systemic), a chemical may not pose any risk of adverse effects if there is no... 

Experimental studies in idealized bronchial structures (e.g., 97-103) or in replicates of casts (e.g., 104-112) allow inhalation of substantial amounts of particles into easily accessible structures without having to deal with secondary redistribution phenomena caused by continuous particle clearing or lung preparation processes. They are performed to obtain information on primary deposition patterns with finer spatial resolution than is possible in in vivo experiments. These types of measurements may also be considered as the experimental match, validating theoretical approaches on particle deposition (see later). Mean local deposition rates, but also the heterogeneity of particle deposition within bifurcating zones, were investigated. Many studies (98-103,105,111) specifically focused on localization of so-called hot-spots, which are sites of enhanced deposition within the larynx or the tracheobronchiolar tree and may be most important rela-... 

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