Unifying concepts underlying the effects of organic dust exposures

Abstract

Defense mechanisms protect the lung very well from inhaled organic dusts. With sufficient exposure to certain dusts, however, susceptible individuals develop hypersensitivity pneumonitis (HP), the organic dust toxic syndrome (ODTS), or asthma. Mucous membrane irritation (MMI) bothers some individuals inhaling grain dust. Allergic asthma is caused by IgE-mediated immunologic responses to allergenic dust contaminants. ODTS can be explained by a nonimmunologic release of interleukin 1 (IL-1) and perhaps other endogenous pyrogens from alveolar macrophages by endotoxin or other ingredients of dusts. The pathogenesis of HP may involve IL-1 release combined with a specific immunological response by effector T-lymphocytes. MMI may be the result of an irritant effect not involving immune responses or mediators.

Indoor Mold, Toxigenic Fungi, andStachybotrys chartarum: Infectious Disease Perspective

“…This is an important point, since as discussed below, most animal models of Stachybotrys pulmonary toxicity rely on direct inoculation of organisms into the airway, in concentrations high enough that they can later be seen in lung tissue. Allergic pulmonary effects of mold have been well described, ranging from upper airway inflammation (rhinitis with coincident conjunctivitis) to asthma, allergic pulmonary aspergillosis (the latter usually affecting patients with intrinsic lung disease and bronchiectasis), and HP (73,301,345,376). While an in-depth discussion of this topic is beyond the scope of this review, some findings are worth mentioning.…”

“…Surprisingly, there was not an association with self-reported hay fever or asthma (222), even though allergic asthma is IgE mediated (345). These authors apparently did not check for IgE to nonmold allergens.…”

A 5-year follow-up study on respiratory disorders and lung function in workers exposed to organic dust from composting plants

“…The primary health eVect of exposure to organic dust is an inXammatory response of the upper airways with congested nose, sore throat, and dry cough frequently in connection with symptoms of the eyes like redness and lacrimation-the so-called mucous membrane irritation (MMI)-subsiding several hours after cessation of exposure (Richerson 1990;do Pico 1992;Rylander 1994). High concentrations of organic dust are capable of inducing toxic reactions such as the organic dust toxic syndrome (ODTS), also called toxic pneumonitis (Lacey and Crook 1988;Rylander 1994).…”

Evaluation of Pulmonary Function in a Composite Textile Processing Unit in Punjab (Pakistan).

“…In this study measurement of particulate matter (PM) aerodynamic arrangement of 2.5 µ fraction were performed using a portable direct-reading equipment TSI DustTrak, Model 8520 (TSI Inc., Shoreview, MN USA)(cf. McNamara et al (2011;Richerson (1990)). The instrument was zeroed before each sampling and mounted on indigenously fabricated tripod in the breathing zone just near each workstation for a working shift.…”

“…Several studies have found an association between occupational exposure to dust, gases and fumes and respiratory health and the same studies have proved a prevalence of respiratory symptoms of 16%-46% (cf. Hedlund et al (2008;Richerson (1990)). Chronic obstructive pulmonary disease (COPD) is a diverse group of lung disorders which is characterized by airflow obstruction and impede normal respiration.…”