Philip R. Morey

Building-associated pulmonary disease from exposure to Stachybotrys chartarum and Aspergillus versicolor.

The authors present an outbreak of disease associated with exposure to Stachybotrys chartarum and Aspergillus species. A courthouse and two associated office buildings had generated discomfort among employees for two years since initial occupancy. Multiple interventions had been unsuccessful An initial evaluation of 14 individuals identified three with potential asthma and three with symptoms consistent with interstitial lung disease. A clinical screening protocol to identify individuals who should be removed from work identified three likely and seven possible cases of building-related asthma. Detailed environmental and engineering assessments of the building identified major problems in mechanical system design, building construction, and operational strategies leading to excess moisture and elevated relative humidities. Moisture-damaged interior surfaces in both buildings were contaminated with S. chartarum, A. versicolor, and Penicillium species. Aspergillus species, especially A. versicolor, at concentrations of 10(1) to 10(4)/m3 dominated the indoor air under normal operating conditions. Bulk samples also revealed large quantities of Stachybotrys. A questionnaire survey of the three case and two control buildings documented between three- and 15-fold increases in symptoms. A nested case-control study suggested emphysematous-like disease in individuals meeting questionnaire definitions for cases. Replication of analysis strategies used in similar previous investigations suggested an association between worsening symptoms and decreased diffusing capacity of the lung. Performance on neuropsychological measures was similar for both cases and controls, although workers with symptoms reported increased levels of current but not past psychiatric symptomatology. Chemical analyses demonstrated the presence of satratoxins G and H. Cytotoxic laboratory analyses demonstrated the presence of agents with biological effectiveness in bulk materials. No association was seen between IgE or IgG antibodies and the presence of disease. This outbreak represents a likely human response to inhaled fungal toxins in indoor environments. Moisture indoors represents a public health issue currently inadequately addressed by building, health, or housing codes.

Evaluation of the Andersen Viable Impactor for Single Stage Sampling

A modified use of the 6-stage Andersen viable sampler for single stage sampling is described. Although size distribution data are not obtainable with such a sampler, it has utility as a simple and convenient method for estimating the total concentration of viable airborne microorganisms. The method was compared in the field to the standard Andersen sampler and a previously described method for single plate sampling. Over a wide range of airborne fungal concentrations (10-3000 CFU/m3), the modified sampler was found to be superior to the previous method and comparable to the standard Andersen sampler (in terms of both precision and accuracy), for estimating total airborne fungal concentration.

Pulmonary Disease Associated with Cafeteria Flooding

An illness among office workers, consisting of cough, fever, chills, muscle aches, and chest tightness was associated with water leaks from a cafeteria. Mean single breath carbon-monoxide diffusing capacity (DLCO) of cases differed significantly from that of non-cases. There was a significant decrease in the percent of predicted DLCO with increasing number of symptoms. Testing for precipitating antibodies to microbial agents found in the building revealed no differences between cases and non-cases. DLCO is an appropriate cross-sectional instrument for field investigations of building-associated respiratory disease.

Gram-negative Bacteria on Cotton with Particular Reference to Climatic Conditions

Various factors that control the contamination of the cotton plant by Gram-negative Bacteria (GNB) were studied. The following cotton plant parts were contaminated with decreasing numbers of GNB: senescent bracts, pericarps, green bracts, seed cotton and leaves. Freezing of green cotton capsules (fruit) caused a significant increase in numbers of GNB on both bracts and seed cotton. Raw cotton derived from cotton plants harvested late in the autumn contained significantly larger numbers of GNB and higher levels of endotoxin than cotton collected early in the harvest season.

Environment influences levels of gram negative bacteria and endotoxin on cotton bracts

Bracts were collected at two geographical locations to determine if biological and physical changes occur in these plant parts as they mature and senesce in the cotton field during late summer and throughout the autumn. The mass median diameter of bracts subjected to laboratory abrasion tests decreases after the first killing freeze. A dramatic increase in the content of gram negative bacteria (GNB) and endotoxin occurs in whole bracts collected after the first killing freeze. The level of GNB and endotoxin in respirable bract dusts increases from 10 to 100 fold after bracts have been frozen in the field.

The Distribution of Gram Negative Bacteria and Endotoxin on Raw Cotton Components

The botanical composition of representative raw cottons from seven different growing regions was determined by manual removal and identification of all trash components greater than 50 micron in size. The number of gram negative bacteria (GNB) and the amount of endotoxin present in each of the separated raw cotton components were quantified. Low middling cotton contained significantly more bract-leaf trash than that found in higher quality cottons such as those in the middling grade division. Significantly more GNB and endotoxin were found in botanical trash components as well as lint of raw cotton derived from the southwest and southeast growing regions as compared to similar botanical components from far west cottons. For representative raw cottons from the 1980 USA crop we determined that 67% of the GNB and 89% of the endotoxin resided on white lint itself, from which all particulate larger than 50 micron in size had been removed manually.

Interactions of a water extract of cotton bract with dog isolated airway smooth muscle.

The inhalation of cotton dust by cotton-mill workers causes byssinosis, a disease characterized by chest tightness and other symptoms indicative of bronchoconstriction. In the present study the dog isolated trachealis smooth muscle preparation was employed to examine the ability of a crude, water extract of cotton bracts (CBE) to (1) cause contractile responses mediated by receptors, (2) modify responses of the tissue to a number of excitatory and inhibitory agents, and (3) alter responsiveness of the preparations to electrical field stimulation mediated by intrinsic cholinergic, excitatory nerves and adrenergic, inhibitory nerves. CBE evoked contraction of the tissues by an action that did not involve muscarinic, histamine, or 5-hydroxytryptamine receptors. The maximum tissue responses to exogenous histamine, 5-hydroxytryptamine, and isoproterenol were enhanced significantly in the presence of CBE, while those to KCl and methacholine were unaffected. The sensitivities (EC50 values) of the tissues to these agents were not, however, altered by CBE. Contractions induced by cholinergic nerve stimulation were increased in the presence of CBE, via a mechanism that appears, at present, to result from a prejunctional facilitation of acetycholine release. Relaxations to adrenergic nerve stimulation were not affected by CBE. Results suggest that, in addition to its direct, contractile activity, CBE can alter indirectly the responsiveness of the tissue to a number of endogenous mediator substances. Intrinsic, cholinergic excitatory nerves may be a target for the acute action of CBE as well.

Endotoxin Content in Cottonseed Oil Mill Dust

The objective of this study was to quantify the amount of endotoxin present in respirable dusts collected in cottonseed oil mills. The level of endotoxin in workplace air exceeded 0.5 µg/m3 in about 30% of the examined samples. The amount of endotoxin found in the dust varied over two orders of magnitude from 0.01 µg to 1.3 µg per mg of vertically elutriated particulate. The endotoxin contamination of cottonseed oil mill dust varied both between and within mills and was not consistently related to the amount of dust captured by the vertical elutriator cotton dust sampler.

Microbial and endotoxin content of botanical trash in raw cotton

The objective of this study was to examine widely varying grades of raw cotton obtained from different geographical regions to see if gram negative bacteria (GNB) and endotoxins are localized specifically on lint or botanical trash components. Removal of trash particles from raw cottons resulted in a decrease in the GNB and the endotoxin contents of the cleaned lint. The seed, bract, and leaf trash components removed from raw cottons each contributed very large amounts of GNB and endotoxin to the total specimen. The small amount of stained lint found in some raw cottons was also a rich source of these microbial materials.

Effects of a cotton bract extract on guinea pig isolated airway smooth muscle

The effects of a water extract of cotton bracts (CBE) on guinea pig isolated trachealis smooth muscle was studied. The ability of CBE to evoke tension responses, to modify tissue reactivity to excitatory and inhibitory agents, and to modify electric field stimulation-induced neurogenic responses was evaluated. CBE caused contraction in low concentrations, which were not mediated by histamine H1-, muscarinic, or 5-hydroxytryptamine (5-HT) receptors, and caused relaxation in high concentrations. In the presence of CBE, the maximum contractile response to 5-HT and the sensitivity to KCl were reduced. The maximum relaxation responses and sensitivities to adenosine and ATP were increased by CBE. In contrast, contractile responses to histamine and methacholine and relaxation responses to isoproterenol were unaffected. Neurogenic cholinergic excitatory responses and neurogenic adrenergic responses did not appear to be affected by CBE. However, the relaxant effect of nonadrenergic inhibitory nerve stimulation was increased in the presence of CBE. These findings differ from previous ones observed in our laboratory for dog isolated trachealis smooth muscle preparations, which indicates that the effects of CBE in isolated airways is species-dependent. Virtually all of the contractile activity of CBE was dialyzable (molecular weight less than 14,000) and retained in ashed samples. Inorganic constituents may contribute to the spasmogenic activity of CBE.