Airborne endotoxin concentrations in various work areas within two cotton textile mills in the People's Republic of China.

As part of a multidisciplinary longitudinal approach to assess the roles of airborne cotton dust and endotoxins in affecting the respiratory health of cotton textile workers, this study was designed to quantify the endotoxin contamination of airborne vertically elutriated and total dusts. Yarn preparation areas (opening through fine spinning) were studied at two cotton textile mills which had been studied 5 years previously in Shanghai. People's Republic of China, Filter, with vertically elutriated (VE) or total dusts were mailed to the United States and endotoxin analyses were performed for each filter in duplicate with the quantitative chromogenic modification of the Limulus amebocyte lysate assay. Dusts from all areas of the textile mills contained endotoxins. Endotoxin burdens in VE dusts from the carding area were similar in both milk while the endotoxin contamination of total dust from carding in Mill 1 was over threefold greater than that of total dust from carding in Mill 2. All other areas differed between milk in both VE and total dust endotoxin burdens. Mean endotoxin levels in VE dusts from all areas of both mills were well above the reported threshold of 90 EU/m3 for acute pulmonary function effects in humans. Comparison of selected areas of both mills from the present study with the same work areas from the previous study showed that, in general, the airborne endotoxin burden was higher than levels found 5 years ago in these two mills. The data suggest that even with reduced or unchanged gravimetric dust levels in these two cotton textile mills, airborne endotoxin levels were higher and provided an increased potential for adverse respiratory response in exposed workers.

Effects of different extraction protocols on endotoxin analyses of airborne grain dusts.

The detection of gram-negative bacterial endotoxins in occupational dusts, specifically those from agricultural environments, is of increasing importance in research on occupational lung disease. In this study, the quantitative chromogenic Limulus amebocyte lysate test for the detection of endotoxins in airborne dusts from spring wheat and oats was examined. Different extraction fluids were tested, as were the effects of time on extraction and of repeated freeze-thaw cycles on the extracts. The data suggest that the chromogenic method can be used effectively in the analysis of environmental dusts or their frozen extracts for endotoxin quantitation. Water appears to be the preferable extraction medium, and the length of extraction time may affect the results.

Composition of extracts of airborne grain dusts: lectins and lymphocyte mitogens.

Airborne grain dusts are heterogeneous materials that can elicit acute and chronic respiratory pathophysiology in exposed workers. Previous characterizations of the dusts include the identification of viable microbial contaminants, mycotoxins, and endotoxins. We provide information on the lectin-like activity of grain dust extracts and its possible biological relationship. Hemagglutination of erythrocytes and immunochemical modulation by antibody to specific lectins showed the presence of these substances in extracts of airborne dusts from barley, corn, and rye. Proliferation of normal rat splenic lymphocytes in vitro provided evidence for direct biological effects on the cells of the immune system. These data expand the knowledge of the composition of grain dusts (extracts), and suggest possible mechanisms that may contribute to respiratory disease in grain workers.

In vitro and in vivo changes in human complement caused by silage.

Aqueous extracts of silage samples from four farms in up-state New York were reacted in vitro with normal human serum. Hemolytic levels of complement component C3 were consumed in a dose-dependent fashion, and the four extracts differed in their relative activity rankings. Studies with chelated serum indicate that the alternative complement pathway is involved in the activation, and the active fragment C3b was demonstrated. Serum levels of hemolytic C3 and C4 in vivo were quantified before and after farmers performed their normal silo unloading operations. Although the study groups were small, suggestive evidence of in vivo complement consumption was found. IgE-related allergy did not appear to be of significance to the study groups. Complement activation may be an initiator of or contributor to adverse reactions in farmers who are exposed to airborne silage dusts.

Human ventilatory response to washed and unwashed cottons from different growing areas.

Thirty volunteer subjects were exposed to controlled amounts of respirable dust generated by the carding of cotton in an experimental cardroom. Eighteen exposures each lasting six hours were performed while carding unwashed and washed cottons from the three major growing regions of the United States. Elutriated dust was analysed gravimetrically and was comparable (0.59 mg/m3 +/- 0.04) for all exposures. Spirometry was recorded before and after each exposure. California cotton resulted in a significantly smaller fall in FEV1 than cotton of the same grade from Texas or Mississippi. All washed cottons resulted in reduced declines when compared with unwashed cottons. For 17 subjects breathing zone personal total dust samples were analysed for airborne endotoxin and compared with the individual's pulmonary function response. A significant correlation between endotoxin exposure and acute decrease in FEV1 was seen. The effect on FEV1 per nanogram of airborne endotoxin was greater for Mississippi cotton than for cotton from the other regions. Airborne endotoxin appears to be an important determinant of acute pulmonary effects of cotton dust. Water washing of cotton results in reduced airborne endotoxin and less bronchoconstriction.

Effects of coal dust and diesel exhaust on immune competence in rats.

The effects on the immune system of rats that had been exposed to a 2-mg/m3 dose of either respirable coal dust, diesel exhaust fumes and particulates, or the combination of these were studied. Animals that were housed similarly but exposed only to filtered air served as controls. After 12 and 24 mo of exposure, the rats were tested for immunocompetency by enumerating antibody-producing cells in the spleen 4 d after immunization with sheep erythrocytes and by monitoring the proliferative response of splenic T-lymphocytes to the mitogens concanavalin A and phytohemagglutinin. The results of this study indicate that no major alterations occurred in the immunologic functions measured as a result of exposure to either coal dust, diesel exhaust fumes and particulates, or their combination.

Airborne endotoxins in a rice production commune in the People's Republic of China.

Concentrations of total and vertical elutriated airborne dusts were quantified for five work areas within a rice production commune near Shanghai, the People's Republic of China. Mean (+/- SE) commune levels of 15.69 +/- 1.91 mg/m3 and 6.00 +/- 1.47 mg/m3 were found for total and vertical elutriated dusts, respectively. Analysis of the airborne dusts for the presence of gram-negative bacterial endotoxins resulted in mean levels of 21.23 +/- 8.63 ng/mg total dust and 14.57 +/- 7.97 ng/mg elutriated dust, with respective airborne concentrations of 492.12 and 100.22 ng endotoxin/m3. These data show that rice production in the People's Republic of China is associated with a dust burden that is contaminated with relatively high levels of endotoxins. The long-term respiratory effects of inhalation of these dusts should be studied.

Endotoxins in baled cottons and airborne dusts in textile mills in the People's Republic of China.

Bulk cotton samples and airborne vertical elutriated cotton dusts were obtained from textile mills in Shanghai, People's Republic of China. Analysis of endotoxin contents revealed that baled cottons which were grown in different countries varied in endotoxin contamination. The two textile mills, which operated at similar overall airborne dust levels, differed markedly in the levels of airborne endotoxins. The data suggest that the biological activity or "toxicity" of airborne cotton dusts may not be correlated directly with gravimetric dust levels.

Changes in humoral immunologic parameters after exposure to volcanic ash.

Occupational exposure to volcanic ash from Mount St. Helens continues during the salvaging of trees in the high dust blow-down area of Washington. We studied the effects of volcanic ash exposure on the level of humoral immune factors IgG, IgA, IgM, C3, C4, and ANA (antinuclear antibody) in a group of volcanic ash-exposed loggers shortly after the major eruption and one year later. Comparisons with similar levels in nonexposed, similarly employed, matched loggers were made. C3 and C4 levels were significantly lower at both time periods in the exposed loggers when compared to the reference group. No differences between groups were observed at either time period for the immunoglobulin levels or ANA. The exposed loggers did show a marked decrease (not seen in the reference group) in serum IgG levels after 1 yr of exposure to the volcanic ash. They likewise showed a significant mean increase in IgA, while the reference group had a mean increase in IgM after 1 yr. These data suggest that exposure to volcanic ash may affect humoral immunologic parameters.

In vivo pulmonary response to Aspergillus terreus spores.

The fate of intratracheally instilled Aspergillus terreus spores was followed in both rabbits and rats. Phagocytosis of the spores by the pulmonary macrophage was rapid in that approx. 42% of the observed spores were associated with the macrophages immediately after instillation. Direct penetration of the lung architecture by the spores was not observed but spores were seen in the alveolar interstitium at 3 hr after instillation and in the tracheobroncheal lymph nodes at 24 hr. Granulomas formed between 48 hr and 1 week after exposure. In the absence of apparent spore or spore extract toxicity and precipitating antibodies against Aspergillus terreus, the observed reactions preclude the possibility that the lesions were the consequence of hypersensitivity. This model of pulmonary response to fungal spores may be of future value for characterizing further the pathology associated with certain occupational exposures to moldy materials.

Endotoxins in cotton: washing effects and size distribution.

Endotoxin contamination was measured in washed and unwashed cottons from three distinct growing areas, California, Mississippi, and Texas. The data show differences in endotoxin contamination based upon the geographic source of the cotton. It is also shown that washing bulk cotton before the carding process results in lower endotoxin in the cotton dust. Washing conditions can affect the endotoxin levels, and all size fractions of the airborne dust contain quantifiable endotoxin contamination. Endotoxin analyses provide a simple and reliable method for monitoring the cleanliness of cotton or airborne cotton dusts.

Occupational exposure to airborne endotoxins during poultry processing.

Airborne gram-negative bacterial endotoxin levels were quantified in a live chicken hanging (shackling) room of a poultry processing plant. The mean respirable dust levels at the entrance and exit of the shackling line were 1.13 +/- 0.12 and 0.72 +/- 0.06 mg/m3, respectively, or approximately 6% of the total dust. Endotoxins constituted 43.3 +/- 2.8 micrograms per gram of respirable dust. Airborne endotoxins were present in the total dust at the mean level of 918.4 +/- 159.0 ng/m3 at the room entrance and 634.0 +/- 96.9 ng/m3 at the exit, with respirable levels of 44.3 +/- 7.8 and 33.6 +/- 2.2 ng/m3. Inhalation of gram-negative bacterial endotoxins can result in respiratory and systemic pathophysiology. The potential for adverse health effects in the working environment of the live poultry processing industry is discussed. Medical studies of workers in this area are required to confirm or deny the existence of occupationally related health effects.

HLA-B8 in sarcoidosis.

One hundred and seventy-four unrelated white patients with biopsied and clinically diagnosed sarcoidosis and a reference population of 97 were tested for HLA antigens. Selected comparisons showed a statistically significant association of HLA-B8 with the sarcoidosis group (28.9%) when compared to the reference group (15.5%).

Immunology of clinically inactive sarcoidosis: serum factors.

Sera from 84 white patients with inactive sarcoidosis were analyzed for immunoglobulins, complement, autoantibodies, alpha 1-antitrypsin and lysozyme. The levels of serum factors were compared with levels in serum from a reference population which was matched for age, sex, ethnic background and geographic location. IgG, IgA, IgD, and C3 levels were similar for both groups, as were frequencies of rheumatoid factor, antinuclear antibody and anti-DNA antibody. Lysozyme levels were significantly lower in the inactive sarcoidosis group but the acute phase reactants alpha 1-antitrypsin, IgM as well as complement consumption were increased. The data suggest that the underlying etiological events of sarcoidosis continue, albeit at a subclinical level.

Cotton dust and complement in vivo.

Cotton grown in Stoneville, Mississippi and harvested by three different methods was examined for anticomplementary activity in human serum in vivo. Subjects exposed to cotton dust in a model cardroom for six hours showed changes in C3c and CH50 after exposure to closed boll harvested, bract removed cotton dust when compared with a group of normal, unexposed controls. Decreases in C3c, :C4, and C3A were associated with decreases in FEV1 after exposure to closed boll harvested bract intact cotton dust. The data from this preliminary study suggest in vivo associations between inhalation of cotton dusts and complement which appear to be independent of endotoxin contamination. These findings suggest a relationship between cotton dust inhalation and complement-mediated respiratory impairment.

Acute experimental pulmonary responses to cardroom cotton dust.

Laboratory rabbits were exposed for 60 min to aerosols of dry cardroom cotton dust 4 days/wk (Tuesday through Friday) for 15 consecutive weeks. As a parameter of pulmonary pathophysiology, arterial blood gases were monitored with time after challenge. Post-exposure blood gas analyses at 1 hr showed progressive decreases in arterial oxygen tension, with concommitant increases in arterial carbon dioxide tension and the alveolar-arterial oxygen gradient. These responses appeared to result from acute reversible airway obstruction which caused unequal gas distribution and ventilation-perfusion inequalities. When a group of proven responder rabbits was challenged with cardroom cotton dust which was first treated in a manner which paralleled the preparation of medical grade cotton, only minor decreases in arterial oxygen tension were observed. The data suggest that some, as yet undefined, agent(s) which was removed by the treatment was responsible for inciting the observed pathophysiology.

Complement activation by commercial allergen extracts of cereal grains.

Commercial allergen extract preparations of whole cereal grains were examined in vitro for their reactivity with the human haemolytic complement cascade. Total haemolytic complement was consumed in a dose-dependent manner which did not correlate with the protein nitrogen content or bacterial endotoxin contamination of the extracts. Alternative pathway activation was shown by C3 conversion in the presence of EGTA while classical complement components C1, C4 and C2 were also much decreased in serum which was free of detectable specific antibody. Very small amounts of allergen extract initiated the formation of complement-dependent factors which were chemotactic for human polymorphonuclear leucocytes. These data suggest a potential for complement activation in vivo by ingestion, inhalation, or injection of cereal grain products.