Is the short term limit value for sulphur dioxide exposure safe? Effects of controlled chamber exposure investigated with bronchoalveolar lavage.

Bronchoalveolar lavage (BAL) which has not previously been used in investigating the effect of sulphur dioxide (SO2) on the human lung was performed on 12 subjects before and after controlled chamber exposure with SO2 for 20 minutes. BAL fluid 24 hours after exposure with 10 mg SO2/m3 (4 ppm, 10 subjects) showed increased alveolar macrophage activity as judged by an increase in lysozyme positive macrophages. Twenty four hours after 20 mg/m3 (4 subjects) a further increase was seen, which was accompanied by an increase in total numbers of macrophages and lymphocytes. Seventy two hours after exposure (4 subjects) cell numbers had virtually returned to pre-exposure levels. These previously uninvestigated reactions indicate potentially noxious effects of SO2 in the lungs at exposure levels that are regarded as relatively safe.     

Increased CD3 positive cells in bronchoalveolar lavage fluid after hydrogen fluoride inhalation.

OBJECTIVES: This study examined whether experimental hydrogen fluoride exposure for 1 hour induces an inflammatory response in the lower respiratory tract that is detectable in bronchoalveolar lavage fluid. METHODS: Nineteen healthy, nonsmoking men were exposed for 1 hour to constant low (<0.6 mg/m3), intermediate (0.7-2.4 mg/m3), or high (2.5-5.2 mg/m3) concentrations of hydrogen fluoride. Bronchoalveolar lavage was performed at least 3 weeks before and 24 hours after the exposure. For 15 subjects differential countings were performed. RESULTS: There was a significant increase in the percentage of CD3 positive cells in the bronchial portion for those exposed to "intermediate" and "high" concentrations. For the "high" exposure group the increase in the bronchoalveolar portion was also significant. A significant correlation was found between the increase in the percentage of lymphocytes and CD3 positive cells in the bronchoalveolar portion (Spearman's coefficient r=0.68, P=0.008). Myeloperoxidase and interleukin-6 increased significantly in the bronchial portion for those exposed to "high" concentrations. There was a significant increase in myeloperoxidase (P=0.005) for all the exposures, while there was a decrease in E-selectin (P=0.007). CONCLUSIONS: Hydrogen fluoride may induce an inflammatory reaction in the airways at concentrations that can occur in the ambient air in the primary aluminum industry.     

Effect of 3 hours of passive smoke exposure in the evening on inflammatory markers in bronchoalveolar and nasal lavage fluid in subjects with mild asthma

Objectives: The aim of this study was to investigate the effect of environmental tobacco smoke (ETS) exposure in the evening on inflammatory changes in bronchoalveolar (BAL) and nasal lavage (NAL) fluid. Methods: Ten subjects with mild asthma [mean (±SD) age, 25 ± 2 years, FEV₁% pred., 93 ± 6%, PC₂₀FEV₁ 0.44 X 5.11 mg/ml methacholine] were exposed to ETS (22.4 ± 1.2 ppm CO) or ambient air (sham) for 3 h (7.00 to 10.00 p.m). Bronchoscopy was performed the following morning at 7.00 a.m. A visual endoscopic score was assessed, and BAL fluids were analyzed for cellular composition and concentrations of histamine, albumin, eosinophilic cationic protein, myeloperoxidase, hyaluronic acid, tryptase, prostanoids and leukotrienes. Nasal lavages were performed 30 min prior to and 30 min after exposures, and NAL fluids were analyzed for histamine, albumin, eosinophilic cationic protein, myeloperoxidase, hyaluronic acid, and tryptase. Results: There was a significant rise in symptoms after ETS exposure compared with sham (P<0.05). Spirometric lung function did not change during or after exposure compared with pre-session values. Visual bronchoscopic scoring revealed no significant effect of ETS exposure, nor did BAL cells and mediators or NAL mediators as compared with pre-challenge or post-sham values. Conclusion: In the subjects tested, a 3-h ETS exposure in the evening appeared not to have an inflammatory effect detectable in BAL or NAL fluid. Received: 21 August 1996 / Accepted: 2 January 1997     

The effects of chrysotile and crocidolite asbestos on the lower respiratory tract: Analysis of bronchoalveolar lavage constituents

This study was designed to evaluate the effects of amphibole and serpentine asbestos inhalation on the constituents of the lower respiratory tract. Bronchoalveolar lavage (BAL) analyses were performed on three groups of rats: one group was exposed to chrysotile (serpentine) asbestos, another group was exposed to crocidolite amphibole asbestos, while a third group was sham-exposed. Intermittent inhalational exposures lasted three months. The total BAL cell yields and the macrophage content of BAL cells were significantly lower after asbestos exposure, especially in the chrysotile-exposed group. These effects persisted for as long as 1 year after the cessation of exposure. Multinucleated macrophages were seen in BAL cells from both asbestos-exposed groups. Striking ultrastructural alterations of macrophage morphology were noted in BAL cells from both groups of asbestos-exposed rats. Chrysotile fibers were not seen in any BAL cells from chrysotile-exposed animals. However, 15 months after terminating the exposure regimen, a sizeable proportion of BAL macrophages from crocidolite-exposed rats contained phagocytosed asbestos fibers. Significantly higher β-glucuronidase and lactate dehydrogenase activity was found in BAL fluids from both asbestos-exposed groups and was detected 17–18 months after exposure had ceased. These observations have served as useful correlates of asbestos-mediated injury to the lower respiratory tract. They have also provided evidence of continual pathological sequelae occurring long after withdrawal from asbestos exposure.     

The effects of chrysotile and crocidolite asbestos on the lower respiratory tract: analysis of bronchoalveolar lavage constituents

This study was designed to evaluate the effects of amphibole and serpentine asbestos inhalation on the constituents of the lower respiratory tract. Bronchoalveolar lavage (BAL) analyses were performed on three groups of rats: one group was exposed to chrysotile (serpentine) asbestos, another group was exposed to crocidolite amphibole asbestos, while a third group was sham-exposed. Intermittent inhalational exposures lasted three months. The total BAL cell yields and the macrophage content of BAL cells were significantly lower after asbestos exposure, especially in the chrysotile-exposed group. These effects persisted for as long as 1 year after the cessation of exposure. Multinucleated macrophages were seen in BAL cells from both asbestos-exposed groups. Striking ultrastructural alterations of macrophage morphology were noted in BAL cells from both groups of asbestos-exposed rats. Chrysotile fibers were not seen in any BAL cells from chrysotile-exposed animals. However, 15 months after terminating the exposure regimen, a sizeable proportion of BAL macrophages from crocidolite-exposed rats contained phagocytosed asbestos fibers. Significantly higher beta-glucuronidase and lactate dehydrogenase activity was found in BAL fluids from both asbestos-exposed groups and was detected 17-18 months after exposure had ceased. These observations have served as useful correlates of asbestos-mediated injury to the lower respiratory tract. They have also provided evidence of continual pathological sequelae occurring long after withdrawal from asbestos exposure.     

Long term effects of alumina on components of bronchoalveolar lavage fluid from rats.

Significant differences in several components of bronchoalveolar lavage fluid (BAL fluid) have previously been reported in aluminium potroom workers compared with controls. The present paper describes the long term effects in rats of one time exposure to potroom aluminium oxide without fluorides (primary alumina (PA)) or with adsorbed fluorides (secondary alumina (SA)) on components of BAL fluid. Alumina dust (40 mg) suspended in saline was instilled intratracheally; controls received saline. Bronchoalveolar lavage (BAL) was performed one, four, and 12 months after exposure. The number of cells in BAL fluid was increased significantly (p < 0.05) by SA but not PA. The increase was mainly macrophages, but the concentrations of neutrophils also increased about 10-fold one and 12 months after exposure. Although albumin and hyaluronan concentrations did not differ from those of controls, fibronectin concentrations were significantly (p < 0.001) increased one year after exposure both in PA exposed and SA exposed rats. The results indicate that SA, possibly because of adhered fluorides, induces early changes in alveolar cell populations including persistent neutrophilia. These cellular changes may have a destructive effect. The late pronounced increase of fibronectin in both PA and SA exposed rats indicates a delayed effect of alumina on the extracellular matrix.     

Reductions in lymphocyte subpopulations after repeated exposure to 1.5 ppm nitrogen dioxide.

In this investigation the effects of repeated exposure to 1.5 ppm NO2 on immune competent cells in bronchoalveolar lavage (BAL) fluid was studied. Special attention was focused on effects on lymphocyte subpopulations. Eight healthy subjects were exposed to 1.5 ppm NO2 every second day on six occasions. Bronchoalveolar lavage fluid was collected at least three weeks before the exposure series as reference and 24 hours after the last exposure. The results obtained were analysed using a non-parametric test for paired observations, with each subject as his own control. Significant reductions were found in the total number and percentage of T cytotoxic-suppressor cells in BAL fluid; this caused an increase in the ratio of T helper-inducer: cytotoxic-suppressor cells. The total number of natural killer cells in the BAL fluid was also reduced. The numbers of all other cell types were unchanged after exposure. No reduction of phagocytosis of opsonised yeast particles by alveolar macrophages in vitro was detected. It is concluded that repeated short term exposures to 1.5 ppm NO2, a moderate occupational concentration, induces significant effects on immune competent bronchoalveolar lymphocytes. This indicates that previous findings of changes in the lymphoid immune system induced by NO2 in animals may well be applicable to humans.     

Effect of a single oral dose of ascorbic acid on body temperature and trace mineral fluxes in healthy men and women.

Several metabolic changes characteristic of the acute-phase response were examined in healthy men and women following a single 1 g dose of ascorbic acid. Utilizing a placebo-controlled, double-blind protocol, oral body temperatures were recorded in rested, fasted subjects (0900 hr) prior to the consumption of 1 g L-ascorbic acid or placebo (n = 10/group). Temperatures were recorded hourly for the next 8 hours, and again the next morning in the rested, fasted state (0900 hr). Blood samples, collected at 0, 4, and 24 hours post-dose, were analyzed for plasma ascorbate, iron, and zinc. Mean oral body temperature was significantly elevated 2 hours post-dose in the experimental subjects compared to controls (+0.7 degrees F, p = 0.03). In the vitamin-dosed subjects, mean plasma ascorbate rose 32% over the control value after 4 hours (1.11 +/? 0.08 and 0.84 +/? 0.06 mg/100 ml, ns). Serum iron levels were similar in the two groups at 0 and 4 hours post-dose, but at 24 hours post-dose mean serum iron of the vitamin-dosed subjects fell to 73% of that recorded for the control subjects (77 +/? 8 and 105 +/? 10 micrograms/100 ml, p = 0.04). Plasma zinc levels were similar for both groups at 0, 4, and 24 hours post-dose. These data indicate that ascorbate administration, at a level commonly supplemented in the US diet, elicits several host metabolic responses similar to those observed following exposure to infectious or inflammatory agents. These metabolic changes are most likely due to the reducing potential of the vitamin and may factor in the reported prophylactic success of vitamin C supplementation.     

Reductions in lymphocyte subpopulations after repeated exposure to 1.5 ppm nitrogen dioxide.

In this investigation the effects of repeated exposure to 1.5 ppm NO2 on immune competent cells in bronchoalveolar lavage (BAL) fluid was studied. Special attention was focused on effects on lymphocyte subpopulations. Eight healthy subjects were exposed to 1.5 ppm NO2 every second day on six occasions. Bronchoalveolar lavage fluid was collected at least three weeks before the exposure series as reference and 24 hours after the last exposure. The results obtained were analysed using a non-parametric test for paired observations, with each subject as his own control. Significant reductions were found in the total number and percentage of T cytotoxic-suppressor cells in BAL fluid; this caused an increase in the ratio of T helper-inducer: cytotoxic-suppressor cells. The total number of natural killer cells in the BAL fluid was also reduced. The numbers of all other cell types were unchanged after exposure. No reduction of phagocytosis of opsonised yeast particles by alveolar macrophages in vitro was detected. It is concluded that repeated short term exposures to 1.5 ppm NO2, a moderate occupational concentration, induces significant effects on immune competent bronchoalveolar lymphocytes. This indicates that previous findings of changes in the lymphoid immune system induced by NO2 in animals may well be applicable to humans.     

纳米氧化钕致SD大鼠肺部炎症反应中 miR-498-5p的表达及意义

目的 探讨纳米氧化钕（NPs-Nd2 O3 ）致SD大鼠肺部炎症反应中miR-498-5p的表达水平及意义。方法 将42只SPF级健康雄性SD大鼠随机分为对照组和NPs-Nd2 O3 染毒组,按照100 mg/kg浓度,采用非暴露式气管内一次性滴注法对大鼠进行NPs-Nd2 O3 染毒处理,在染毒第7、14和28 d后处死大鼠。计算肝脏、脑、肾脏、脾脏、睾丸、肺脏的脏器系数;采用电感耦合等离子体质谱法（ICP-MS）检测肝脏、脑、肾脏、脾脏、睾丸、肺脏中钕元素的含量;酶联免疫吸附法（ELISA）测定血清、肺泡灌洗液及肺组织中肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）的含量;实时荧光定量PCR检测大鼠肺组织中miR-498-5p的相对表达水平; TargetScan、 mireap、miRanda网站预测与miR-498-5p相互作用的下游靶基因; Pearson相关分析miR-498-5p与炎症因子TNF-α、IL-6的相关性。结果 NPs-Nd2 O3 染毒后,大鼠肺脏的脏器系数增加（t=-3.408,P=0.005）;肝脏、脑、肾脏、脾脏、睾丸、肺脏中均检测到钕元素;血清、肺泡灌洗液及肺组织中TNF-α、IL-6的含量升高（P<0.05）;NPs-Nd2 O3 染毒第7、14和28 d后肺组织中miR-498-5p的相对表达水平升高（7 d组: t= -21.236,P<0.001;14 d组: t= -4.631,P=0.010;28 d组: t= -6.132,P=0.001）,miR-498-5p表达与TNF-α含量呈正相关（ r =0.787,P=0.012）,与IL-6含量呈正相关（ r =0.708,P<0.033）;KEGG富集分析发现与miR-498-5p作用的靶基因其中有27个mRNAs参与JAK/STAT通路,19个mRNAs参与NF-κB通路。结论 NPs-Nd2 O3 经呼吸道进入体内可引起肺部明显炎症反应;NPs-Nd2 O3 染毒组大鼠肺组织中miR-498-5p表达水平升高,并与TNF-α、IL-6含量呈正相关;MiR-498-5p可能通过JAK/STAT通路和NF-κB通路参与NPs-Nd2 O3 诱导的肺部炎症。     

Plasma and lung macrophage responsiveness to carotenoid supplementation and ozone exposure in humans

OBJECTIVE: To examine the effect of ozone exposure and vegetable juice supplementation on plasma and lung macrophage concentrations of carotenoids. DESIGN: A randomized trial. SETTING: Subjects were exposed to ambient air prior to antioxidant supplementation and to ozone after antioxidant supplementation or placebo. Exposures occurred while exercising intermittently in a controlled metabolic chamber at the Human Studies Division, US EPA. SUBJECTS: In all, 23 healthy subjects between ages of 18 and 35 y. INTERVENTIONS: Subjects consumed a low fruit and vegetable diet for 3 weeks. After the first week, subjects underwent a sham exposure to filtered air with exercise, followed by bronchoalveolar lavage (BAL). Subjects were randomly assigned into supplement (one can vegetable juice, vitamins C and E daily) or placebo (orange soda, placebo pill daily) groups for 2 weeks. After the 2-week intervention, subjects were exposed to 0.4 ppm (784 microg/m(3)) ozone for 2 h with exercise followed by BAL. Blood samples were drawn before, immediately after and 3 h postexposure on each exposure day. The concentrations of nine carotenoids were determined by HPLC in BAL macrophages and plasma samples. RESULTS: Plasma concentrations of all the carotenoids that were present in the vegetable juice (except cis-beta-carotene) increased significantly in the supplemented group. Lung macrophage alpha-carotene concentrations increased significantly, lycopene isomers increased slightly, and all other carotenoids decreased (nonsignificantly) in the supplementation group following the intervention. Ozone exposure resulted in decreases in several carotenoids in plasma of the placebo group, but not in the supplemented group. CONCLUSIONS: Lung macrophage concentrations of carotenoids can be manipulated by diet. Ozone is a potent environmental oxidant that appears to reduce plasma carotenoids in nonsupplemented individuals.     

Characteristics of alveolar cells and soluble components in bronchoalveolar lavage fluid from non-smoking aluminium potroom workers.

Aluminium potroom workers have been reported to develop severe pneumoconiosis and bronchial hyperreactivity. The influence of inhalation of aluminium oxide and fluorides on the alveolar milieu was studied by bronchoalveolar lavage (BAL) in 14 male non-smoking potroom workers; 28 non-smoking healthy volunteers served as controls. The total numbers, concentrations, and proportions of various alveolar cells did not differ between the groups. The concentrations of albumin and fibronectin in BAL fluid were significantly higher (p less than 0.01 for both) in the exposed workers, reflecting an increased alveolar capillary permeability and an activation of alveolar macrophages (AMs). The concentration of angiotensin converting enzyme, another AM marker, was, however, decreased (p less than 0.01) in the workers. The concentration of hyaluronan, a fibroblast marker, did not differ between the groups. AMs from workers had a decreased capacity (p less than 0.05) to interact with yeast C3b particles but not to ingest them. The expression of HLA-DR and OKM1 on the cell surfaces of AMs were equal in the two groups. The BAL findings were not accompanied by restrictive lung disease in the workers. The fact that only a discrete alveolitis was found in the potroom workers may be due to a low grade of exposure to alumina and fluorides and to frequent use of respiratory protection equipment.     

Effect of a single oral dose of ascorbic acid on body temperature and trace mineral fluxes in healthy men and women

Several metabolic changes characteristic of the acute-phase response were examined in healthy men and women following a single 1 g dose of ascorbic acid. Utilizing a placebo-controlled, double-blind protocol, oral body temperatures were recorded in rested, fasted subjects (0900 hr) prior to the consumption of 1 g L-ascorbic acid or placebo (n = 10/group). Temperatures were recorded hourly for the next 8 hours, and again the next morning in the rested, fasted state (0900 hr). Blood samples, collected at 0, 4, and 24 hours post-dose, were analyzed for plasma ascorbate, iron, and zinc. Mean oral body temperature was significantly elevated 2 hours post-dose in the experimental subjects compared to controls (+0.7 degrees F, p = 0.03). In the vitamin-dosed subjects, mean plasma ascorbate rose 32% over the control value after 4 hours (1.11 +/- 0.08 and 0.84 +/- 0.06 mg/100 ml, ns). Serum iron levels were similar in the two groups at 0 and 4 hours post-dose, but at 24 hours post-dose mean serum iron of the vitamin-dosed subjects fell to 73% of that recorded for the control subjects (77 +/- 8 and 105 +/- 10 micrograms/100 ml, p = 0.04). Plasma zinc levels were similar for both groups at 0, 4, and 24 hours post-dose. These data indicate that ascorbate administration, at a level commonly supplemented in the US diet, elicits several host metabolic responses similar to those observed following exposure to infectious or inflammatory agents. These metabolic changes are most likely due to the reducing potential of the vitamin and may factor in the reported prophylactic success of vitamin C supplementation.     

Extracellular matrix components in bronchoalveolar lavage fluid in quartz exposed rats

To investigate the long term effects of quartz, bronchoalveolar lavage (BAL) and analysis of lung silica were performed in rats (n = 20) one, four, and 12 months after exposure to intratracheally instilled crystalline silica. Total and relative concentrations of silica in the lungs were highest one month after exposure. At this time BAL fluid concentrations of total cells, macrophages, and lymphocytes increased five to 10-fold compared with saline instilled controls (n = 19). The number of polymorphonuclear cells (PMNs) increased about 200-fold. The increased number of PMNs persisted during the year. Furthermore, albumin and fibronectin concentrations increased continually during the year, about two to fivefold the values of controls. Hyaluronan, by contrast, increased during the four month period (about eightfold) but decreased after one year to the one month concentration. Phospholipids in BAL fluid, raised already after one month, remained high at one year. The findings suggest progressive damage of the alveolar and interstitial tissues. Moreover, the increases in components of the extracellular matrix capable of building fibrotic networks are in agreement with the microscopical findings of fibrosis. Because only total cells, macrophages, and albumin concentrations correlated weakly with the silica contents of the lung, it is unlikely that the relation between quartz burden and the reaction in the lung is simple.     

Effects of chronic and acute ozone exposure on lipid peroxidation and antioxidant capacity in healthy young adults

BACKGROUND: There is growing evidence for the role of oxidative damage in chronic diseases. Although ozone (O3) is an oxidant pollutant to which many people are exposed, few studies have examined whether O3 induces oxidative stress in humans. OBJECTIVES: This study was designed to assess the effect of short-and long-term O(3) exposures on biomarkers of oxidative stress in healthy individuals. METHODS: Biomarkers of lipid peroxidation, 8-isoprostane (8-iso-PGF), and antioxidant capacity ferric reducing ability of plasma (FRAP) were analyzed in two groups of healthy college students with broad ranges of ambient O3 exposure during their lifetimes and previous summer recess either in Los Angeles (LA, n = 59) or the San Francisco Bay Area (SF, n = 61). RESULTS: Estimated 2-week, 1-month, and lifetime O3 exposures were significantly correlated with elevated 8-iso-PGF. Elevated summertime exposures resulted in the LA group having higher levels of 8-iso-PGF than the SF group (p = 0.02). Within each location, males and females had similar 8-iso-PGF. No regional difference in FRAP was observed, with significantly higher FRAP in males in both groups (SF: p = 0.002; LA: p = 0.004). An exposure chamber substudy (n = 15) also showed a significant increase in 8-iso-PGF as well as an inhibition of FRAP immediately after a 4-hr exposure to 200 ppb O3, with near normalization by 18 hr in both biomarkers. CONCLUSIONS: Long-term exposure to O3 is associated with elevated 8-iso-PGF, which suggests that 8-iso-PGF is a good biomarker of oxidative damage related to air pollution.     

Extracellular matrix components in bronchoalveolar lavage fluid in quartz exposed rats.

To investigate the long term effects of quartz, bronchoalveolar lavage (BAL) and analysis of lung silica were performed in rats (n = 20) one, four, and 12 months after exposure to intratracheally instilled crystalline silica. Total and relative concentrations of silica in the lungs were highest one month after exposure. At this time BAL fluid concentrations of total cells, macrophages, and lymphocytes increased five to 10-fold compared with saline instilled controls (n = 19). The number of polymorphonuclear cells (PMNs) increased about 200-fold. The increased number of PMNs persisted during the year. Furthermore, albumin and fibronectin concentrations increased continually during the year, about two to fivefold the values of controls. Hyaluronan, by contrast, increased during the four month period (about eightfold) but decreased after one year to the one month concentration. Phospholipids in BAL fluid, raised already after one month, remained high at one year. The findings suggest progressive damage of the alveolar and interstitial tissues. Moreover, the increases in components of the extracellular matrix capable of building fibrotic networks are in agreement with the microscopical findings of fibrosis. Because only total cells, macrophages, and albumin concentrations correlated weakly with the silica contents of the lung, it is unlikely that the relation between quartz burden and the reaction in the lung is simple.     

Characteristics of alveolar cells and soluble components in bronchoalveolar lavage fluid from non-smoking aluminium potroom workers

Aluminium potroom workers have been reported to develop severe pneumoconiosis and bronchial hyperreactivity. The influence of inhalation of aluminium oxide and fluorides on the alveolar milieu was studied by bronchoalveolar lavage (BAL) in 14 male non-smoking potroom workers; 28 non-smoking healthy volunteers served as controls. The total numbers, concentrations, and proportions of various alveolar cells did not differ between the groups. The concentrations of albumin and fibronectin in BAL fluid were significantly higher (p less than 0.01 for both) in the exposed workers, reflecting an increased alveolar capillary permeability and an activation of alveolar macrophages (AMs). The concentration of angiotensin converting enzyme, another AM marker, was, however, decreased (p less than 0.01) in the workers. The concentration of hyaluronan, a fibroblast marker, did not differ between the groups. AMs from workers had a decreased capacity (p less than 0.05) to interact with yeast C3b particles but not to ingest them. The expression of HLA-DR and OKM1 on the cell surfaces of AMs were equal in the two groups. The BAL findings were not accompanied by restrictive lung disease in the workers. The fact that only a discrete alveolitis was found in the potroom workers may be due to a low grade of exposure to alumina and fluorides and to frequent use of respiratory protection equipment.     

Wheat flour exposure results in recruitment of inflammatory cells in the lungs of healthy individuals

BACKGROUND: Flour dust in bakeries is known to cause allergic as well as nonallergic respiratory symptoms. Fungal alpha-amylase is a commonly used baking additive that has been shown to have allergenic properties. The aim of this study was to investigate any effects on bronchoalveolar lavage (BAL) cells and peripheral blood lymphocytes (PBL) of healthy individuals exposed to airborne wheat flour dust with or without fungal alpha-amylase added. METHODS: Fifteen subjects were exposed during 1 hr in an exposure chamber, ten individuals to wheat flour alone and five with alpha-amylase added. BAL was performed 2-6 weeks before and 1 day after the exposure. BAL cells were differentially counted and flowcytometric analysis of the expression of activation, adhesion, and subset markers on alveolar macrophages (AM) and T cells in BAL fluid and peripheral blood were carried out. RESULTS: Exposure to wheat flour dust increased the total number of cells in BAL fluid from 75.4 (i.q. range 70.4-104.1) to 127.4 (92.1-187.4) cells x 10(6)/L, P < 0.01. There was a significant difference in the change of total BAL cell concentration between the study group exposed to wheat flour only (n = 10; increase with 91.9 x 10(6)/L) and the group exposed to wheat flour with the baking additive fungal alpha-amylase (n = 5; decrease with 5.4 x 10(6)/L). The exposure level of respirable dust was lower in the group that received alpha-amylase and the increase in BAL cell concentration showed a positive correlation with the concentration of respirable dust in the exposure chamber (r = 0.80, P < 0.001). The phenotypic analysis of AM indicated an influx of monocytic cells. CONCLUSIONS: The results indicate that the concentration of respirable dust, but not alpha-amylase, is of importance for the recruitment of inflammatory cells to the peripheral airways in healthy individuals exposed to wheat flour dust.     

Cell response in bronchoalveolar lavage fluid after sulfur dioxide exposure

Environmental chamber exposure and bronchoalveolar lavage (BAL) were used to study the dose-response relationship between short-term exposure to sulfur dioxide (SO2) and inflammatory reactions in the human lung as reflected in BAL fluid. Healthy subjects were exposed to 10, 13, 20, or 30 mg/m3 for 20 min. BAL was performed several weeks preexposure and 24 h postexposure. Mast cells, lymphocytes, lysozyme positive macrophages, and the total number of macrophages were significantly increased after SO2 exposure. A dose-dependent increase in the cell response in BAL fluid was observed after exposure to 10-20 mg/m3, but no further increase was detected after 30 mg/m3. Inflammatory cell response was found in BAL fluid at SO2 levels that occur in industrial indoor environments worldwide, and cell response to SO2 was also seen below the short-term exposure limit of Sweden and many other countries (13 mg/m3).     

Pulmonary toxicity in hamsters of smoke particles from Kuwaiti oil fires.

The Kuwaiti oil wells set on fire by retreating Iraqi troops at the end of the Persian Gulf War released complex particles, inorganic and organic gases, and hydrocarbons into the atmosphere, damaging the environment where many people live and work. In this study, we assessed the health effects of particles from the Kuwaiti oil fires by instilling hamsters intratracheally with particles (<3.5 microM in size) collected in Ahmadi, a residential area in Kuwait located downwind of hundreds of oil fires. Twenty-four hours after instillation, we performed bronchoalveolar lavage (BAL) to assess various indicators of pulmonary inflammation, including neutrophil and macrophage numbers; albumin, an index of air-blood barrier permeability; and activities of three enzymes: lactate dehydrogenase (LDH; an indicator of cell injury), myeloperoxidase (MPO; which indicates activation of neutrophils), and ss-N-acetylglucosaminidase (GLN; which is indicative of damage to macrophages or neutrophils). We compared the response of hamsters instilled with particles from Ahmadi to animals instilled with urban particles collected in St. Louis, Missouri. We also compared the Ahmadi particles against a highly fibrogenic positive control ([alpha]-quartz) and a relatively nontoxic negative control (iron oxide). When compared to hamsters instilled with particles from St. Louis, the animals treated with the Ahmadi particles had between 1.4- and 2.2-fold more neutrophils in their BAL fluids. The Ahmadi hamsters had more macrophages and lower MPO and LDH activities, but comparable albumin levels and GLN activities. Thus, the acute toxicity of the Ahmadi particles was roughly similar to that of urban particles collected in the United States, when identical masses were compared. However, the relatively higher concentrations of particles measured in Kuwait and Saudi Arabia during the oil fires (at times more than 16 times higher than the EPA standard) is of particular concern. In addition, since the long-term effects of exposure to these particles remains unknown, further studies are needed to fully assess the health effects of the Kuwaiti oil fires.