Respiratory function in active firefighters.

BACKGROUND: Exposure to environmental pollution during firefighting may results in the development of respiratory disorders in firefighters. METHODS: The health effects of firefighting on respiratory function was investigated in a group of 128 active firefighters by recording respiratory symptoms and measuring lung function. In addition, 88 control workers, not exposed to known pollutants were studied for the prevalence of acute and chronic respiratory symptoms. RESULTS: Significantly higher prevalences of dyspnea, nasal catarrh, sinusitis, and hoarseness were recorded in firefighters compared to control workers (P < 0.01). One subject developed asthma symptoms following two intense firefighting episodes. A high prevalence of acute symptoms experienced during and after fire extinguishing was also documented among these firefighters. Eye and throat irritation as well as headache were prominent. A logistic regression analysis of chronic respiratory symptoms demonstrated that odds ratios were significant for both duration of work exposure and for smoking. Lung function testing demonstrated a decrease in FEF75 in relation to predicted suggesting obstructive changes in the smaller airways. A regression analysis of ventilatory capacity tests indicated a positive relationship of forced vital capacity with length of employment, 1 s forced expiratory volume as well as FEF50 were related to smoking, and FEF75 was related to both smoking and length of employment. CONCLUSIONS: Our data suggest that firefighters are at risk for developing acute and chronic respiratory symptoms as well as obstructive airway changes.

Respiratory findings in livestock farmworkers.

In this cross-sectional study, the prevalence of acute and chronic respiratory symptoms and lung function were investigated in 236 (169 male and 67 female) livestock farmworkers raising domestic animals, including cattle and horses. The prevalence of acute and chronic respiratory symptoms was recorded by administering a modified version of the British Medical Research Council questionnaire on respiratory symptoms. Lung function was measured by recording the maximum expiratory flow-volume curves from which the forced vital capacity, the one-second forced expiratory volume, and the maximum expiratory flow rates at 50% and the last 25% were measured. There was a significantly higher prevalence of almost all chronic respiratory symptoms in farmers compared with controls: highest among men for chronic cough (27.2%) and highest among women for dyspnea (28.3%). Typical symptoms of occupational asthma were diagnosed in 3.6% of the male and 1.5% of the female livestock farmers. A logistic regression analysis performed on chronic respiratory symptoms of livestock workers indicate significant effects of smoking (P < 0.001) on all symptoms except occupational asthma. A large number of male and female livestock farmworkers complained of acute work-related symptoms: highest for dry cough (52.2%) and shortness of breath (44.9%). Lung function data among these workers demonstrated a trend toward lower lung function in general. Multivariate analysis of lung function parameters indicate significant effects of length of employment and smoking in male and length of employment in female livestock farmworkers. The data suggest that employment in livestock farming may be associated in a dose-dependent manner with the development of acute and chronic respiratory symptoms and lung function changes.

Respiratory findings in chemical workers exposed to low concentrations of organic and inorganic air pollutants.

BACKGROUND: Occupational exposure to respiratory irritants may effect respiratory function in workers exposed to ambient air pollutants in the workplace. METHODS: We studied 567 male and 135 female workers employed in two chemical plants in Zagreb, Croatia. Measurements of the ambient concentrations of air pollutants were performed. The mean age of the men was 37 years and mean duration of employment was 12 years; a majority of these workers were smokers. The mean age of the women was 37 years with a mean duration of employment of 14 years; only one-third of the women smoked. An unexposed group of 340 male and 110 female unexposed workers was also studied. Acute and chronic work related symptoms were recorded for all workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. RESULTS: There were higher prevalences for all chronic respiratory symptoms in exposed than in unexposed workers particularly among women, a majority of which were nonsmokers. Occupational asthma was recorded in three (0. 5%) of the men and in two (1.5%) of the women workers. Logistic regression analysis indicated that the presence of chronic respiratory symptoms among exposed workers was primarily associated with the amount of smoking. Additionally, there were high prevalences of acute symptoms during the work shift. Among the chemical workers these were greatest for eye irritation (male: 43. 9%; female: 51.9%), dryness of the throat (male: 43.4%; female: 57. 0%) and irritation of the throat (male: 37.4%; female: 56.6%). Ventilatory capacity data among the chemical workers demonstrated that most of the measured tests, particularly the FVC and FEV1 were significantly decreased compared to predicted (P < 0.01 or P < 0. 05)). In particular nonsmoking women exhibited abnormal lung function. The effect of smoking among exposed workers was demonstrated on all ventilatory capacity tests by regression analysis for all measured respiratory parameters. Both length of exposure and age were correlated with lung function loss for FVC. Measured pollutant levels were for the most part within acceptable standard limits. CONCLUSIONS: Our data suggest that in this population of chemical workers exposed to low levels of pollutants respiratory symptoms were primarily associated with smoking. Environmental effects, possibly due to an interaction of pollutants were also suggested.

[Respiratory function and allergic reactions in paper recycling workers]. / Respiracijska funkcija i alergijske reakcije radnika na recikliranju papira.

Respiratory function and allergic reactions were studied in 101 male workers in paper recycling and in 87 nonexposed male control workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves with readings on forced vital capacity (FVC), one-second forced expiratory volume (FEV1), and maximum expiratory flows at 50% and the last 25% (FEF50 and FEF25, respectively). Skin prick test with paper dust allergens, some nonoccupational allergens, and total immunoglobulin IgE analysis were used to assess immunological status. Significantly higher prevalences of all chronic respiratory symptoms were recorded in the exposed workers than in controls. The highest prevalence was recorded for chronic cough (36.6%), followed by chronic phlegm (34.7%), chronic bronchitis (33.7%), sinusitis (31.7%), nasal catarrh (29.7%), and dyspnea (16.8%). Occupational asthma was diagnosed in four paper recycling workers only (4.0%). Values of FEF50 and FEF25 were significantly lower than predicted, indicating obstructive changes located mostly in the smaller airways. Skin tests to paper allergens were found positive in 16 (15.8%) paper recycling workers and none in controls. An increase in total immunoglobulin IgE was found in 21 of 101 paper recycling workers and in two of 37 of controls (P < 0.05). Our data indicate that exposure to air pollutants in paper recycling industry may lead to the development of respiratory symptoms accompanied by lung function and immunological impairment.

Nafarelin controlled release injectable: theoretical clinical plasma profiles from multiple dosing and from mixtures of microspheres containing 2 per cent, 4 per cent and 7 per cent nafarelin.

Nafarelin controlled release injectable (CRI) releases a decapeptide drug for target one month therapy. Nafarelin, a luteinizing hormone releasing hormone agonistic analogue, is microencapsulated in biodegradable poly(lactide-co-glycolide) microspheres and given by intramuscular injection. Clinical data from a human single dose Phase I clinical study are modelled to develop theoretical multiple dose profiles and theoretical single dose profiles from mixtures of two or three formulations. Single dose injections of nafarelin CRI microspheres (4 mg nafarelin) containing 2, 4, or 7 per cent nafarelin all achieve useful plasma drug levels throughout the target 30 day interval. Therapeutic suppression of testosterone levels was observed in all subjects participating in the phase I clinical study. Highest plasma nafarelin levels are achieved in the 0-10 and 20-35 day post-injection intervals. Theoretical multiple dosing profiles generated from the single dose clinical results show significant oscillations in plasma nafarelin levels depending on the particular dosing interval selected. Thirty or forty day dosing intervals yield significant variability in plasma nafarelin levels at steady state; 15 day dosing intervals show less variability. Therapeutic testosterone suppression was observed in the single dose study, so the nafarelin dose per injection can be reduced in multiple dosing therapies. Theoretical plasma nafarelin profiles from certain mixtures of 2 and 4 per cent nafarelin microspheres or 2 and 7 per cent nafarelin microspheres indicate that a 60 day product could be achieved. In general, all three formulations yield their lowest plasma drug levels during the 10-20 day post-injection interval. Therefore any mixture of these formulations will likewise exhibit low plasma drug levels during this interval.