Pulmonary function and respiratory symptoms in forest firefighters

As part of a national study of surgical departments is Israel, cardiac surgery patients undergoing open heart surgery between 1987 and 1989 were followed-up prospectively. Of these, 1,046 patients had coronary artery bypass grafting (CABG) and are the subject of this report. The six-months mortality after surgery was 12.9% among 202 women and 4.1% among 844 men. Female gender was an independent predictor of mortality even after controlling for the effect of 14 putative risk factors. The adjusted relative risk for mortality in women compared to men was 2.79 (1.5-5.2). In an attempt to understand this excessive mortality among women, a detailed analysis in one of the participating hospitals revealed differences associated with surgical technique by gender, such as proportion of patients with entirely venous grafting vs internal mammary artery grafts (IMA). Thirty percent of women vs 4.8% of men had entirely venous grafting. Adjusting the data for differences in the proportion of venous grafting has obliterated the difference in mortality between the genders in that hospital. We suggest that interventions to reduce mortality among women should involve a more careful choice of female candidates for CABG surgery, as well as introduction of modifications in the operating technique.     

Pulmonary manifestations in cement workers in Jordan

The literature on obsessive-compulsive disorder (OCD) in children and adolescents is reviewed. The disorder is characterized by obsessions (recurrent troublesome thoughts) and compulsions (ritualized thoughts or behaviors performed repetitively in response to an irresistible urge). OCD is far more common among children and adolescents than was previously believed. Good epidemiological studies from different parts of the world are still needed to determine if prevalence is equally high. Boys seem to have an earlier age of onset of OCD than girls. Male female ratio changed with age of onset, with males predominating in early onset and increasing numbers of females occurring during adolescence. Increasing evidence supports a neurobiological theory for etiology of OCD, specifically a frontal lobe--basal ganglia dysfunction.     

Pulmonary function in perlite workers

Pulmonary function was studied in 117 men employed in three plants engaged in the mining and processing of perlite. Of these, 38 had been employed for ten years or more; 18 for 15 years or more and four men for 20 years or more. Review of chest films confirmed previous studies which showed no changes indicative of pneumoconiosis. Measurement of forced vital capacity (FVC) by Jones Pulmonor and by Collins 9-liter spirometer did not show reductions correlated with length of exposure, after effects of cigarette smoking had been taken into account. There was instead a slight increase in FVC associated with years in the perlite industry. The distribution of individuals with FVC below 80% of predicted also showed no association with duration of perlite exposure. Although there were slight reductions in forced expiratory volume in one second (FEV1) and in FEV1/FVC% which were associated with years in the perlite industry and which could not be explained by cigarette smoking, these reductions were not statistically significant. In summary, the population of men available for study in the major perlite-producing area of the United States, who have worked for periods up to 23 years, showed no evidence of pneumoconiosis by chest radiography or by measurement of forced vital capacity. Nevertheless, continued control of dust to ensure exposures below nuisance dust levels is essential. Medical surveillance should also continue with records being retained for periodic reevaluation.     

Mucociliary clearance and respiratory function in foundry workers

The aim of the study was to establish whether changes occur in respiratory function, particularly mucociliary clearance, among second fusion smeltery workers. The research covered 93 male smelters employed in steel forming and casting and 116 male workers of an electric power station, considered as non-exposed. Physiological, pathological and occupational histories of all subjects under study were available. An ECCS respiratory symptoms questionnaire was administered to all subjects ad the two groups also underwent a general medical examination, a spirometry and a chest X-ray. During the medical examination sputum was collected from the subjects to measure mucus transport rate on frog palate, expressed as Normalised Frog Palate Transport Rate (NFPTR). For the environmental research, dust, fumes and gas samplings were taken either at a fixed station or by means of personal dosimeters. Environmental research revealed very low concentrations of respiratory irritants (total dust: 0.2-6.8 mg/m3; respirable dust: 0.1-4.9 mg/m3; total silica: < 2-15.5%; respirable silica: < 0.004-0.3 mg/m3; iron: 0.008-0.085 mg/m3; chromium and manganese: < 0.001 mg/m3; fumes and gases: well below the TLV. The two groups were homogeneous with regard to age and smoking habits. Exposed workers showed rales, dyspnoea and spontaneous phlegm more frequently than non-exposed workers. NFPTR alterations were checked in 49 out of 81 exposed and in 18 out of 81 non-exposed subjects (chi squared = 22.9; p < 0.001). Stratification of the results according to smoking habits further confirmed the strong association between occupational exposure and NFPTR alterations. Smelters showed significantly lower mean NFPTR values compared to non-exposed subjects; also, the mean value of NFPTR in the exposed was below 0.70, which is considered the lowest individual limit in normal subjects. The only variable which explains a large part of the variability of NFPTR is past work in a smeltery rather than in an electric power station. The spirometries showed that only the mean PEF values were significantly lower among the exposed. Stratified analysis of the results according to smoking habits in the two groups revealed a close association between smeltery work and reduction of PEF to under 80% of the ECCS 1983 theoretical values, independently of smoking habits. We also compared the mean PEF values, both as measured values and as percent values of the ECCS 1983 theoretical values, stratified for occupational exposure and smoking; the results again showed that differences between these mean values were mainly due to current or past work in the foundry.(ABSTRACT TRUNCATED AT 400 WORDS)     

Prevalence and predictors of work related respiratory symptoms in workers exposed to organic dusts

Treatment of initial caries, albeit an everyday occurrence for the dental practitioner, presents considerable demands of patient assessment and diagnosis. Whatever decisions are made--to restore caries or to attempt to arrest its progress--the adoption of a maintenance program is of paramount importance. Patient motivation, in respect to dietary control and satisfactory oral hygiene, is central to a successful outcome, and in the future, practice management programs may include RAC as a diagnostic aid. New methods of caries management are more dynamic than traditional methods and place restoration of the lesion toward the bottom of the list of possible treatments, with the biologic rather than the mechanistic approach being a priority. However, the teaching of RAC in dental schools and the third-party funding of diagnostic tests and diagnosis are also required to reflect the increasing complexity of management of initial caries. If restorative intervention is indicated following diagnosis and RAC, treatment of initial caries should involve a minimal-intervention adhesive technique.     

Pulmonary complications and respiratory function changes after bone marrow transplantation in children

We prospectively assessed the frequency of pulmonary complications and the natural course of lung function after bone marrow transplantation (BMT), as well as the effect of several risk factors in a homogeneous group of 39 children who underwent allogeneic or autologous BMT for haematological malignancies between 1992 and 1995. Four patients developed pneumonia within the first 3 months and three 3-6 months after BMT. A considerable percentage of acute bronchitis was recorded throughout the follow-up. Three patients died after the 6 month visit because of pneumonia (two patients) and pulmonary aspergillosis (one patient). No patients had obstructive lung disease syndrome. At 3 months after BMT, forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and transfer factor of the lung for carbon monoxide (TL,CO) significantly decreased, but FEV1/FVC ratio and maximal expiratory flow at 25% of FVC remained unchanged, suggesting a restrictive defect with diffusion impairment. At 18 months, there was a progressive recovery in lung function, although only 11 patients had normalized. Seropositivity for cytomegalovirus had a significant effect on lung function whereas graft-versus-host disease also had an effect, although it was not statistically significant. Baseline respiratory function, type of transplant, type of conditioning regimen and respiratory infections did not significantly affect the outcome of BMT. The high frequency of severe lung function abnormalities found in this study, suggests a careful functional monitoring in all subjects undergoing bone marrow transplantation, even in the absence of respiratory symptoms.     

Respiratory function and symptoms in urban office workers in relation to oxidant air pollution exposure

Similar populations of male and female office workers in San Francisco, which has little air pollution, and in Los Angeles, which experiences frequent photochemical smog episodes, were surveyed in an attempt to document excess respiratory symptoms and dysfunction in Los Angeles relatable to air pollution. Most results of forced expiratory tests, single-breath N2 tests, and questionnaire interviews did not differ significantly between cities. Los Angeles women reported nonpersistent cough and phlegm more often than did San Francisco women. Smokers in both cities showed increased functional abnormalities. These results suggested that Los Angeles oxidant exposure is far less significant than smoking as a risk factor in development of chronic respiratory disease in sedentary indoor workers in good general health. Oxidant exposure has not been ruled out as a significant risk to more heavily exposed on more highly susceptible persons.     

硅酸盐水泥水化产物体积分数定量计算

为了研究硬化水泥浆体微观结构与其宏观性能之间的定量关系,基于Jennings-Tennis(J-T)模型提出了2种C-S-H的划分,给出了硅酸盐水泥水化各产物体积分数计算公式;采用水灰质量比为0.23,0.35和0.53的硬化水泥浆体对公式进行验证并与Powers模型计算结果进行比较.结果表明:水灰质量比为0.23,0.35和0.53的硬化水泥浆体产物中低密度与高密度C-S-H凝胶的体积分数之比分别为0.24,0.54和3.24;其中毛细孔和未水化水泥的体积分数与Powers模型所得的结果一致,验证了体积分数计算公式的合理性.     

Association of respiratory symptoms and lung function in young adults with use of domestic gas appliances

BACKGROUND: There is evidence from some studies that people living in homes with gas stoves and other unvented gas appliances experience more respiratory symptoms than those who use other fuels for cooking and heating, but other studies have found no such association. We have investigated whether the use of gas appliances is associated with an increased risk of respiratory symptoms and whether sensitisation to common environmental allergens modifies any such association. METHODS: A stratified random sample of 15,000 adults aged 20-44 years, living in three towns in East Anglia, UK, were sent a questionnaire on asthma and hayfever. From those who responded, a random sample of 1864 were invited to complete an extended questionnaire that included questions on use of gas appliances, to give blood samples for measurements of total IgE and specific IgE to common allergens, and to undergo tests of respiratory function, 659 women and 500 men agreed to an interview. The association of the use of gas appliances with respiratory symptoms, total IgE, specific IgE, and respiratory function was assessed by logistic and multiple regression models. FINDINGS: Women who reported they mainly used gas for cooking had an increased risk of several asthma-like symptoms during the past 12 months including wheeze (odds ratio 2.07 [95% CI 1.41-3.05]), waking with shortness of breath (2.32 [1.25-4.34]), and asthma attacks (2.60 [1.20 -5.6]). Gas cooking increased the risk of symptoms more in women who were atopic than in non-atopic women but the difference did not reach significance (p . 0.05). Women who used a gas stove or had an open gas fire had reduced lung function (forced expiratory volume in 1 s [FEV1]) and increased airways obstruction (FEV1 as a percentage of forced vital capacity) compared with women who did not. These associations were not observed in men. INTERPRETATION: In East Anglia, the use of gas cooking is significantly associated with subjective and objective markers of respiratory morbidity in women but not in men. Women may be more susceptible than men to the products of gas combustion or they may have greater exposure to high concentrations of these products because they cook more frequently than men.     

Risk factors for sensitisation and respiratory symptoms among workers exposed to acid anhydrides: a cohort study

OBJECTIVES: To examine the relation between exposure to acid anhydrides and the risk of developing immediate skin prick test responses to acid anhydride human serum albumin (AA-HSA) conjugates or work related respiratory symptoms; to assess whether these relations are modified by atopy or smoking. METHODS: A cohort of 506 workers exposed to phthalic (PA), maleic (MA), and trimellitic anhydride (TMA) was defined. Workers completed questionnaires relating to employment history, respiratory symptoms, and smoking habits. Skin prick tests were done with AA-HSA conjugates and common inhalant allergens. Exposure to acid anhydrides was measured at the time of the survey and a retrospective exposure assessment was done. RESULTS: Information was obtained from 401 (79%) workers. Thirty four (8.8%) had new work related respiratory symptoms that occurred for the first time while working with acid anhydrides and 12 (3.2%) were sensitised, with an immediate skin prick test reaction to AA-HSA conjugates. Sensitisation to acid anhydrides was associated with work related respiratory symptoms and with smoking at the time of exposure to acid anhydride. When all subjects were included and all three acid anhydrides were taken into account there was no consistent evidence for an exposure-response relation, but with the analysis restricted to a factory where only TMA was in use there was an increased prevalence of sensitisation to acid anhydrides and work related respiratory symptoms with increasing full shift exposure. This relation was apparent within the current occupational exposure standard of 40 micrograms.m-3 and was not modified significantly by smoking or atopy. CONCLUSIONS: Intensity of exposure and cigarette smoking may be risk factors for sensitisation to acid anhydrides. Exposure is also a risk factor for respiratory symptoms. As there was evidence for sensitisation to TMA at full shift exposures within the occupational exposure standard this standard should be reviewed.     

A broad line NMR and MRI study of water and water transport in Portland cement pastes

The results of a magnetic resonance spin-spin relaxation analysis and broad-line magnetic resonance imaging (MRI) (gradient-echo and stray-field imaging) study of water and water transport in Portland cement pastes are presented. The effect of varying the cure conditions and the water to cement (w/c) ratio of the sample of mix are discussed. The water sorptivity and the concentration dependence of the hydraulic diffusion coefficient are calculated for samples prepared with a 0.5 w/c ratio and, therefore, an open pore structure. In the case of 0.3 w/c ratio samples, little water transport is observed, and a closed pore structure is inferred.     

Differences in depressive symptoms between traditional workers and shiftworkers

To investigate the effect of physical exertion on simple reaction time and continuous attention of sport participants, an experiment was conducted with 46 male university students and 12 male cyclists. The subjects were assigned to three experimental and two control groups. The subjects of the experimental groups were asked to perform, following a 5-min, period of warming up, a high intensity exercise protocol for 5 min., on a mechanically braked cycle ergometer (Group A) or a moderate intensity exercise protocol for 30 min, on the same cycle ergometer (Groups B and C). Shortly before and immediately after the physical exercise subjects of all groups were asked to perform a test of simple reaction time and continuous attention. The subjects of the control groups were asked to perform at rest both tests of the simple reaction time and the continuous attention twice, with a 10-min. and a 35-min. interval between the first and second attempts, respectively. The results did not support the notion that exercise of moderate or high intensity influences significantly the cognitive performance of aerobically trained or untrained subjects. The results are discussed in the light of the current research findings concerning exertion and human psychomotor performance.     

Reaction rate and product morphology in carbon composite iron ore pellets with and without Portland cement

Abstract

The aim of this work is to study the reaction rate and the morphology of intermediate reaction products during iron ore reduction when iron ore and carbonaceous materials are agglomerated together with or without Portland cement. The reaction was performed at high temperatures, and used small size samples in order to minimise heat transfer constraints. Coke breeze and pure graphite were the carbonaceous materials employed. Portland cement was applied as a binder, and pellet diameters were in the range 5·6–6·5 mm. The experimental technique involved the measurement of the pellet weight loss, as well as the interruption of the reaction at different stages, in order to submit the partially reduced pellet to scanning electron microscopy. The experimental temperature was in the range 1423–1623 K, and the total reaction time varied from 240 to 1200 s. It was observed that above 1523 K the formation of liquid slag occurred inside the pellets, which partially dissolved iron oxides. The apparent activation energies obtained were 255 kJ mol^–1 for coke breeze containing pellets, and 230 kJ mol^–1 for those pellets containing graphite. It was possible to avoid heat transfer control of the reaction rate up to 1523 K by employing small composite pellets.     

Effect of environmental and clinical factors on lung function and respiratory symptoms in adolescents with alpha1-antitrypsin deficiency

Individuals identified in the Swedish neonatal alpha1-antitrypsin (AAT) screening study were followed prospectively from their first to their eighteenth year of life. The aim of this study was to analyse the effect of environmental factors, i.e. active and passive smoking, and of clinical factors on lung function and the occurrence of respiratory symptoms in AAT-deficient adolescents. The study group consisted of 88 protease inhibitor (Pi)ZZ and 40 PiSZ adolescents. Medical history including respiratory symptoms, and active and passive smoking were recorded at each follow-up up to the age of 18 y. Lung function tests were performed at the present check-up. At the age of 18 y, both forced expiratory volume in one second (FEV ) and FEV1/vital capacity (VC) were significantly lower in the smoking than in the non-smoking subgroup, and significantly more smokers than non-smokers reported the presence of phlegm. The mean FEV1/VC ratio was lower for those presently exposed to parental smoking. Multiple linear regression analysis indicated that clinical liver disease in early life, active smoking and parental smoking were independent determinants of FEV1/VC. The results suggest that marginal deviations in lung function and the symptom of phlegm among AAT-deficient adolescents occur characteristically early in the subgroup of smokers. Parental smoking may contribute to decreased lung function.     

Pulmonary function in former alcoholics

Data are presented on lactation and postpartum amenorrhea collected in a survey in Banaras Hindu University in India. The data pertain to 323 women aged 15-35 years having had at least 1 live birth. Data were available for 250 women who had had second-order live births. The mean duration of lactation is about 1 1/2 times the mean duration of postpartum amenorrhea. The former is 15.5 months after 1st births, and the latter is 6.11 months and 6.46 months after 1st births. Breast-feeding and post-partum amenorrhea are interrelated; the correlation coefficient between the 2 is .275 in the case of 1st birth and .257 in the case of 2nd birth. Generally the pattern of the 1st 2 births for a mother is the same if both children survive. There may be physiological, dietary, and other factors that also influence the resumption of ovulation after a birth.     

Mortality of iron miners in Lorraine (France): relations between lung function and respiratory symptoms and subsequent mortality

An increased mortality from lung and stomach cancer was found in previous studies on Lorraine iron miners. A detailed analysis, however, was not possible due to the lack of data for survivors. In this study the cohort included 1178 workers selected at random from all the 5300 working miners aged between 35 and 55 at the start of the follow up period, which ranged from 1975 to 1985. Occupational exposures and tobacco consumption, lung function tests, and respiratory symptoms were assessed for each subject in 1975, 1980, and 1985. This study confirmed the excess of lung cancer (standardised mortality ratio (SMR) = 389, p < 0.001) and of stomach cancer (SMR = 273, p < 0.05). There was no excess of lung cancer in non-smokers and moderate smokers (< 20 pack-years) or the miners who worked only at the surface or underground for less than 20 years. A significant excess (SMR = 349, p < 0.001) was found in moderate smokers when they worked underground for between 20 and 29 years. Heavy smokers (over 30 pack-years) or subjects who worked underground for more than 30 years experienced a high risk: SMR = 478 (p < 0.001) for moderate smokers who worked underground for over 30 years; 588 (p < 0.001) for heavy smokers who worked underground for between 20 and 29 years; and 877 (p < 0.001) for heavy smokers who worked underground for over 30 years. This showed an interaction between smoking and occupational exposure. The excess mortality from lung cancer was because there were some subjects who died young (from 45 years old). Comparison with the results of a previous study showed that additional hazards produced by diesel engines and explosives increased the mortality from lung cancer. The SMR was higher than 400 (p < 0.001) from 45 years old instead of from 56 years. A relation was found between a decrease in vital capacity (VC), forced expiratory volume in one second (FEV1) and of FEV1/VC and mortality from all causes and from lung cancer in heavy smokers or men who had worked underground for more than 20 years. Respiratory symptoms were related to mortality from lung cancer among smokers (moderate and heavy) who worked underground for more than 20 years. It is considered that the risk of lung cancer in the Lorraine iron miners was mainly due to dust, diesel engines, and explosives although the role of low exposure to radon daughters could not be totally excluded.     

Miscellaneous symptoms occurring in workers engaged in the manufacture of PVC

Five cases of lincomycin-clindamycin-associated acute pseudomembranous colitis, demonstrating a spectrum of clinical, histological and radiological severity, were encountered over a five-months period. All patients presented with watery diarrhoea without the passage of macroscopic blood or pus. Two patients were seriously ill with fulminant colitis, but responded rapidly to corticosteroids given parenterally and supportive therapy. The diagnosis of acute colitis should be considered in all patients developing diarrhoea during or up to three weeks after beginning therapy with lincomycin or clindamycin and can be confirmed by sigmoidoscopic examination. Withdrawal of the antibiotic and symptomatic treatment is appropriate for mild cases of colitis, but our experience suggests that corticosteroid therapy is safe and effective in severe cases. Indiscriminate use of these antibiotics should be avoided.