Effect of passive smoking on respiratory function in cigarette factory workers
Dr. Ilidia Fritze Hernández M.D. , Dr. Marta Pernas Gómez M.D. ,
Dr. Lourdes Arencibia Flores M.D.
ABSTRACT:
A descriptive study was conducted at the Orlando Nodarse Cigarette Factory in Havana to evaluate respiratory function in 174 workers—both smokers and non-smokers— using respiratory function tests (RFT), following confirmation that both smoking and tobacco smoke pollution were important risk factors at the factory. Results show that many of the workers had abnormal respiratory function test variables, with restrictive respiratory disorders or airway constriction as the most common finding. No significant differences were found between smokers and non-smokers, demonstrating abnormal values for each RFT variable. Recommendations aimed at changing habits and at improving environmental working conditions at this cigarette factory are outlined.Subject Headings: TOBACCO SMOKE POLLUTION/adverse effects; SMOKING/adverse effects; TOBACCO INDUSTRY; OCCUPATIONAL EXPOSURE; RESPIRATORY FUNCTION TESTS; VITAL CAPACITY; FORCED EXPIRATORY VOLUME; MAXIMAL MID-EXPIRATORY FLOW RATE; RISK FACTORS.
The goals and guidelines of the 1992-2000 plan for preserving and promoting the health of the Cuban population are based on an assessment of changes brought about in the population's health by the implementation of various health programs and the transformations that have taken place in Cuban society. The reduction of non-transmissible disease morbidity and mortality is one of the fundamental goals set for this period.1
In a morbidity study at the Orlando Nodarse Cigarette Factory in Havana, several risk factors favoring the onset of chronic obstructive lung disease were identified, particularly heavy smoking in a considerable number of workers and inadequate environmental conditions characterized essentially by the continuous presence of smoke from the cigars and cigarettes of smoking workers, rendering all workers passive smokers. Thus, the development of a health assessment program for this center required an accurate evaluation of respiratory function for all workers as an essential element for the subsequent adoption of measures aimed at reducing morbidity from chronic obstructive lung disease. Studies indicate that such an assessment should not be limited to simple clinical evaluation, demonstrating that without respiratory function testing, clinical evaluation is generally incomplete due to the high incidence of false negative observations reported. 2,3 Even in cases with positive clinical findings, one-to-one correspondence between the degree of subjective and objective clinical manifestations and the magnitude of functional disorders are seldom found, particularly in the obstructive type of disorders.4
Clearly, the use of respiratory function testing is recommended to ensure better characterization of bronchopulmonary function.
The aims of this study were to describe the behavior of RFT variables in the individuals studied, and to compare respiratory function in smokers and non-smokers.
Methods
The study was carried out in a cigarette factory in Cerro municipality, Havana, in coordination with the Héroes de Girón Polyclinic. The factory has 245 workers, 145 men and 93 women; 148 of them smokers. In all, 171 workers (73.1% of the total) were randomly included in the study on a voluntary basis. The age of subjects fluctuated between 20 and 71 years. Sex, height and age were considered in determining normal RFT values, as per standard reference tables.
A survey was conducted to identify respiratory symptoms detected and reported by each subject. Each worker was examined, including auscultation, and also underwent respiratory function testing in the morning, using Japanese Microspiro H-298 computerized equipment. Several factors were taken into consideration to evaluate respiratory function: Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Maximum Expiratory Flow (MEF) and the relation between the FEV1 and the FVC (FEV1%).
Workers participating in the study were divided into two groups: smokers and non-smokers. Within each group, they were subdivided according to values obtained in the RFTs (normal or decreased).
Forced expiratory maneuver quality was checked observing the flow-volume curve which the registration equipment automatically integrates while allowing verification of expiratory effort.
A number of variables were considered in determining the homogeneity of the two groups, such as time spent working at the factory, age and sex of each subject. The number of cigars and cigarettes smoked by workers was not included as a useful variable because it was impossible to calculate exactly, since unrestricted smoking is permitted during working hours, and no one keeps track of amounts smoked.
For non-smokers, degree of exposure to second-hand smoke was likewise impossible to measure, since such exposure was basically continuous throughout the work day and also impossible to quantify
Data was analyzed using FOXPLUS software. Statistical treatment applied included the chi-square test to detect relations between selected variables (Ho: lack of relation or independence), and another two tests to detect percentage differences (Po=P) using MICROSTAT software.
Results
One hundred and seventeen of the workers included in the study were smokers and 57 were non-smokers.
The physical exam performed at the time of respiratory function testing was negative in all cases. (IS there a period here, or is there something missing?) this is a pretty straightforward translation... you can substitute "for all subjects" for "in all cases", but that's all there is...
Decreased FVC was found in 69 smokers and 42 non-smokers. Statistical analysis did not reveal an association between smoking and abnormally low FVC (Table 1).
Table 1. Results of FVC values among sample subjects and association with the smoking
habit
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FEV1% results, in subjects with a normal FVC and in those showing a decrease in this variable, show that only 48 workers had normal values, 15 had airway obstruction, 98 had constricted lungs, and 13 a mixed disorder. A greater percentage of obstructive and constrictive respiratory disorders was detected among smokers (Table 2). Statistical analysis did not show an association between the smoking habit and the presence of decreased values of FEV1% for any FVC value.
Table 2. Results of FEV1% values in sample subjects and association with the smoking habit
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For normal FEV cases, X2 p=0.3211 (Ho accepted)
For decreased FEV cases, X2 p=0.2053 (Ho accepted)
Among the 48 workers showing normal values of FVC and FEV1%, 26 smokers and 8 non-smokers with a reduced MEF were found, indicating obstruction of the small airways.
Table 3 Morphological and functional changes
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X2: p=0.0581
Ho accepted.
Smoking was not statistically significant for the onset of reduced values of MEF (Table 3).
Discussion
The great number of smokers in the sample reflects the general situation of the factory. Despite the fact that a complete cause-and-effect study was not carried out, nearly all workers interviewed consider that the ease with which they can obtain cigarettes and cigars is significant, in addition to the fact that designated smoking areas are in close proximity to the production area, thus eliminating any practical or significant limitations on smoking in the factory.
Constricted lungs and airway obstruction in a considerable part of the sample suggests a deteriorating process in the small airways and possibly in the alveolar septum,5,6 constituting in fact the most severe consequence of the increase in phagocytic activity and local liberation of proteases.
Other possible causes for constrictive/obstructive disorders cannot be ruled out, given the limited scope of this study. For example, air quality in the area surrounding the factory exerts a sustained influence on the workers' airways and alveoli. Sedimentary powders and other airborne particles, and also the presence of irritating substances such as sulfur dioxide in the air, are factors which stimulate phagocytic activity and local release of proteolytic enzymes.
The decreased FEV1% index can be interpreted as demonstrating the presence of obstructive respiratory disease, and although present in a small percentage of subjects from the two groups (Table 2), it is significant when considering individual care and treatment of each subject.
It is a known fact that the continuing presence of cigarette smoke in the airways produces a transformation of the epithelium and also an increase in mucous secretion and edema. These factors could explain the decrease in FEV1% in 15 subjects (ten smokers and five non-smokers).
In the absence of other functional changes, a reduction in the MEF is the expression of airway obstruction of less than 2mm in diameter. The results shown in Table 3 suggest that some morphological and functional changes in the small airways are occurring, without other apparent changes, which allows us to conclude that in these individuals morpho-funtional deterioration is less advanced allowing for a greater probability of recovery upon the elimination of the causes of these disorders.
In short, from the functional point of view, the most relevant findings are the appearance of abnormally low values in all variables studied and the impossibility of demonstrating significant differences for any of them between smokers and non-smokers. That is, onset of functional respiratory changes occurs in the same proportion among the subjects of both groups. With regards to the size of the sample relative to the overall numbers of workers in the factory, and given the statistical analysis performed, it appears that passive smoking has important repercussions on the results. The high degree of air contamination from cigar and cigarette smoke consumed constitutes a risk factor of utmost importance, as reported in the literature.7-15.
Without analyzing possible quantitative differences associated with exposure to smoke among smokers and non-smokers since it would go beyond the scope of this study, it is clear to us that all those who work in the factory are more or less exposed to the smoke coming from the cigars and cigarettes consumed. All results obtained confirm that in smokers and non-smokers alike, there are functional repercussions.
Conclusions
- Abnormal values were found in all variables studied as part of the FRT in a large
proportion of subjects; restrictive respiratory disorder or constricted lungs occurred in the greatest percentage of subjects from the sample studied.
- These findings were true for smokers and non-smokers (or passive smokers) alike, which is attributed to the high degree of environmental exposure to smoke suffered by the passive smokers, without ruling out the possible influence of other environmental factors in the geographic area.
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This article originally appeared in Spanish in the Revista Cubana de Medicina General Integral
, vol. 14, No. 2, (pp. 113-18), March-April, 1998.
Copyright (c) 1999, MEDICC - Medical Education Cooperation with Cuba