|Year : 2018 | Volume
| Issue : 1 | Page : 47-53
Work-Related respiratory symptoms and cardiopulmonary function impairment of factory workers in a cement company in South-West Nigeria
Happiness Anulika Aweto, Bosede Abidemi Tella, Adetutu Islamiyyah Lateef
Department of Physiotherapy, University of Lagos, Lagos, Nigeria
|Date of Web Publication||2-Jul-2018|
Happiness Anulika Aweto
Department of Physiotherapy, Faculty of Clinical Sciences, College of Medicine, University of Lagos, PMB 12003, Idi-Araba, Lagos
Source of Support: None, Conflict of Interest: None
Background: Cement factory workers are exposed to dangerous cement dust while at workplace especially in the developing countries where little or no safety standards are followed. This study investigated the work-related respiratory symptoms and cardiopulmonary functions' impairment in cement factory workers in South-West, Nigeria. Materials and Methods: Seventy cement exposed workers and 70 age-matched unexposed individuals participated in this cross-sectional study. A self-administered questionnaire was used to assess their sociodemographic characteristics, clinical details, and respiratory symptoms. Selected cardiopulmonary parameters of participants were measured. Data were analyzed using the Statistical Package for Social Sciences version 20.0. Independent t-test was used to compare the selected cardiopulmonary parameters of the two groups. Results: The mean age of cement-exposed group was 31.57 ± 8.32 years, and the unexposed group was 31.50 ± 8.57 years. The prevalence of respiratory symptoms among the cement-exposed group were as follows: 71.4% for cough, 45.7% for phlegm, 67.1% for wheeze, 38.6% for breathlessness, and 48.6% for chest tightness while those for the unexposed group were as follows: 50% for cough, 15.7% for phlegm, 5.7% for wheeze, 2.9% for breathlessness, and 7.1% for chest tightness. There were significant differences between the mean values of forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1)/FVC ratio, peak expiratory flow rate, systolic blood pressure, and diastolic blood pressure (P < 0.05) of the cement-exposed group and those of the unexposed group. Conclusion: Respiratory symptoms were higher among cement factory workers than the age-matched unexposed individuals. FVC, FEV1, FEV1/FVC ratio, and peak expiratory flow rate were reduced while blood pressure was increased in cement factory workers.
Keywords: Cardiopulmonary functions, cement factory workers, respiratory symptoms, work-related
|How to cite this article:|
Aweto HA, Tella BA, Lateef AI. Work-Related respiratory symptoms and cardiopulmonary function impairment of factory workers in a cement company in South-West Nigeria. Afr J Med Health Sci 2018;17:47-53
|How to cite this URL:|
Aweto HA, Tella BA, Lateef AI. Work-Related respiratory symptoms and cardiopulmonary function impairment of factory workers in a cement company in South-West Nigeria. Afr J Med Health Sci [serial online] 2018 [cited 2019 Apr 26];17:47-53. Available from: http://www.ajmhs.org/text.asp?2018/17/1/47/235737
| Introduction|| |
Work-related disorders are the major cause of complaints and disability in the working population. Respiratory conditions impose burden on the society and are among the leading causes of death. Multiple determinants serve to increase the burden of chronic respiratory disease some of which include occupational exposures, tobacco smoke, and lung infection. The worldwide communities, especially the people in developing countries, are facing increasing risk of developing respiratory diseases due to the production of smoke and dust in different occupational and industrial sectors. Environmental- and work-related respiratory diseases account for a significant portion of preventable illnesses and they are the leading work-related illnesses in the United States based on the frequency, severity, and preventability of diseases. Exposure to various dusts, chemicals, vapor, and fumes in the workplace is a contributory factor to the development of chronic obstructive pulmonary disease (COPD) of which 19.2% of COPD cases in the USA are attributable to work exposure. Exposure to quarry dust has a detrimental effect on lung function, as shown in prerevolution Libyan quarry workers.
Cement is manufactured through a series of processes that include mining, crushing, and grinding of raw materials, blending, and kiln burning to form clinker, cement milling and packaging. Dust emitted during these processes, exposes workers to the hazard of work-related respiratory diseases. Several studies have been done to investigate the prevalence of work-related respiratory problems associated with exposure to dust in cement factories among workers and have yielded different results.,,, Most of the studies reported a high prevalence of respiratory symptoms and signs such as coughing, sputum, wheezing, and dyspnea as well as alteration of the pulmonary indices of cement workers.,,,, However, few researchers have reported no significant difference in most respiratory symptoms between exposed and unexposed workers.,, Previous studies have also reported reduction in lung function in workers exposed to high concentrations of asbestos dust.,,,, There is higher prevalence of work-related respiratory problems in developing countries than in developed countries mainly because workers work without proper personal protective equipment or ventilation.,
In Nigeria, various studies have shown the role of work-related exposure to environmental pollutants (wood and stone dust) in the incidence of respiratory diseases and symptoms such as upper respiratory tract infection, breathlessness, chronic obstructive airway disease, and asthma.,,,,,, This high prevalence of work-related respiratory problems in Nigeria may be due to little or no implementation of occupational health and safety standards at workplace. This study investigated the work-related respiratory symptoms and cardiopulmonary functions deficits of factory workers in a cement factory in South-West, Nigeria.
| Materials and Methods|| |
A total of 140 participants whose ages ranged from 18 to 60 years were recruited for this cross-sectional analytical survey. The sample size calculation was done using the formula:
After calculation, the minimum sample size arrived it was 101.2. Seventy of them (58 males and 12 females) were cement workers (cement-exposed group) who were consecutively recruited from Lafarge cement factory in Ewekoro, Ogun state, Nigeria while the remaining 70 (37 males and 33 females) were civil servants (control group) who were purposively recruited from Federal Medical Centre, Idi-Aba, Ogun state. The two groups were similarly matched in age. Included into the study were individuals who had worked for at least 1 year in either of the two establishments. Individuals that were excluded from the study were those who have had recent major surgeries and those who declined participation. Ethical approval was obtained from the Health Research and Ethics Committee of Lagos University Teaching Hospital, Idi-Araba, Lagos State, Nigeria (REF NO: ADM/DCST/HREC/APP/230). Approvals were also obtained from the cement factory and the management of Federal Medical Centre, Idi-Aba. Written informed consent was obtained from the participants.
Procedure for data collection
After appropriate approvals were obtained and before the commencement of the study, a preliminary lecture was given to the prospective participants on the aims and procedure for the study. Height and weight of each participant were measured with height meter and weighing scale, respectively. Body mass index was calculated using the formula; body mass index (BMI) = weight (kg) divided by height 2 (m 2). Pulmonary function parameters forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and peak expiratory flow rate (PEFR) were assessed in sitting position using a portable spirometer (SP10 CONTEC: Hamburg, Germany) at a fixed time of the day (8 a. m.) to minimize the diurnal variation. The participants in sitting position were asked to take the deepest breath they could and then exhale into the sensor as hard as possible, for as long as possible. A nose clip was used just before each participant exhaled into the mouthpiece. That guaranteed that breath flowed only through the mouth. Each participant performed this procedure three times and the mean value taken and recorded. It was necessary to coach the participants to achieve their maximal expiratory efforts before taking the actual measurements because FEV1 is highly dependent on the amount of force used by the participant in early expiration. Percentage ratio of the two volumes (FEV1/FVC) was calculated for each participant. Safety measures were adapted using a new disposable mouthpiece for each participant, cleaning the surface of the spirometer with a towel soaked in a disinfectant solution after use by each participant and allowing a delay of at least 10 min before the next participants took his/her measurement. Forced vital capacity is the largest volume of gas that can be forcefully exhaled from the lungs after a maximal inspiratory effort. FEV1 is the volume gas expired in the 1st s of maximal expiration after a maximal inspiration. PEFR is the maximal expiratory flow rate achieved, and this occurs very early in the forced expiratory maneuver.
The blood pressure of each of the participants was measured with mercury sphygmomanometer and stethoscope in sitting position. These measurements were taken two times and the mean values calculated and recorded.
The questionnaire was self-administered after the cardiopulmonary function tests were done.
Questionnaire design and administration
The British Medical Research Council questionnaire  – a standardized questionnaire on respiratory symptoms was adapted for this study. It has five sections (Sections A-E). Section A (7 Questions): collected information on the demographic/physical characteristics of the participants. These were age, gender, department/unit, duration of present employment, weight, height, systolic and diastolic blood pressure (DBP). Section B (13 Questions): collected information on past medical history. Section C (26 Questions): collected information on the occurrence of respiratory symptoms. Section D (8 Questions): collected information on participants' smoking habit and Section E (3 Questions): collected information on the participants' use of respiratory protective equipment.
The participants were assured that their responses would be kept confidential before the copies of the questionnaire were distributed to them by the researchers. The completed questionnaires were also immediately collected by the researchers.
Data were analyzed using the Statistical Package for Social Sciences version 20. Descriptive statistics of mean and standard deviation were used to summarize data. Inferential statistics of independent t-test was used to compare data between the two groups. Statistically significant level was set at P < 0.05.
| Results|| |
The mean ages of the cement-exposed and cement-unexposed (control) groups were 31.57 ± 8.32 years and 31.50 ± 8.57 years, respectively. The mean years of work experience for the cement-exposed and unexposed groups were 7.10 ± 5.38 years and 6.41 ± 5.02 years, respectively. The mean BMI of the cement-exposed and the control groups were 24.65 ± 2.9 kg/m 2 and 24.24 ± 4.26 kg/m 2, respectively [Table 1].
Sixteen (22.9%) and one (1.4%) of the cement-exposed group reported seasonal allergies and heart problem respectively as their past cardiopulmonary conditions while only one (1.4%) and none of the cement-unexposed group reported seasonal allergies and heart problem respectively as their past cardiopulmonary conditions [Table 2].
The prevalence of respiratory symptoms among the cement-exposed group was as follows: 67.1% for wheeze, 38.6% for breathlessness, and 48.6% for chest tightness while those for the unexposed group were as follows: 5.7% for wheeze, 2.9% for breathlessness, and 7.1% for chest tightness [Table 3].
[Table 4] shows the severity of the respiratory symptoms in the participants. Forty-three (61.4%) of the cement-exposed and 13 (18.6%) of the cement-unexposed participants reported that they usually become short of breath when hurrying on level ground. Thirty-two (45.7%) of the cement-exposed and 9 (12.9%) of the cement-unexposed participants reported that they wheeze when they run/climb stairs fast.
[Table 5] shows the history of respiratory symptoms in the past 3 years and the use of appropriate protective respiratory gadget (PRG) by participants. Fourteen (14%) of the cement-exposed group and only one (1.4%) of the control group reported that in the past 3 years, they had periods of increased cough and phlegm lasting for 3 weeks or more. Forty-two (60%) of the cement-exposed group and 3 (4.3%) of the cement-unexposed group wear PRGs at work.
|Table 5: History of respiratory symptoms in the past 3 years and use of appropriate protective respiratory gadget|
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Comparison the mean values of the cardiopulmonary parameters of the cement-exposed group with those of the unexposed group showed significant differences in FVC (P = 0.001), FEV1(P = 0.001), FEV1/FVC ratio (P = 0.012), PEFR (P = 0.003), systolic blood pressure (SBP) (P = 0.0001), and DBP (P = 0.0001) [Table 6].
| Discussion|| |
The aim of this study was to investigate the work-related respiratory symptoms and cardiopulmonary function impairment of factory workers in a cement company in South-West, Nigeria, and compare them with those of the aged-matched cement-unexposed apparently healthy individuals. The point to 3 years prevalence and severity of respiratory symptoms among the cement-exposed group were much higher than the unexposed group. Unfortunately, just 60% of the cement-exposed group wore PRGs at work, and only 50% of them had their PRGs test fitted for them. There were significant differences between the mean values of selected cardiopulmonary parameters (FVC, FEV1, FEV1/FVC ratio, PEFR, SBP, and DBP) of the cement-exposed group and the cement-unexposed group. While FVC, FEV1, FEV1/FVC ratio, and PEFR were significantly reduced, SBP and DBP were significantly increased in the cement-exposed group.
The finding that the prevalence and severity of respiratory symptoms among the cement-exposed group were much higher than the unexposed group could be attributed to cement dust exposure at the workplace as 40% of the cement-exposed group work without wearing PRGs, and some of them that wore the PRGs might have been using wrongly fitted sizes. This could be asserted because the demographic and physical characteristics of the participants of both groups were similar. The production of dust and smoke in various occupational and industrial sectors has been implicated in increasing the risk of development of respiratory diseases especially in developing countries where workers in these sectors are not adequately protected. There is higher prevalence of work-related respiratory problems in developing countries than in developed countries mainly because workers work without proper personal protective equipment or ventilation., This finding corroborates previous studies.,,,, They reported high prevalence of respiratory symptoms and signs such as coughing, sputum, wheezing, dyspnea, and alteration of the pulmonary indices of cement workers. However, few others reported that there was no significant difference in most respiratory symptoms between exposed and unexposed workers.,,
The finding that FVC, FEV1, FEV1/FVC ratio, and PEFR were significantly reduced in the cement-exposed group compared to the unexposed group implies that the pulmonary capacities and functions of the cement factory workers were more compromised than that of the unexposed workers. The higher rates of wheeze (67.1%), chest tightness (48.6%), and breathlessness (38.6%) reported by the cement exposed workers buttress the decreased lung capacities and functions of these cement factory workers. Neghab and Choobineh  observed that the PEFR of cement exposed laborers in Iran was 19% lower than normal. The prevalence rates of cough, wheezing, phlegm, and breathlessness among these laborers were 31.8%, 28.4%, 26.1%, 17.0%, and 15.9%, respectively. There was no significant difference in FVC and FEV1 of the two groups. A number of studies have found that there are decreased lung functions of cement workers and other occupations with heavy dust exposure.,, In a cross-sectional study, Mwaiselage et al. found an annual decline of 49.1ml in FEV1 and of 23.1ml in FVC for an average worker exposed to total cumulative dust levels of 28.9 mg/year. Among none smoking healthy adults, the expected age-related rate of decline in FEV1 is 20–30 ml/year.
The SBP and DBP were significantly increased in the cement-exposed group compared to the cement unexposed group. This could also be due to high exposure to cement dust. This means that exposure to cement dust does not only affect the respiratory system but also the cardiovascular system.
| Conclusion/Recommendation|| |
Respiratory symptoms were higher among cement factory workers than the age-matched unexposed individuals. Forced vital capacity, FEV1, FEV1/FVC ratio, and PEFR were significantly reduced while blood pressure was increased in cement factory workers.
Based on the findings of the study, the following recommendations are suggested.
The full cardiopulmonary medical examination should be carried out on individuals who are to be offered employment in cement factories to identify those whose cardiopulmonary systems are already compromised so that they would be advised to seek other types of employments.
The employers of labor in cement factories should put in place accepted engineering control measures such an enclosure or confinement of the cement operation in order to localize cement dust from getting into the general ventilation.
The employers should provide adequate PRGs and respirators which are applicable and suitable for the purpose intended for employees of cement factories to protect their health.
The employers should be responsible for the establishment and maintenance of a written respiratory protection program with required worksite-specific procedures and elements for required respirator use which must be administered by a suitably trained program administrator.
The employers should provide a medical evaluation to determine the employee's ability to use a respirator before the employee is fit tested or required to use the respirator in the cement factory.
The employers should ensure that periodic follow-up medical examination is provided for an employee of a cement factory.
The employer should provide PRGs, respirators, training, and medical evaluations at no cost to the employee.
Limitation of study
The main limitation of this study is that the participants in the two groups (cement exposed and cement unexposed) were not gender matched. This is important because spirometric values are gender dependent. It was largely because cement factories in Nigeria have more male dominant workforce than female while the civil service set up where the controls were recruited from, had no particular gender dominance in its workforce.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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