Pulmonary function of control and industrially exposed Nigerians in asbestos, textile, and toluene diisocyanate-foam factories

Respiratory symptoms and lung function impairment in underground gold miners in ghana

SUMMARY BACKGROUND

This is the first study in Ghana in the Obuasi gold mines where the silica content of the respirable dust is 10%, less than in previously studied gold mines, with only 23% of the miners having ever smoked.

OBJECTIVES

The study was to assess the prevalence of respiratory impairment in the Ghanaian gold miner and to quantify the effects of the respirable dust on pulmonary function

DESIGN

A cross sectional epidemiological study

METHOD

The study was carried out using MRC respiratory symptoms questionnaire, spirometry, and personal respirable dust measurements.

RESULTS

A total of 1236 miners were studied. The mean age was 39.7 +/-5.8 (SD) years with a mean of 12.6 +/- 6.7 (SD) years underground service and a mean total cumulative exposure to dust of 10.34 +/-5.61 (SD) mg.m(-3).years. The prevalence of chronic bronchitis was 21.2% and not clearly related to cumulative exposure. MRC breathlessness grade>/=2 was 31.3%, significantly related to cumulative respirable dust exposure after adjustment of age and smoking. There was however significant reduction in FEF(25-75%) with increasing dust exposure and an interaction with ever smoking. There was no correlation between cumulative exposure to respirable dust and FEV(1) % predicted in any group, suggesting that exposure to respirable silica at a mean level of 0.06 mg/m(3) had no deleterious effect on FEV(1) in a population with little tuberculosis, good housing and a low level of cigarette smoking.

CONCLUSION

The prevalence of chronic bronchitis in the Ghanaian gold mine is related more to smoking than any occupational factors.

Prevalence of respiratory symptoms among wheat flour mill workers in Ibadan, Nigeria

BACKGROUND

While investigations into occupational health problems of various groups of workers have been conducted in Nigeria, so far, very little attention has been paid to the health status of workers in the grain industry. The prevalence of respiratory symptoms among wheat flour mill workers and control groups in a medium size industrial setting in Nigeria was studied.

METHODS

The study employed a cross-sectional analytical design. Data were collected using structured interviews, work-site observations, and physical examination. Respondents consisted of 91 flour-millers, 30 matched internal controls from the maintenance unit of the same flour mill factory, and 121 matched external controls.

RESULTS

Fifty-four percent of the flour-millers reported at least one respiratory symptom compared with 30% of the internal controls (P < 0.05) and 19% of the external controls (P < 0.001). Most symptoms were significantly more prevalent among the flour-millers compared with control subjects, and this trend was more evident amongst non-smokers than ex-smokers.

CONCLUSIONS

The study concluded that wheat flour mill workers in Nigeria, like grain workers elsewhere, were at an increased risk of developing both pulmonary and non-pulmonary symptoms compared with control subjects. The result has implications for improved dust control measures in the grain industry in Nigeria.

A respiratory survey in a black Johannesburg workforce

BACKGROUND

The burden and determinants of airway disease in the population of southern Africa, which is currently undergoing rapid, often uncontrolled, urbanisation and industrialisation, are unknown. Previous surveys have focused on specific occupational groups and few have included women. This paper describes the respiratory status in a 30% probability sample of 206 men and 203 women drawn from an urban black Johannesburg workforce of almost 1500, all working for an educational institution.

METHODS

Subjects answered a respiratory questionnaire and performed spirometric tests. Symptom rates and age and height standardised forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC%, and forced expiratory flow (FEF25-75) were analysed by gender in relation to smoking, past work exposures, past and recent respiratory conditions, and socioeconomic indicators.

RESULTS

Symptom prevalence was high, bronchitic symptoms in men being related to smoking and previous occupational exposure, and in women to smoking despite the low intensity of their habit. Phlegm and wheezing were related to childhood respiratory illness in both men and women. FVC and FEV1, based on all subjects including smokers, were higher than previously reported for black residents of southern Africa. FVC was also positively related to education and job category. Higher values for ever smokers than for never smokers suggested health selection into the habit, while significant negative smoking effects were seen only on FEV1/FVC% and only in women.

CONCLUSIONS

Despite the high prevalence of symptoms--some smoking related--in this urban workforce, lung function levels were higher than previously reported in African blacks, and may reflect improving socioeconomic conditions.

Exposures to polyvinyl chloride, methyl ketone and other chemicals. The pulmonary and non-pulmonary effect

As part of the continuing assessment of the health impact of exposures in the emerging industries of Nigeria, a study was conducted to determine the relative impact of exposures encountered in four operations of a shoe factory. The health impact assessment consisted of spirometric lung function evaluations and environmental measurement for polyvinyl chloride (1.6 +/- 5 ppm). The study showed that there were differences among exposure subgroups with respect to pulmonary, neurological and dermal toxicities and that these differences were dictated by the types of exposure encountered. Pulmonary toxicity was most severe in the vinyl chloride-exposed subgroup. Neurological impact was most severe in the leather and methylethyl ketone-exposed subgroup and dermal toxicity most severe in the subgroup exposed to plasticizers and stabilizers. There existed substantial deficits in lung function (forced expiratory volume, forced vital capacity FEV1, FVC) among the subgroups relative to normal, non-industrially exposed Nigerians of similar age and height. The deficits in lung function, particularly in FVC, paralleled the variations in the prevalence of restrictive lung disease, which for the whole study group was 56.5 cases per 1000 person-years. The vinyl chloride-exposed subgroup had the highest prevalence of restrictive lung disease, 92.6 cases per 100 person-years. Step-wise multiple regression suggested that 27% of the deficit in FEV1 was explainable by the number of exposures. The use of person-years as a denominator gives a better estimate of risk than the total number of subjects as it incorporates both the number exposed and the total exposure experience.(ABSTRACT TRUNCATED AT 250 WORDS)

Some acute and long-term effects of exposure in welding and thermal-cutting operations in Nigeria

The analysis of welding fumes has shown that toxic gases are present that are irritating to the respiratory system; these gases include nitrogen dioxide and ozone, as well as the oxides of cobalt and chromium. The acute and long-term effects of exposure are assessed in the context of a welding and metal plant in Nigeria. Evidence of long-term respiratory impairment and potential lung cancer was found.

Respiratory and nonrespiratory morbidity in a titanium oxide paint factory in Nigeria

A study of 67 subjects in a small titanium oxide paint factory in Nigeria showed 50-54% frequency for airway symptoms, 20-40% for neurological symptoms, and 10-27% for other symptoms. The symptoms were well correlated with exposure (p less than .05) and pulmonary function tests (PFTs). The directly exposed subjects had likelihood odds ratios of 5 to 17 of presenting symptoms compared to controls. The PFT deficit, relative to the expected value, was significantly higher for those with airway symptoms than for those of other symptom categories (p less than .005). There were 28 (42%) cases of restrictive lung impairment. Exposure to cotton dust had confounding influence on the PFT of subjects previously exposed. Smoking rate was very low. These findings indicate the need for worker protection in a manufacturing plant in Nigeria.

Pulmonary function and symptoms of Nigerian workers exposed to cement dust

The pulmonary and nonpulmonary effects of cement dust exposure in 52 randomly selected, directly exposed cement workers and 24 maintenance workers were investigated. Compared with the nonindustrially exposed population, both subgroups had significantly (P less than 0.001) lower lung function. The lung function of the exposed subjects was probably influenced by the level of physical activity and the level of dust exposure. The more directly exposed cement packers had significantly (P less than 0.05) lower lung function than the less exposed cement loaders. There was no significant difference in the lung function of the directly exposed groups and the maintenance group, but the physically more active cement loaders showed higher lung function values than the maintenance workers. The lung function of the cement workers also decreased with the duration of employment. Cement dust produced significant (P less than 0.001) workshift depression in the lung function of the subjects. The symptoms presented by the subjects were cough and phlegm production, skin irritation, chest tightness, conjunctivitis, catarrh, stomachache, and boils. The prevalence of stomachache among the subjects becomes significant in the light of a finding by other workers of hepatic granuloma in cement workers. The measured dust level in the cement depot was 30.81 mg/m3.

Pulmonary function of exposed and control workers in a Nigerian nonsoapy detergent factory

Respiratory symptoms and spirometric pulmonary function data [i.e., first-second forced expiratory volume (FEV1.0) and forced vital capacity (FVC)] for 128 (30%) males who were exposed to alkyl benzene sulphonate in a detergent factory and for 56 (76%) unexposed workers in the same factory are reported herein. Exposed subjects had been employed for 1 month to 15 yr, and they generally complained of cough and mucus secretions, nasal catarrh, chest pain, and breathlessness. Unexposed workers had been employed for 1 month to 13 yr and had a significantly lower (P less than .001) frequency of symptoms, as well as significantly higher (.01 greater than P greater than .001) FEV1.0 and FVC than the exposed workers. The reduction in pulmonary function of exposed subjects from the predicted was significantly higher (.01 greater than P greater than .001) than that experienced by the unexposed subjects. There was a significant 8-hr workshift depression in lung function. There was radiological evidence of pulmonary fibrosis, but lack of pre-employment chest radiographs renders this inconclusive. Respiratory symptoms in exposed subjects decreased with duration of employment, which probably indicates the exodus from the work force of those who could not tolerate the nonsoapy detergent.

Pulmonary function and symptoms of Nigerian workers exposed to Carbon black in dry cell battery and tire factories

The pulmonary function and symptoms of 125 workers exposed to carbon black in dry cell battery and tire manufacturing plants were investigated. There was no significant difference in the pulmonary function of the subjects in the two plants. There was good agreement in the symptoms reported in the two different factories: cough with phlegm production, tiredness, chest pain, catarrh, headache, and skin irritation. The symptoms also corroborate those reported in the few studies on the pulmonary effects of carbon black. The suspended particulate levels in the dry cell battery plant ranged from 25 to 34 mg/m3 and the subjects with the highest probable exposure level had the most impaired pulmonary function. The pulmonary function of the exposed subjects was significantly lower than that of a control, nonindustrially exposed population. The drop in the lung function from the expected value per year of age was relatively constant for all the study subgroups but the drop per year of duration of employment was more severe in the earlier years of employment. This study has underscored the need for occupational health regulations in the industries of developing countries.