Occupational exposure to cotton dust in cottonseed oil mills

Evaluation of Dust Exposure among the Workers in Agricultural Industries in North-East India

This study aims to quantify dust exposure among the workers in four different industrial settings: rice mills, flour mills, oil mills, and tea factories and to compare the obtained data with the permissible exposure limit (PEL) of Indian Union Ministry of Labour as well as to compare the dust exposure across activities and seasons. RespiCon(TM) particle sampler was used for collecting dust concentration in the breathing zone of the workers. In total, 149 workers participated in the study and 204 samples were collected. Samples were collected in the vicinity of different processing operations. Samples in the rice mills were collected for two consecutive years in two seasons; however samples from other industries were collected for 1 year. The results indicate that geometric mean (GM) of dust exposure was significantly (P < 0.0001) different among industrial settings. Respirable dust were 8.22, 5.76, 2.98, and 6.34mg m(-3) and total dust exposure were 81.05, 111.02, 56.68, and 39.85mg m(-3) in the rice mills, oil mills, flour mills, and tea factories, respectively. Considerable variations in dust exposure were observed in different activities in the rice and oil mills; however variation was relatively less in the flour mills and tea factories. In the rice mills, dust concentration was higher in winter than those obtained in autumn and it is significantly different (P < 0.05) for inhalable dust and total dust. Positive correlation was obtained in thoracic dust (r (2) = 0.94) and inhalable dust (r (2) = 0.97) with total dust and thoracic dust with inhalable dust (r (2) = 0.89). The results show that majority of the workers are exposed to higher level of respirable dust as compared to the PEL, while total dust exposure to all the workers were higher than the PEL; thus, immediate reduction of dust exposure among the workers is necessary for preventing respiratory system impairment.

Cyclic hydrostatic pressure and cotton particles stimulate synthesis by human lung macrophages of cytokines in vitro

BACKGROUND

Inhalation of particulates is a leading cause of the development of lung diseases and current understanding of the complex relationship between lung metabolism and airborne particulates is incomplete. It is well established that mechanical load is important in the development of the lung and in lung cell differentiation. The interaction between particle exposure and physical forces on alveolar macrophages is a physiologically relevant issue, but as yet understudied. This study examines the effect of cyclic hydrostatic pressure and cotton particles on synthesis of cytokines by human alveolar macrophages.

METHODS

Alveolar macrophages were obtained from patients with lung disease, either from lavage samples or from lung tissue resection. The commonly used cell line THP-1 was included in the experiments. Cell cultures were exposed to cotton particles and/cyclic hydrostatic pressure (3 or 5 psi); control cultures were exposed to medium only. TNFalpha, IL-1beta and IL-6 were assayed in the culture media using specific ELISAs. Cells were characterized using morphology and markers specific for macrophages (Jenner/Giemsa staining, CD14 and CD68).

RESULTS

Exposure to cotton particles stimulated cytokine synthesis by macrophages from all three sources; exposure to cyclic hydrostatic pressure alone did not stimulate cytokine synthesis significantly. However, the combination of both particles and cyclic hydrostatic pressure increased the simulation of cytokine synthesis still further. Cell characterization demonstrated that the large majority of cells had a macrophage morphology and were positive for CD14 and CD68.

CONCLUSION

These data suggest an interaction between cyclic hydrostatic pressure and particulate exposure, which increases alveolar macrophage cytokine production. This interaction was only observed at the higher cyclic hydrostatic pressure. However, in patient samples, there was considerable variation in the amount by which secretion of an individual cytokine increased and there was also variation in the mechanosensitivity of cells from the three different sources. Cyclic hydrostatic pressure, therefore, may be an important modulator of the response of alveolar macrophages to cotton particles, but the source of the cells may be a confounding factor which demands further investigation.

Across-shift lung function variation in cottonseed oil workers

BACKGROUND

The effects of cotton dust on pulmonary function among workers employed in cotton-spinning mills are well known. However, little data exist on the prevalence of this disorder in 'non-textile' cotton industries, including cottonseed oil mills, where high levels of exposure to dust have been demonstrated.

AIMS

This study was performed in order to determine the across-shift and across-week decline of FEV(1) and respiratory symptoms among workers in a cottonseed oil mill.

METHODS

Sixty-six exposed and 48 unexposed workers of a cottonseed oil mill in Turkey were investigated by questionnaire and lung function test (LFT). LFTs were performed before and after shift on all the working days of the week. Acute airway response was defined as an across-shift decline in FEV(1) of 5% or more on the first working day.

RESULTS

Smoking was the only risk factor for having respiratory symptoms. Acute airway response was more frequently observed in the exposed group as compared to the unexposed group (OR = 6.2, 95% CI = 2.3-16.7). The median across-shift decline in FEV(1) on the first day (120 ml) significantly improved on the following days (10, 50, 60 and -30 ml).

CONCLUSION

Smoking appears to be the main risk factor for having respiratory symptoms. Cottonseed dust may cause an acute pulmonary function decline on the first working day, but not on the following days of the week. This decline is associated with respiratory symptoms in exposed workers.