|Year : 2018 | Volume
| Issue : 1 | Page : 45-48
Effect of organic dust exposure on pulmonary functions in workers of vegetable market with special reference to its microbial content
Arun Goel1, Balram Ji Omar2, Rajesh Kathrotia1, Prashant M Patil1, Sunita Mittal1
1 Department of Physiology, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
2 Department of Microbiology, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
|Date of Web Publication||18-Apr-2018|
Dr. Rajesh Kathrotia
Department of Physiology, All India Institute of Medical Sciences, Rishikesh - 249 203, Uttarakhand
Source of Support: None, Conflict of Interest: None
Context: Wholesale vegetable market is a rich source of generation of organic dust as loads of fruits and vegetables are loaded and unloaded here daily. Thus, regular workers are exposed to this organic dust for a considerable period of time depending on their work schedule. This study was planned to determine the microbial status of organic dust and to explore its association with pulmonary functions in the workers of wholesale vegetable market in Rishikesh. Materials and Methods: It was a cross-sectional exploratory/observational study. Thirty-five apparently healthy adult males were selected from vegetable market having no history of any chronic illness. Smokers and alcoholic were excluded from the study. The same number of age- and sex-matched controls with the same exclusion criteria were recruited from workers not working in the vegetable market and also not exposed to any other kinds of organic dust. Microbial culture of air in the vegetable market was done. It was compared with the microbial status of air in the working place of controls. Pulmonary functions of all the workers were performed with the help of digital spirometer (Helios 401). Results: Bacterial and fungal concentration was found to be significantly higher in the air of vegetable market as compared to air in the workplace of controls (such as coagulase-negative staphylococci >25 colony-forming unit (CFU) at incubation temperature vs. 10–12 CFU at incubation temperature, significant growth of Mucor, Aspergillus niger, and Candida nonalbicans in vegetable market as compared to workplace of controls). Pulmonary function parameters (percentage forced expiratory volume in 1st s (FEV1), percentage predicted forced expiratory flow in mid-half of expiration, and FEV1) of workers exposed to organic dust in vegetable market were also significantly lower (P < 0.05). Conclusion: Exposure of organic dust is associated with compromised pulmonary functions and there is a need of formulation of safety guidelines.
Keywords: Forced expiratory flow in mid half of expiration, forced expiratory volume in 1st s, forced expiratory volume in 1st s/forced vital capacity, microbial content, vegetable market
|How to cite this article:|
Goel A, Omar BJ, Kathrotia R, Patil PM, Mittal S. Effect of organic dust exposure on pulmonary functions in workers of vegetable market with special reference to its microbial content. Indian J Occup Environ Med 2018;22:45-8
|How to cite this URL:|
Goel A, Omar BJ, Kathrotia R, Patil PM, Mittal S. Effect of organic dust exposure on pulmonary functions in workers of vegetable market with special reference to its microbial content. Indian J Occup Environ Med [serial online] 2018 [cited 2019 Mar 19];22:45-8. Available from: http://www.ijoem.com/text.asp?2018/22/1/45/230345
| Introduction|| |
Organic dust may be generated from various sources such as vegetable market, poultry, animal farms, and textile industry. The contaminated air may contain various bacteria, fungi, spores, organic fiber, endotoxin, and peptidoglycan and many of them may act as allergen, inflammatory mediator, or in some other ways to act on respiratory system. Manifestation may occur in the form of various allergic, obstructive, or restrictive lung disorders. Various studies have shown adverse health effects of dust generated from herbs or other such organic matter on pulmonary functions and immunological responses.,,, In some of them, workers in the poultry were found to have a high risk of chronic obstructive pulmonary disorders.,
It has also been shown in few studies that there is a high risk of respiratory morbidity and mortality in farmers and farm-related workers.,, In fact, agricultural workers and farmers have been shown to have a high risk of asthma in the European community respiratory health survey. An interesting thing was that these agricultural workers and farmers were having a lower prevalence of smoking. This suggests some role of repeated exposure of organic dust or bioaerosol to which these workers were exposed in causing respiratory problems in them. Endotoxins in organic dust have been found to be associated with derangement in pulmonary function.
Wholesale vegetable market in developing countries may provide ideal condition for generation of organic dust because of handling of a big amount of agricultural commodities, poor storage resulting in decay of fruits and vegetables. In addition, there may be improper sanitary conditions and poor hygiene that further aggravate the situation.
There is a limited number of data for such kind of studies in Indian participants. Against this background, we, therefore, tried to assess the respiratory status of apparently healthy participants working in vegetable market of Rishikesh and thus having continuous exposure of organic dust.
| Materials and Methods|| |
The study was conducted in the wholesale vegetable market of Rishikesh. The study recruited 35 apparently healthy adult male workers between the age group of 20 and 50 years from the vegetable market. Only those workers were selected who were working in the vegetable market regularly for at least last 1 year.
Age- and sex-matched controls were selected from city dwellers not exposed to organic dust of any kind. Inclusion criteria required participants to be free from any mental and physical illness. A thorough history was taken and clinical examination was done for all the participants to rule out any obvious cardiorespiratory illness. Smokers and alcoholics were excluded from the study. Informed written consent was obtained from all the participants after explaining them the nature of the study, and ethical clearance was sought from the Institute Ethics Committee.
The measures of pulmonary functions such as forced expiratory volume in 1st s (FEV1), forced vital capacity (FVC), FEV1% (percentage of FEV1 with respect to FVC), forced expiratory flow in mid half of expiration (FEF25-75), and peak expiratory flow rate (PEFR) were assessed with a portable computerized spirometer (RMS Helios 401, Recorders and Medicare Systems, Chandigarh, India). It is a turbine-based device with optical sensors with flow rate of ± 16 L/s with maximum volume of 8 L. Accuracy standards of device are according to the latest American Thoracic Society (ATS) standards.
Anthropometric measurement of height and weight of participants was carried out. Spirometry was performed with a single trained person to rule out any measurement bias. Pulmonary functions of the participants were recorded in accordance with the guidelines of the ATS. Best of three maneuver with a maximum variation of 5% or 100 ml (whichever is greater) was taken for analysis.
At the same time, samples of air were also taken from three different sites of working place of the participants for the microbial analysis.
Methodology for air cultures
Three types of media were used Columbia Blood Culture plates, CPS3 Id (chromogenic media), and Sabouraud's Dextrose agar with antibiotics. Three sets of each plate were kept at three different sites of vegetable market about 50–80 m apart at the same level from the ground 5 m away from the shops so as not to be specific to a particular type of vegetable shop. They were exposed to air for 25–30 min, closed, and incubated at 37° (BA and CPS3ID plates) and 25° (SDA) for 24 h and 2 weeks (for SDA). The same was done in the environment of control group.
Spirometer records the measured or absolute values of respiratory parameters along with the percentage-predicted values depending on anthropometric data of the participants. Although participants in two groups were similar with respect to anthropometric parameters, percentage-predicted values were used for the data analysis to further neutralize any effect of these anthropometric indices (age, height, weight, smoking status, etc.) on values of pulmonary parameters.
Values in two groups were compared with unpaired Student's t-test assuming unequal variance.
Bacterial and fungal concentration in samples of air was also compared in two groups with respect to their types and number of colony forming units.
| Results|| |
Two groups were found to be comparable with respect to their anthropometric data such as age, height, and weight [Table 1]. The percentage-predicted values of FVC, FEV1%, PEFR, FEF25-75, and FEV1/FVC in percentage of absolute values in two groups are depicted in [Table 1]. It was found that values of all the above parameters except PEFR were found to be higher in controls than in cases or participants exposed to organic dust in the vegetable market. A significant difference (P< 0.05) with greater values in control was found in FEF25–75 percentage predicted, FEV1 percentage predicted, and FEV1/FVC in percentage of absolute values, whereas FVC percentage predicted was also found to be higher in control, but it was not statistically significant (P > 0.05). PEFR percentage predicted was found to be higher in cases as compared to controls. However, it was not found to be statistically significant (P > 0.05).
|Table 1: Pulmonary function parameters along with baseline characteristics of the participants|
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The results of air culture in terms of growth of bacteria and fungi found in various culture media at their incubation temperature are shown in [Table 2]. Samples for air culture were collected from the vegetable market as well as from workplace of control group.
|Table 2: Results of air culture in terms of growth of bacteria and fungi|
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| Discussion|| |
Vegetable market poses a challenge to the health of workers at least in terms of their respiratory status. Continuous exposure of microbial agents, spores, fibers, etc. in organic dust act as triggers for localized or systemic reactions in the body of exposed workers. Apart from that, other unhygienic conditions in vegetable market such as spread of cow dung here and there, heaps of unused or decaying vegetables and fruits, improper disposal of garbage, and improper sanitary conditions only worsen the already existing health-compromising atmosphere.
Expiratory flow rates are affected by airflow resistance, elastic properties of lung, muscular effort, etc., In our data, highest significant difference (P = 0.02) is found in FEF25–75 percentage predicted values which is usually an indicator of airflow resistance in mid and small airways. A similar decline in pulmonary functions has also been reported by some studies in which agriculture workers were exposed to high level of airborne microorganisms and endotoxins while handling agricultural products., It has also been shown that workers in agriculture market who are having high bronchial reactivity can undergo bronchospasm as a result of exposure to microorganism, fumes, and dust prevalent in the atmosphere. Although sample size is small to assign any causative role of organic dust in increasing airflow resistance in airways of workers in wholesale vegetable market, a significant difference in flow rate and presence of microbial agent in organic dust indicate that organic dust may be related to difference in pulmonary functions in two groups. PEFR (PEFR% predicted) values are found to be higher in the group exposed to organic dust though it is not statistically significant (P > 0.05). PEFR is mainly an effort dependent parameter and is greatly affected by muscular strength. Hence, there may be chances that workers in wholesale vegetable market were able to apply more muscular effort while recording pulmonary function. It may be because of their increased muscular strength related to their occupation as compared to controls.
Compromised respiratory status related with exposure of bioaerosols in vegetable market has also been documented in a study done in India. Apart from causing nonspecific airway irritation, handling of agricultural products is found to be associated with exposure of various antigens derived from these commodities that can be associated with specific immunoglobulin response against them. This can result in a wide variety of respiratory problems ranging from mucosal irritation to nonallergic asthma, allergic alveolitis, organic dust toxic syndrome, and hypersensitivity pneumonitis., In addition, there may be some role of organophosphorus pesticides which may be frequently associated with agricultural products in causing manifestation of obstructive respiratory disorder. It may do so by increasing the local availability of acetylcholine due to inhibition of acetylcholinesterase, thus causing the constriction of bronchial smooth muscle.
On doing the microbial sampling of air, bacterial and fungal concentration was found to be significantly higher in the air of vegetable market as compared to air in the workplace of controls. The microbial organisms isolated from the media plates included coagulase-negative Staphylococcus, Bacillus, Streptococcus spp., Staphylococcus aureus, and Enterococcus. The fungal plates showed growth of Mucor and Aspergillus niger and Aspergillus flavus. One of the plates also showed growth of Candida spp. (nonalbicans). No Gram-negative organism was seen on any culture plates in vegetable market area.
It has been shown in some studies that decay of agricultural commodities is associated with high concentration of bacteria and fungi in the environment., Among these aerosolized microorganisms, it has been earlier shown that spore-forming Gram-positive bacteria survive in the air for a considerable time and even nonspore forming Gram-negative bacteria lasts for few hours. In the present study, a wide variety of organisms are found in the air of vegetable market environment as compared to that of workplace of controls. Environmental organisms are usually nonpathogenic. However, daily exposure to organism in high microbial concentration found in samples of market area can be associated with a decline in pulmonary function found in workers of vegetable market.
Various factors such as collection of agricultural items from diverse sources, spraying of fruits and vegetables with water leading to suspension of microorganisms in the air, presence of stray animals in the area, decomposition and decay of agricultural products, and poor sanitation and improper waste disposal may be responsible for generation of organic dust and thus compromised respiratory status of the participants exposed to them.
Limitations of the study
Due to the cross-sectional design of the study, a causal association of vegetable market environment with the pulmonary functions cannot be ascertained. Furthermore, there may be underestimation of association between organic dust and pulmonary functions because of inclusion of active workers in the vegetable market.
| Conclusion|| |
Exposure of organic dust in area of vegetable market is associated with compromised pulmonary functions and there is a need of formulation of safety guidelines.
There should be further research into the participant with more appropriate study design and larger sample size. Due to the association of organic dust with compromised pulmonary functions, we recommend that there should be formulations of some guidelines for handling the agricultural commodities and for maintaining cleanliness and hygiene in the vegetable market along with the proper sanitation and waste disposal.
This study was financially supported by Intramural grant from AIIMS Rishikesh (Grant no.IEC/IM/16/RC/14).
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]