Study of Respiratory Symptoms and Pulmonary Function among Neem Oil Industry Workers

Abstract

This study aims to investigate the pulmonary functions and respiratory symptoms of workers in the neem oil extraction industry in Tamil Nadu, India, who are exposed to neem oil dust and chemicalsin their occupational environment. Fifty male workers from the exposed group and 50 male workers from the non-exposed group to neem dust and chemicals were investigated for this study. A modified respiratory assessment questionnaire based on the American Thoracic Society (ATS) standard and portable hand-held spirometry were used to assess their respiratory symptoms and pulmonary function. Respiratory symptoms such as coughing, sneezing, wheezing, and, nasal irritation are found to be higher in the exposed groups than in the controlled groups. The pulmonary function of exposed workers had doubled respiratory problems than the controlled groups, which indicates the impacts of dust and chemicals generated during neem oil extraction on workers’ health. Forced expiratory volume in one second (FEV₁)/forced vital capacity FVC)% was noted regarding the duration of exposure to neem oil dust (P < 0.001). Also, there was a high difference between the heavily exposed and the lightly exposed (P < 0.001). Hence, to mitigate these problems, the oil mill workers should be cautious and wear personal protection equipment during working hours, and it is recommended to have an exhaust ventilation system.

INTRODUCTION

Neem oil is a naturally occurring, beneficial oil that is derived from the seeds of the neem tree (Azadirachta indica). Azadirachtin is a bioactive compound in neem oil, which is used for its pesticide properties. Neem oil is the most demanding product widely used worldwide due to its potential anti-biotic properties. However, the workers working in the neem oil industry are exposed to several factors that affect their health. Because there are volatile organic compounds (VOCs) and severe dust particle emissions during the cleaning process and extraction process in industries such as PM_2.5, PM₁₀, and total volatile organic compounds (TVOC).

The components of oil seeds are Azadirachta excelsa, Azadirachta siamensis, and Azadirachta indica. Neem kernel lipids are similar to the normal glycerides from other oil seeds and contain arachidic acid (1–3%), oleic acid (50–60%), linoleic acid (8–16%), palmitic acid (13–15%), and stearic acid (14–19%). C₃₅ H₄₄ O₁₆ is the chemical formula for neem. The seeds of the neem tree (Azadirachta indica) are used to make neem oil. The oil extraction process can be done using various methods like drying the seeds, decortication, pressing or crushing the seeds, collecting the oil, and optional refining. A complex tetranortriterpenoid called azadirachtin is thought to be responsible for the symptoms of neem oil poisoning.[1]

The investigation of respiratory symptoms and pulmonary function among neem mill workers in the neem oil extraction industry is situated in Thiruvachi village panchayat of Erode district of Tamil Nadu state, India, and its geocoordinates are 11.336 latitude and 77.719 longitude. The geographical location of the study site is shown in Figure 1. The meteorological conditions of the studied location during investigation are relative humidity varied from 68% to 72%, temperature varied from 27°C to 35°C, and wind speed was about 13 km/h. Also, the average outside air quality index was in moderate condition (51–100 HAQI) during the investigation. In the neem oil mill, there are four sections, namely, the store room section, dust cleaning section, seed breaking section, and oil extraction section which were considered for the study, as shown in Figure 2. During this process, workers did not wear any masks on their faces for safety precautions. It was observed that the dust cleaning section has more dust compared to the other three sections. Therefore, this dust can affect the workers working in the industry, and it was experienced that, the dust was mostly settled upon the machines. During inhalation, the dust goes inside the lung and causes respiratory symptoms, which affects the pulmonary health of neem mill workers. Neem oil mill workers are staying in a cottage, which was located inside the industry, and the workers work 12 h/day with morning break hours of 20 minutes, lunch hours of 45 minutes, and evening break hours of 20 minutes. They are working 6 days/week. Mostly, mill workers stay inside the dust-exposed indoor environment. Before gathering data, a clear introduction was given by outlining the goal and purpose of the study to the participants and written consent was obtained. Guidelines of the ethic committee of Kongu Institutions were followed during this experimental trial and conducted as per the recommendations from the ethics committee of Kongu Institutions and this study was approved by the Kongu Engineering College Ethical Committee (KEC/R and D/EC/2022-23/001). Several studies investigated the respiratory symptoms and pulmonary function status among workers in the textile mill industry, flour mill industry, and cotton mill industry.[2,3] But there are limited and no studies conducted for the neem oil mill industry in the scope of assessing the pulmonary function and respiratory status of the neem oil workers. So, the present study aims to investigate the respiratory symptoms and pulmonary health of neem mill workers who were frequently exposed to neem dust and chemicals. Even though the exposure limit of dust particles and chemical concentration is higher in the neem oil industry during the extraction process, there have been no prior studies to investigate its effect among neem oil industry workers. The present study aims to investigate the respiratory symptoms and pulmonary function among the neem oil industry workers who are exposed to neem dust particles and VOCs.

Figure 1.

Geographical location of the neem oil extraction industry

Figure 2.

Various sections in a neem oil extraction industry

MATERIALS AND METHODS

Study population

A comparative cross-sectional study was conducted among neem oil mill workers in Erode city, Tamil Nadu, India, with a study population comprising 65 individuals employed in the oil extraction industry. The simple random sampling method is used to recruit the workers, and the target population consisted of male textile workers exposed to neem dust and chemicals in the factory, recruited from various sections, including the storeroom, dust cleaning, seed breaking, and oil extraction sections. The inclusion criteria stipulated male gender, age between 21 and 55 years, and a minimum of two years of exposure to neem dust and chemicals in the current job. Exclusion criteria encompassed a past occupational history of exposure to respiratory hazards other than neem dust and chemicals, systematic diseases affecting the respiratory system, and refusal to provide informed consent. Individuals with a history of asthma, tuberculosis, heart disease, and other respiratory illnesses were also excluded. Following the application of these criteria, 50 neem oil mill workers aged 21–55 years were enrolled in the study after obtaining written consent. Administrative office workers from the same factory, free of neem dust and age- and sex-matched, were selected as the control group. The control group excluded individuals with a history of smoking, asthma, or chronic obstructive pulmonary disease (COPD). Ultimately, 90 male workers were included in the study, divided into two groups: 50 workers exposed to neem dust and chemicals generated during processing; and 40 workers not exposed to neem dust continuously and frequently, serving as a comparison group.

Questionnaire-based data collection

The American Thoracic Society’s standard respiratory questionnaire[4] was used to survey the likely respiratory complications. In addition to sociodemographic information (sex, age, and education), the questionnaire asks about respiratory symptoms. The mentioned questionnaire analyzes the employee’s phlegm, shortness of breath, acute cough symptoms, and wheezing to assess their respiratory health. The general characteristics of the oil mill workers are shown in Table 1.

Table 1.

General characteristics of the exposed group

Characteristics		Exposed groups (neem mill workers) (n=50)		n (%)		Control groups (office workers) (n=40)		n (%)		P
Age year, mean (range)		40.8±13.2				42.5±11.6				0.05*
Height (cm)		171.32±2.74				170.28±1.89				0.39
Weight (kg)		67.31±1.12				66.92±2.19				0.47
Smoking habits										0.50
Smokers		40		80		25		62.5
Non-smokers		10		20		15		37.5
Total		50		100		40		100
Respiratory symptoms										0.0427*
Mild		5		10		35		85
Moderate		25		50		5		15
Heavy		20		40		0		0
Total		50		100		40		100
Working unit										0.0458*
Store room section		10		20		10		25
Dust cleaning section		10		20		10		25
Seed-breaking section		5		10		10		25
Oil extraction section		25		50		10		25
Total		50		100		40		100
Duration of employment/years										0.346
<10 years		45		90		30		75
>10 years		5		10		10		25
Total		50		100		40		100

Pulmonary function test

A portable spirometer was used to measure pulmonary function (Medical International Research, Italy). Forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), peak expiratory flow rate (PEFR), and forced expiratory flow (FEF_25–75%) measurements were made on the workers, as shown in Figure 3. To achieve the proper measurement of spirometry, the occupational hygienist made sure that the posturing of the participants was done by sitting upright, touching feet flat on the floor with legs uncrossed, and using a chair with arms. The participants were given instructions to practice forceful expiration and deep inspiration before the procedure. Once three acceptable readings were recorded as results, the best reading among the three was used for additional research.

Figure 3.

Pulmonary test conducted with neem oil industry workers

RESULTS

During the neem oil extraction process, chemical called azadirachtin is present in neem seeds and can be considered potentially harmful if not used properly. Azadirachtin is a bioactive compound in neem oil, which is used for its pesticide properties. However, it is important to follow safety guidelines when using neem oil products to minimize any potential risks. It was noted during the study that the neem oil mill workers (exposed workers) were not taking any preventive measures to minimize exposure to oil dust while they were at work.

Workplace environment

The offices of oil mills are crowded and range in size from 300 to 800 square feet. It was noted that the oil mills use equipment with 15 horsepower. During the study period, the workplace had a normal temperature and humidity of 27°C and 80%, respectively. The neem oil mill’s workplace air monitoring reveals a significant amount of neem oil dust. It was noted during the study that the neem oil mill workers spend the entire day in occupational settings. The workers are frequently exposed to higher concentrations of neem oil dust and chemicals. Furthermore, no exhaust system from a neem oil mill could be seen.

Respiratory symptoms

Among the total workers (N = 50), 90% of the employees of oil mills experienced breathing difficulties, frequent coughing, sneezing, wheezing, chest tightness, and nasal irritation of the respiratory tract as shown in Table 2. A mong neem oil mill workers (N = 50), nearly 20% of people had a cough, 18% had sneezing issues, 14% had whizzing problems, 8% had chest tightness, 4% had phlegm, 12% had breathlessness, and 24% had nasal irritations. Many oil mill workers reported having respiratory problems because dust particles can easily enter a person’s respiratory system when they are exposed to them. These particles stick to the inner wall of the respiratory tract and obstruct the inhalation and exhalation of air. Because the respiratory tract’s inner cell wall does not accept foreign particles (oil dust), mild irritation of the respiratory tract is the primary symptom of a respiratory disorder. The prevalence of respiratory symptoms between exposed and non-exposed workers is shown in Figure 4.

Table 2.

Prevalence of respiratory symptoms among exposed (neem oil mill workers) and control groups (office workers)

Respiratory symptoms		Exposed groups (neem oil mill workers) (n=50) %		Control groups (office workers) (n=40) %		P
Cough		10 (20%)		7 (17.5%)		<0.001
Sneezing		9 (18%)		8 (20%)		<0.001
Wheezing		7 (14%)		5 (12.5%)		<0.001
Chest tightness		4 (8%)		2 (5%)		<0.001
Phlegm		2 (4%)		3 (7.5%)		<0.001
Breathlessness		6 (12%)		4 (10%)		<0.001
Nasal irritation		12 (24%)		11 (27.5%)		<0.001

Figure 4.

The prevalence of respiratory symptoms among exposed groups (neem oil mill workers) and control groups (office workers)

Pulmonary function status

The lung function test or pulmonary function test (PFT) was carried out with the aid of spirometry to learn about lung diseases in the neem oil mill industry. Table 1 shows the parameters such as age (in mean), height (in centimeters), weight (in kg), and smoking history, Whereas, Table 3 shows the parameters like FEV₁(L), FEV₁/FVC%, FVC (L), and PEFR (L/S) undertaken for the lung function test to be carried out. It was found that as their working experience increased, their FEV₁/FVC percentage decreased, making them more susceptible to lung diseases. The mean values of FVC, FEV₁, FEV₁/FVC, and PEFR had a significant reduction among neem oil mill workers compared to control groups. Workers who have occupational respiratory disease may experience pulmonary hypertension issues, become disabled, and lose their ability to work. The most likely cause of occupational lung diseases is dust deposition in the lung, which is affected by the types of dust, duration of exposure, and size of airborne dust in the external respiration region. The lung function status of normal and impaired spirometry among exposed (neem mill oil workers) and control (office workers) is shown in Table 4.

Table 3.

Comparison of pulmonary function parameters among the exposed group (neem oil mill workers) and the control group (office workers)

Variables		Neem-oil mill workers (n=50) (mean±SD)		Control groups (office workers) (n=40) (mean±SD)		P
FVC (L)		3.57±1.65		6.12±1.52		<0.001
FVC % pred (L)		73.85±2.97		95.18±2.45		<0.001
FEV1 (L)		3.18±1.08		4.58±1.58		<0.001
FEV1% pred (L)		72.97±3.15		84.15±2.48		<0.001
FEV1/FVC% (L)		85.91±8.59		94.23±3.76		<0.001
FEV1/FVC% pred (L)		92.18±7.86		116.47±8.2		<0.001
PEFR (L/S)		4.19±1.07		5.13±1.08		<0.001
PEFR% pred (L/S)		60.15±10.15		70.56±11.7		<0.001

Table 4.

Lung function status among exposed (neem oil mill workers) and control (office workers)

Variables		Neem oil mill workers (exposed groups) (n=50)		Office worker (control groups) (n=40)
Lung functions
Normal lung function		5 (10%)		34 (85%)
Impaired lung function		45 (90%)		6 (15%)
Obstructive pattern		15 (30%)		2 (5%)
Restrictive pattern		30 (60%)		4 (10%)

DISCUSSION

The global burden of occupational respiratory diseases has continued to be caused by occupational exposure to respiratory hazards. Numerous studies have been carried out to determine the potential causes of the issue. However, the results are contradictory and ambiguous, which may make it more difficult to plan and carry out efficient intervention strategies. To estimate the combined prevalence of occupational respiratory diseases among industry workers in India, a systematic review and meta-analysis were conducted. It was discovered that the combined prevalence of occupational respiratory symptoms was 51.6% (95% CI: 43.6–59.6).[5] This number is higher than those reported for industry workers in the United Kingdom (22%),[6] Bangladesh (34%),[7] Eastern Nepal (21.1%),[8] and Hong Kong (27.2%).[9] The differences could be explained by the different types of industries and the lack of personal protective equipment provided to industry workers. Differences in the workers’ educational backgrounds could be one of the additional reasons. The workers employed in this sector are mostly illiterate and come from socially and economically weaker sections of the industrial sector.[10] This is probably going to make the employees less compliant with occupational respiratory disease prevention measures, which will then make the problem in our study worse. However, the combined prevalence is in line with research among woodworkers in Cameroon (51%),[11] France (56.6%),[12] and Iran (53%).[13]

The daily inhalation of dust-contaminated air lowers their quality of life as well as that of the workers, and these employees are afflicted with a variety of respiratory illnesses.[14,15] Inhaled dust particles that become lodged in the lungs irritate and cause an inflammatory response. Fibrosis, which affects oxygen diffusion and lung function, results from the healing of this inflammatory response.[16,17] FVC (L) is a metric for lung size (in liters) that describes how much air can be exhaled after a prolonged inhalation. Here, the FVC (L) of the exposed group was low, which indicates that the exposed group has higher pulmonary problems. Halvani et al.[18] found that exposed workers had lower spirometric parameters; this decrease was statistically significant in the case of neem oil workers because there is much concentration of neem dust particles in the air. Sakar et al.[19] conducted a study on ceramic workers, and the results showed reduced spirometric indices in workers who had been exposed, this drop was significant due to a higher concentration of neem dust particles coming from the cleaning section. Neghab et al.[20] observed a notable decline in the FEV₁ and FVC of exposed workers in their study. In this case, the decline in the FEV₁/FVC% or PEFR (L/S) found may be due to the workers in the neem oil industry not wearing any face mask, so the dust particles directly enter the respiratory systems and get settled along the way through the lungs.

Few earlier studies reported on oil spill workers’ lung function, and those that have been done have produced mixed results.[21,22,23,24] Following the fishermen, Prestige oil spills who were assigned to clean-up efforts did not differ in terms of lung function, despite raised levels of lung damage markers being seen.[21] To enable comparison with earlier studies of oil spill cleanup workers as well as studies of other environmental exposures like smoking and air pollution, this work analyzed raw lung function measurements.[25,26,27,28] The majority of the study’s participants were uneducated and had no idea of the dangers to their health from unclean working conditions. Industrial employees in wealthy countries take occupational health very seriously, whereas this topic is largely ignored in developing nations.[29] Dust concentration in the ginning factories was higher (1.2–6.0 mg/m³) due to inadequate ventilation, exceeding the allowable exposure limit for cotton dust in India of 0.2 mg/m³.[30] The participants in this study worked without any personal protection equipment for 8–12 hours each day in all the sectors. Thus, their health was in danger. In this study, experienced that exposed workers’ health is at risk, whereas the health of the non-exposed group is very good considering respiratory systems.

CONCLUSION

This study focuses on respiratory systems and lung function tests on neem oil mill workers’ health. The high TVOC concentrations in the oil extraction area were a result of inadequate ventilation at operations and were higher than the OSHO standard values. The FEV₁ (L), FEV₁/FVC%, FVC (L), and PEFR (L/S) are measured for the workers in the industry, which leads to lung-related issues. Due to the higher VOC in the industry, the neem oil mill workers are advised to use protections to reduce health risks. Regarding the handling, use, transportation, storing, disposal of hazardous substances, and cleaning up suitable measures should also be increased to prevent health issues. Additionally, safety particulars about the hazardous substances they may be exposed to, such as exposure standards, nature of hazards, and potential way of entry into the body, should be provided. To address concentrations of VOCs that accumulated during the extraction process in the oil mill, it was advised to install indoor dust and VOC control systems.

Financial support and sponsorship

This work was supported by the Indian Council for Medical Research (5/8-4/30/ENV/2020-NCD-II) and Shankar Subramaniam, and Naveenkumar Raju has received the funding support.

Conflicts of interest

There are no conflicts of interest.

Author contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Shankar Subramaniam, Abbas Ganesan and Naveenkumar Raju. The first draft of the manuscript was written by Abbas Ganesan and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Ethics approval

This study was approved by the Kongu Engineering College Ethics Committee.

Participant’s consent for study

Informed consent was obtained from all individual participants included in the study.