Introduction

Tobacco (Nicotiana tabacum) is a significant commercial crop in India. Common varieties grown on Indian farms include Flue-Cured Virginia (FCV) tobacco, country tobacco, burley tobacco, leaf-wrapped (Bidi) tobacco, rustica tobacco, and chewing tobacco. India is the world’s fourth-largest producer and exporter of unprocessed tobacco. In 2020–21, exports of tobacco and tobacco products contributed approximately INR 63,000 million [~ US $790 million] in foreign exchange1.

According to FAO (2022), in India, the tobacco harvested area is 0.45 million ha with 0.76 million tonnes of production with a yield of 1.68 tonnes/ha in 20202. Tobacco is a drought-tolerant, hardy and short-lived crop grown on soils where other crops are not profitable. In tobacco cultivation, there are different operations, namely sowing (nursery management), transplanting of seedlings, intercultural operations, spraying and fertilizer application, topping of flowering buds, de-budding of auxiliary buds, harvesting of leaves, transportation of leaves, stringing of leaves before keeping them in the barn for curing, loading the barn, curing, unloading the barn, bulking the cured leaf, grading of leaves and bailing. About 45.7 million people in India depend on the tobacco sector for their livelihoods. It comprises 6 million farmers, 20 million farm labourers, 4 million leaf harvesters, 8.5 million workers in processing and 7.2 million workers in manufacturing and exports, retailing, and trading3.

Most studies on tobacco farmworkers confine to Green Tobacco Sickness (GTS)4,5,6,7,8but there are very few studies on musculoskeletal disorders among tobacco workers9,10,11,12. There are studies on different crops and postures adopted during cultivation practices13,14,15,16,17 but a lack of studies on tobacco. There is a need for a detailed study on tobacco cultivation related to the musculoskeletal and postural aspects. The postures adopted for different operations are odd, with repetitive activities differing from other crops, like harvesting, stringing and curing tobacco leaves several times as the maturity of leaves is at a different time. Moreover, workers must be very careful of the absorption of nicotine from the plants. The mechanization levels in tobacco cultivation are low, resulting in many manual activities during cultivation, exposing the workers to tobacco plants and leaves. Musculoskeletal problems are prevalent globally (1.71 billion people), as reported in the Global Burden of Diseases (GBD)18. Low back pain is the major cause of impairment and the leading cause of disability.

The odd postures lead to musculoskeletal disorders and health hazards. The present study attempts to study the musculoskeletal disorders prevalent among tobacco farm workers by conducting a survey and assessment of postures during tobacco cultivation activities using REBA, BPDS and ODS techniques.

Results

Musculoskeletal disorders among tobacco farm workers

Personal details

One hundred twenty tobacco farmworkers were personally visited and interacted with. Among all, 53% (64) were males and 47% (56) were females. Among the male workers, the age distribution of participants was 20–30 years—25%, 30–40 years—30%, 40–50 years—25% and above 50 years—20%. Among females, 25% were 20–30 years, 27% were 30–40 years, 37% were 40–50 years and 11% were above 50 years. Illiteracy was higher in females (77%) than in males (50%). 22% of males and 11% of females had primary education; 9% of males and 7% of females had middle school education; 13% of males and 3% of females had matriculation education; 6% of males and 2% of females had senior secondary education.

All 120 (64 males and 56 females) workers worked on tobacco farms during cultivation season. During the tobacco off-season, 51 males and 54 females were involved in agricultural activities in crops like paddy, maize, bengal gram, chilli, and sugar-cane farms. Thirteen males (20%) were engaged in other non-farm activities like vehicle driving (9%), construction work and painting (1.5%) each and no other work (8%). Two females did not work on any other crop farm. The ownership of landholding among males was 1–2 acres (8%), 2–4 acres in (1%), more than 4 acres in (5%) and 86% of male workers were landless. Female workers did not own any land and depended on daily farm activities and other work for sustenance. The distribution of local and migrant workers among genders was males (33% and 76%) and females (57% and 43%) respectively.

Tobacco cultivation details

Among all, 89% of males and 98% of females worked between 1 and 4 months per year and 8% of males and 2% of females for 4–8 months and 3% of males worked more than 8 months. The work experience in terms of years (1–10 years) for 89% of males and 61% of females, 10–20 years for 3% of males and 36% of females and more than 20 years for 8% of males and 3% of females, respectively.

Wages earned

The daily wages for tobacco cultivation farmworkers depend on the type of operation; the wages varied from INR 200 (~$ 2.5) onwards. The survey indicated that 58% of males and 59% of females earn INR 200–300 (~ $ 2.5 to 4) per day. 16% of males and 11% of females earn INR 300–400 (~ $ 4 to 5) per day, whereas 25% each male and females earn INR 400–500 (~ $ 5 to 6) and 10% males and 5% females earned more than INR 500 (~ $ 6).

Tools used

The tools and implements used during tobacco cultivation were pre-planting tillage operation, mouldboard plough for heavy soils, disc plough for light soils and cultivator and planking for levelling the field. Animal-drawn cultivators, blade harrows, tractor-drawn cultivators and sickle and weeding tools (licki) were used for intercultural operations. Knapsack and tractor-drawn sprayers are used for plant protection, bamboo baskets to transport leaves in the field, barns to cure tobacco leaves and square wooden balers for baling tobacco leaves.

Musculoskeletal disorders (MSD)

The information on MSD of 120 tobacco farm workers was analyzed (Fig. 1a). Discomfort leading to MSD, the most frequently reported during the last 7 days, most affected body parts were one or both knees (23%) followed by neck (21%), shoulders and both ankles/feet (19%), elbows and wrist hands (14%), lower back (13%), upper back (8%) and one or both hips/thighs/buttocks (7%) were reported.

Distribution among genders

MSD reported during the survey showed that female workers had higher problems than male workers. Among females, affected body parts were one or both knees 54%, followed by ankles/feet (45%), shoulders (38%), neck (36%), lower back (29%), elbows (23%), wrist/hands (20%), hips/thighs/buttocks (16%) and upper back (9%). In males, the highest knees and ankles/feet problems (41%), followed by neck (38%), shoulders (36%), wrist/hands (33%), elbows (25%), hips/thighs/buttocks (22%), lower back (20%) and upper back (11%) was reported (Fig. 1b).

MSD among different age groups

The comparison of MSD affecting body parts among different age groups is shown in Fig. 1c. The age group of 20–30 years had the highest MSD in the neck (43%), shoulders (40%), elbows and lower back (27%) and upper back (13%) compared to other age groups. Because younger workers had higher work capacity and were involved in difficult cultivation practices18 inexperience also leads to higher MSD than older age groups. This age group had lower knee problems than the older age group, which can be age-related in the older age group.

Fig. 1
figure 1

Musculoskeletal disorders of tobacco farmworkers a MSD trouble during last 7 daysb MSD among different genders c MSD among different age groups.

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Statistical analysis

Table 1 provides the Chi-square test (pertaining to independence of attributes) results of (age versus MSD) and separately of (gender versus MSD) for the attributes age (at two levels < 30 and > = 30) and gender (at two levels male and female) individually against the attribute MSD (at two levels yes and no) for the various body parts considered. Even though, at the conventional 5% level of significance, no Chi-square test statistic has come out to be significant, it can be seen that when less orthodox (liberal) level of significance, as, say, 20% is considered, as regards to MSD, age seems to be statistically significant for the body part knees; gender, for the body parts viz., hands and separately for knees. Thus, it can be inferred that, the MSD affects the workers differentially on the limbs for both genders and also for different age groups.

Table 1 Individual characteristics (age and gender) and their association with musculoskeletal disorders (MSDs) for farm workers (n = 120).
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Postural assessment during cultivation activities

Rapid entire body assessment (REBA)

For an objective assessment of posture, the “REBA score” was calculated for each operation with the help of “Ergo Plus Industrial Software”.

Tobacco transplanting

Female workers were mostly involved in manually transplanting tobacco seedlings as it was time-consuming and labour-intensive. So, six-woman farm workers were assessed for transplanting operation. The average “REBA score” in manual transplanting observed was 8 (high risk, investigate and implement change), which showed the level of MSD risk. The average risk index score was 2 (RI > 1), indicating a high-risk task to the fraction of the population (Table 2).

Intercultural operation (weeding)

The average REBA score for manual weeding was 8.166 (High risk, investigate and implement change) and showed the MSD risk level. The average risk index score was 2.04 (RI > 1) and it indicated a high risk for some fraction of population (Table 2).

Harvesting of tobacco leaves

The average REBA score for subjects was 8.2 (high risk, investigate and implement change), indicating MSD risk. The average risk index score was 2.04 (RI > 1), indicating high risk for a fraction of population (Table 2).

Stringing of tobacco leaves

The average REBA score was 6.833 (medium risk. Further investigate, change soon) for tobacco harvesting with MSD risk. The average risk index score was 1.70 (RI > 1), indicating that the task was high-risk (Table 2).

Body part discomfort score (BPDS)

The body part discomfort score was computed for tobacco cultivation operations with the help of a postural discomfort sheet. The mean score for manual transplanting of seedlings for female workers was 39.5, with an average age of 42.5. The BPDS for weeding was 40.20 for female workers of average age 40.5 years and harvesting BPDS was 50.25 (average age 40.5 years). Stringing of tobacco leaves was performed by males of the average age of 37.6 years and the BPDS was 34.33 (Table 2).

Overall discomfort score (ODS)

The overall discomfort score for tobacco farm workers in selected operations was highest in the harvesting of tobacco leaves (3.90), followed by transplanting of seedlings (3.82), manual weeding (2.87) and stringing of tobacco leaves (2.66) (Table 2).

Table 2 Postural assessment scores of different cultivation activities.
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Discussion

A survey was conducted among farm workers to assess the prevalence of MSD because of tobacco cultivation practices. It was found in the survey majority of females work on farms located in their native place, whereas males migrate to work away from their homes as migrant workers. The female workers had higher MSD compared to male workers. This may be attributed to their activities that require the adoption of odd postures. The body flexibility in females may be the reason to work in transplanting, weeding and harvesting. The results reported by15 also inferred higher MSD among female workers19. also observed similar work patterns and health problems among females. It was also observed that the younger group reported higher MSD than the older group. This may be because of performing activities that are energy intensity activities and require odd postures. Inexperience can also be a confounding factor. However, the most common problem reported among the older age group was a knee problem.

The transplanting of tobacco seedlings is performed in a bending posture, requiring repetitive actions of standing, bending and walking forward with a REBA score of 8 (High risk, investigate and implement change). Transplanting needs frequent posture changes resulting in higher physiological demand and excessive postural stresses. Similar results are reported by20 in vegetable transplanting. However, there are no studies on tobacco transplanting. Weeding is one of the important activities for the removal of weeds manually with the help of sickle and “licki”. This is performed in a squatting position; a push-pull movement is done to operate the sickle or licki. These tools are short handles and interaction with soil needs squatting or sitting posture. In squatting, during the weeding operation, there is a bending of the spine, neck and knee and twisting and bending movement of the wrist. Similar reporting was done for farm operations16.The REBA score was 8.166 (High risk, investigate and implement change). In all the operations, the REBA scores was high (transplanting, weeding and harvesting), indicating the potential cause of MSD risk as observed in the survey. The stringing operation was less strenuous, as observed by REBA, BPDS and ODS.

The tobacco transplanter machines improved the worker’s bending and standing posture. The standing posture is better than the bending posture21. The long handle tools can be operated in standing posture in weeding will improve the posture and reduce the drudgery22,23. The harvesting is also performed in odd posture and there is contact of the human body with tobacco plants and leaves, which results in nicotine absorption24,25,26,27. Leaves can be plucked and collected in a bamboo basket with the help of personal protective gadgets like gloves. So, improvising existing practices can be adopted more easily in transplanting, weeding and harvesting operations.

The MSD of farm workers in tobacco cultivation affected one or both knees, ankles/feet, shoulders and neck, wrist/hands and lower back. It may result in discomfort, disability, long-term effects and reduced work efficiency. It can be concluded that farmworkers work in awkward postures during different operations. Postural analysis showed that farm workers are exposed to higher risk in transplanting seedlings, harvesting tobacco leaves and weeding. Most of the postures adopted had high REBA, BPDS and ODS scores. To reduce the postural and physiological stresses, appropriate ergonomic tools or machine interventions are needed to improve the posture of farm workers. These interventions will reduce the MSD risk and improve the safety of tobacco farm workers.

Materials and methods

Sample size

The sample size (number of tobacco-related farm workers) has been considered as 120. The reason is that, referring to Snedecor and Cochran (1989), and with the corresponding version for ‘proportion’ (as in the former it was given for estimation of mean) taken from Biradar (2002). The following formula has been employed: n = z2pq/ L2. For the sample to have a 50:50 male: female ratio, the proportion of (1/2) was considered and accordingly, say, p = (1/2) for males, and hence q= (1- p) = (1/2) for females was taken. Moreover, this proportion estimate was desired to be correct to within limit (on both sides) of, say, L = (1/10). As the sample size is large, a normal distribution was assumed and accordingly, at a 95% confidence interval (or at 5% level of significance), the z value was 1.96. In this way, the value of n was obtained as 96. Moreover, as it was expected that the number of female (or male) workers might be skewed significantly from the 50:50 premise, some (1/5)th of 96 was added to the sample size to bring the groups closer to parity, resulting in a sample size of 120. A larger sample size generally leads to more precise estimates, a stronger ability to detect true effects, and a greater likelihood of finding statistically significant results. It also reduces the margin of error and increases confidence in the results.

Assessment of musculoskeletal disorders

The study was conducted in Andhra Pradesh, a southern state of India. In the study, 120 tobacco farmworkers were selected based on purposive random sampling for the survey19. In Andhra Pradesh, FCV (Flue-cured Virginia) is cultivated in three soil regions, namely Northern Light Soils (NLS), Southern Light Soils (SLS) and Southern Black Soils (SBS). Two soil regions (NLS and SLS) were selected to collect data from tobacco farm workers involved in tobacco cultivation for the complete season. In NLS and SLS regions, 120 tobacco farm workers’ information was collected in two districts (West Godavari and Prakasam) at six locations: Devarapalli, Gopalapuram, Koyyalagudem, Kandukur I and II, Kanigiri (Fig. 2).

Fig. 2
figure 2

(Source:https://en.m.wikipedia.org/wiki/File:India_Andhra_Pradesh_locator_map.svg)

Study area of tobacco cultivation in Andhra Pradesh, India.

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Information on farm workers and musculoskeletal disorders

The survey proforma was developed based on literature28,29,30,31 and a pilot study of tobacco cultivators. The pilot survey was conducted among tobacco cultivators with the help of developed Performa in Devarapalli, West Godavari district of Andhra Pradesh. Most cultivators (farmers) were not involved in cultivation practices. Because the land size was larger and owners would either lease out or confine to monitoring the cultivation. The labours are hired from local as well as other places. These above facts were considered, the survey of tobacco farm workers was undertaken. Information was collected from the tobacco farm workers through personal interviews with the help of a developed survey proforma. The survey questionnaire was developed in English and translated into the local language (Telugu). The proforma (Annexure-I) consisted of personal details, work details in tobacco cultivation and musculoskeletal disorders using the Standard Nordic questionnaire32.

The personal details included name, location, age, gender, educational qualification, occupation, landholding, involvement in agricultural and non-agricultural activities, family size and place of work (local or migrant). The work details of tobacco cultivation were collected, including working months in tobacco crop per year, work experience in terms of years, daily wages and type of tools or implements used in cultivation33.

Postural analysis during tobacco cultivation activities

The four major cultivation practices were selected based on the duration of activity and adoption of odd postures, namely transplanting of seedlings, weeding, harvesting and stringing of tobacco leaves to assess the posture. The details of these operations are given below.

Transplanting of tobacco seedlings

The farm is prepared into furrows for planting the seedlings in a row with light irrigation. The FCV (Flue-cured Virginia) tobacco planting was done manually from mid-September to mid-October in Northern Light soils (NLS) and mid-October to mid-November in Southern Light soils (SLS). The row-to-row and plant-to-plant spacing is kept at 100 and 60 cm and 70 and 50 cm for NLS and SLS, respectively.

Intercultural operations

In intercultural operations, weeding is performed manually to remove weeds between crop rows and plants with the help of a hand tool-sickle (daranti) and weeding tool (licki). This operation helps in the removal of weeds and loosening of soil around the plants for root growth.

Harvesting of tobacco leaves

Farm workers start harvesting tobacco leaves in January and continue until March. They work early in the morning, around 6:00 to 11:00 a.m. This operation is carried out 7 to 8 times per season because only well-matured leaves are harvested from the bottom to the top of the plant at different intervals.

Stringing of tobacco leaves

After harvesting, the stringing of tobacco leaves is done immediately with the help of jute rope (sutli) manually. Two persons in sitting posture give 2–3 leaves alternatively to another person (standing position) who ties leaves manually with the help of a jute rope on the stick for curing tobacco leaves in the barns.

Assessment of the posture

The following techniques were used for measuring the postural parameters of farm workers in selected operations in tobacco cultivation

  1. (1)

    REBA (rapid entire body assessment).

  2. (2)

    BPDS (body part discomfort score).

  3. (3)

    ODS (overall discomfort score).

REBA (rapid entire body assessment)

The working postures of tobacco farm workers during different activities were assessed with the REBA method34 to evaluate the risk of musculoskeletal disorders (MSD) associated with tobacco cultivation. It systematically evaluates the musculoskeletal system’s upper and lower parts for biomechanical and MSD risks in associated operations. It is a single-page worksheet divided into two body segment sections labelled “A and B”. Section “A” consists of neck, trunk and leg analysis, including additional force or load score of subjects. Section “B” has arm and wrist analysis. The section “A and B” scores together give REBA scores. This total score represents the level of MSD risk. “Ergo plus Industrial Software” was used to calculate each operation’s total REBA score. A few of the observations taken are shown in Fig. 3.

Risk Index (RI)

The risk index35 estimates the magnitude of physical stress and MSD risk in a particular task of selected subjects. RI value of 1 or less indicates a “normal risk to healthy subjects”, whereas RI > 1 indicates “high risk for the population”. As the RI value increases, the level of MSD risk also increases correspondingly.

Fig. 3
figure 3

Sample observations for REBA analysis for the stringing of tobacco leaves. Sections A: Neck, Trunk and Leg and Section B: Arm and wrist.

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BPDS (body part discomfort score)

Corlett and Bishop (1976) used body mapping for the assessment of postural discomfort of farm workers in tobacco cultivation36. In this method, the perceived discomfort refers to a part of the body. The human body is divided into 27 regions, and the worker is asked to indicate the region’s most painful during the operations. The subjects mention all body parts with discomfort, starting with the worst, the second worst and so on, until all parts experiencing discomfort are mentioned. The ten-point scale is used to assess discomfort from “no discomfort to maximal discomfort”.

Overall discomfort rating (ODR)

The assessment of overall discomfort rating of tobacco farmworkers was assessed using a 5-point discomfort scale. This scale value of “1” for no discomfort and “5” for extreme discomfort21. The overall discomfort rating given by each subject is added and averaged to get the mean rating.

Selection of subjects

For this study, twenty-four tobacco farm workers were randomly selected from 25 to 50 years13,20 who were engaged in different cultivation activities. It comprised eighteen females involved in transplanting, weeding and harvesting tobacco leaves, which female workers predominately perform. As males performed this activity, six male workers were selected for stringing tobacco leaves. The criteria for selection of subjects were that they must have experience working in tobacco cultivation for at least five years and must have been engaged in doing all the farm operations (seed bed preparation, transplanting of tobacco seedlings, weeding operations, topping, harvesting and stringing of tobacco leaves, loading and unloading of tobacco leaves in curing barn, grading, bulking and bailing etc.).