Occupational Health Problems among Workers of Cashew Processing Units in Kollam District, Kerala

Abstract

The cashew processing industry plays a vital role in supporting the livelihoods of a large number of individuals in southern Kerala. Therefore, this study aimed to determine the prevalence of occupational health problems and associated factors among cashew workers. This cross-sectional survey was conducted among 360 cashew workers. Socio-demographics, musculoskeletal disorders (MSDs), respiratory symptoms, and dermatological problems were collected through a scheduled interview. Log binomial regression analysis was done. The prevalence of MSDs, chronic lung diseases (CLDs), and dermatological problems were 55.8%, 18.9%, and 47.5%, respectively. Female workers and workers with a lower education level were significantly more likely to report MSDs. Male workers and those with more years of employment were significantly more likely to report CLDs. Workers in the shelling and peeling section were significantly more likely to report dermatological problems. Targeted interventions to improve the occupational health of cashew workers are needed.

INTRODUCTION

Approximately 2.3 million men and women around the world fall victim to work-related accidents or diseases resulting in 360,00 work-related deaths every year.[1] Prolonged working hours and workplace exposure to air pollution, including particulate matter, gases, and fumes, were identified as key risk factors for work-related deaths. Despite a 14% decline in such fatalities from 2000 to 2016, deaths associated with heart disease and stroke due to extended working hours increased by 41% and 19%, respectively.[2]

Kerala ranks sixth in cashew production among all Indian states.[3] The cashew processing industry is pivotal in sustaining the livelihoods of numerous individuals in southern Kerala; nevertheless, it remains highly labor-intensive.[4,5] In cashew plantations and processing facilities, employees face health issues such as fingertip irritation, skin burns, respiratory ailments, cancer, and reproductive disorders due to inherent task-related risks.[6,7] Female workers engaged in tasks such as shelling, peeling, and grading often experience musculoskeletal issues due to prolonged sitting and the absence of adequate rest intervals. These health risks are associated with their work, such as exposure to smoke from furnaces, contact with cashew nut shell liquid, inappropriate sitting postures, and avoiding rest intervals to maximize output.[4] Indian processors have typically depended on skilled workers.[6] Literature on occupational health problems among workers of cashew processing units is limited in Kerala. This study aims to determine the prevalence of occupational health problems such as musculoskeletal disorders (MSDs), respiratory symptoms, and dermatological problems and factors associated with them among cashew processing workers in Kollam district, Kerala.

METHODOLOGY

Study design

This was a cross-sectional analytical study.

Study setting

The study was conducted in the registered cashew processing units in Kollam district. Kollam is the biggest seller of processed cashews worldwide. Nearly 80% of India’s export-quality cashew kernels are prepared in Kollam.

Study population

The study included workers aged 18-60 years from the roasting, shelling, peeling, and grading sections. Workers with less than one year of work experience were excluded.

Study duration

The study duration was seven months, and the data collection period was from March 01 to April 30, 2023.

Sample size calculation

With the reported prevalence of 36% low-back pain in cashew workers[7] a confidence level of 95%, a precision of 20%, and a design effect of two to account for the cluster sampling design, the sample size was estimated to be 342, which was rounded off to 360 so that we could select 30 participants from each of the 12 clusters.

Sampling technique

Kollam district has six taluks: Kollam, Karunagapally, Kunnathur, Punalur, Pathanapuram, and Kottarakkara. The study was conducted in the Kollam taluk due to administrative and logistical considerations. A list of registered and operational cashew processing units in this taluk was obtained. Using the lottery method, 12 units were chosen and 30 eligible workers were recruited for the study from each of these units (clusters). A list of workers in each unit was created and each worker was assigned a serial number. Computer-generated random numbers were used to select workers from the list. The worker counts for each of the 12 units were as follows: 303, 307, 330, 371, 431, 326, 375, 321, 405, 389, 430, and 334.

Data collection

The selected cashew processing units were visited and participants were interviewed between 10 AM and 4 PM. The interview was conducted in the local language, Malayalam.

Study tools

A pre-tested semi-structured interview schedule was used to gather information on the participants’ sociodemographic profile, MSDs using a validated questionnaire adapted from the Standardized Nordic Questionnaire, respiratory symptoms using a validated questionnaire derived from the Indian Study on Epidemiology of Asthma, Respiratory Symptoms, and Chronic Bronchitis in Adults (INSEARCH) Questionnaire, and dermatological problems using a validated questionnaire adapted from the Nordic Occupational Skin Questionnaire (NOSQ-2002/long version). A validated Malayalam version of the INSEARCH questionnaire was already available, and the authors conducted a language validation for the Standardized Nordic Questionnaire and NOSQ-2002/long version.

Operational definitions

Work-related MSD was defined as the presence of at least one musculoskeletal symptom during the last 12 months and the last seven days such as ache, pain, discomfort, and numbness in one of the nine body regions.

Asthma

Asthma was identified if the respondent answered “yes” to one of the items such as wheezing or whistling sound from the chest or chest tightness or breathlessness in the morning and to one of the following items such as having asthma or an attack of asthma in the past 12 months or using inhalers or oral bronchodilators.

Chronic Bronchitis was defined by the presence of cough with sputum for three or more months in a year for a period of two or more years; “yes” to item “Do you usually bring up phlegm from your chest most of the morning for at least three consecutive months during the year?” and to one of the two items, that is “Do you usually cough first thing in the morning?” or “Do you usually bring out phlegm from your chest first thing in the morning?”.

Atopic dermatitis was defined as the presence of an itchy rash that has been coming and going for at least six months, and occasionally affecting skin creases.

Contact urticaria was defined as the presence of itchy wheals appearing and disappearing rapidly (within hours) on hands, wrists, or forearms caused by skin contact with fruits, vegetables, rubber gloves, and so on.

Statistical analysis

Data were entered using Microsoft Excel sheet and analyzed using the STATA version 14. MSDs, chronic lung diseases (CLDs), dermatological problems, and other work-related health problems such as eye strain were summarized using frequencies and percentages.

The sociodemographic variables associated with MSDs in the last seven days, CLDs, and dermatological problems were analyzed using a Chi-square test and with 95% confidence intervals (CIs), unadjusted prevalence ratios (UPRs) were calculated. A log binomial regression analysis was performed, including variables that had a P value less than 0.2 in the unadjusted analysis, and adjusted prevalence ratios (APRs) with 95% CIs were calculated. A P value less than 0.05 was considered statistically significant.

Ethical considerations

Written informed consent was obtained from each participant before the data collection. The study was approved by the Institutional Ethical Committee. In addition, we obtained prior permission from the factories, and the interviews were conducted in the presence of each factory’s managers.

RESULTS

The distribution of participants in the study, based on sociodemographic factors, is described in Table 1. Table 2 presents the prevalence of various occupational health problems.

Table 1.

Distribution of study participants according to socio-demographic factors (n=360)

Socio-demographic factors	Categories	Frequency (n)	Percentage (%)
Age (in years)	Below 49	206	57.2
	49 and above	154	42.8
Sex	Male	38	10.6
	Female	322	89.4
Education	Below high school	103	28.6
	High school and above	257	71.4
Socioeconomic status	BPL*	303	84.2
	APL+	57	15.8
Section	Roasting	38	10.6
	Shelling	112	32.7
	Peeling	131	36.4
	Grading	79	21.9
Work experience	Below 16 years	174	48.3
	16 years and above	186	51.7

BPL* below poverty line, APL⁺ above poverty line

Table 2.

Musculoskeletal disorders (MSDs), respiratory symptoms, chronic lung diseases, dermatological problems, and other work-related health problems among study participants (n=360)

	Last 12 months		Last 7 days
	n	%	n	%
Body parts affected by MSD*
Neck	60	16.7	26	7.2
Shoulders	234	65.0	104	28.9
Elbows	159	44.2	73	20.3
Wrists/Hands	157	43.6	74	20.6
Upper back	27	7.5	13	3.6
Lower back	247	68.6	130	36.1
One or both hips/thighs	55	15.3	24	6.7
One or both knees	228	63.3	120	33.3
One or both ankles/feet	143	39.7	77	21.4
Respiratory symptoms
Wheeze+	64	17.8
Morning breathlessness	104	28.9
Breathlessness on exertion+	230	63.9
Breathlessness without exertion+	30	8.3
Breathlessness at night+	57	15.8
Cough at night+	99	27.5
Cough in morning	66	18.3
Phlegm in morning	120	33.3
Breathing never satisfactory	60	16.7
Attack of asthma+	4	1.1
Chronic lung diseases
Asthma	35	9.7
Chronic bronchitis	45	12.5
Both these diseases	12	3.3
Dermatological problems
Atopic dermatitis	76	21.1
Contact urticaria	68	18.9
Dry skin	95	26.4
Other work-related health problems
Eye strain	75	20.8

*Musculoskeletal disorders. ⁺Past 12 months. Percentage does not add to 100 due to multiple answers

Table 3 displays the results of bivariate and log binomial regression analysis showing the association of sociodemographic variables with the risk of MSDs in the last one week. Table 4 displays the results of bivariate and log binomial regression analysis showing the association of sociodemographic variables with the risk of CLDs. Table 5 displays the results of bivariate and log binomial regression analysis showing the association of sociodemographic variables with the risk of dermatological problems.

Table 3.

Socio-demographic variables associated with musculoskeletal disorders (MSD) in the last 7 days: results of bivariate analysis and log binomial regression analysis (n=360)

Variables	MSD-Last 7 days
	Total	Yes n (%)	No n (%)	Unadjusted PR (95% CI)	P	Adjusted PR* (95% CI)	P
Age (in years)
49 and above	154	96 (62.3)	58 (37.7)	1.22 (1.02-1.47)	0.030	1.05 (0.88-1.25)	0.600
Below 49	206	105 (51.0)	101 (49.0)	Ref	-	Ref	-
Sex
Female	322	195 (60.6)	127 (39.4)	3.84 (1.83-8.04)	<0.001	3.74 (1.76-7.92)	0.001
Male	38	6 (15.8)	32 (84.2)	Ref	-	Ref	-
Education
Below high school	103	74 (71.8)	29 (28.2)	1.45 (1.22-1.73)	<0.001	1.30 (1.08-1.56)	0.006
High school and above	257	127 (49.4)	130 (50.6)	Ref	-	Ref	-
Socioeconomic status
BPL	303	175 (57.8)	128 (42.2)	1.27 (0.94-1.71)	0.122	1.16 (0.89-1.50) 0.277
APL	57	26 (45.6)	31 (54.4)	Ref	-	Ref	-
Section
Shelling	112	78 (69.6)	34 (30.4)	4.41 (2.10-9.29)	<0.001	1.02 (0.83-1.25)	0.837
Peeling	131	70 (53.4)	61 (46.6)	3.38 (1.60-7.17)	0.001	0.86 (0.69-1.08)	0.198
Grading+	79	47 (59.5)	32 (40.5)	3.77 (1.77-8.03)	0.001	-	-
Roasting	38	6 (15.8)	32 (84.2)	Ref	-	Ref	-
Work experience (years)
16 and above	186	120 (64.5)	66 (35.5)	1.39 (1.14-1.68)	0.001	1.18 (0.97-1.44)	0.099
Below 16	174	81 (46.6)	93 (53.5)	Ref	-	Ref	-

*Variables that had a P<0.2 in the bivariate analysis were included in the model. ⁺Variables that are constant within every unit are omitted in the log binomial regression analysis. (Section-Grading). MSD: Musculoskeletal disorders, BPL: Below poverty line, APL: Above poverty line, PR: Prevalence Ratio

Table 4.

Socio-demographic variables associated with chronic lung diseases (asthma, chronic bronchitis, or both) among the participants: results of bivariate analysis and log binomial regression analysis (n=360)

Variables	Chronic lung diseases
	Total	Yes n (%)	No n (%)	Unadjusted PR (95% CI)	P	Adjusted PR* (95% CI)	P
Age (in years)
49 and above	154	31 (20.1)	123 (79.9)	1.12 (0.73-1.72)	0.603	not included in the final
Below 49	206	37 (18.0)	169 (82.0)	Ref	-	adjusted model
Sex
Male	38	12 (31.6)	26 (68.4)	1.82 (1.07-3.07)	0.026	3.39 (1.54-7.47)	0.002
Female	322	56 (17.4)	266 (82.6)	Ref	-	Ref	-
Education
Below high school	103	25 (24.3)	78 (75.7)	1.45 (0.94-2.25)	0.095	1.33 (0.84-2.11)	0.217
High school and above	257	43 (16.7)	214 (83.3)	Ref	-	Ref	-
Socioeconomic status
APL	57	11 (19.3)	46 (80.7)	1.03 (0.57-1.83)	0.931	not included in the final
BPL	303	57 (18.8)	246 (81.2)	Ref	-	adjusted model
Section
Roasting+	38	12 (31.6)	26 (68.4)	3.12 (1.39-6.99)	0.006	-	-
Shelling	112	21 (18.8)	91 (81.3)	1.85 (0.86-3.97)	0.113	1.53 (0.71-3.31)	0.279
Peeling	131	27 (20.6)	104 (79.4)	2.04 (0.97-4.26)	0.059	2.09 (1.01-4.33)	0.047
Grading	79	8 (10.1)	71 (89.9)	Ref	-	Ref	-
Work experience (years)
16 and above	186	44 (23.7)	142 (76.3)	1.72 (1.09-2.70)	0.019	1.77 (1.12-2.80)	0.014
Below 16	174	24 (13.8)	150 (86.2)	Ref	-	Ref	-

*Variables that had a P<0.2 in the bivariate analysis were included in the model. ⁺Variables that are constant within every unit are omitted in the log binomial regression analysis. (Section-Roasting). BPL: Below poverty line, APL: Above poverty line, PR: Prevalence Ratio

Table 5.

Socio-demographic variables associated with dermatological problems among the participants: Results of bivariate analysis and log binomial regression analysis (n=360)

Variables	Dermatological problems
	Total	Yes n (%)	No n (%)	Unadjusted PR (95% CI)	P	Adjusted PR* (95% CI)	P
Age (in years)
49 and above	154	74 (48.1)	80 (52.0)	1.02 (0.82-1.27)	0.856	not included in the final
Below 49	206	97 (47.1)	109 (52.9)	Ref	-	adjusted model
Sex
Female	322	161 (50.0)	161 (50.0)	1.90 (1.10-3.27)	0.021	1.13 (0.60-2.11)	0.705
Male	38	10 (26.3)	28 (73.7)	Ref	-	Ref	-
Education
Below high school	103	56 (54.4)	47 (45.6)	1.22 (0.97-1.52)	0.087	1.02 (0.81-1.28)	0.861
High school and above	257	115 (44.8)	142 (55.3)	Ref	-	Ref	-
Socioeconomic status
BPL	303	149 (49.2)	154 (50.8)	1.27 (0.90-1.80)	0.171	1.16 (0.84-1.61)	0.369
APL	57	22 (38.6)	35 (61.4)	Ref	-	Ref	-
Section
Shelling	112	70 (62.5)	42 (37.5)	2.38 (1.37-4.12)	0.002	2.02 (1.40-2.94)	<0.001
Peeling	131	67 (51.2)	64 (48.8)	1.94 (1.11-3.39)	0.020	1.69 (1.17-2.46)	0.006
Grading+	79	24 (30.4)	55 (69.6)	1.15 (0.62-2.16)	0.654	-	-
Roasting	38	10 (26.3)	28 (73.7)	Ref	-	Ref	-
Work experience (years)
16 and above	186	93 (50.0)	93 (50.0)	1.12 (0.90-1.39)	0.328	not included in the final
Below 16	174	78 (44.8)	96 (55.2)	Ref	-	adjusted model

*Variables that had a P<0.2 in the bivariate analysis were included in the model. ⁺Variables that are constant within every unit are omitted in the log binomial regression analysis. (Section-Grading). BPL: Below poverty line, APL: Above poverty line, PR: Prevalence ratio

DISCUSSION

In our study, we found that the prevalence of MSDs was 55.8%. This finding is consistent with a study conducted in the informal sectors of hairdressers in Ethiopia, where the prevalence of MSDs was found to be 55.7% in the past seven days.[8] Similar results were observed in a study among female readymade garment workers in Bangladesh, where 57% of the workers reported musculoskeletal pain in at least one body part during the last month.[9] According to a study conducted in cashew workers in Karkala, Karnataka, India, 36.25% of the participants complained of work-related musculoskeletal pain.[10] Another study conducted in Udupi district, Karnataka, India, reported a prevalence of musculoskeletal discomfort of 28.5% among the study population.[11]

Women were 3.7 times more likely to report MSDs compared to men. Most of the workers engaged in cashew processing were involved in shelling, peeling, or grading, and currently, all workers assigned to these tasks are women. They may experience musculoskeletal issues due to prolonged sitting and the absence of adequate rest intervals.[4,12] Lindberg[13] reported that only female cashew workers work in all labor-intensive jobs at a piece rate, whereas male cashew workers receive monthly payments in Kerala, India. These findings indicate that female workers are more prone to developing MSDs compared to male workers. Workers with a lower education level were 1.3 times more likely to report MSDs in the last week compared to those with a higher education level. Krishnan et al.[14] found that the frequency of musculoskeletal symptoms in any body region increased in workers with lower levels of education.

Chronic lung diseases were prevalent in 18.9% of participants. According to a study conducted in cashew workers in Cuddalore district, Tamil Nadu, India,[7] 8% of the participants reported respiratory problems. Josino et al.[15] conducted a study investigating the detrimental effects of particulate matter with an aerodynamic diameter less than 4 micrometers (PM4.0) and total suspended particles (TSPs) present in exhaust gases from the combustion of cashew nut shell (CNS) on the respiratory system of mice.

In this study, male workers were 3.4 times more likely to have CLDs compared to female workers. Male workers are employed in the roasting section. A study conducted among cashew workers in Cuddalore district, Tamil Nadu, India,[7] found that respiratory problems were predominantly observed (68.8%) among workers involved in roasting. A study by de Oliveira Galvão et al.[16] focused on the characterization of elemental composition and analysis of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM) as well as the assessment of genotoxic activity associated with artisanal cashew nut roasting, demonstrated that it poses a significant occupational problem with harmful effects on workers’ health. Those involved in this activity are exposed to higher concentrations of fine particulate matter (PM2.5) and 12 PAHs.[16] The PM2.5 can penetrate the lungs and enter the body through the bloodstream, affecting major organs. Exposure to PM2.5 can cause diseases such as stroke, lung cancer, and chronic obstructive pulmonary disease (COPD),[17] indicating a higher risk for male workers in the roasting section to develop CLDs. Workers with 16 or more years of work employment were 1.8 times more likely to have CLDs compared to those with less work experience. Occupational lung diseases (OLDs) are caused, aggravated, or exacerbated by workplace exposures,[18] indicating that workers with more years of experience are at a higher risk of developing CLDs due to prolonged exposure.

Of the participants, 47.5% reported at least one dermatological problem. Pasricha et al.[19] conducted a study among workers employed in the cashew nut industry in Karnataka, India, and found cashew nut shell oil’s cauterizing effect on skin, leading to changes with repeated exposure. Andonaba et al.[20] conducted a study among women in the handcraft shelling chain of cashew nuts in Burkina Faso. The prevalence of all dermatosis and dermatitis was estimated to be 98.21% and 88.39%, respectively. High prevalence in this study was probably because it was conducted among only the shelling workers.

Workers in the shelling section were twice as likely, and those in the peeling section were 1.7 times more likely to report dermatological problems compared to those in the roasting section. Andonaba et al.[20] found a prevalence of 98.21% for all dermatoses and 88.39% for dermatitis among women in the handcraft shelling chain of cashew nuts in Burkina Faso. Pasricha et al.[19] reported that the strong cauterizing effect of the cashew nut shell oil on the skin can lead to various skin changes. Shelling and peeling activities, involving cutting the outer shell and removing the kernel’s skin, collectively indicate a high risk of dermatological problems for workers in these sections.

The study has limitations, including the cross-sectional design impeding causality establishment and the risk of overreporting and subjectivity with self-reported data. Generalizability is limited as the workers are from a single district in Kerala.

CONCLUSION

The high prevalence of occupational health problems among cashew workers underscores the need for targeted interventions. Focusing on MSDs in female workers with lower education, chronic lung issues in experienced male workers, and dermatological issues in shelling and peeling workers could greatly enhance their health outcomes.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.