Occupational hazards of Indian shrimp farm workers

Abstract

The paper reviews a range of global aquaculture health and safety literature to inform and contribute to the development of a socio-economic profile of Indian shrimp farm workers including the occupational hazards and injuries they face. In addition, 60 shrimp farm workers were interviewed from each of the states of Andhra Pradesh, Maharashtra, Gujarat and Tamil Nadu. The study revealed that all shrimp farm workers were male, 58% were migrants, and ages ranged from 23 to 53 years with work experience of 5 to 24 years. Few workers (14%) had no formal schooling and many had secondary-level education. Reported physical hazards were high (93%) followed by biological (82%), chemical (77%), ergonomic (71%) and psycho-social (71%) hazards. The majority of physical injuries reported related to slips, falls and cuts (51%), electric shocks (44%), sunburn (41%), dehydration/headaches (40%) and fractures (27%). Approximately 30%–39% had some chemical injury with skin infections/breathing problems. Indian shrimp farm workers face similar occupational hazards and injuries to shrimp farm workers in other countries. The occupational health and safety of shrimp farm workers should be integrated into the concept of ‘One Health’ to ensure aquaculture sustainability and safe, meaningful and good quality employment to workers.

KEYWORDS:

• Hazards
• injuries
• shrimp
• farmers
• India

Introduction

1. Production and workforce: In India, aquaculture is dominated by shrimp farming and now it is the third largest producer of farmed shrimp globally with extensive farming regions distributed in the east and west coasts of the country (CIBA 2020). The sector has generated more than 300,000 jobs (DAHDF 2017). Farmed shrimp production touched 711,674 tons in 2019, of which 87% was exported, earning foreign exchange of US$ 438 billion (MPEDA 2019). According to the annual report of the Coastal Aquaculture Authority (CAA 2017–2018), the majority of the shrimp farmers are smallholders with a farm area of below 2 ha (31,528 numbers) (CAA 2018). But, there are no precise statistics available on worker numbers in the Indian shrimp farming sector. However, in a shrimp farm of 1 ha area it is estimated that at least two workers are required. India has 108,526 ha area utilized for L. vannamei shrimp farming, so approximately 217,052 workers are estimated to be in the sector. No major studies are currently available on the demographics, work conditions, socio-economic status and the occupational hazards faced by Indian shrimp farm workers. This paper addresses some of those gaps.

2. Sector hazards – global and country-specific: The Food and Agriculture Organization (FAO) highlighted the global importance of occupational hazards in aquaculture (FAO 2018). The world’s estimated 19 million aquaculture workers regularly contend with hazardous conditions. The Blue Growth Initiative of the FAO highlighted the importance of decent work in fisheries and aquaculture (FAO 2015). Moreover, fishing is considered a dangerous occupation and associated with multiple risk factors. The International Labour Organization (ILO) reported a figure of 24,000 fishermen dying every year (ILO 1999). Studies related to occupational hazards of workers in the aquaculture sector in India are very meagre. In Europe, at a relatively early stage, Robertson et al. (1981) investigated the incidence of leptospirosis through a sero-epidemiological survey in the United Kingdom and found a trout fish farm worker had died from serologically confirmed leptospirosis. Christoffersen and Olsen (1993) reported chemical eye injuries in northern Norway and found that 14% of aquaculture workers had superficial corneal erosions. Fish bile was the causative agent for the injury, but the mechanisms for the corneal damage were not clear. Watterson et al. (2012) examined the public health impact assessment of tilapia aquaculture. Thorvaldsen et al. (2020) concluded that the prevalence of musculoskeletal diseases stands out as a challenge for workers’ health. Durborow (1997) reviewed the occupational safety interventions for aquaculture jobs in the United States. Erondu and Anyanwu (2005) reviewed potential hazards and risks associated with the aquaculture industry and found the sector presented many potential hazards and risks including those in occupational health and safety, environmental health, food safety and public health. Cavalli et al. (2020) reviewed the available Brazilian data on aquaculture injuries and diseases. In the African continent, Karanja et al. (2003) reported that the aquaculture sector was exposed to numerous hazards. In Turkey, Mert and Ercan (2015) found that the aquaculture industry faced prevalence of potential health hazards and risks. Within India, Sharma and Ray (2002) and Sharma et al. (2007a) documented the ergonomic problems of women prawn peelers in Maharashtra state. Sharma (2007b) also examined the workload of fisherwomen in aquaculture and their occupational problems. Sethulakshmi and Sharma (2017) have further described the use of sea safety devices in marine fisheries. Around the world, Watterson et al. (2008) reported on environmental and health impact assessments for wild capture fishing and farmed fish. Watterson (2018) noted aquaculture hazards that contributed to occupational health risks resulting in occupational injury and disease.

3. The Indian shrimp industry state profiles: A total of 108,526.27 ha is under L. vannamei culture in nine maritime Indian states producing 815,745 tons (2020–2021). Andhra Pradesh has the greatest area under shrimp production, followed by Gujarat and Tamil Nadu. All India average productivity is 7.52 MT/ha/year. Areas under cultivation and estimated production figures are presented in Table 1 based on information available from MPEDA (2021).

Table 1. Area under cultivation and estimated production of L. vannamei (2020–2021).

State	Area under cultivation (in ha)	Estimated production (in tons)	Productivity (tons/ha/year)
Andhra Pradesh	71,921	634,672	8.82
Gujarat	8986	50,410	5.60
Tamil Nadu	8600	44,735	5.20
Maharashtra	1183.49	4252.1	3.5

This study has drawn on the wider literature to fill in some gaps in India needed to produce and assess the profile of shrimp farm workers regarding occupational hazards and related employment conditions in the states of Andhra Pradesh, Gujarat, Maharashtra and Tamil Nadu in India. A brief profile of shrimp farming in the selected states follows.

Andhra Pradesh: The state has a 50.41% share in the country’s shrimp production and earns close to 53% of the overall revenue (MPEDA 2020). India is the world’s second-largest producer of farmed fish, and the state of Andhra Pradesh is by far the most important producer of farmed fish in India (Belton et al. 2017). The highest number of L. vannamei shrimp farms are in East Godavari and Nellore districts (Andhra Pradesh Department of Fisheries Portal 2020) so information was collected from shrimp farm workers from these districts.

Gujarat: Gujarat ranks second in L. vannamei shrimp production after Andhra Pradesh (MPEDA 2021) and has the largest coastal area (1600 km length) with approximately 0.38 million ha of brackish water area (Commissioner of Fisheries, Government of Gujarat 2020). Gujarat has 12 coastal districts and a Union Territory of Diu but only four of the districts, viz. Valsad, Navsari, Surat and Bharuch, are major shrimp producers. Commissioner of Fisheries, Government of Gujarat (2017) and information was collected from shrimp farm workers from these districts.

Tamil Nadu: Shrimp farming has grown considerably in this state and has emerged as a major commercial activity owing to the introduction of specific pathogen-free shrimp, L. vannamei. Nagapattinam district is the major shrimp farming district so shrimp farm workers were selected from here.

Maharashtra: The state has 52,001 ha of potential brackish water area, of which 10,400 ha is considered suitable for brackish water farming. The state stands 6th in terms of shrimp production with 6567 tons, and 7th in terms of number of shrimp farms (CIBA 2020). In Maharashtra, L. vannamei farming plays a vital role in shrimp aquaculture and is practiced in five coastal districts Palghar, Thane, Raigad, Ratnagiri and Sindhudurg districts, and information was collected from these districts.

Materials and methods

In India, the estimated brackish water area suitable for shrimp cultivation is around 1.19 million ha spread over 10 states and union territories, viz. Andhra Pradesh, Tamil Nadu, Maharashtra, Gujarat, West Bengal, Odisha, Kerala, Karnataka, Goa and Puducherry.

The traditional brackish water farming systems are most common in West Bengal and Kerala whereas commercial shrimp farms are mainly located in Andhra Pradesh and Tamil Nadu (CAA 2020). L. vannamei is the preferred species by shrimp farmers in India.

Locale of the study

The locations of the present study were Andhra Pradesh, Maharashtra, Gujarat and Tamil Nadu as these states play a major role in the country’s shrimp production, with Andhra Pradesh and Gujarat being the top two states (MPEDA 2020).

Sampling

In these four states, around 90,690 ha area is used for L. vannamei farming. It can be estimated that in one ha farm area, two workers are required. With this estimate, the number of shrimp farm workers is 181,380 (n = 90,690 ×  = 181,380). For the present study, information was collected from 240 shrimp farm workers from the states of Andhra Pradesh (n = 60), Maharashtra (n = 60), Gujarat (n = 60) and Tamil Nadu (n = 60). A total of 60 shrimp farm workers who were working fulltime (8 h in a day) in a farm were selected from each state. Part time workers were not selected for the study. In the absence of data on shrimp farm workers, purposive sampling was done. Sixty workers were selected on the basis of existing knowledge of working practices in the sector as the number of workers most likely to provide an informative sample. Objectives of the study were communicated to the workers orally. Consent was taken orally from them and information was collected using an interview schedule. Approval for the study was obtained from the Head of Fisheries Economics, Extension and Statistics Division of the Indian Council of Agricultural Research-Central Institute of Fisheries Education (ICAR-CIFE), Mumbai.

Tool used

The interview schedule was designed and piloted with 10 workers. The schedule collected information about the general profile of shrimp farm workers, including age, education, working experience, religion, monthly income, monthly expenditure on health, residential status and health insurance. Interviews were conducted by the authors/researchers who all have Bachelor’s degrees in Fisheries Science and are trained in data collection. They were natives of the respective states, so interviews were conducted in a language which was understood by the workers, i.e. Telugu in the case of workers in Andhra Pradesh, Tamil in Tamil Nadu, Gujarati in Gujarat, Marathi in Maharashtra; and in case of migrant workers from Odisha and West Bengal, Odiya, Bengali and Hindi language were used.

The definition of hazard by OSHA (2018) was used,

something which has the potential to cause harm and, in practical terms, it is associated with a condition or activity that, if left uncontrolled, can result in an injury or illness and when it is experienced in the workplace is considered as occupational hazard.

An occupational injury was defined as ‘any type of injury that occurs to a worker as related to the specific occupational hazard’ (Tadros et al. 2018).

A list of potential occupational hazards faced by shrimp farm workers was prepared by referring to the literature and discussions with three fisheries professionals and one social scientist.

Thereafter, three shrimp farm workers with higher experience were selected from each state as the key informants. These key informants were asked to add any other occupational hazards faced by shrimp farm workers. Hazards were then classified into physical, chemical, biological, ergonomic and psycho-social.

The shrimp farm workers were asked whether they have/had faced any kind of occupational hazards and injuries during their work in shrimp farming and the responses were recorded in an ordinal scale (Yes/No).

The work activity of shrimp farm workers was recorded. This was divided into three categories: pre-stocking, stocking and post-stocking. Pre-stocking activities included scrapping, water filling, setting bird fence, setting crab fence, fixing of aerators, liming the pond, applying bleaching powder, chain pulling and manuring. Stocking activities included shrimp seed stocking, and post-stocking activities included feeding, medicine/probiotic application, sampling, check tray monitoring and harvesting.

Statistical test

One-way analysis of variance (ANOVA) was performed to test if there was a statistically significant difference at 5% level of significance between income, age and experience of shrimp farm workers in different states. A Kruskal–Wallis test was performed to test whether there was any significant difference (p < 0.05) among the states for each of the occupational hazards.

Data were statistically analysed using statistical software IBM-SPSS 22.0.

Results and discussion

Activity profile

Workers involved in shrimp farming were employed fulltime. They resided at the shrimp farm itself and worked as per the demand of the activity which could be at any time of day or night. Shrimp farm workers reported they spent a minimum of 8 h and a maximum of 12 h per day in different farm-related activities, with a day’s holiday per week. Work hours depended on the needs and activities of the job determined by the farm owner/employer who employed them daily/weekly/monthly. Hence, it was difficult for the shrimp farm workers to assign a specific number of work hours being done daily. Their holidays and work leave were also dependent upon the agreement with the farm owner. The workers were usually allowed one month’s paid leave per year.

According to ILO recommendations, a labourer/worker should work for 48 h in a week with one compulsory day’s holiday (ILO 2015). India’s Ministry of Labour and Employment states that according to the Factories Act 1948, every adult (a person who has completed 18 years of age) cannot work for more than 48 h per week and not more than 9 h in a day according to Section 51 of the Act. The spread over should not exceed 10–12 h. Typically shrimp farm workers were working in this range.

The work activity of shrimp farm workers could be divided into three categories as described earlier: pre-stocking, stocking and post-stocking. The work involved in each stage is set out below, where exposure to a wide range of occupational health as well as safety hazards and risks is clear.

Pre-stocking activities

Scrapping: This includes cleaning of all the waste materials (feed waste, black soil, faecal and medicine waste) deposited at the centre/dyke of the pond. First, the waste material deposited on centre is piled up by a tractor on the pond dyke and from the dyke it is cleaned by the workers manually. This process takes around one day for complete scrapping of one pond of 1 ha with the involvement of two to four workers.

Water filling: This is a regular activity in shrimp farming. Daily observation of the water level is carried out and a 1.5 m water level is maintained in every pond. Every day the duty is assigned to one worker.

Setting the bird fence: Very thin invisible plastic wire fencing over the pond surface is used to protect the cultured species (L. vannamei) from birds. Workers fix the bamboo poles along the periphery of the pond dyke and set the plastic wire on the bamboo poles by moving within the pond water body. It takes around one to two days to complete the bird fencing of one ha pond with the involvement of four to six workers.

Setting a crab fence: The shrimp farm workers fix the crab net around the pond. It takes around 1–2 h to completely fix a crab fence of one ha pond with the involvement of three to four workers. The crab net is fixed on the last and first pond of the farming area.

Fixing of an aerator: In one ha pond, six aerators are fixed. To do this for one aerator, three to four shrimp farm workers are involved and it takes around 2 h. So, for one ha pond around 12 h is required for fixing six aerators. The aerator bamboo poles/mild steel rods need to be set vertically in the pond bottom in order to fix the position of the aerators so the aerator does not move from its designated place.

Liming the pond: This involves broadcasting the lime (dolomite, calcium carbonate, calcium oxide and calcium hydroxide) all over the pond. Four shrimp farm workers are involved and it takes around 30 min to completely lime one ha pond.

Applying bleaching powder: Bleaching powder (@ 30 ppm) is usually applied in the pond for the purification of water. For a pond of 1 ha it takes 1–2 h with the involvement of one to two workers.

Chain pulling: The organic load such as faecal matter and unutilized feed waste settles at the pond bottom during shrimp culture. This may create unhealthy production conditions in the pond and the shrimp may be adversely affected. Therefore, a chain-pulling activity is carried out to disturb deposited organic load in the bottom of the pond. Then the centrifugal force of the aerator concentrates the organic load at the centre of the pond. After this, the organic load is removed by a syphoning procedure. Three to four shrimp farm workers are involved for 3–4 h for 1 ha pond water area.

Manuring: Manure application is done fortnightly for each pond of one ha and involves three to four shrimp farm workers for 3–4 h.

Stocking activities

Shrimp seed stocking: Stocking of seed is usually carried out during early morning hours from 4 to 7 AM This stocking activity involves acclimatization of shrimp seeds in portable quarantine tanks. These quarantine tanks are cleaned with KMnO₄ solution every time before use. In a day, a maximum of 5–6 ponds can be stocked with the involvement of 15–20 shrimp farm workers. Some of the farms hire extra temporary daily wage workers for seed stocking.

Post-stocking activities

Feeding: This is a regular activity during the culture period and is carried out four times per day and two workers are involved at each feeding time. One worker tows the float along the feeder line while another worker broadcasts the feed. The activity lasts for 30 min for one pond of one ha. Two shrimp farm workers carry out this activity for 2 h in one day.

Medicine and probiotic application: This is also done at regular intervals. Medicines and probiotics are applied in the pond for maintaining healthy conditions of shrimp, pond water and soil. One to two shrimp farm workers are involved and it takes 1–2 h daily.

Sampling: Sampling is carried out weekly. A cast net is used and the worker handling the cast net throws it on the pond from the catwalk bridge. It involves four to five shrimp farm workers and takes 1–2 h for 1 pond.

Check tray monitoring: The check trays are monitored every day to observe the feed intake by the shrimp. These check trays are tied to the catwalk bridge. Observations are done by lifting the check trays. One shrimp farm worker takes 15–20 min for one pond.

Harvesting: Harvesting activity involves 10–15 workers for 1 ha pond and takes 4–5 h. A drag net is used during harvesting time and requires continuous force exertion of 4–5 h with continuous water contact.

Some of the shrimp farm workers had reduced injury risks through access to and use of personal protective equipment such as gloves, gum shoes and head caps.

According to the Agricultural Skill Council of India (ASCI 2016), the role of an aquaculture worker in many places includes similar activities. Bhattacharya (2010) in West Bengal reported that traditional and scientific shrimp farming required 101 person days per acre.

Demographic profile

Information about age, work experience, religion, caste, education, monthly income, expenditure on health, health insurance and residential status of shrimp farm workers was collected and is presented below.

Age: All shrimp farm workers were male and their ages ranged from 23 to 53 years. Andhra Pradesh had the highest average age 36 ± 11 and the lowest average age was found in Tamil Nadu, i.e. 32 ± 9 years.

Thorvaldsen et al. (2020) reported that the Norwegian fish farming employees’ ages ranged from 25 to 34 years.

Work experience: Work experience of shrimp farm workers ranged from 5 to 24 years. Workers from Andhra Pradesh had the longest work experience of 13 years ± 10 compared to other states.

Religion: The shrimp farm workers belonged to Hindu (76.66%), Muslim (10.41%) and Christian (12.93%) religions.

Caste: Shrimp farm workers belonged to General category (13.3%), ‘Other Backward Caste’ (OBC) (53.33%) and Scheduled Caste/Scheduled Tribe (SC/ST) (33.34%). The majority of the shrimp farm workers were from OBC.

Education: Few workers (13.75%) reported they had no formal schooling at all, 28.33% had primary-level schooling and a majority (54.16%) had secondary-level education.

Monthly income: Monthly incomes of shrimp farm workers of all the states ranged from US$101-106 with an average monthly income of US$103. The average monthly income was relatively higher in Tamil Nadu: US$ 103 ± 6.

According to the National Statistics Office, the average annual income of an Indian worker is estimated to be US$1358 (US$113 per month) for the year 2020–2021 (MOSPI 2021). In the present study, the annual income of shrimp farm workers was US$ 1238 (US$ 103 per month): less than the country’s per capita average annual income.

The International Poverty Line World Bank estimate defines extreme poverty as living on less than $1.90 per day measured in 2011 purchasing power parity prices (NITI Ayog 2021). In the present study, the estimation of average daily income of a shrimp farm worker was US$ 3.3 ± 0.2.

According to India’s Ministry of Labour and Employment, the country’s Seventh Pay Commission recommended daily wages of US$ 7.5 and US$ 9.0 for unskilled and skilled workers, respectively. The national minimum wage stands at US$ 2.23 per day (MoL&E 2021). This can be considered the national floor-level wage which refers to the minimum level of wage that is applicable to all categories of workers across the country (Ministry of Labour and Employment GoI 2021). The present study found the per day average income of shrimp farm workers ranged from US$ 3.3 to 3.5 which is more than the national daily wage.

Monthly expenditure on health: Average monthly expenditure on health by shrimp farm workers ranged from US$ 2.5 to 5.0. This expenditure was highest in Maharashtra (US$ 4.8 ± 1.3) and lowest in Gujarat state (US$ 2.69 ± 0.6). Health expenditure was mainly on the treatment of skin infections, body pain, headaches, fever and cough.

Health insurance: None of the shrimp farm workers reported that they had any kind of health insurance.

Residential status: The residential status of workers in the study area was categorized either as local or migrant. A shrimp farm worker was considered local if he belonged to the same state where the farm was situated. The study revealed that 42.5% of workers were local and 57.5% workers were migrants from other states. The demographic profile of shrimp farm workers of studied states in the study is presented in Table 2.

Table 2. Demographic profile of shrimp farm workers.

Parameters	Andhra Pradesh (60)	Gujarat (60)	Tamil Nadu (60)	Maharashtra (60)	Overall (240)
Age (years)	36 ± 11	35 ± 1	32 ± 9	34 ± 11	34 ± 1
Experience (years)	13 ± 10	6 ± 5	10 ± 7	7 ± 5	9 ± 1
Religion	Hindu: 79% (47)	Hindu: 75% (45)	Hindu: 75% (45)	Hindu: 78.3% (47)	Hindu: 77% (184)
	Muslim: 21% (13)	Christian: 25% (15)	Muslim: 17% (10)	Muslim: 3.0% (2)	Muslim: 10% (25)
			Christian: 8% (5)	Christian:18% (11)	Christian: 13% (31)
Caste	General: 12% (07)	General: 32% (19)	OBC: 60% (36)	General: 10% (6)	General: 13% (32)
	OBC: 48% (29)	OBC: 55% (33)		OBC: 50% (30)	OBC: 53% (128)
	SC/ST: 40% (24)	SC/ST: 13% (8)	SC/ST: 40% (24)	SC/ST: 40% (24)	SC/ST: 33% (80)
Education	No formal education: 18% (11)	No formal education: 3% (2)	No formal education: 15% (9)	No formal education: 18% (11)	No formal education: 14% (33)
	Primary: 22% (13)	Primary: 37% (22)	Primary: 37% (22)	Primary: 18% (11)	Primary: 28% (68)
	Secondary: 58% (35)	Secondary: 48% (29)	Secondary: 48% (29)	Secondary: 61% (37)	Secondary: 54% (130)
	Grade 12: 1.7% (1)	Grade 12: 11% (7)		Grade 12: 1.7% (1)	Grade 12: 4% (9)
Monthly income (₹)	US$ 101 ± 5	US$ 101 ± 6	US$ 103 ± 6	US$ 101 ± 7	US$ 101 ± 0.5
Monthly expenditure health (₹)	US$ 4 ± 3	US$ 2.7 ± 0.3	US $4.4 ± 2	US$ 4.8 ± 1.3	US$ 4.0 ± 0.1
Health insurance	Yes: 0	Yes: 0	Yes: 0	Yes: 0	Yes: 0
	No: 100% (60)	No: 100% (60)	No: 100% (60)	No: 100% (60)	No: 100% (60)
Residential Status	Local: 57% (34)	Local: 20% (12)	Local: 63% (38)	Local: 30% (18)	Local: 43% (102)
	Migrant: 43% (26)	Migrant: 80% (48)	Migrant:37% (22)	Migrant: 70% (42)	Migrant: 58% (138)

Note: Figures in parentheses are number of shrimp farm workers.

One-way analysis of variance (ANOVA) revealed no statistically significant difference at 5% level of significance between income, age and experience of shrimp farm workers of different states (p > 0.05) as clear from Table 3.

Table 3. Results of ANOVA for income, age and experience of shrimp farm workers.

Parameters	F (Cal)	p-Value
Income	1.284516	0.280404
Age	1.429849	0.234709
Experience	12.23385	1.81E−07

It is clear from this study that even though shrimp farm workers were working in different states their demographic profile was similar.

Most studies in India have reported on the socio-economic status of shrimp farmers. SwathiLekshmi et al. (2005) studied the socio-economic profile of shrimp farmers of Nellore in Andhra Pradesh and Nagapattinam in Tamil Nadu, where they revealed that 40% of shrimp farmers had collegiate level of education and 37% had medium levels of annual income. Patil et al. (2019) reported that the highest number of shrimp farmers in Palghar district, Maharashtra were in the middle-age group. Vadher and Manoj (2014) reported that around 30.2% of Gujarat state shrimp farmers were graduates or post-graduates, 18% of farmers had primary-level education and 3% of the shrimp farmers were non-literate. Bhattacharya’s (2010) study in West Bengal revealed that shrimp farmers of all the categories (small, medium and large) were above the poverty line. However, as expected, it is clear shrimp farmers have a better socio-economic status than the shrimp farm workers.

Before presenting the information about occupational hazards, it was important to understand the activity profile of shrimp farm workers. After gaining an understanding of the work and various activities required to be done by the shrimp farm worker; a list of the hazards and injuries reported by the shrimp farm workers was then compiled and these are presented in Table 4.

Table 4. Potential occupational hazards and injuries faced by shrimp farm workers.

Identified hazards	Activities	Potential injuries/problems
Physical hazards
Use of sharp instruments Uneven working ground Slippery surface Working at height Continuous contact with water High temperature Electric power line contact	Setting of bird fence Setting crab fence Fixing of aerator Chain pulling Manuring Feeding Sampling Check tray monitoring Harvesting	Slips & falls Cuts in fingers Leg/hand fracture Electric shock Dehydration Headache Sun burn
Chemical hazards
Liming agents such as (dolomite, calcium carbonate, calcium oxide and calcium hydroxide) Disinfectants like bleaching powder, water quality enhancer muriate potash	Liming the pond Applying bleaching powder Water quality management	Burnt skin Skin irritation Skin infection Inhalation issues Eye infection
Biological hazards
Causal organisms
Mosquito Snake Leech Crab Water-borne pathogens Bacteria Virus Fungi Parasite
Others
Water pollution Algal bloom
	Setting bird fence Setting crab fence Fixing of aerator Liming the pond Liming the pond Chain pulling Manuring Shrimp seed stocking Medicine and probiotic application Harvesting	Snake bite Cuts in fingers Leech bite Irritation in feet Skin infection
Ergonomic hazards
Repetitive movement Carrying heavy weight Prolonged static standing/sitting Force exertion	Scrapping Setting bird fence Setting crab fence Fixing of aerator Shrimp seed stocking Feeding Harvesting	Pain in
		Neck Back Shoulder Upper back Knee Thigh
Psycho-social hazards
Irregular work hours Night work shift Violence/conflict Bullying Financial problems	Extended working period Irregular working hours	Stress Anxiety Depression

Shrimp farm workers were asked whether they face or had faced any kind of hazards during their work in shrimp farming and the responses were recorded using an ordinal scale (Yes/No). The results are presented in Table 5.

Table 5. Occupational hazards faced by shrimp farm workers.

States	Physical	Chemical	Biological	Ergonomic	Psycho-social
Andhra Pradesh (n = 60)	93% (56)	75% (45)	83% (50)	78% (47)	68% (41)
Tamil Nadu (n = 60)	97% (58)	87% (52)	73% (44)	70% (42)	82% (49)
Gujarat (n = 60)	95% (57)	61% (37)	88% (53)	70% (42)	63% (38)
Maharashtra (n = 60)	88% (53)	83% (50)	85% (51)	67% (40)	70% (42)
Total (N = 240)	93% (224)	77% (184)	82% (198)	71% (171)	71% (170)

It is clear from self-reporting in Table 5 that overall 60% or more of shrimp farm workers had faced some kind of hazard. Physical hazards were highest in numbers (93%), followed by biological (83%), chemical (77%), ergonomic (71%) and psycho-social (71%) hazards.

In all the states at least 88% of shrimp farm workers had faced some kind of physical hazards and at least 73% had faced biological hazards. In addition, at least 60% reported chemical, ergonomic and psycho-social hazards.

Rawool (2005), Sathe (2008), Patil and Sharma (2018), Salunkhe (2018), Patil and Sharma (2019), Patil et al. (2019), Patil and Sharma (2020), and Patil and Sharma (2021) noted a wide range of issues faced by shrimp farmers of Maharashtra. Swathilekshmi et al. (2008) looked at how shrimp farmers of Tamil Nadu access information.

Erondu and Anyanwu (2005) in Nigeria reported occupational hazards in aquaculture were physical, chemical and biological. Ngajilo and Jeebhay (2019) found workers in aquaculture environments were at increased risk of acquiring occupational diseases and injuries. Watterson et al. (2020) reported both scale and depth of occupational safety and health (OSH). They also revealed challenges especially in rural and remote areas of Asia and the northern hemisphere that needed to be addressed. Myers (2010) conducted a comprehensive review on occupational hazards associated with aquaculture and reported drowning, electrocution, crushing-related injury, hydrogen sulphide poisoning, and head injuries as causes of death. Mshelia et al. (2019) reviewed aquaculture in Nigeria, identifying physical, chemical, biological, ergonomic and behavioural potential hazards.

Physical hazards and injuries

Hazards in the environment that can injure workers with or without contact are categorized as physical hazards (OSHA 2012). Physical hazards, presented in Table 6, caused injuries such as slips and falls, cuts, fracture, electric shock, dehydration, headache and sunburn.

Table 6. Physical injuries faced by shrimp farm workers.

State	Slips and falls	Cuts	Fracture	Electric shock	Dehydration	Headache	Sunburn
Andhra Pradesh (n = 60)	43% (26)	53% (32)	28% (17)	45% (27)	40% (24)	40% (24)	47% (28)
Gujarat (n = 60)	55% (33)	52% (31)	23% (14)	45% (27)	38% (23)	42% (25)	40% (24)
Tamil Nadu (n = 60)	55% (33)	52% (31)	20% (12)	45% (27)	38% (23)	42% (25)	40% (24)
Maharashtra (n = 60)	57% (31)	48% (29)	35% (21)	42% (25)	42% (25)	35% (21)	38% (23)
Total (N = 240)	51% (123)	51% (123)	27% (64)	44% (106)	40% (95)	40% (95)	41% (99)

Table 6 reveals the majority of workers reported slips, falls and cuts (51%) followed by electric shock (44%), sunburn (41%), dehydration/headache (40%) and fractures (27%).

Ngaruiya et al. (2019) found the fisher folk in Kampi Samaki, Kenya had physical injuries such as sunburns, falls, pricks from spines and cuts.

Ochs et al. (2021) reported many of the physical injuries in Canadian marine aquaculture were caused by bodily reaction and (over) exertion or being struck by or against an object.

Douglas (1995) also reported trips, slips and falls were common hazards at fish farms and hatcheries in USA due to wet walking surfaces, including raceway walls, catwalks, docks, dykes and pond liners, frequently coupled with narrow access points which created a high degree of risk.

Darek and Moreau (2009) in Canada studied about injuries and hazards of Canadian aquaculture practices and found that falls, transport, machinery, electricity, fire, extreme temperatures, diving, noise and confined spaces were the major cause of injuries.

Cole et al. (2009) reviewed occupational hazards and safety concerns in the aquaculture industry. Physical hazards from tractors, electricity, drowning, repetitive lifting, extreme environments and decompression illness were identified.

The physical hazards and injuries faced by Indian shrimp farm workers reported in this study are therefore similar to the findings of other researchers such as Ochs et al. (2021), Douglas (1995), Darek and Moreau (2009) and Cole et al. (2009).

Chemical hazards and injuries

Some chemicals can cause illness, skin irritation or breathing problems (NIOSH 2015).

Chemical hazards in aquaculture are already presented in Table 4 and cases of related ill-health in shrimp farm workers are featured in Table 7.

Table 7. Chemical injuries faced by shrimp farm workers.

State	Burnt skin	Skin irritation	Skin infection	Breathing problems	Eye infection
Andhra Pradesh (n = 60)	30% (18)	33% (20)	37% (22)	37% (22)	35% (21)
Gujarat (n = 60)	35% (21)	38% (23)	40% (24)	38% (23)	35% (21)
Tamil Nadu (n = 60)	35% (21)	38% (23)	40% (24)	38% (23)	35% (21)
Maharashtra (n = 60)	28% (17)	35% (21)	37% (22)	46% (24)	43% (26)
Total (N = 240)	32% (77)	36% (87)	38% (92)	38% (92)	37% (89)

Table 7 shows approximately 30%–39% of shrimp farm workers had some chemical injuries like burnt skin (32%), skin irritation (36%), skin (38%) and eye infection (37%). Breathing problems (38%) due to chemical inhalation were most prevalent.

Liming agents such as dolomite, calcium carbonate, calcium oxide and calcium hydroxide were commonly used for pond manuring and fertilization. Bleaching powder and muriate potash were also used for water quality enhancement. The use of these chemicals may cause infection in skin, eye and breathing problems.

Uronu and Lekei (2004) reported that in fish ponds in Tanzania, various inorganic fertilizers, lime, pesticides and formaldehyde were extensively used and can cause burns or skin irritation resulting in severe cases of occupational dermatitis. Their inhalation may lead to respiratory illnesses such as bronchitis, rhinitis and asthma.

Granslo et al. (2009) studied occupational allergy from exposure to Artemia fish fry feed in Norwegian aquaculture. Asthma and skin irritations were found in shellfish farm workers due to brine shrimp feed exposure.

Anh et al. (2007) reported dermatitis among fish farmers engaged in peri-urban aquatic food production in Hanoi, Vietnam. They found that river water used for aquaculture, contaminated with untreated wastewater, can cause dermatitis.

Cole et al. (2009) listed chemical and toxic exposures (ammonia, hydrogen sulphide, chemical cocktails), and infectious disease risk (antimicrobial self-injection, microbes, parasites, protozoans, dinoflagellates) in fish farming.

The chemical hazards and injuries faced by shrimp farm workers reported in the present study were similar to the findings of Uronu and Lekei (2004), Granslo et al. (2009), Anh et al. (2007) and Cole et al. (2009).

Biological hazards and injuries

The existence of some harmful workplace living organisms can injure or infect or transmit diseases to human beings. These are called biological hazards (OSHA 2015).

Illness and injuries associated with biological hazards are presented in Table 8.

Table 8. Biological hazards, illnesses and related injuries faced by shrimp farm workers.

States	Snake bite	Cuts from biological hazards	Leech bite	Feet irritation	Skin infection
Andhra Pradesh (n = 60)	23% (14)	28% (17)	27% (16)	42% (25)	58% (35)
Gujarat (n = 60)	13% (8)	38% (23)	30% (18)	35% (21)	38% (35)
Tamil Nadu (n = 60)	15% (9)	38% (23)	40% (24)	30% (18)	35% (21)
Maharashtra (n = 60)	8% (6)	35% (21)	30% (18)	27% (16)	53% (32)
Total (N = 240)	15% (37)	35% (84)	32% (76)	33% (80)	51% (123)

Biological hazards were noted by half of shrimp farm workers in Table 8. About 30% of workers reported cuts from biological hazards (35%), feet irritation (33%), skin infection (51%), snake bite (15%) and leech bite (32%).

Erondu and Anyanwu (2005) reported cuts due to catfish stings, snake and fish bites in fish farm workers. Charmish (1996) studied occupational injuries of tilapia fish farmers in Israel and found cases of where individuals pricked by spines of Tilapia sp. infected by Vibrio vulnificus had finger amputations.

According to Dorooshi (2012), catfish species have strong pectoral fins with spines which are capable of pricking fish farmers. Catfish have sharp teeth which can cause biting during sorting and harvesting. The biting and pricking caused by fish spines and sharp teeth can lead to injuries which are mainly non-fatal.

Olaoye et al. (2015) found venomous catfish stings were a common environment hazard on Nigerian catfish farms. These stings can be innocuous, but sometimes significant morbidity may result including severe pain, retained foreign bodies, infection, respiratory compromise and arterial hypotension.

The paper’s findings of biological hazards and injuries are similar to the observations made by other researchers such as Erondu and Anyanwu (2005), Dorooshi (2012) and Olaoye et al. (2015).

Ergonomic hazards and injuries

Hazards which can cause harm in the musculoskeletal system are termed ergonomic hazards. These hazards include repetitive movement, manual handling, workplace/job/task action, uncomfortable workstation height and poor body positioning.

Ergonomic problems faced by shrimp farm workers are presented in Table 9.

Table 9. Ergonomic injuries faced by shrimp farm workers.

State	Neck pain	Back pain	Shoulder pain	Upper back pain	Knee pain	Thigh pain
Andhra Pradesh (n = 60)	55% (33)	58% (32)	58% (35)	48% (29)	45% (27)	58% (35)
Gujarat (n = 60)	57% (34)	53% (32)	47% (28)	50% (30)	45% (27)	48% (29)
Tamil Nadu (n = 60)	45% (21)	58% (35)	53% (32)	50% (30)	50% (30)	47% (28)
Maharashtra (n = 60)	53% (32)	53% (32)	50% (30)	48% (29)	45% (27)	48% (29)
Total (N = 240)	50% (120)	55% (131)	52% (125)	49% (118)	46% (111)	50% (121)

Results reveal 45%–55% of shrimp farm workers had some body pain. Turner et al. (2018) reported that the most commonly found injuries among aquaculture workers in Washington State USA were being struck by/against an object, and work-related musculoskeletal disorders, specifically sprains, strains and tears of the lumbar region or shoulder. Borah (2018) found that among freshwater aquafarmers in India, 92%–100% of workers working for a long time in water or in wet conditions had faced muscle injury, cuts, skin diseases, eye problems, gastrointestinal disorders, bronchial and lung disorders.

The findings of ergonomic hazards and injuries were similar to studies by Turner et al. (2018) and Borah (2018).

Psycho-social hazards and injuries

Psycho-social hazards may occur in the workplace (WHO 2016). The most common psycho-social problems were reported to be stress, anxiety and depression. The research results on these are presented in Table 10. Self-reported illnesses like these present many and varied challenges to researchers: for example in separating stress from anxiety, their causes, inter-relationships and their diagnosis.

Table 10. Psycho-social problems faced by shrimp farm workers.

State	Stress	Anxiety	Depression
Andhra Pradesh (n = 60)	38% (23)	28% (17)	38% (23)
Gujarat (n = 60)	32% (19)	27% (16)	36% (22)
Tamil Nadu (n = 60)	36% (22)	35% (21)	30% (18)
Maharashtra (n = 60)	33% (20)	28% (17)	38% (23)
Total (N = 240)	35% (84)	30% (71)	36% (86)

In Table 10, about 30% of shrimp farm workers reported they felt stressed (35%), depressed (29%) and had anxiety (36%) due to various reasons like being away from home and family, less income, and workloads. Causes of such problems could also include workplace boredom, production pressure demands and repetitive tasks.

As the World Health Organization (WHO 2001) has indicated, work plays a psychological role in the formation of self-esteem, a sense of order, and in the shaping of a person’s self-identity. Work and sound health are highly and positively correlated in the sense that the healthier a worker is, the more likely s/he is to work both effectively and efficiently.

The potential occupational hazards in the fish production sector in Nigeria were found to put fish processors at a greater risk of depression. Exceptionally high workloads could also affect workers and contribute to depression and anxiety which might then also be risk factors for occupational injuries (Olaoye and Ojebiyi 2020). Moreau and Neis (2009) found that in Canadian aquaculture, adverse symptoms of prolonged work could include appetite loss, disturbed sleep, constantly sulking, muscle fatigue, loss of energy, indecisiveness and poor concentration at work. Similar results were found in the present study.

Ngajilo et al. (2022) found occupational health and safety in Tanzanian aquaculture and impacts on health had not been well studied. Within the industry, there are considerable gender differences that, along with climate change, have an impact on worker health and safety. However, in the present study, all shrimp farm workers were male so gender differences could not be studied.

Naylor Rosamond et al. (2021) conducted a 20-year retrospective review of global aquaculture. They found that pressure on the aquaculture industry to embrace comprehensive sustainability measures during this period had improved industry governance, technology, siting and management in many cases. They recommended that further investments are needed in an array of pathogens, parasites and pests (PPP) prevention strategies across different aquaculture sub-sectors. They recognized that treatments after PPP problems emerge are largely futile. They suggested that future policies and programmes should promote aquaculture as a food systems approach that examines nutrition, equity, justice and environmental outcomes and trade-offs across land and sea.

A study by Watterson et al. (2020) on global state OSH reported that Norway has extensively researched offshore aquaculture OSH, raised standards, and reduced harms, while other countries especially in Asia, which employ a large portion of workers, appear to have done little.

In South America, Cavalli et al. (2015) highlighted the ‘One Health, One Aquaculture’ concept. This involves conducting aquaculture practices under one integrated umbrella. The World Organization for Animal Health (OIE), the FAO and the WHO all acknowledge the One Health concept as a crucial element of disease (Rabinowitz et al. 2013). Kahn et al. (2014) described the connections between people, animals and their common environment that make up ‘One Health’. Hence, collaboration between social, environmental and health scientists as well as other professionals is encouraged by the concept. It is a multidisciplinary and interdisciplinary strategy, according to Gomaz et al. (2014). Globally, it is argued, aquaculture productivity must rise in order to incorporate methods that lessen risks to ecological, human and animal health, including controlling and, where possible, preventing health and safety hazards for workers in aquaculture. The One Health concept applied to aquaculture, therefore, contains many aspects involving animal, human and environmental health, political, economic and social developments.

To reduce injuries from aquaculture labour, Cole et al. (2009) suggested regulatory standards should include personal protective measures, health surveillance and sound management practices. To do this, it is now necessary for the aquaculture industry to discuss workplace safety issues with employees. All regulatory agencies should encourage preventative practices and establish a formal platform to record injuries.

In India, with 160,000 ha area used for shrimp farming and the industry being a major employer for young people in the nation, applying the One Health concept to sustainable aquaculture production for safe, meaningful employment can be recommended (Stentiford et al. 2020). Nigerian researchers found that a 1% improvement in fish farmers’ health condition can lead to a 21% increase in work efficiency (Egbetokun et al. 2012). In this context, it is the right time to extend the One Health approach beyond antimicrobial resistance and zoonotic diseases to include occupational health and safety of workers in the sector.

Finally, the Kruskal–Wallis test was used to identify any significant differences with reference to occupational hazards faced by shrimp farm workers across different states. The results revealed there was no significant difference (p > 0.05) and this is presented in Table 11.

Table 11. Results of Kruskal–Wallis test.

	Mean ranks of hazards
States	Physical	Chemical	Biological	Ergonomic	Psycho-social
Andhra Pradesh (n = 60)	122	115	126	128	122
Gujarat (n = 60)	121	120	115	118	121
Tamil Nadu (n = 60)	120	123	127	120	119
Maharashtra (n = 60)	119	123	113	122	119
Hazards	Asymptotic. sig
Physical	0.998
Chemical	0.907
Biological	0.516
Ergonomic	0.977
Psycho-social	0.990

Limitations of the study

The study sheds light on neglected groups of workers across India and provides new information on hazards, risks and injury linked to income and education and wider working conditions. There may be some limitations of the study due to demographic, recording and other factors. However, similarities across different states, strongly suggest most activities on shrimp farms are the same and thus occupational hazards faced by many workers are also similar in nature.

Conclusions

The present study reviews global aquaculture health and safety literature followed by interviews with 240 Indian shrimp farm workers to document their socio-economic profile including occupational hazards and injuries they face.

It is concluded that more than half of the shrimp farm workers had faced some kind of hazard with physical hazards presenting the highest perceived risk, then biological, chemical, ergonomic and psycho-social hazards. For physical injuries, the majority of workers reported slips, falls and cuts followed by electric shock, sun burn, dehydration/headache and fractures. The reported chemical injuries were burnt skin, skin irritation, skin and eye infection and breathing problems due to chemical inhalation. Reported biological injuries were skin infection, cuts, feet irritation, leech and snake bites. Ergonomic injuries were pain in neck, back, shoulder, upper back, knee and thigh. Feelings of stress, depression and anxiety were the common psycho-social problems. These findings are similar to the literature cited.

Based on the findings, it is recommended that occupational health and safety of shrimp farm workers be given prime importance by the Government and the farm owners. Hazard identification, education and training are essential requirements for the health and safety of shrimp farm workers. Thus documenting hazards, evaluating risks and accordingly identifying appropriate methods to prevent the hazard by following national and international standards is recommended. Greater information about hazards and injuries would help to identify opportunities for targeted interventions.

It is recommended the ‘One Health’ concept be adopted for shrimp farming, integrating and embedding occupational health and safety measures in all its policies. This is necessary as the sector is experiencing rapid growth and development. Incentives can be provided to the employers/farm owners who adopt the concept and apply it effectively. Sustainable aquaculture through this approach should always include employment/enhanced employment opportunities which are safe, meaningful and of high quality. Studies on economic losses from poor health and safety, and effective prevention measures could be useful next steps in the research.

Disclosure statement

Dr Lissandra Souto Cavalli is Aquaculture Section Editor for All Life journal; Dr Arpita Sharma and Dr Andrew Watterson are Associate Editors for All Life journal. The paper was handled by other Editors in order to avoid any conflict of interest. Besides this information, no further potential conflict of interest was reported by the authors.

Data availability statement

The data supporting the findings of this study are publicly available in the Zenodo data repository at https://doi.org/10.5281/zenodo.7858246.