Sanjay Kini 1 , *Avinash Kumar 1
1 Department of Community Medicine, Manipal University
*Author of correspondence
Abstract
Introduction: Unprotected handling of sea food in industry will cause allergic manifestations like rhinitis, conjunctivitis, dermatitis etc.
Methods:
A cross sectional study was done in a sea food processing industry in coastal Karnataka among 221 employees. It was found that 27.9% had skin rashes, 16.1% had rhinitis. Skin rashes were evident in the first five years of occupation in about 72% of the employees who had developed skin rash. Rhinitis and obstructive lung disease were observed in subjects who had an occupational history above five years.
Conclusions:
Specially designed programmes are necessary to assist sea food processing industries to develop appropriate control strategies to prevent or control occupational hazards.
INTRODUCTION
Worldwide about 72% of harvested fish and shellfish are used for human consumption 1 .
There has been an increased reporting of adverse reactions, including immune mediated reactions due to increased levels of production and consumption of sea food 2 . Fish processing communities and fish eating populations are more prone to allergic reactions due to fish 3 . It is observed that the prevalence of immediate type fish allergy is higher when

the intake of fish constitutes a greater part in the diet of the community 4 . Though the reaction is common in general population their data regarding prevalence in the occupational settings is scarce. Recently some studies have reported serious concerns over bacterial and parasitic diseases arising from sea food exposure 5 . Manual or automated processing of crabs, prawns, mussels, fish and fishmeal production causes the workers involved to get commonly exposed to various constituents of sea food 6 . Sensitization through inhalation may result from aerosolisation of seafood and cooking fluid during processing which are potentially hazardous occupational situations. Unprotected handling of sea food and its biproducts may cause occupational dermatitis. Workers exposed to arthropods (crustaceans), molluscs, pisces (bony fish) and other agents derived from seafood have reported occupational allergies. Some other occupations which has potential hazard of exposure to sea food allergens are oyster shuckers, lab technicians, researchers, fishmongers and fishermen 7 .
The seafood industry is an important contributor to the regional economy of the coastal part of Karnataka. The fishing and seafood processing industries in coastal Karnataka employs approximately 10,000 workers. These workers are directly dependent on the industry, supplying daily food for a significant part of coastal Karnataka. The workforce is quite seasonal with the highest degree of exposure to sea food occurring during harvest season, which varies according to the type of seafood. Comprehensive data pertaining to specific health outcomes associated with occupational allergy in the seafood processing industry is lacking in part of coastal Karnataka. Hence this study was undertaken with objectives of determining the various allergic disorders occurring in sea food processing industry and to determine the various occupational settings in which exposure to sea food occurs.
MATERIALS AND METHODS
A cross sectional study was undertaken among the employees of a sea food processing industry in Coastal Karnataka. The industry consisted of 226 employees and was equipped with a modern processing plant which had a capacity of 50 ton frozen storage, 2 ton chiller storage, 0.1 ton per cycle blast freezer with connected electrical and plumbing works. It also contained a modernized laboratory which tested and emphasized on quality assurance of the finished products. The senior management officer of the industry was approached and was explained about the importance of the study and written consent was obtained. The study was conducted through interview of the employees using a semi-structured pretested questionnaire after obtaining their consent. The respondents were assured that all results of the study would be treated confidentially. The survey instrument comprised questions on socio-demographic profile of the respondents, types of seafood processed and the production processes involved, duration of occupation, presence and nature of occupational health problems present in the employees. This was followed by detailed clinical examination of the employees by two physicians who had an expertise in the field of

occupational health. Spirometry was done to find out manifestations of obstructive lung disease (OLD) in those subjects with a history of asthamatic symptoms.
Data entry and analysis was conducted using Statistical package for social sciences (version
15). Univariate analysis was conducted to summarize the distribution of each measured variable. Chi square test was used to explore relationship between various risk factors and occupation related health disorders.
The study obtained a response rate of 93.4% (N=226). Majority of the respondents were in the operational section of processing sea foods (92%) and were often in direct contact with handling of sea food. Others were welders, drivers, factory managers and risk control operators. The most common sea food processed (Fig 1) were Mackerals and Sardine fishes
(85%). Rest of the sea foods were prawns, bony fishes like hake, pilchard and lobsters. Most common procedure used were fishmeal production, freezing, cutting and degutting procedures. Other associated seafood processing activities were farming, drying, smoking, mincing, frying and filleting.
60
50
40
30
20
10
0
90
80
70
85
11
2,5 1
Mackerals &
Sardines
Prawns Bony fishes Lobsters
0,5 others percentage
Some of the occupational health problems as reported by the employees were skin rashes, rhinitis, conjunctivitis, asthamatic symptoms and other non-specific allergic symptoms like angioedema. On detailed clinical examination it was found that skin rashes accounted for majority of the work-related health problems. Table 1 depicts the proportion of respondents who had various occupational health problems.
Table 1: Proportion of respondents with various occupational health problems (n=211)
Health problems
Skin rashes
Rhinitis
Number (%)
59 (27.9)
34 (16.1)

Obstructive lung disease (OLD)
Conjunctivitis
Angioedema
13 (6.1)
6 (2.8)
1 (0.4)
It was also found that the duration of occupation had a significant bearing on the type of work related health symptoms (Table 2). Skin rashes were evident in the first five years of occupation in about 72% of the employees who had developed skin rash. Rhinitis and obstructive lung disease were observed in subjects who had an occupational history above five years.
Table 2: Distribution of the proportion of subjects developing occupational health problems during the specified time interval
Duration of occupation
(years)
0-5
5-10
10-20
 20
Skin rashes
(n=59)
42 (71.8)
15 (25.4)
2 (3.3)
0 (0.0)
Rhinitis
(n=34)
7 (20.5)
12 (35.2)
14 (41.1)
1 (2.9)
Number (%)
OLD (n=13) Conjunctivitis
(n=6)
1 (7.6) 4 (66.6)
4 (30.7)
7 (53.8)
1 (7.6)
1 (16.6)
1 (16.6)
0 (0.0)
Angioedema
(n=1)
0 (0.0)
1 (100.0)
0 (0.0)
0 (0.0)
DISCUSSION
A thorough scrutiny of most of the workplace suggested inadequate control of inhalation and skin exposure which was common in some small rooms where there was overcrowding of employees which may be contributing to the burden of the disease. Activities such as cutting or degutting, scrubbing or cleaning, cooking or boiling and drying provide a potential source for sensitization through inhalation of aerosols. An alternative source of sensitization could be unprotected skin exposure, due to the lack of personal protective equipment such as gloves. The most commonly reported work related problem was skin rashes which could be attributed to the irritants used in sea food processing like vinegar, biochemical sensitizers like onion, garlic and spices and the proteins originating from some fishes 8-10 . Skin symptoms are of high concern since it has been found in some of the studies that skin conditions can be debiliating 11 . These studies have shown that despite cessation of work the symptoms were persistent.
In contrast to skin disease, disease like asthama due to occupational exposure is largely under reported. In our study 6.1% of employees had developed asthama due to occupational exposure of sea food. In comparision to this figure it has been observed that much higher prevalences rates of 7-36% for occupational asthma has been reported in the literature, based largely on direct investigator assessments of individual workers. In 2001 a study on workers involved in white fish, salmon (only from slaughtery), as well as shrimp

and herring processing in Norway, it was found that processing workers reported respiratory symptoms and exhibited decreased lung function more often compared to a control population of administration workers in the same factories 12 .
With respect to the duration of occupational exposure and development of symptoms it was observed that dermatitis developed in employees within five years. Results are consistent with studies done elsewhere where the average duration of occupation before the development of dermatitis was 2.3 years 13 . In our study Obstructive lung disease developed after an exposure of atleast five years. Similar results were found in other studies wherein poor prognostic features of workers with occupational asthma included a longer period of exposure before the development of symptoms, longer duration of symptoms before diagnosis and severity of disease at time of diagnosis 14 .
CONCLUSIONS AND RECOMMENDATIONS
Allergic manifestations developing in employees of sea food processing industry are of serious concern. It is recommended that further epidemiological studies focusing on quantification of disease burden attributed to seafood exposure should be conducted. It is necessary for the development of appropriate industrial hygiene monitoring techniques for exposure characterization of those workers at risk and medical surveillance protocols that utilize more sensitive immunological markers for early diagnosis. Specially designed programmes are necessary to assist sea food processing industries to develop appropriate control strategies to prevent or control occupational hazards.
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