Abstract               Welding light leads to exposure of invisible and visible optical radiation, near and far infrared, ultraviolet A, B and C from visible light in welding worker in significant amount. Fabrication industry is developing greatly with urbanization. But awareness of welding health hazards and use of protective equipment is not yet sufficient. So This study was carried out to investigate occurrence of colour vision deficiency in welding worker. FM 100 hue colour vision test was performed by 30 welding worker and 30 age matched nonwelder control subjects. 14 subjects had undefined and 16 subjects had tritan blue type of colour vision deficiency. Only 4 worker having none to slight abnormality were using UV protection glass. Welding workers are more susceptible for colour vision deficiency along with other health hazards as compared to nonwelder people.

Key Words: Colour vision deficiency, Welding light, UV rays, FM 100hue colour discrimination test.

 

 

 

INTRODUCTION

According to World Health Organization (WHO), there are approximately 250 million cases of work-related injuries per year worldwide.¹ One of the jobs that contribute to these occupational injuries is the welding process, especially in developing countries. Welding emits a wide spectrum of radiations ranging between 200 nm and 1400 nm². Welding is common essential procedure in engineering works and is associated with varied health hazards. Welding is one of the most intense artificial sources of invisible and visible optical radiation, near and far infrared, ultraviolet A, B and C from visible light, emitted in various degrees by the various types of welding that may cause ocular damage of different types.

 

Figure 1:

The welding fumes contain many harmful substances like manganese, chromium, nickel, arsenic, asbestos, silica, beryllium, cadmium, nitrogen oxides, phosgene, fluorine compounds, CO, cobalt, copper, lead, ozone, selenium and zinc. Other hazards include Heat, Noise and Musculoskeletal injuries. Occupational color vision loss is usually sub-clinical, and workers are unaware of any deficit. It can be assessed using sensitive tests, such as the Farnsworth-Munsell 100 Hue (FM-100) or the Lanthony D-15 desaturated panel (D-15 d) test. India is developing country, majority of the welding workers are not trained, and few of them are using personal protection equipment during welding. This study mainly focuses on effect of welding in colour vision in welding worker having chronic exposure to welding arc.

 

MATERIALS AND METHODS

Online Fransworth-Munsell 100 hue colour vision test was performed by 30 welding workers and 30 age and sex matched 30 non welding group in Ghatlodia, Ahmedabad, Gujarat, India.

Inclusion Criteria: Age between 20 to 40 years, having minimum experience of more than one year, and having 6-8 hours of work, 6 days per week. Fransworth-Munsell 100 hue colour vision test belongs to the group of hue discrimination, also called arrangement tests. The aim of the test is to order the shown color plates in the correct order—any misplacement can point to some sort of color vision deficiency. Farnsworth described the F-M 100 hue test the first time in 1949 and since then it is widely used all around the world. The overall error score relates more or less to the severity of your color vision deficiency. Based on the error score Vingrys and King-Smith developed in 1988 a possibility to compute the so called main confusion axis, which can be used to detect the cvd type. Total error score in FM hue is more than 360. Less than 60 is suggestive of normal colour vision.

 

Table 1:

Statistical Method: Paired t-test was applied to compare data between test group and control group.

 

Statistical Method: Paired t-test was applied to compare data between test group and control group.

 

OBSERVATIONS AND RESULTS

In this cross sectional study colour vision of 30 welding worker were investigated. Mean age welding worker and control group was 30± 7.12 years. Total error score was obtained from FM 100 hue colour vision performed by welding workers and control group. Mean total error score was higher in test group as compared to control group Table-1.

 

Table 1: Comparison of total error score between two group

 

 

 

Table 2: Shows Colour vision deficiency type in test group according to severity.

DISCUSSION

Result shows that total error score in test group is significantly increased than control group. This finding favour that colour vision of welding worker is significantly affected. Colour vision deficiency have been noticed in workers exposed to several solvents, metals and other industrial chemicals⁴. Since the mid-1960s, we have known that even moderate intensities of light can damage the retinas of rats^[3] Study of Shahriari et al shows pathological effect of UV light on the retina using electroretinography. An obvious decrease was observed in voltage amplitude of photopic ERG and concluded that the cone cells are the site of pathological effect.⁵ Colour vision test by Lanthony D-15 desatured panel was administered to welder’s group in study of Bowler et al.⁶ and Mergler et al.⁷ and it was observed that color vision in exposed welders was significantly impaired in both eyes.^7,8 Gupta and Spingh evaluated color vision deficiency among welding worker and report that approximately 75% of welders had color vision deficiency due to exposure to radiant energy.⁹ Anirudhdha mahindraker et al had reported in their case report study on two subjects who were continuously monitored for 3 year to detect weld arc related maculopathy by Spectral domain optical coherence tomography (SD-OCT) imaging. 

 

CONCLUSIONS

Welding workers are more susceptible for dyschromatopsia along with other health hazards as compared to nonwelder people. Use of protective equipment may decrease the risk of occupational health hazards in welding worker. Proper education of health hazards related to welding and information related to importance of use of protective equipment during welding should be provided to welding workers.

 

 

 

 

REFERENCES

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