Assessment of
ultraviolet radiation exposure of welders working in Shahrud City, Iran, 2014
Vatani J, PhD 1*,
Ghasemzadeh H, BSc 2,
Raei M, MSc 3
1- Assistant Prof.,
Dept. of ergonomics, School of Public Health, Hamedan
University of Medical Sciences, Hamedan, Iran. 2- MSc Student, Dept of
Occupational Health, School of Public Health., Shahroud University of Medical Sciences, Semnan, Iran. 3- Faculty member, Health
Research Center, School of Public Health, Baqiyatallah
University of Medical Sciences, Tehran, Iran.
Abstract
Received:
April 2015, Accepted: June 2015
|
Background: Farmers and welders who work in open spaces and are
exposed to direct sunlight are often exposed to sunlight radiation on the neck and head. Thus, they may be afflicted with various types of skin cancer. The aim of the
present study was to investigate the amount of UV exposure in
welders working in Shahrud City, Iran. Materials and Methods: This cross-sectional, descriptive, analytical study was conducted from 9 a.m. to 3 p.m. in indoor environments on all welders working in Shahrud City (n = 50) in 2014. An ultraviolet radiation (UVR) meter was used to measure UVR and the instrument was calibrated and
utilized using factory instructions. Moreover, All data obtained through
the demographic checklist and self-reporting, and information related to UVR exposure were entered into SPSS software and analyzed. Results: The results
showed that average UVR exposure with personal protection was 0.27 ± 1.15 Conclusions: This study indicated that UVR is among the main harmful factors
in occupational environments. Welders are vulnerable to skin and eye disease
due to UVR exposure. UV exposure in welders working in Shahrud
City is below the threshold value; therefore, it can cause injury and damage
to the welders. Furthermore, insurance status, daily radiation exposure
amount, received radiation exposure amount, and use of protection equipment
had no significant relationship with incidence of disease in welders. |
Keywords: Welding, Ultraviolet Rays, Eye diseases, Skin diseases, Insurance.
Introduction
Electromagnetic radiation
with 100 to 400 nm wavelength is called ultraviolet radiation (UVR). Different
wavelengths of UVR have different effects (1, 2). The main natural source for
generating UVR is the sun. Artificial sources of UVR are UV lamps and the
welding industry (2). The rate of UVR from the sun which reaches the earth’s
surface is reduced considerably by the ozone layer in the atmosphere. The
strength of UVR reaching the Earth is increased by the thinning of* the ozone layer (3). Tanned skin is one of
the primary effects and early aging is a long-term effect of UV exposure (3, 4).
Farmers and workers who work in open spaces and are exposed to direct sunlight
are often exposed to sunlight radiation on the neck and head, and thus, they
may be afflicted with various types of skin cancer (2, 5).
In the study by Kim et al.
in South Korea, it was shown that macular degeneration in welders is not related to age, rather is it mostly
developed due to exposure to the welding arc (3). In a study on 102 white men,
no relationship was found between the damage to the inner layer of the cornea
among welders and exposure to UVR (6). In the study by Hang, it was shown that UVR in
aluminum welders places the skin and eyes at great risk (7). Studies indicate
that UVR exposure with energy above 10 j/cm2 causes acute responses,
including skin erythema, and long-term (chronic)
exposure to UVR resulting from sunlight leads to skin cancer (3, 5, 8). The study by Peng indicated
that the permanent use of eye protection equipment in welding can prevent any
harm to the corneal layer (9). Furthermore, many relationships have been found
between UVR exposure and skin deformation (9).
The study by Vatani et al. illustrated that welders in the Sarcheshmeh Copper Complex, Kerman, Iran, were exposed to
low levels of UVR (UV = 0.09 j/cm2), and thus, the probability for
emergence of disease due to UVR was low (10).
The study by Birt showed that, in addition to exposure to UVR, welders
are also exposed to welding fumes, chronically and acutely, which leads to
various diseases including respiratory tract
irritation, bronchitis, changes in lung function, and lung cancer (11). Welders
are vulnerable to skin and eye diseases due to contact with a broad range of
UVR (12-16). The aim of this study was the investigation of the rate of UV
exposure in welders working in Shahrud City, Iran, in
2011.
Materials and Methods
This
cross-sectional, descriptive, analytical study was conducted from 9 a.m. to 3 p.m. in indoor environments on all welders working in Shahrud City (n = 50) in 2014. Shahrud
is a City in Semnan Province, Iran. Shahrud is situated about an altitude of
4413 ft (1345 m). It is located at latitude 36°25'N and longitude 055°01'E and some 410
kilometers to the east of Tehran. Now, it is the second largest City of Semnan Province, and also its county has the same position in the province.
The
ultraviolet radiation meter (model EX–4, Hagner Photometric Instruments Ltd, UK) was used for measuring UVR and the instrument was
calibrated and utilized using factory instructions. The UVR meter is a direct reading instrument
which shows results directly after measurement.
First,
using a checklist, demographic information were
obtained from
welders including age, years of service, insurance, marital status, any disease of the eyes and skin,
and use of personal protection equipment. Considering results of medicine, lacrimation,
irritation, and redness of the eye and ocular symptoms
as well as tanned and dry skin as the
result of
welding were recorded as the symptoms of skin disease caused by a welding job
(1, 10). In addition, the electrode used for welding was 2–5 mm in diameter with a voltage of 21–24 V and current of 60 to 210 A.
Subsequently, UV exposure on the hand, in front of personal protection equipment, on the face, and behind the protection equipment was measured as follows. First, welders were asked to weld in their usual
work conditions and the UVR meter was placed exactly on their hand in a way that the sensor was facing
the welding process, and the obtained
number was recorded. Then, the instrument was placed in front of the protection equipment with the sensor facing the welding process, and the amount of radiation was recorded. Finally, the UVR meter
was placed inside the protection equipment and on the face so that the sensor is facing the welding process and UVR rate was
recorded (10).
Finally, all
information obtained through the demographic checklist and self-reporting, and
information related to UVR exposure were entered into SPSS software (version
13, SPSS Inc., Chicago, IL, USA). Data were analyzed using indexes of mean, SD,
number and percentage, 95% confidence level, and Kruskal-Wallis
test and the Pearson correlation coefficient. Furthermore, the significance
level was considered as 0.05 in all tests (10).
Results
Average age and working experience of welders were 39.46 ± 11.89 and 16.9 ± 11.66 years, respectively. In total, 86% (43 cases) of the welders
were insured and 80% (40 cases) were married. Among them, 14 cases (28%) used
eye and face protection equipment (welding shield and goggles), 29 cases (58%)
used the welding shield and gloves (to protect hands and face), and 6 cases
(12%) used all personal protection equipment (shield, gloves, and goggles).
Only 1 case (2%) of welder did not use any personal protection equipment.
Average UVR exposure with personal protection was 0.27 ± 1.15
Furthermore, there was a statistically significant relationship (P
= 0.030) between working experience and disease. Results indicated that in 80%
of cases (40 cases) skin radiation exposure was above the permitted level.
There was a 21.9% prevalence of disease in subjects with daily radiation
exposure duration of less than 8 hours. The prevalence of desease
was 44.4% among subjects with daily exposure duration of above 8 hours.
However, this difference was not statistically significant. Disease prevalence
in welders with radiation exposure of less and more than the standard limit was
20% and 32.5%, respectively, which was not a significant difference. Moreover,
no statistically significant relationship was observed between the use of
personal protection equipment and use of welding equipment and presence of
disease in welders (Table 1).
Table
1: Risk factors related to disease incidence
|
|
Incidence of disease |
|
|
|
|
Yes |
No |
P |
|
Variable
|
mean ± SD |
mean ± SD |
|
|
Radiation
exposure with protection equipment |
0.05
± 0.04 |
0.36
± 1.37 |
0.39 |
|
Radiation
exposure without protection equipment |
4.48
± 1.56 |
4.00
± 1.75 |
0.36 |
|
Radiation
exposure on the hand |
2.73
± 1.56 |
2.47
± 1.55 |
0.60 |
*
Permitted UVR exposure limit in welding is 1
Average radiation exposure with and without protection equipment as
well as average skin exposure among individuals with skin disease were 0.05 ± 0.038, 4.2 ± 1.21, and 2.85 ± 1.39
Discussion
UVR is among the major harmful factors in occupational environments
(1-4). It is especially important in jobs such as welding and working while
exposed to sunlight. Excessive UVR exposure threatens the health of workers and
results in various diseases. Tanned skin is one of the primary effects and
early aging is a long-term effect of UV exposure (3-5).
Welders are vulnerable to skin and eye disease due to UVR exposure
(12). The current study investigated the amount of UV exposure in welders
working in Shahrud City and its relationship with
skin and eye disease.
Considering the findings, UVR in the welding industry causes eye or
skin diseases, or both groups of diseases. As results indicate, there is a
significant relationship between age and working experience of welders, and
these diseases. The incidence of eye disease due to UVR in welders was 53.3%,
incidence of skin diseases was 33.3%, and incidence of both groups of diseases
was 13.3%.
Results showed that in 80% of (40) welders, skin radiation exposure
is higher than the permitted level which supports findings by Vatani. In addition, insurance status, daily radiation
exposure amount, received radiation exposure amount, and use of protection
equipment had no significant relationship with incidence of disease in welders.
Received radiation amount in Shahrud welders
was higher than the permitted level (recommended standard for exposure is 1,000
s and less than 1
Moreover, reviewed UVR amount in the use of welding equipment for
cutting metals is above the standard level for welding equipment (P = 0.004).
Specified electrodes with 3–5 mm diameters generate more UVR compared to
electrodes with other diameters. This is consistent with findings of the
studies by Antonini, and Vatani.
Using the Pearson correlation coefficient (P = 0.003), a direct
relationship was observed between voltage and received radiation amount
(0.497). In other words, increasing the voltage of welding instruments
increases received UVR. This finding is consistent with that of the studies by
Kim EAKBG, Emil Obalak, and Vatani.
Conclusion
According to results, 32.6% of welders who were insured suffered
from diseases resulting from UVR exposure, which shows high expenditures of
compensation and treatment of welders’ diseases by the insurance companies. If
exposure is reduced in welders to below the permitted level using appropriate
methods, not only will their health be insured, but also useful working
continuation, increased productivity, and reduced compensation costs will
observed.
Considering the findings of the current research, appropriate
clothing, masks, and specific shield with suitable protection level should be
used during welding operation. Moreover, voltage should be set at an
appropriate level (increasing voltage increases UVR received from welding
instrument) and electrodes with 3-5 mm diameters, which generate more UVR than
other electrodes, should not be used.
The investigation of the incidence of diseases resulting from UVR
and UVR exposure in other industries and farmers is also recommended.
Acknowledgement
We would like to thank the Research Department of Shahroud University of Medical Sciences, Iran, for funding
this study as a research plan.
Conflict of interest: Non declared
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* Corresponding
author: Javad Vatani, Dept.
of ergonomics, School of Public Health, Hamedan University
of Medical Sciences, Hamedan, Iran.
Email Address: jvatani@gmail.com