Chemical and Physical Hazards in Different Small Workshops Activities

Workers in informal small-scale industries (SSI) in developing countries involved in welding, spray painting, woodwork, and metalwork are exposed to various hazards with consequent risk to health. The present study was to assess occupational exposures to chemical and physical hazards among workers in small workshops. Three different industrial activities were selected for this study. These activities are: car repairing, welding, and wood processing. Inside the selected workshops, different physical hazards as noise, heat stress, illumination, and dust as well as air pollutants of carbon monoxide (CO) nitrogen dioxide, (NO2), sulphur dioxide (SO2), and benzene were measured at the same two periods of the day (morning and evening) using calibrated devices. Analyzed data revealed high significant increase in the selected areas in the levels of noise, thermal stress, illumination, and dust during morning and evening exposure between as compared to the control area in the selected areas respectively. Only for NO2, levels of the other gases pollutants inside all exposed workshops are higher than those inside the control workshops. In conclusion, the workers at the studied industries were exposed to potential occupational hazards. These findings should be considered as s a preventive measures for monitoring and application of control strategies in such workplace environment INTRODUCTION Small-scale industries (SSI) have existed as an informal sector since the pre-colonial times making various tools, ornaments and cooking utensils without regard to occupational hazards. Small-scale industries are determined by the number of persons employed which are less than 10 persons on the average. It represents a major sector for economic investment that brings a lot of benefits to the country as well as the individuals.(1,2) Workers in informal small-scale 615 Bull High Inst Public Health Vol.38 No.3 [2008] industries (SSI) in developing countries involved in welding. Spray painting, woodwork, and metalwork workes are exposed to various hazards with consequent risk to health.(3) Workers in SSI are exposed to a variety of work-related hazards, where they are not using protective equipment and had health complaints perceived to be related to their work. Workers and employers were both aware of occupational and environmental health hazards, but absence of a clear policy on the informal sector and the lack of permanent workplaces do not encourage investment in occupational health and safety.(4) Although the Small-scale industries include a wide variety of industrial activities, the most important and common types are car repairing, metal processing, and wood processing activities.(3,4) Workers in automobile repair shop are at high risk of exposure to noise, vibration, heat stress, and radiation. Haematological changes, skin diseases, cancer, musculoskeletal, psychological stress, chronic poising, and irritation are the most health disorders among workers in automobile repair shop.(5) Industrial welding has been associated historically with lung diseases, and current welding techniques continue to produce many potential exposures to particulates and gases as carbon monoxide (CO), nitrogen dioxide (NO2) sulphur Dioxide (SO2), and bezyene. Moreover, some studies suggest that these workers are at risk of serious respiratory, neurological, and reproductive effects. (6,7) Industries that have a high risk of wood-dust exposure include sawmills, dimension mills, furniture industries, cabinet makers, and carpenters.(8) The main sources of harmful dust emission at the workplace are during technological processes.(9) The present study was conducted to shad lights on occupational exposures to chemical and physical Khaled F. El-Said 616 hazards among workers in small workshops MATERIAL AND METHODS Three industrial activities were selected for this study. These activities are: car repairing, welding, and wood processing. From each activity, three workshops were selected.The selected control site means the same type of activity without the presence of sources of exposures as in the other three shops. Inside the selected workshops, different physical hazards as noise, heat stress, and illumination were measured at the same two periods of the day (morning and evening). During the present study, noise levels were assessed by the TES-1352A(10) programmable and calibrated sound level Meter. Heat stress index (Wet Bulb Globe Temperature WBGT(10) was used to determine the heat stress levels at selected workshops. The illumination levels were determined by a calibrated light meter (TES 1336A)(10). Dust or total suspended particulates (TSP) was collected inside the selected workshops by calibrated personal samplers (Staplex® PST-2X Personal Air Sampler).(11) Different air pollutants were measured inside all selected workshops by the standard methods and instruments. The selected air pollutants were total suspended particulates (TSP), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and benzene. Levels of these pollutants were assessed also at two different periods; morning and evening. The MIRAN 205B Series SapphIRe-XL Portable Ambient Air Analyzer was used for assessment of the selected gaseous air pollutants.(12) Statistical Analysis Results of the collected data were statistically analyzed using the SPSS program version16.0 software. Descriptive Statistics and test of significant (ANOVA) were also used for studying the 617 Bull High Inst Public Health Vol.38 No.3 [2008] significance differences between the studied factors. RESULTS AND DISCUSSION Workers in these rapidly developing countries are be exposed to excessive amounts of both physical and chemical pollutants. Small size industries workers, in particular, are routinely exposed to dust, gases, fumes, and heat, amongst other pollutants. Occupational exposures to heat, illumination and noise are unavoidable in the small size industries, but these exposures could be minimized through efficient control measures at the worksite and or the proper use of appropriate personal protective equipment. However, personal protective equipment and exposure control measures are rarely used at many worksites, and are given little importance and preference by many employers.(13,14) Concerning physical hazards, measurements for noise levels, dry and wet bulb temperatures, illumination as well as level of indoor gases as SO2, NO2, and CO were taken during the normal operation and on a normal working day . Table 1: Descriptive statistics of Physical hazards in car repairing workshops Evening Morning Time IN IN Place Dust Light Noise Heat Dust Light Noise Heat Parameter 1.91 157.15 77.025 35.42 2.21 176.25 86.29 33.9 Mean 0.62 16.10 14.36 3.48 1.01 3.19 16.42 2.03 SD 1.53 39.3 34.7 9.3 2.45 10 45.2 6 Range 1.07 141.7 62.6 30.8 1.07 171 63.8 30.8 Min 2.6 181 97.3 40.1 3.52 181 109 36.8 Max Khaled F. El-Said 618 Table (2): Comparison of the levels of physical Hazards in car repairing workshop


INTRODUCTION
Small-scale industries (SSI) have existed as an informal sector since the pre-colonial times making various tools, ornaments and cooking utensils without regard to occupational hazards.Small-scale industries are determined by the number of persons employed which are less than 10 persons on the average.It represents a major sector for economic investment that brings a lot of benefits to the country as well as the individuals. (1,2)rkers in informal small-scale Bull High Inst Public Health Vol.38 No. 3 [2008]   industries (SSI) in developing countries involved in welding.Spray painting, woodwork, and metalwork workes are exposed to various hazards with consequent risk to health. (3)rkers in SSI are exposed to a variety of work-related hazards, where they are not using protective equipment and had health complaints perceived to be related to their work.Workers and employers were both aware of occupational and environmental health hazards, but absence of a clear policy on the informal sector and the lack of permanent workplaces do not encourage investment in occupational health and safety. (4)though the Small-scale industries include a wide variety of industrial activities, the most important and common types are car repairing, metal processing, and wood processing activities. (3,4)rkers in automobile repair shop are at high risk of exposure to noise, vibration, heat stress, and radiation.Haematological changes, skin diseases, cancer, musculoskeletal, psychological stress, chronic poising, and irritation are the most health disorders among workers in automobile repair shop. (5)dustrial welding has been associated historically with lung diseases, and current welding techniques continue to produce many potential exposures to particulates and gases as carbon monoxide (CO), nitrogen dioxide (NO2) sulphur Dioxide (SO2), and bezyene.Moreover, some studies suggest that these workers are at risk of serious respiratory, neurological, and reproductive effects. (6,7)dustries that have a high risk of wood-dust exposure include sawmills, dimension mills, furniture industries, cabinet makers, and carpenters. (8)The main sources of harmful dust emission at the workplace are during technological processes. (9)The present study was conducted to shad lights on occupational exposures to chemical and physical hazards among workers in small workshops

MATERIAL AND METHODS
Three industrial activities were selected for this study.These activities are: car repairing, welding, and wood processing.
From each activity, three workshops were selected.The selected control site means the same type of activity without the presence of sources of exposures as in the other three shops.
Inside the selected workshops, different physical hazards as noise, heat stress, and illumination were measured at the same two periods of the day (morning and evening).
During the present study, noise levels were assessed by the TES-1352A (10) programmable and calibrated sound level Meter.Heat stress index (Wet Bulb Globe Temperature WBGT (10) was used to determine the heat stress levels at selected workshops.The illumination levels were determined by a calibrated light meter (TES 1336A) (10) .Dust or total suspended particulates (TSP) was collected inside the selected workshops by calibrated personal samplers (Staplex® PST-2X Personal Air Sampler). (11)fferent air pollutants were measured inside all selected workshops by the standard methods and instruments.The selected air pollutants were total suspended particulates (TSP), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and benzene.Levels of these pollutants were assessed also at two different periods; morning and evening.
The MIRAN 205B Series SapphIRe-XL Portable Ambient Air Analyzer was used for assessment of the selected gaseous air pollutants. (12)

Statistical Analysis
Results of the collected data were statistically analyzed using the SPSS program version16.0software.Descriptive Statistics and test of significant (ANOVA) were also used for studying the significance differences between the studied factors.

RESULTS AND DISCUSSION
Workers in these rapidly developing countries are be exposed to excessive amounts of both physical and chemical pollutants.Small size industries workers, in particular, are routinely exposed to dust, gases, fumes, and heat, amongst other pollutants.
Occupational exposures to heat, illumination and noise are unavoidable in the small size industries, but these exposures could be minimized through efficient control measures at the worksite and or the proper use of appropriate personal protective equipment.
However, personal protective equipment and exposure control measures are rarely used at many worksites, and are given little importance and preference by many employers. (13,14)ncerning physical hazards, measurements for noise levels, dry and wet bulb temperatures, illumination as well as level of indoor gases as SO2, NO2, and CO were taken during the normal operation and on a normal working day .In Tables 1 and 2, in car repairing, there are significant high increase levels of noise exposure (evening), thermal stress, illumination, and dust exposure between exposure and control area respectively and there is no significant differences in the level of noise (morning) and control.In Car repairing, the level of dust in morning and night are below the standard level placed by ACGIH of 0.1 -3.3 mg/m 3 . (15)n Tables 3 and 4 the production targets.In addition, some of the workers worked overtime. (15 )wever, average level of noise in the metal processing represent high level of noise exposure which does not comply with the international standard ( OSHA) of 85 dB (15 ) .Wood processing workers. (16,17) workers in car repairing, wood processing and metal processing are exposed to low level of illumination in the morning and night which are below the OSHA standard level of 500 Lux which in turn can cause serious health effects as glare, cathartic, and eye strain and these Bull High Inst Public Health Vol.38 No. 3 [2008]   finding are in accordance with recent studies (18) In wood processing workshops the level of dust in the morning and night are higher than the standard level placed by ACGIH of 0. among workers in such exposure.(18) Wood processing workshop represents the highest level of dust exposures among exposed workers in comparison with control workers in relation to the car repairing, metal processing workshop.(19) The highest level of CO (12.71±5.4ppm) was found inside the wood processing workshops during the evening period.The lowest one (4.9 ± 0.89 ppm)

Survey
was obtained during the morning period inside the car repairing workshops as shown in table 7. pollutants (8,9,11) Except for NO2, levels of the other three pollutants inside all exposed workshops showed higher value than those inside the control workshops.
This refers to the affecting of workers inside these workshops by the emission source of these pollutants. (20)This could be due to the affecting of the control workshops by the outdoor heavy traffic activities because of its location in the main street compared to the exposed workshops. (21)e highest levels of the above three pollutants were found in wood processing exposed workshops because of the presence of other sources rather than the industrial operations such as heavy smoking activity inside the workplace area. (21)nerally, levels of air pollutants during the evening periods are higher than levels of the morning periods.Most of activities in the selected workshops, particularly car repairing, occur at the evening time. (21) some cases, levels of the indoor levels of some air pollutants exceed the outdoor values, such as the high levels of benzene inside the car repairing workshops compared to the outdoor levels.
This can be explained by the temporary sources of these pollutants at different periods and conditions.For the same example, benzene is used inside the car repairing workshops for cleaning of the internal part of car motors. (22)

CONCLUSION
In conclusion, the workers at the studied industries were exposed to higher heat, noise, and illumination as well as higher levels of CO, SO2, and NO2 than were experienced by the comparison areas.
These findings should be used as a preventive measures for monitoring and application of control strategies in such workplace environment.
, there are significant high increase in the level of noise, thermal stress, illumination, and dust in the morning and evening exposure between exposure and control area in metal Processing workshop .Although the overall mean noise level at the selected area was >85 dB in almost all working areas, none of the workers used earmuffs or plugs, or even a helmet with ear protection.The average length of the workday during the general work shift was 10-12 hours, depending on