This study was carried out on the workers of a lead refinery industry and two control groups in Zanjan city in Iran. The scalp hair samples were collected from 25 workers who were occupationally exposed to lead contamination as a case group and from 25 subjects among the staff of the same industry and 25 subjects among Zanjan citizens as the first and second control groups respectively. A flame atomic absorption spectrophotometer used to determine lead level in all of the samples. The age of all subjects in the three groups was matched. The mean concentrations of hair lead in the workers (case group), the staff (control groupA) and the citizens (control group B) were 131.7±93.4 µgr/gr, 21.1±13.2 µgr/gr and 27.9±14.1 µgr/gr respectively. The mean concentration of hair lead in the case group was more than hair lead of normal range found in humans (0-30 µgr/gr). The mean of hair lead level in the citizens who had used gas vehicles was statistically higher than who had not used it (36.9±12.2 µgr/gr vs. 16.6±4.9 µgr/gr, P<0.001).
Background and aims: Puncture workers are exposed to hand-arm vibration when opening and closing the wheel bolts with an impact wrench, which can affect their health. The aim of this study was to evaluate the exposure of heavy vehicles puncture workshops to hand-arm vibration caused by impact wrenches and to present control methods in Sabzevar.Methods: This interventional study was performed with the participation of 20 employees of heavy vehicle puncture workshops. Demographic characteristics of employees and characteristics of impact wrenches were recorded. The vibration acceleration of the impact wrench was measured according to ISO 5349-1. To control the vibration transmitted to the employees, felt and elastomer coatings were used in the impact wrench handle.
Results:The vibration total value in the front and rear handles of the impact wrench were 32.34 ± 14.88 m/s 2 and 45.22 ± 21.99 m/s 2 , respectively. Acceleration equivalent to exposure (8 hours) due to impact wrench, was 16.38 ± 14.66 m/s 2 which is more than the permissible occupational exposure. The maximum vibration was in the Z axis and in the rear handle of the impact wrench. The use of felt in the handle of the impact wrench was 70% and the use of elastomer was 43%, which reduced the transmission of vibration acceleration Conclusion: According to the results of this study, the 8-hour exposure of workers in heavy-duty puncture workshops with hand-arm vibration caused by impact wrenches is more than the allowed limit of occupational exposure. Felt and elastomer are effective in reducing hand-arm vibration transmission. Felt is more efficient and reduces vibration to the permissible level of daily exposure (5 m/s 2 ).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.