The Relationship Between The Levels Of Pb, Cd, Mn In Welders And The Impairments Of Nervous System

Objective To explore the relationship between the levels of three kinds of metal in welders and the impairments of central nervous system and peripheral nervous system, and confirm whether severe oxidative stress makes contribution to them.Methods This study is a cross-sectional one. The exposure group was composed of full-time welders from two vehicle factories in some city by cluster sampling (82 welders were included in analysis), while operators with elemental information alike in the control group (51 operators were included in the analysis). A questionnaire self-designed including elemental status, working history, symptoms of nervous system, something about life and so on was administered to the two groups. The levels of whole blood Pb, Cd and serum Mn were measured via the graphite atomic absorption spectrometry; and the status of oxidative stress in vivo was known by dint of the determination of the anti-peroxidase such as Superoxide dismutase (SOD) and Glutathione peroxidase (GSH-Px), and Malonyldialdehyde (MDA). And the status of nervous systems was known after the acknowledgement of the neurobehavioral function by means of the Neurobehavioral Core Test Battery (NCTB) approved by the World Health Organization and measurement of the transmit velocity, latency and wave height of peripheral middle nerve. Then the data were analyzed with SPSS for windows 10.0.Results The results included: (1)There are definite impairments of neurobehavioral function which affects mood states, the eye-hand coordination and memory and some observable nervous symptoms such as hypersomnia, powerless and dull in welders. And they varied in different kinds of welding.(2)The neurobehavioral function in welders hasa close relation to the levels of whole blood Pb, Cd and serum Mn in vivo, and it worsens, in a whole, while the levels of those metals ascend.(3)Sex and alcohol consume are the influential factors of whole blood Pb in vivo, and sex, steel welded kinds, ventilation and tobacco consume for whole blood Cd while the electrode kinds for serum Mn.(4)The levels of oxidative stress in welders have a close relation to the levels of whole blood Pb, Cd and serum Mn in vivo and the cumulated exposure time of welding. The higher the levels of the three metals, the more aggravated the oxidative stress. And the similar relation is echoed between the nervous system status in welders and the levels of oxidative stress in welders, the higher the levels of oxidative stress were, the more aggravated the nervous system status.(5)Optimizing the occupational stress, amplifying the knowledge and the reducing the consume of tobacco and alcohol would all do good to the nervous system status in welders.(6)A measurement battery consisted of simple reaction time, the minimal simple reaction time, forward digit span and right dotting plus the levels of Glutathione peroxidase (GSH-Px) and Malonyldialdehyde (MDA) in serum can be applied for the periodic surveillance for welders.Conclusion There are sub-clinical but definite impairments of nervous system in welders, in which the oxidative stress play a significant role reasonable, which have a close relation to the levels of Pb, Cd, Mn in vivo.