Neurological and neurophysiological examinations of workers exposed to arsenic levels exceeding hygiene standards

Objectives: The assessment of the neurotoxic effect of arsenic (As) and its inorganic compounds is still the subject of interest due to a growing As application in a large array of technologies and the need to constantly verify the principles of prevention and technological parameters. The aim of this study was to determine the status of the nervous system (NS) in workers exposed to As at concentrations exceeding hygiene standards (Threshold Limit Values (TLV) – 10 μg/m3, Biological Exposure Index (BEI) – 35 μg/l) and to analyze the relationship between the NS functional state, species of As in urine and As levels in the workplace air. Material and Methods: The study group comprised 21 men (mean age: 47.43±7.59) employed in a copper smelting factory (mean duration of employment: 22.29±11.09). The control group comprised 16 men, matched by age and work shifts. Arsenic levels in the workplace air (As-A) ranged from 0.7 to 92.3 μg/m3; (M = 25.18±28.83). The concentration of total arsenic in urine (Astot-U) ranged from 17.35 to 434.68 μg/l (M = 86.82±86.6). Results: Syndrome of peripheral nervous system (PNS) was manifested by extremity fatigue (28.6%), extremity pain (33.3%) and paresthesia in the lower extremities (33.3%), as well as by neuropathy-type mini-symptoms (23.8%). Electroneurographic (ENeG) tests of peroneal nerves showed significantly decreased response amplitude with normal values of motor conduction velocity (MCV). Stimulation of sural nerves revealed a significantly slowed sensory conduction velocity (SCV) and decreased sensory potential amplitude. Neurophysiological parameters and the results of biological and environmental monitoring showed a relationship between Astot, AsIII (trivalent arsenic), the sum of iAs (AsIII+AsV (pentavalent arsenic))+MMA (monomethylarsonic acid) concentration in urine and As levels in the air. Conclusions: The results of the study demonstrate that occupational exposure to inorganic arsenic levels exceeding hygiene standards (TLV, BEI) generates disorders typical of peripheral neuropathy

Industrial activities

Causes of increased propension to sleepiness in industrial employees can be roughly divided into two classes. The first group of causes is common to all production activities, and includes: shift and night work, work-related stress, physical and mental fatigue, and the use of illegal or legal drugs and alcohol. All these causes have been discussed in previous chapters. Some industrial activities may also expose workers to specific factors that may increase the drowsiness. An effective prevention of the potential damage of drowsiness in industries must carefully consider these intrinsic causes of sleepiness. This chapter will examine briefly the causes of increased daytime sleepiness in industrial activities, considering separately the organizational and physical factors and the properly neurotoxic agents that can be that may be present in the production cycle