Analysis of neurotransmitters associated with neuropsychiatric status in workers following lead exposure

To explore the correlation between neuropsychiatric status and blood neurotransmitter in lead workers, and to provide theoretical basis for the prevention and treatment of lead workers.

The study applied cross-sectional survey, 74 occupational lead exposed workers in a battery factory in a city of Hebei province were selected as the lead exposed group, and 62 workers (non-lead workers) were selected as the control group. The occupational health symptoms questionnaire and health examination and POMS (Profile of Mood State, POMS) emotional test questionnaire were applied to investigate the nearly emotional status of the studied objects, ICP-MS was used to determine the blood lead level of all subjects, HPLC (High performance liquid chromatography, HPLC) was applied to determine the concentration of neurotransmitter in peripheral blood of all studied subjects, and all results were applied the Pearson's correlation analysis.

The blood lead concentration of the lead workers group (163.23±40.77 ug/L) was significantly higher than that in the control group (43.62±14.50 ug/L), and the difference was statistically significant. From the analysis of neuropsychiatric status, the neurological symptoms in the lead workers group were higher than that in the control group, among which the symptoms of sleep disturbance, dizziness, fatigue, numbness of limbs and dampness and coldness of limbs were more obvious. Among the symptoms of digestive system, the incidence of abdominal pain, abdominal distension, constipation and nausea and vomiting were higher. According to the POMS emotion questionnaire, the scores of 5 negative emotions and 1 positive emotion in the lead exposure group were higher than that in the control group, and the difference was statistically significant. Related to the control group, the concentration of neurotransmitters such as DA, 5-HT, GABA, Gly, Trp and Glu were statistically decreased, p<0.001. There was a negative correlation between neurotransmitters in peripheral blood and blood lead levels in lead workers, among which 5-HT had the greatest correlation with lead levels (r=-0.569, p<0.001). 5-HT and Trp were significantly correlated with tension-anxiety (T), depression-depression (D), anger-hostility (A), Vigor-hyperactivity (V), fatigue-inertia (F), and confusion-confusion (C). 5-HT, Trp and GABA were significantly correlated with the survey symptoms, among which, the sleep disorder, constipation and fatigue had most significantly positive correlation with 5-HT or Trp, r-value was respectively 0.373, 0.233 and 0.563.

Lead exposure not only causes the alteration of neuropsychiatric behavior of lead workers, but also changes gastrointestinal symptoms. Serotonin may be involved as the main neurotransmitter synthesized in intestinal, and the synthesis and metabolism may be regulated by intestinal flora.