SLEEP QUALITY AND MENTAL HEALTH IN TWO POPULATIONS EXPOSED TO TOXIC SUBSTANCES IN BRAZIL

Resumo

INTRODUCTION: Inadequate sleep has been linked to impairments in body functions, whereas chemical exposure impacts sleep quality through certain mechanisms and molecular pathways. This study aimed to analyze sleep quality in three populations exposed to chemicals using health parameters. MATERIALS AND METHODS: A cross-sectional study was conducted with 189 residents in Volta Redonda city (Rio de Janeiro); and 66 endemic workers. Clinical and toxicological tests were performed. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI) and ActTrust actimetry; Cd; Pb; Ni; Mn; BZN; and TLN in blood and urine (by GFAAS and GC MS); and genotyping (by PCR). RESULTS: STUDY 1: Higher Mn levels were associated with the morning chronotype (p < 0.01). The evening chronotype with poorer sleep quality; higher Pb levels in blood; and BZN and TLN in urine (p < 0.01) in non-occupationally exposed individuals (p < 0.01). Moreover, most participants (57%) reported poor sleep quality; and higher Cd levels in urine in residents with higher scores for daytime dysfunction (p = 0.01) and sleep disturbance (p < 0.01); Mn (p < 0.01) and Ni (p = 0.03); for sleep disturbance; and TLN; for sleep duration (p < 0.05). STUDY2: Exposure to multiple agrotoxics (carcinogenic; neurotoxic and endocrine disrupting substances) was observed; approximately 51% presented at least two typical symptoms of poisoning after contact and/or handling; mainly associated with working time (PR: 2.09; 1.23 to 3.55); exposure to pyrethroids (PR: 1.16; 1.01 to 1.34) and organophosphates (PR: 1.25; 1.07 to 1.47); with a poor or very poor sleep quality (PR: 1.40; 1.19 to 1.64). Score of sleep quality was 7.8 points in the PSQI score and 60% of the population was classified as poor sleep (PSQI > 5). Additionally, the total sleep time was 5 to 6 hours, and positive correlation between the hormone T4 and total sleep time (p <0.05). A positive correlation between the scales of common mental disorders and PSQI ( rho=0.66; p< 0.05). CONCLUSION: Exposure to toxic contaminants influenced populations sleep patterns and the different chronotypes; in addition to potentially affecting sleep quality by activating the neural circadian system.