Work schedules, light exposure and their effects on biological rhythms of workers in an Amazon extractive reserve

• Grant number: 11/50169-6
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2011
• End date: April 30, 2013
• Field of knowledge: Health Sciences - Collective Health - Public Health
• Agreement: University of Surrey
• Principal Investigator: Claudia Roberta de Castro Moreno
• Grantee: Claudia Roberta de Castro Moreno
• Principal researcher abroad: Debra Jean Skene
• Institution abroad: University of Surrey , England
• Host Institution: Faculdade de Saúde Pública (FSP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• City of the host institution: São Paulo

Abstract

Light exposure is an important factor for adaptation to non-standard work hours. Many of those who work irregularly show rhythm problems or "social jet lag" that causes fatigue, mood deterioration, sleep problems, reduced work performance and ill health. This study aims to understand the patterns of light exposure and working time, and their implications for sleep patterns/timing and the biological rhythms of 700 rubber tappers living at-the Chico Mendes Extractive Reserve. Our principal hypotheses is that there is a correlation between the extent of social misalignment and adverse health problems among this population. They work from 3:00 to 12,00h, from Monday to Friday, with 2 days-off. The study will be conducted in two-phases: in the first phase of the study data relating to sociodemographic characteristics, anthropometric measurements, diet, lifestyle, chronotype, working conditions and morbidities of the study population will, be collected. In the second phase the workers will be selected according to their chronotype (extreme morning and evening). To obtain information on the activity/rest cycle and light exposure, they will wear an actigraph for 14 consecutive days. Salivary melatonin will also be collected. These measurements will allow us to estimate how biological timing is affected by their working time. (AU)