Association between awakening cortisol levels and cardiovascular performance in sugarcane rural workers.

Sudden deaths without known causes have been reported among rural workers in the last decade, especially in low and middle-income countries. The current study aimed to analyse the association between awakening cortisol response and cardiovascular performance in rural workers before and after the harvesting period. Fifty-four rural male workers and 48 residents were included (non-rural workers) from a sugarcane production area in São Paulo, Brazil. Morning salivary cortisol were analysed before and 7 months after the beginning of burnt sugarcane harvesting. Cardiovascular performance (blood pressure, pulse pressure and heart rate HR) was evaluated using the Incremental Shuttle Walking Test (ISWT). Our findings revealed a negative association between CAR and cardiovascular performance in rural workers at the harvesting period. Specifically, morning cortisol levels significantly increased after seven months of intense harvesting activity, allied to improvements in physical performance, systolic blood pressure and heart rate reactivity to a cardiopulmonary task. No association was observed in the resident group. Altogether, these findings suggest that, at least in the short-term, rural workers presented an adaptive response to the physical demands of sugarcane harvesting work. Longitudinal studies are essential to investigate the long-term effects of harvesting activity on rural workers' health.

Effects of biomass burning on nasal mucociliary clearance and mucus properties after sugarcane harvesting.

OBJECTIVE: Biofuel from sugarcane is widely produced in developing countries and is a clean and renewable alternative source of energy. However, sugarcane harvesting is mostly performed after biomass burning. The aim of this study was to evaluate the effects of harvesting after biomass burning on nasal mucociliary clearance and the nasal mucus properties of farm workers. METHODS: Twenty seven sugarcane workers (21-45 years old) were evaluated at the end of two successive time-periods: first at the end of a 6-month harvesting period (harvesting), and then at the end of a 3-month period without harvesting (non-harvesting). Nasal mucociliary clearance was evaluated by the saccharine transit test, and mucus properties were analyzed using in vitro mucus contact angle and mucus transportability by sneeze. Arterial blood pressure, heart rate, respiratory rate, pulse oximetry, body temperature, associated illness, and exhaled carbon monoxide were registered. RESULTS: Data are presented as mean values (95% confidence interval). The multivariate model analysis adjusted for age, body-mass index, smoking status and years of working with this agricultural practice showed that harvesting yielded prolonged saccharine transit test in 7.83 min (1.88-13.78), increased mucus contact angle in 8.68 degrees (3.18-14.17) and decreased transportability by sneeze in 32.12 mm (-44.83 to -19.42) compared with the non-harvesting period. No significant differences were detected in any of the clinical parameter at either time-period. CONCLUSION: Sugarcane harvesting after biomass burning negatively affects the first barrier of the respiratory system in farm workers by impairing nasal mucociliary clearance and inducing abnormal mucus properties.